Neoadjuvant camrelizumab plus apatinib for locally advanced microsatellite instability-high or mismatch repair-deficient colorectal cancer (NEOCAP): a single-arm, open-label, phase 2 study.

BACKGROUND: PD-1 blockade is highly efficacious for mismatch repair-deficient colorectal cancer in both metastatic and neoadjuvant settings. We aimed to explore the activity and safety of neoadjuvant therapy with PD-1 blockade plus an angiogenesis inhibitor and the feasibility of organ preservation in patients with locally advanced mismatch repair-deficient colorectal cancer. METHODS: We initiated a single-arm, open-label, phase 2 trial (NEOCAP) at Sun Yat-sen University Cancer Center and the Provincial Hospital of Traditional Chinese Medicine, Guangzhou, China. Patients aged 18-75 years with untreated mismatch repair-deficient or microsatellite instability-high or POLE/POLD1-mutated locally advanced colorectal cancer (cT3 or N+ for rectal cancer, and T3 with invasion ≥5mm or T4, with or without N+ for colon cancer) and an Eastern Cooperative Oncology Group performance score of 0-1 were enrolled and given 200 mg camrelizumab intravenously on day 1 and 250 mg apatinib orally from day 1-14, every 3 weeks for 3 months followed by surgery or 6 months if patients did not have surgery. Patients who had a clinical complete response did not undergo surgery and proceeded with a watch-and-wait approach. The primary endpoint was the proportion of patients with a pathological or clinical complete response. Eligible enrolled patients who received at least one cycle of neoadjuvant treatment and had at least one tumour response assessment following the baseline assessment were included in the activity analysis, and patients who received at least one dose of study drug were included in the safety analysis. The study is registered with ClinicalTrials.gov (NCT04715633) and is ongoing. FINDINGS: Between Sept 29, 2020, and Dec 15, 2022, 53 patients were enrolled; one patient was excluded from the activity analysis because they were found to be mismatch repair-proficient and microsatellite-stable. 23 (44%) patients were female and 29 (56%) were male. The median follow-up was 16·4 (IQR 10·5-23·5) months. 28 (54%; 95% CI 35-68) patients had a clinical complete response and 24 of these patients were managed with a watch-and-wait approach, including 20 patients with colon cancer and multiple primary colorectal cancer. 23 (44%) of 52 patients underwent surgery for the primary tumour, and 14 (61%; 95% CI 39-80) had a pathological complete response. 38 (73%; 95% CI 59-84) of 52 patients had a complete response. Grade 3-5 adverse events occurred in 20 (38%) of 53 patients; the most common were increased aminotransferase (six [11%]), bowel obstruction (four [8%]), and hypertension (four [8%]). Drug-related serious adverse events occurred in six (11%) of 53 patients. One patient died from treatment-related immune-related hepatitis. INTERPRETATION: Neoadjuvant camrelizumab plus apatinib show promising antitumour activity in patients with locally advanced mismatch repair-deficient or microsatellite instability-high colorectal cancer. Immune-related adverse events should be monitored with the utmost vigilance. Organ preservation seems promising not only in patients with rectal cancer, but also in those with colon cancer who have a clinical complete response. Longer follow-up is needed to assess the oncological outcomes of the watch-and-wait approach. FUNDING: The National Natural Science Foundation of China, Guangdong Basic and Applied Basic Research Foundation, and the Cancer Innovative Research Program of Sun Yat-sen University Cancer Center. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

The effects of oxaliplatin-based adjuvant chemotherapy in high-risk stage II colon cancer with mismatch repair-deficient: a retrospective study.

BACKGROUND: For high-risk stageIImismatch repair deficient (dMMR) colon cancers, the benefit of adjuvant chemotherapy remains debatable. The principal aim of this study was to evaluate the prognostic value of high-risk factors and the effect of oxaliplatin-based adjuvant chemotherapy among dMMR stageIIcolon cancers. METHODS: Patients with stage II dMMR colon cancers diagnosed between June 2011 and May 2018 were enrolled in the study. Clinicopathological characteristics, treatment, and follow-up data were retrospectively collected. The high-risk group was defined as having one of the following factors: pT4 disease, fewer than twelve lymph nodes harvested (< 12 LNs), poorly differentiated histology, perineural invasion (PNI), lymphatic vascular invasion (LVI), or elevated preoperative carcinoembryonic antigen (CEA). The low-risk group did not have any risk factors above. Factors associated with disease-free survival (DFS) were included in univariate and multivariate Cox analyses. RESULTS: We collected a total of 262 consecutive patients with stage II dMMR colon cancer. 179 patients (68.3%) have at least one high-risk factor. With a median follow-up of 50.1 months, the low-risk group was associated with a tended to have a better 3-year DFS than the high-risk group (96.4% vs 89.4%; P = 0.056). Both elevated preoperative CEA (HR 2.93; 95% CI 1.26-6.82; P = 0.013) and pT4 disease (HR 2.58; 95% CI 1.06-6.25; P = 0.037) were independent risk factors of recurrence. Then, the 3-year DFS was 92.6% for the surgery alone group and 88.1% for the adjuvant chemotherapy group (HR 1.64; 95% CI 0.67-4.02; P = 0.280). Furthermore, no survival benefit from oxaliplatin-based adjuvant chemotherapy was observed in the high-risk group and in the subgroups with pT4 disease or < 12 LNs. CONCLUSIONS: These data suggests that not all high-risk factors have a similar impact on stage II dMMR colon cancers. Elevated preoperative CEA and pT4 tumor stage are associated with increased recurrence risk. However, oxaliplatin-based adjuvant chemotherapy shows no survival benefits in stage II dMMR colon cancers, either with or without high-risk factors.

Long-Term Outcomes of dMMR/MSI-H Rectal Cancer Treated With Anti-PD-1-Based Immunotherapy as Curative-Intent Treatment.

BACKGROUND: Neoadjuvant anti-PD-1 therapy has shown encouraging efficacy in patients with deficient DNA mismatch repair (dMMR)/microsatellite instability-high (MSI-H) locally advanced rectal cancer (LARC), which suggests its potential as a curative-intent therapy and a promising treatment option for organ preservation. We aimed to investigate the long-term outcomes of patients with dMMR/MSI-H LARC who experienced clinical complete response (cCR) after anti-PD-1 therapy. METHODS: We retrospectively analyzed patients with dMMR/MSI-H LARC who achieved cCR and received nonoperative management following neoadjuvant anti-PD-1-based treatment from 4 Chinese medical centers. Patients were followed up for at least 1 year after they achieved cCR, their clinical data were collected, and survival outcomes were analyzed using the Kaplan-Meier method. RESULTS: A total of 24 patients who achieved cCR and received nonoperative management from March 2018 to May 2022 were included, with a median age of 51.0 years (range, 19.0-77.0 years). The median treatment course to reach cCR was 6.0 (range, 1.0-12.0). Fifteen patients (62.5%) continued their treatments after experiencing cCR, and the median treatment course was 17.0 (range, 3.0-36.0). No local regrowth or distant metastasis was observed in a median follow-up time of 29.1 months (range, 12.6-48.5 months) after cCR. The 3-year disease-free and overall survivals were both 100%. CONCLUSIONS: Patients with dMMR/MSI-H locally advanced or low-lying rectal cancer who achieved cCR following anti-PD-1-based therapy had promising long-term outcomes. A prospective clinical trial with a larger sample size is required to further validate these findings.

Neoadjuvant Immunotherapy Leads to Major Response and Low Recurrence in Localized Mismatch Repair-Deficient Colorectal Cancer.

BACKGROUND: Our study aimed to evaluate the efficacy and feasibility of neoadjuvant anti-PD-1 treatment for localized mismatch repair-deficient (dMMR) colorectal cancer (CRC). PATIENTS AND METHODS: The study cohort included patients with localized dMMR CRC who received PD-1 inhibitors as neoadjuvant therapy from 3 medical centers in Southern China. Main eligibility criteria included age between 18 and 75 years, ECOG performance status of 0 or 1, and receipt of ≥2 doses of PD-1 inhibitors. RESULTS: A total of 73 patients were included. Most of the tumors were locally advanced, including 19 (26.0%) T4a and 29 (39.7%) T4b. Most patients (79.5%) received PD-1 inhibitor monotherapy. Objective response per radiologic assessment was achieved in 62 (84.9%) patients, including 17 (23.3%) with complete response (CR) and 45 (61.6%) with partial response, with a median time to response of 9.6 weeks. Patients with T4a/4b disease had a similar response rate as those with T2-3 disease (84.0% vs 85.4%; P=.999). As of writing, a total of 50 patients have undergone surgery. Pathologic CR was achieved in most (57.1%) patients and remained high (59.5%) even among the 38 patients with T4a/4b disease. The 17 patients with CR did not undergo surgery and adopted a watch-and-wait strategy. After a median follow-up of 17.2 months (range, 3.4-45.1 months), the overall median recurrence-free and overall survivals were not reached. Among patients undergoing surgery or achieving CR, the 2-year tumor-specific disease-free and overall survival rates were both 100%. During neoadjuvant treatment, grade 3-4 adverse events occurred in 8 patients; 4 required acute intervention. Severe postoperative complications were recorded in 4 patients, 3 of whom required a second surgery. CONCLUSIONS: Neoadjuvant therapy with PD-1 blockade is highly effective for localized dMMR CRC, with an acceptable safety profile and low recurrence rate. This treatment holds promise for becoming the new standard of care for localized dMMR CRCs.

Neoadjuvant Immune Checkpoint Inhibition Improves Organ Preservation in T4bM0 Colorectal Cancer With Mismatch Repair Deficiency: A Retrospective Observational Study.

BACKGROUND: Colorectal cancer with mismatch repair deficiency is usually less aggressive and associated with a lower risk of distant metastasis. Immune checkpoint inhibition, rather than traditional chemoradiotherapy, has shown great advantages in treating such patients. OBJECTIVE: This study aimed to verify the hypothesis that locally very advanced (T4b) colorectal cancer without distant metastases might present with higher probability of mismatch repair deficiency and be more sensitive to neoadjuvant immune checkpoint inhibition. DESIGN: This study was designed as a single-center retrospective observational study. SETTINGS: The study was conducted in a tertiary referral center in China. PATIENTS: The study included patients who were clinically diagnosed with T4bM0 colorectal cancer from 2008 to 2019. MAIN OUTCOME MEASURES: Clinicopathological characteristics, mismatch repair status, and survival outcomes of patients with mismatch repair deficiency were analyzed. RESULTS: A total of 268 patients were included. The incidence of patients with mismatch repair deficiency in the T4bM0 population was 27.6% (75/268), with 84.0% (63/75) in the colon and 16.0% (12/75) in the rectum. For tumors located in the proximal colon, 45.0% (50/111) exhibited mismatch repair deficiency, whereas the incidence of mismatch repair deficiency in sigmoid colon cancer and rectal cancer was only 15.9% (25/157). Neoadjuvant immune checkpoint inhibition significantly reduced the open surgery rate ( p = 0.000) and multivisceral resection rate ( p = 0.025). The pathological complete remission rate in the neoadjuvant immune checkpoint inhibition group was significantly higher than that in neoadjuvant chemoradiotherapy/chemotherapy group (70.0% vs 0%; p = 0.004). No tumor downstaging was observed after neoadjuvant chemotherapy. Neoadjuvant immune checkpoint inhibition provided significantly better disease-free survival ( p = 0.0078) and relatively longer overall survival ( p = 0.15) than other groups. LIMITATIONS: This study is limited by the possible selection bias and small sample size. CONCLUSIONS: Our data depicted the high incidence of mismatch repair deficiency in T4bM0 mismatch repair deficiency and the effectiveness of the neoadjuvant immune checkpoint inhibition group in organ preservation. Precision oncology requires identification of the protein status of mismatch repair at initial diagnosis to make a rational treatment decision for these patients. See Video Abstract at http://links.lww.com/DCR/B952 . LA INHIBICIN DEL PUNTO DE CONTROL INMUNITARIO NEOADYUVANTE MEJORA LA PRESERVACIN DE RGANOS EN EL CNCER COLORRECTAL TBM CON DEFICIENCIA DE REPARACIN DE ERRORES DE COINCIDENCIA UN ESTUDIO OBSERVACIONAL RETROSPECTIVO: ANTECEDENTES:Los pacientes con cáncer colorrectal con deficiencia en la reparación de desajustes suelen (dMMR) ser menos agresivos y se asocian con un menor riesgo de metástasis a distancia. La inhibición del punto de control inmunitario, en lugar de la quimiorradioterapia tradicional, ha mostrado grandes ventajas en el tratamiento de estos pacientes.OBJETIVO:Este estudio tuvo como objetivo verificar nuestra hipótesis de que el CCR localmente muy avanzado (T4b) sin metástasis a distancia podría presentarse con una mayor probabilidad de dMMR y ser más sensible a la inhibición del punto de control inmunitario neoadyuvante.DISEÑO:Este estudio fue diseñado como un estudio observacional retrospectivo de un solo centro.CONFIGURACIÓN:El estudio se realizó en un centro de referencia terciario en China.PACIENTES:Se incluyeron pacientes con diagnóstico clínico de CCR T4bM0 desde 2008 hasta 2019.PRINCIPALES MEDIDAS DE RESULTADO:Se analizaron las características clinicopatológicas, el estado de MMR y los resultados de supervivencia de los pacientes con dMMR.RESULTADOS:Se incluyeron un total de 268 pacientes. La incidencia de dMMR en la población T4bM0 fue del 27,6% (75/268), con un 84,0% (63/75) en colon y un 16,0% (12/75) en recto. Para los tumores ubicados en el colon proximal, el 45,0% (50/111) exhibió dMMR, mientras que la incidencia de dMMR en el cáncer de colon sigmoideo y el cáncer de recto fue solo del 15,9% (25/157). La inhibición del punto de control inmunitario neoadyuvante redujo significativamente la cirugía abierta y la tasa de resección multivisceral ( p = 0,000 y p = 0,025, respectivamente). La tasa de PCR en el grupo de inhibición del punto de control inmunitario neoadyuvante fue significativamente mayor que en el grupo de quimiorradioterapia/quimioterapia neoadyuvante (70,0% frente a 0%, p = 0,004). No se observó reducción del estadio del tumor después de la quimioterapia neoadyuvante. La inhibición del punto de control inmunitario neoadyuvante proporcionó una supervivencia sin enfermedad significativamente mejor ( p = 0,0078) y una supervivencia general relativamente más larga ( p = 0,15) que otros grupos.LIMITACIONES:Este estudio está limitado por el posible sesgo de selección y el pequeño tamaño de la muestra.CONCLUSIONES:Nuestros datos representan la alta incidencia de dMMR en T4bM0 CRC y la eficacia del grupo de inhibición del punto de control inmunitario neoadyuvante en la preservación de órganos. La oncología de precisión requiere la identificación del estado de la proteína MMR en el diagnóstico inicial para tomar una decisión de tratamiento racional para estos pacientes especiales. Consulte el Video Resumen en http://links.lww.com/DCR/B952 . (Traducción-Dr. Yesenia Rojas-Khalil ).

Universal germline testing among patients with colorectal cancer: clinical actionability and optimised panel.

PURPOSE: Universal germline testing in patients with colorectal cancer (CRC) with a multigene panel can detect various hereditary cancer syndromes. This study was performed to understand how to choose a testing panel and whether the result would affect clinical management. METHODS: We prospectively enrolled 486 eligible patients with CRC, including all patients with CRC diagnosed under age 70 years and patients with CRC diagnosed over 70 years with hereditary risk features between November 2017 and January 2018. All participants received germline testing for various hereditary cancer syndromes. RESULTS: The prevalence of germline pathogenic variants (PVs) in cancer susceptibility genes was 7.8% (38/486), including 25 PVs in genes with high-risk CRC susceptibility (the minimal testing set) and 13 PVs in genes with moderate-risk CRC susceptibility or increased cancer risk other than CRC (the additional testing set). All the clinically relevant PVs were found in patients diagnosed under age 70 years. Among them, 11 patients would not have been diagnosed if testing reserved to present guidelines. Most (36/38) of the patients with PVs benefited from enhanced surveillance and tailored treatment. PVs in genes from the minimal testing set were found in all age groups, while patients carried PVs in genes from the additional testing set were older than 40 years. CONCLUSION: Universal germline testing for cancer susceptibility genes should be recommended among all patients with CRC diagnosed under age 70 years. A broad panel including genes from the additional testing set might be considered for patients with CRC older than 40 years to clarify inheritance risks. TRIAL REGISTRATION NUMBER: NCT03365986.

Nonoperative Management of dMMR/MSI-H Colorectal Cancer following Neoadjuvant Immunotherapy: A Narrative Review.

Immunotherapy with PD-1 blockade has achieved a great success in colorectal cancers (CRCs) with high microsatellite instability (MSI-H) and deficient mismatch repair (dMMR), and has become the first-line therapy in metastatic setting. Studies of neoadjuvant immunotherapy also report exciting results, showing high rates of clinical complete response (cCR) and pathological complete response. The high efficacy and long duration of response of immunotherapy has prompt attempts to adopt watch-and-wait strategy for patients achieving cCR following the treatment. Thankfully, the watch-and-wait approach has been proposed for nearly 20 years for patients undergoing chemoradiotherapy and has gained ground among patients as well as clinicians. In this narrative review, we combed through the available information on immunotherapy for CRC and on the watch-and-wait strategy in chemoradiotherapy, and looked forward to a future where neoadjuvant immunotherapy as a curative therapy would play a big part in the treatment of MSI-H/dMMR CRC.

Prognostic value of a novel biomarker combining DNA ploidy and tumor burden score for initially resectable liver metastases from patients with colorectal cancer.

BACKGROUND: Colorectal cancer liver metastases (CRLM) has not been identified as a unified disease entity due to the differences in the severity of metastatic disease and tumor aggressiveness. A screen for specific prognostic risk subgroups is urgently needed. The current study aimed to investigate the prognostic value of DNA ploidy, stroma fraction and nucleotyping of initially resectable liver metastases from patients with CRLM. METHODS: One hundred thirty-nine consecutive patients with initially resectable CRLM who underwent curative liver resection from 2006 to 2018 at Sun Yat-sen University Cancer Center were selected for analysis. DNA ploidy, stroma fraction and nucleotyping of liver metastases were evaluated using automated digital imaging systems. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox regression models. RESULTS: DNA ploidy was identified as an independent prognostic factor for RFS (HR, 2.082; 95% CI 1.053-4.115; P = 0.035) in the multivariate analysis, while stroma-tumor fraction and nucleotyping were not significant prognostic factors. A significant difference in 3-year RFS was observed among the low-, moderate- and high-risk groups stratified by a novel parameter combined with the tumor burden score (TBS) and DNA ploidy (72.5% vs. 63.2% vs. 37.3%, P = 0.007). The high-risk group who received adjuvant chemotherapy had a significantly better 3-year RFS rate than those without adjuvant chemotherapy (46.7% vs. 24.8%; P = 0.034). CONCLUSIONS: Our study showed that DNA ploidy of liver metastases is an independent prognostic factor for patients with initially resectable CRLM after liver resection. The combination of DNA ploidy and TBS may help to stratify patients into different recurrence risk groups and may guide postoperative treatment among the patients.

Dickkopf-related protein 1, a new biomarker for local immune status and poor prognosis among patients with colorectal liver Oligometastases: a retrospective study.

BACKGROUND: It was reported that tumor-expressed dickkopf-related (DKK) proteins affect micro-environment. However, the influence of DKK1 on colorectal cancer (CRC) liver oligometastases (CRCLOM) remains unclear. METHODS: CRC cases after resection of liver oligometastases were enrolled in Sun Yat-Sen University Cancer Center with intact clinical data. Serum DKK1 was detected by ELISA assay. Immunofluorescent staining examination for CD3 and CD8 in slices were also conducted. RESULTS: Among 65 patients included, the recurrence-free survival (RFS) and overall survival (OS) were significantly better in the low serum DKK1 group (RFS: P = 0.021; OS: P = 0.043). DKK1 was overexpressed in stage IV CRC patients in TCGA data. The number of CD8+ tumor-infiltrating lymphocytes (TILs) in invasive margin of CRC liver oligometastases was significantly higher in low serum DKK1 group (P = 0.042). CONCLUSION: Elevated serum DKK1 level was associated with poorer RFS and OS, and less CD8+ TILs in invasive margin in CRC liver oligometastases. DKK1 might serve as a supplementalprognostic factor for clinical risk score and a potential target for immunotherapy.

Downregulation of NMI promotes tumor growth and predicts poor prognosis in human lung adenocarcinomas.

BACKGROUND: N-myc (and STAT) interactor (NMI) plays vital roles in tumor growth, progression, and metastasis. In this study, we identified NMI as a potential tumor suppressor in lung cancer and explored its molecular mechanism involved in lung cancer progression. METHODS: Human lung cancer cell lines and a mouse xenograft model was used to study the effect of NMI on tumor growth. The expression of NMI, COX-2 and relevant signaling proteins were examined by Western blot. Tissue microarray immunohistochemical analysis was performed to assess the correlation between NMI and COX-2 expression in lung cancer patients. RESULTS: NMI was highly expressed in normal lung cells and tissues, but lowly expressed in lung cancer cells and tissues. Overexpression of NMI induced apoptosis, suppressed lung cancer cell growth and migration, which were mediated by up-regulation of the cleaved caspase-3/9 and down-regulation of phosphorylated PI3K/AKT, MMP2/MMP9, ß-cadherin, and COX-2/PGE2. In contrast, knockdown of NMI promoted lung cancer cell colony formation and migration, which were correlated with the increased expression of phosphorylated PI3K/AKT, MMP2/MMP9, ß-cadherin and COX-2/PGE2. Further study showed that NMI suppressed COX-2 expression through inhibition of the p50/p65 NF-κB acetylation mediated by p300. The xenograft lung cancer mouse models also confirmed the NMI-mediated suppression of tumor growth by inhibiting COX-2 signaling. Moreover, tissue microarray immunohistochemical analysis of lung adenocarcinomas also demonstrated a negative correlation between NMI and COX-2 expression. Kaplan-Meier analysis indicated that the patients with high level of NMI had a significantly better prognosis. CONCLUSIONS: Our study showed that NMI suppressed tumor growth by inhibiting PI3K/AKT, MMP2/MMP9, COX-2/PGE2 signaling pathways and p300-mediated NF-κB acetylation, and predicted a favorable prognosis in human lung adenocarcinomas, suggesting that NMI was a potential tumor suppressor in lung cancer.

Serum biomarkers REG1A and REG3A combined with the traditional CEA represent a novel nomogram for the screening and risk stratification of colorectal cancer.

BACKGROUND: To develop and validate a serum protein nomogram for colorectal cancer (CRC) screening. METHODS: The serum protein characteristics were extracted from an independent sample containing 30 colorectal cancer and 12 polyp tissues along with their paired samples, and different serum protein expression profiles were validated using RNA microarrays. The prediction model was developed in a training cohort that included 1345 patients clinicopathologically confirmed CRC and 518 normal participants, and data were gathered from November 2011 to January 2017. The lasso logistic regression model was employed for features selection and serum nomogram building. An internal validation cohort containing 576 CRC patients and 222 normal participants was assessed. RESULTS: Serum signatures containing 27 secreted proteins were significantly differentially expressed in polyps and CRC compared to paired normal tissue, and REG family proteins were selected as potential predictors. The C-index of the nomogram1 (based on Lasso logistic regression model) which contains REG1A, REG3A, CEA and age was 0.913 (95% CI, 0.899 to 0.928) and was well calibrated. Addition of CA199 to the nomogram failed to show incremental prognostic value, as shown in nomogram2 (based on logistic regression model). Application of the nomogram1 in the independent validation cohort had similar discrimination (C-index, 0.912 [95% CI, 0.890 to 0.934]) and good calibration. The decision curve (DCA) and clinical impact curve (ICI) analysis demonstrated that nomogram1 was clinically useful. CONCLUSIONS: This study presents a serum nomogram that included REG1A, REG3A, CEA and age, which can be convenient for screening of colorectal cancer.

DNA ploidy and stroma predicted the risk of recurrence in low-risk stage III colorectal cancer.

BACKGROUND: For clinically low-risk stage III colorectal cancer, the decision on cycles of adjuvant chemotherapy after surgery is disputed. The present study investigates the use of additional biomarkers of ploidy and stroma-ratio(PS) to stratify patients with low-risk stage III colorectal cancer, providing a basis for individualized treatment in the future. METHODS: This study retrospectively enrolled 198 patients with clinical-low-risk stage III colorectal cancer (T1-3N1M0) and analyzed the DNA ploidy and stroma ratio of FFPE tumor tissues. The patients were divided into PS-low-risk group (Diploidy or Low-stroma) and PS-high-risk group (Non-diploid and High-stroma). For survival analyses, Kaplan-Meier and Cox regression models were used. RESULTS: The results showed that the 5-year DFS of the PS-high-risk group was significantly lower than that in the PS-low-risk group (78.6 vs. 91.2%, HR = 2.606 [95% CI: 1.011-6.717], P = 0.039). Besides, in the PS-low-risk group, the 5 year OS (98.2 vs. 86.7%, P = 0.022; HR = 5.762 [95% CI: 1.281-25.920]) and DFS (95.6, vs 79.9%, P = 0.019; HR = 3.7 [95% CI: 1.24-11.04]) of patients received adjuvant chemotherapy for > 3 months were significantly higher than those received adjuvant chemotherapy for < 3 months. We also found that the PS could stratify the prognosis of patients with dMMR tumors. The 5-year OS (96.3 vs 71.4%, P = 0.037) and DFS (92.6 vs 57.1%, P = 0.015) were higher in the PS-low-risk dMMR patients than those in the PS-high-risk dMMR patients. CONCLUSION: In this study, we found that PS can predict the prognosis of patients with stage III low-risk CRC. Besides, it may guide the decision on postoperative adjuvant chemotherapy.

Efficacy of PD-1 inhibitors for colorectal cancer and polyps in Lynch syndrome patients.

BACKGROUND: Programmed death-1 (PD-1) inhibitor is effective for colorectal cancer (CRC) with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H). We aimed to explore its effects on CRCs and colonic polyps in Lynch syndrome (LS) patients. METHODS: LS patients with CRC who had evaluable tumours and received at least 2 cycles of PD-1 inhibitors were retrospectively included. PD-1 inhibitors were given as a monotherapy or in combination with other therapies, including anticytotoxic T-lymphocyte-associated antigen-4 treatment, radiotherapy, chemotherapy, and targeted therapy. Correlations of treatment responses with clinicopathological characteristics and genomic profiles were analysed. RESULTS: A total of 75 LS patients were included, with a median age of 39 years. The median duration of follow-up was 27 months (range, 3-71). The objective response rate (ORR) was 70.7%, including 28.0% (n = 21) complete responses and 42.7% (n = 32) partial responses. Four of five cases of LS CRCs displaying proficient MMR (pMMR) or microsatellite stable (MSS) were not responsive. Mucinous/signet-ring cell differentiation was associated with a lower ORR (P = 0.013). The 3-year overall survival and progression-free survival were 91.2% and 82.2%, respectively. A polyp was detected in 26 patients during surveillance. Seven adenomas disappeared after treatment, and they were all larger than 7 mm. CONCLUSION: PD-1 inhibitors are highly effective for dMMR and MSI-H LS CRCs, but not for pMMR or MSS LS CRCs or mucinous/signet-ring cell CRC. Large LS adenomas may also be eliminated by anti-PD-1 treatment. DATA AVAILABILITY STATEMENT: Due to the privacy of patients, the related data cannot be available for public access but can be obtained from Pei-Rong Ding (dingpr@sysucc.org.cn) upon reasonable request. The key raw data have been uploaded to the Research Data Deposit public platform (www.researchdata.org.cn).

A novel screening method of DNA methylation biomarkers helps to improve the detection of colorectal cancer and precancerous lesions.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignancies, and early detection plays a crucial role in enhancing curative outcomes. While colonoscopy is considered the gold standard for CRC diagnosis, noninvasive screening methods of DNA methylation biomarkers can improve the early detection of CRC and precancerous lesions. METHODS: Bioinformatics and machine learning methods were used to evaluate CRC-related genes within the TCGA database. By identifying the overlapped genes, potential biomarkers were selected for further validation. Methylation-specific PCR (MSP) was utilized to identify the associated genes as biomarkers. Subsequently, a real-time PCR assay for detecting the presence of neoplasia or cancer of the colon or rectum was established. This screening approach involved the recruitment of 978 participants from five cohorts. RESULTS: The genes with the highest specificity and sensitivity were Septin9, AXL4, and SDC2. A total of 940 participants were involved in the establishment of the final PCR system and the subsequent performance evaluation test. A multiplex TaqMan real-time PCR system has been illustrated to greatly enhance the ability to detect precancerous lesions and achieved an accuracy of 87.8% (95% CI 82.9-91.5), a sensitivity of 82.7% (95% CI 71.8-90.1), and a specificity of 90.1% (95% CI 84.3-93.9). Moreover, the detection rate of precancerous lesions of this assay reached 55.0% (95% CI 38.7-70.4). CONCLUSION: The combined detection of the methylation status of SEPT9, SDC2, and ALX4 in plasma holds the potential to further enhance the sensitivity of CRC detection.

Efficacy and safety of neoadjuvant imatinib therapy for patients with locally advanced rectal gastrointestinal stromal tumors: A multi-center cohort study.

Background: Several issues on neoadjuvant imatinib therapy remain controversial despite its widespread application for rectal gastrointestinal stromal tumors (GIST). We aimed to describe the clinicopathological characteristics of this specific population, and compare the surgical and oncologic outcomes between patients with or without neoadjuvant imatinib therapy. Patients and methods: A cohort of 58 consecutive locally advanced rectal GIST patients receiving surgical treatment between January 2007 and July 2019 at Sun Yat-sen University Cancer Center and Yunnan Cancer Hospital was retrospectively analyzed. Recurrence-free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method. Results: There were 33 (56.9%) patients who received neoadjuvant imatinib therapy. Among them, 20 (60.6%) patients had partial response (PR) as their best response, 11 (33.3%) patients had stable disease (SD), and 2 (6.1%) patients had progressive disease (PD). The median tumor size reduced from 5.2 to 4.0 cm after treatment (p < 0.001), and an attained "maximal response" was primarily achieved (32/33) on the 12th month after treatment. The most common adverse event was anemia. There were 27 adverse events occurred, most of which were grade 1 (19/27). With respect to intraoperative and postoperative surgical outcomes, no significant difference was found between patients with or without neoadjuvant Imatinib therapy except that patients with neoadjuvant treatment had a significant higher rate of preventive ileostomy (p = 0.004). Patients received neoadjuvant treatment had a superior 2-years RFS outcome than those without, though the difference was no significant (91.7% vs. 78.9%, p = 0.203). There were no significant differences in the 2-years OS rates (95.2% vs. 91.3%, p = 0.441). Conclusion: Neoadjuvant imatinib therapy is an effective and safe treatment for locally advanced rectal GISTs. Further studies are warranted to validate the long-term prognostic benefit for patients with rectal GISTs receiving neoadjuvant imatinib therapy.

B2M and JAK1/2-mutated MSI-H Colorectal Carcinomas Can Benefit From Anti-PD-1 Therapy.

ß2-microglobulin (B2M) and Janus kinases 1 and 2 (JAK1/2) mutations have been suggested as genetic mechanisms of immune evasion for anti-programmed cell death protein 1 (PD-1) therapy. Whether B2M and JAK1/2 lose-of-function mutation can cause primary resistance to anti-PD-1 therapy in colorectal carcinoma (CRC) patients remains controversial. Here, we sought to compare the efficacy of anti-PD-1 therapy in DNA mismatch repair deficient/microsatellite instability-high CRC patients with or without B2M or JAK1/2 mutations. Thirty-Five CRC patients who received anti-PD-1 therapy were enrolled in this study. All tumor samples underwent next-generation sequencing. The clinical and molecular data from 110 CRC patients sequenced with the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay and accessed through cBioportal were also analyzed in this study. Of the 35 CRC patients from our center, 10 (28.6%) had a B2M loss-of-function mutation, and 8 (22.9%) had a JAK1/2 loss-of-function mutation. Compared with B2M wild-type CRCs, B2M-mutated CRCs did not show a higher frequency of resistance to anti-PD-1 therapy (P=0.71). There was even better response to anti-PD-1 therapy in patients with JAK1/2 mutation than in those without (P=0.015). Of the 110 CRC patients in the MSK-IMPACT datasets, 13 (11.8%) had a B2M mutation, and 15 (13.6%) had a JAK1/2 mutation. After analyzing the response to anti-PD-1 therapy in these 110 patients, we found similar results (P=0.438 and 0.071, respectively). Moreover, patients with B2M or JAK1/2 mutation had a lower tumor mutational burden score compared with those without. B2M and JAK1/2 loss-of-function mutations occur frequently in microsatellite instability-high CRC. Our study demonstrated that patients with CRC harboring B2M or JAK1/2 mutations should not be excluded from anti-PD-1 therapy.

Inflammation promotes resistance to immune checkpoint inhibitors in high microsatellite instability colorectal cancer.

Inflammation is a common medical complication in colorectal cancer (CRC) patients, which plays significant roles in tumor progression and immunosuppression. However, the influence of inflammatory conditions on the tumor response to immune checkpoint inhibitors (ICI) is incompletely understood. Here we show that in a patient with high microsatellite instability (MSI-H) CRC and a local inflammatory condition, the primary tumor progresses but its liver metastasis regresses upon Pembrolizumab treatment. In silico investigation prompted by this observation confirms correlation between inflammatory conditions and poor tumor response to PD-1 blockade in MSI-H CRCs, which is further validated in a cohort of 62 patients retrospectively enrolled to our study. Inhibition of local but not systemic immune response is verified in cultures of paired T cells and organoid cells from patients. Single-cell RNA sequencing suggests involvement of neutrophil leukocytes via CD80/CD86-CTLA4 signaling in the suppressive immune microenvironment. In concordance with this finding, elevated neutrophil-to-lymphocyte ratio indicates inhibited immune status and poor tumor response to ICIs. Receiver operating characteristic curve further demonstrates that both inflammatory conditions and a high NLR could predict a poor response to ICIs in MSI- CRCs, and the predictive value could be further increased when these two predictors are combined. Our study thus suggests that inflammatory conditions in MSI-H CRCs correlate with resistance to ICIs through neutrophil leukocyte associated immunosuppression and proposes both inflammatory conditions and high neutrophil-to-lymphocyte ratio as clinical features for poor ICI response.

Anti-PD-1-based immunotherapy as curative-intent treatment in dMMR/MSI-H rectal cancer: A multicentre cohort study.

BACKGROUND: In a portion of patients with DNA mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) rectal cancer, clinical complete response (cCR) could be achieved after anti-programmed cell death protein 1 (anti-PD-1) immunotherapy. However, no data are available concerning the safety of omitting surgery and adopting immunotherapy as a curative-intent treatment for these patients. METHODS: We retrospectively collected a series of patients with dMMR/MSI-H rectal adenocarcinoma who had cCR after receiving anti-PD-1 immunotherapy and adopted immunotherapy as curative-intent treatment from six institutions. Survival outcomes were analysed using the Kaplan-Meier method. RESULTS: Nineteen patients were included with a median age of 48 (range 19-63). One patient was diagnosed with stage I disease, four with stage II disease and fourteen with stage III disease. Sixteen patients received anti-PD-1 immunotherapy as the first line of therapy, and eleven patients were treated with single-agent anti-PD-1 antibodies. The median time from the start of treatment to cCR was 3.8 (range 0.7-6.5) months. During a median follow-up of 17.1 (range 3.1-33.5) months since achieving cCR, no local or distant relapse was observed. Two-year local recurrence-free survival, distant metastasis-free survival, disease free-survival and overall survival for the whole cohort were 100%, 100%, 100% and 100%, respectively. CONCLUSIONS: For patients with dMMR/MSI-H locally advanced rectal cancer who achieved cCR during anti-PD-1 immunotherapy, adopting immunotherapy as curative-intent treatment might be an alternative option. Longer follow-up and larger cohorts are warranted to verify this innovative treatment approach.

RCC1 Expression as a Prognostic Marker in Colorectal Liver Oligometastases.

Introduction: Regulator of chromatin condensation 1 (RCC1) is a major guanine-nucleotide exchange factor for Ran GTPase, and it plays key roles in various biological processes. Previous studies have found that RCC1 may play a role in the development of tumors, but little is known about the relationship between RCC1 and colorectal liver oligometastases (CLOs). Methods: One hundred and twenty-nine pairs of matched human CLO samples, including both primary tumor and its liver metastasis specimens, were subjected to immunohistochemistry to determine the location and expression levels of RCC1. Associations between RCC1 and survival as well as gene expression profiling were explored. Results: In this study, we first observed that RCC1 was mildly increased in CLO tumor tissues compared with normal tissues, and the localization was primarily nuclear. In addition, our study found that high RCC1 expression in liver oligometastases was an independent prognostic marker for unfavorable recurrence-free survival and overall survival (p = 0.036 and p = 0.016). Gene expression profiles generated from microarray analysis showed that RCC1 was involved in pathways including "Myc targets," "E2F targets" and "DNA repair" pathways. Conclusion: Our data indicated that RCC1 was expressed mainly in the nucleus, and strong and significant associations were found between RCC1 expression levels and the survival of CLO patients. These findings indicated that RCC1 may play a role in CLO development.

Voltage-gated sodium channel Nav1.5 promotes tumor progression and enhances chemosensitivity to 5-fluorouracil in colorectal cancer.

Nav1.5, encoded by SCN5A, has been associated with metastasis in colorectal cancer (CRC). Here, we investigated the mechanism by which Nav1.5 regulates tumor progression and whether Nav1.5 influences chemosensitivity to 5-fluorouracil (5-FU) in CRCs. CRC cases were evaluated for Nav1.5 expression. Elevated Nav1.5 expression was associated with poor prognosis in CRCs, whereas stage II/III patients with upregulated SCN5A expression could have better survival after receiving 5-FU-based adjuvant chemotherapy. In CRC cells, SCN5A knockdown reduced the proliferation, migration and invasion. According to RNA sequencing, SCN5A knockdown inhibited both the cell cycle and epithelial-mesenchymal transition. In addition, Nav1.5 stabilized the KRas-calmodulin complex to modulate Ras signaling, promoting Ca2+ influx through the Na+-Ca2+ exchanger and Ca2+ release-activated calcium channel. Meanwhile, SCN5A knockdown increased the 50% inhibitory concentration to 5-FU by upregulating 5-FU-stimulated apoptosis in CRCs. In conclusion, Nav1.5 could progress to proliferation and metastasis through Ca2+/calmodulin-dependent Ras signaling in CRC, and it could also enhance 5-FU-stimulated apoptosis. Clinically, patients with stage II/III CRCs with elevated SCN5A expression demonstrated poor prognosis, yet those patients could benefit more from 5-FU-based chemotherapy than patients with lower SCN5A expression.