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.

Neoadjuvant Chemotherapy With CAPOX Versus Chemoradiation for Locally Advanced Rectal Cancer With Uninvolved Mesorectal Fascia (CONVERT): Initial Results of a Phase III Trial.

OBJECTIVE: To compare neoadjuvant chemotherapy (nCT) with CAPOX alone versus neoadjuvant chemoradiotherapy (nCRT) with capecitabine in locally advanced rectal cancer (LARC) with uninvolved mesorectal fascia (MRF). BACKGROUND DATA: nCRT is associated with higher surgical complications, worse long-term functional outcomes, and questionable survival benefits. Comparatively, nCT alone seems a promising alternative treatment in lower-risk LARC patients with uninvolved MRF. METHODS: Patients between June 2014 and October 2020 with LARC within 12 cm from the anal verge and uninvolved MRF were randomly assigned to nCT group with 4 cycles of CAPOX (Oxaliplatin 130 mg/m2 IV day 1 and Capecitabine 1000 mg/m2 twice daily for 14 d. Repeat every 3 wk) or nCRT group with Capecitabine 825 mg/m² twice daily administered orally and concurrently with radiation therapy (50 Gy/25 fractions) for 5 days per week. The primary end point is local-regional recurrence-free survival. Here we reported the results of secondary end points: histopathologic response, surgical events, and toxicity. RESULTS: Of the 663 initially enrolled patients, 589 received the allocated treatment (nCT, n=300; nCRT, n=289). Pathologic complete response rate was 11.0% (95% CI, 7.8-15.3%) in the nCT arm and 13.8% (95% CI, 10.1-18.5%) in the nCRT arm ( P =0.33). The downstaging (ypStage 0 to 1) rate was 40.8% (95% CI, 35.1-46.7%) in the nCT arm and 45.6% (95% CI, 39.7-51.7%) in the nCRT arm ( P =0.27). nCT was associated with lower perioperative distant metastases rate (0.7% vs. 3.1%, P =0.03) and preventive ileostomy rate (52.2% vs. 63.6%, P =0.008) compared with nCRT. Four patients in the nCT arm received salvage nCRT because of local disease progression after nCT. Two patients in the nCT arm and 5 in the nCRT arm achieved complete clinical response and were treated with a nonsurgical approach. Similar results were observed in subgroup analysis. CONCLUSIONS: nCT achieved similar pCR and downstaging rates with lower incidence of perioperative distant metastasis and preventive ileostomy compared with nCRT. CAPOX could be an effective alternative to neoadjuvant therapy in LARC with uninvolved MRF. Long-term follow-up is needed to confirm these results.

Relationship of HER2 Alteration and Microsatellite Instability Status in Colorectal Adenocarcinoma.

BACKGROUND: The impact of HER2 somatic mutations in colorectal carcinoma (CRC) has not been well studied and its relationship with microsatellite instability-high (MSI-H) is yet to be fully elucidated. MATERIALS AND METHODS: From February 2017 to February 2020, the data of patients with CRC who underwent next-generation sequencing and had detailed record of clinicopathological information were investigated. HER2 alteration and its relationship with MSI-H were analyzed. RESULTS: Among 731 patients who underwent sequencing, 55 patients (7.5%) had HER2 alteration, including 29 (4.0%) with HER2 somatic mutations, 24 (3.3%) with HER2 gene amplification, and 2 patients (0.2%) with both HER2 mutations and amplification. R678Q was the most common mutated kinase domain, and no HER2 kinase domain in-frame insertions/deletions were found in HER2 mutated cases. MSI-H was found in 5.2% of our cohort and 36.8% of MSI-H patients had HER2 mutation. For HER2 mutated cases, 48.3% were MSI-H, whereas none of the HER2 amplification cases were MSI-H. MSI-H patients with HER2 mutation had significantly worse median progression-free survival for programmed death-1 (PD-1) antibody than those without HER2 alteration (p = .036). CONCLUSION: High MSI-H rate was found in HER2 mutated cases, but no MSI-H was found in HER2 amplification cases. MSI-H patients with HER2 mutated had worse progression-free survival for PD-1 antibody than those without. IMPLICATIONS FOR PRACTICE: This study highlights the high microsatellite instability-high (MSI-H) rate in HER2 mutated cases but no MSI-H in HER2 amplification cases. Moreover MSI-H patients with HER2 mutated had worse progression-free survival for programmed death-1 antibody than those without. Further research to explore the internal relationship between HER2 alteration and MSI-H is needed.

Comparison of Immune Microenvironment Between Colon and Liver Metastatic Tissue in Colon Cancer Patients with Liver Metastasis.

BACKGROUND: Liver metastasis is an indicator of unfavorable responses to immunotherapy in colorectal cancer patients. However, the difference of immune microenvironment between primary tumors and liver metastases has not been well understood. PATIENTS AND METHODS: Fifty-four colon cancer with liver metastasis patients who received resection of both primary and metastasis lesions have been analyzed. The immune score is based on the density of infiltrating immune cells (CD3+ cell, CD8+ cell, CD11b+ cell, CD11c+ cell, and CD33+ cell) in the center and margin of the tumor. The expression of immune markers between the primary tumor and hepatic metastases was analyzed using Wilcoxon's signed rank test. RESULTS: All the five markers had higher expression in tumor margins than center tumor in both primary tumor and hepatic metastases lesions. The expression of CD11c and CD11b had no difference between metastatic lesions and primary tumor. In tumor margins, except CD11b, all the other 4 markers expressed significantly higher in hepatic metastases than in primary tumor. Intra-tumor, CD3 had higher expression in primary tumor than in hepatic metastases, while CD33 had higher expression in hepatic metastases than in primary tumor. CD8+ CD3+ cells of the total CD8+ cell population in primary tumor was significantly higher than in hepatic metastases (36.42% vs. 24.88%, p = 0.0069). CONCLUSIONS: The immune microenvironment between primary tumor and hepatic metastasis is different. More immunosuppressing cells in liver may partially explain why immunotherapy in colon cancer is less effective with liver metastatic disease.

Clinical and Cancer-Related Predictors for Venous Thromboembolism in Cancer Patients Presenting to the Emergency Department.

BACKGROUND: The accurate detection of cancer-associated venous thromboembolism (VTE) can avoid unnecessary diagnostic imaging or laboratory tests. OBJECTIVE: We sought to determine clinical and cancer-related risk factors of VTE that can be used as predictors for oncology patients presenting to the emergency department (ED) with suspected VTE. METHODS: We retrospectively analyzed all consecutive patients who presented with suspicion of VTE to The University of Texas MD Anderson Cancer Center ED between January 1, 2009, and January 1, 2013. Logistic regression models were used to identify risk factors that were associated with VTE. The ability of these factors to predict VTE was externally validated using a second cohort of patients who presented to King Hussein Cancer Center ED between January 1, 2009, and January 1, 2016. RESULTS: Cancer-related covariates associated with the occurrence of VTE were high-risk cancer type (odds ratio [OR] 3.64 [95% confidence interval {CI} 2.37-5.60], p < 0.001), presentation within 6 months of the cancer diagnosis (OR 1.92 [95% CI 1.62-2.28], p < 0.001), active cancer (OR 1.35 [95% CI 1.10-1.65], p = 0.003), advanced stage (OR 1.40 [95% CI 1.01-1.94], p = 0.044), and the presence of brain metastasis (OR 1.73 [95% CI 1.32-2.27], p < 0.001). When combined, these factors along with other clinical factors showed high prediction performance for VTE in the external validation cohort. CONCLUSIONS: Cancer risk group, presentation within 6 months of cancer diagnosis, active and advanced cancer, and the presence of brain metastases along with other related clinical factors can be used to predict VTE in patients with cancer presenting to the ED.

Evaluation of capecitabine and oxaliplatin administered prior to and then concomitant to radiotherapy in high risk locally advanced rectal cancer.

BACKGROUND AND OBJECTIVES: Systemic failure remains a predominant issue in locally advanced rectal cancer (LARC). A new strategy using capecitabine and oxaliplatin (XELOX regimen) administered prior to and then concomitant to radiotherapy for high risk LARC is developed in our practice. The aim of the present study was to evaluate the short-term efficacy and toxicities of this strategy. METHODS: Patients were treated with one cycle XELOX regimen (oxaliplatin 130 mg/m(2) on day 1 with capecitabine 1,000 mg/m(2) twice daily for 14 days every 3 weeks), followed by chemoradiation (50 Gy over 5 weeks) with modified XELOX regimen (oxaliplatin dose reduction to 100 mg/m(2)), and total mesorectal excision. Tumor response, toxicities, and surgical complications were recorded. RESULTS: Forty-two patients treated with the strategy were identified. All patients completed planned dose of induction chemotherapy and concurrent chemoradiotherapy. Grade 3 toxicities were thrombocytopenia (4.8%), diarrhea (7.1%), proctitis (4.8%), and radiation dermatitis (7.1%). Five patients (12.5%) developed postoperative complications. Pathologic complete response (pCR) and nearly pCR were achieved in 7 (15.0%) and 13 patients (35.0%). CONCLUSIONS: The preliminary results suggest that induction chemotherapy followed by chemoradiotherapy with capecitabine and oxaliplatin in LARC is well tolerated. The strategy achieves favorable short term outcome in terms of pCR and nearly pCR rate, which warrants further investigation.

Recanalization of anastomotic occlusion following rectal cancer surgery using a rendezvous endoscopic technique with transillumination: A case report.

BACKGROUND: Colorectal anastomotic occlusion is a serious complication of colorectal cancer surgery. Although several treatment strategies have been proposed, the management of anastomotic occlusion remains challenging. In this report, we present a case of anastomotic occlusion recanalization performed using a novel technique involving two endoscopes, one for radial incision and the other serving as a guide light. This novel technique offers significant advantages in terms of operational feasibility, reduced invasiveness, rapid recovery, and shortened hospital stay. CASE SUMMARY: A 37-year-old man underwent low anterior resection and prophylactic double-lumen ileostomy for rectal cancer in June, 2023. Two months later, complete anastomotic occlusion was observed on colonoscopy. Therefore, we developed a novel atresia recanalization technique. Two endoscopes were placed, one through the colonic anastomosis and the other through the anus. A radial incision was successfully made from the colonic side, guided by the light of the endoscope from the anal side. Atresia recanalization was performed within 20 minutes. Three weeks after recanalization, colonoscopy revealed that the diameter of the colorectal anastomosis was approximately 16 mm and the patient therefore underwent stoma reversal in September. During the follow-up period of approximately one year, the patient remained well and no stenosis or obstruction symptoms were observed. CONCLUSION: Endoscopic atresia recanalization of colorectal anastomotic occlusion assisted by an opposing light source is safe and effective.

Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy for initially unresectable locally advanced colon cancer: short-term outcomes of an open-label, single-centre, randomised, controlled, phase 3 trial.

Background: Neoadjuvant chemotherapy (NACT) is commonly used to downstage the tumor in locally advanced colon cancer (LACC) and improve the R0 resection rate. Neoadjuvant chemoradiotherapy (NACRT) is the standard treatment for locally advanced rectal and esophageal cancers, but its benefits in LACC remain poorly understood. This study aimed to compare the effects and safety of NACRT and NACT on R0 resection and survival rates in initially unresectable LACC. Methods: This was an open-label, single-center, randomized, controlled trial conducted between May 11, 2019 and May 30, 2022. Forty-five patients with initially unresectable LACC were randomly allocated to the NACT (control, n = 20) or NACRT (research, n = 25) group. The NACT group received XELOX (oxaliplatin 100-130 mg/m2, qd, d1, every 3 weeks; and capecitabine 1000 mg/m2, bid, d1-d14, every 3 weeks) for 4 cycles. The NACRT group, in addition to chemotherapy, received daily irradiation (GTV 45-50 Gy/25 F; CTV 42.5-45 Gy/25 F). Surgery was scheduled 6-12 weeks after neoadjuvant treatment and adjuvant chemotherapy was administered if the patient developed resectable LACC. The primary endpoint was the 5-year overall survival (OS) rate. The secondary outcomes included the 3-year progression-free survival (PFS) and R0 resection rates. This study was registered with ClinicalTrials.gov (NCT03970694). Findings: In short-term outcome analysis, NACRT significantly improved the R0 resection rate (80% for NACRT vs. 20% for NACT, P < 0.001). The NACRT and NACT groups had a 3-year OS of 87.6% and 75% (P = 0.037) and a 3-year PFS of 76% and 45% (P = 0.049), respectively. The 5-year OS was not reached. In the NACRT group, no local or regional recurrence was observed in patients who underwent surgery during the follow-up period, compared to two patients in the NACT group. Both NACT and NACRT were well tolerated, with no significant differences in severe adverse events. The most commonly observed grade 3-4 AE was myelosuppression (39% for NACRT and 47% for NACT, P = 0.609). No grade 5 AEs were observed between the two groups. Interpretation: Adding radiation to NACT increased the R0 resection rate, prolonged the PFS, and potentially improved OS in selected patients with initially unresectable LACC. The trial findings indicate that this approach is safe, feasible, and may confer a survival benefit. Funding: This study was supported by grants from the National Natural Science Foundation of China (82373213 to Dr Gao, 82202952 to Dr Wang); and the Natural Science Foundation of Guangdong Province (2023A1515010290 to Dr Chang). Funding sources were not involved in the study design, data collection, analysis and interpretation, writing of the report, or decision to submit the article for publication.

Long-term outcomes of intraoperative chemotherapy with 5-FU for colorectal cancer patients receiving curative resection (IOCCRC): a randomized, multicenter, prospective, phase III trial.

BACKGROUND: We aimed to compare combined intraoperative chemotherapy and surgical resection with curative surgical resection alone in colorectal cancer patients. METHODS: We performed a multicenter, open-label, randomized, phase III trial. All eligible patients were randomized and assigned to intraoperative chemotherapy and curative surgical resection or curative surgical resection alone (1:1). Survival actualization after long-term follow-up was performed in patients analyzed on an intention-to-treat basis. RESULTS: From January 2011 to January 2016, 696 colorectal cancer patients were enrolled and randomly assigned to intraoperative chemotherapy and radical surgical resection (n=341) or curative surgical resection alone (n=344). Intraoperative chemotherapy with surgical resection showed no significant survival benefit over surgical resection alone in colorectal cancer patients (3-year DFS: 91.1% vs. 90.0%, P=0.328; 3-year OS: 94.4% vs. 95.9%, P=0.756). However, colon cancer patients benefitted from intraoperative chemotherapy, with a relative 4% reduction in liver and peritoneal metastasis (HR=0.336, 95% CI: 0.148-0.759, P=0.015) and a 6.5% improvement in 3-year DFS (HR=0.579, 95% CI: 0.353-0.949, P=0.032). Meanwhile, patients with colon cancer and abnormal pretreatment CEA levels achieved significant survival benefits from intraoperative chemotherapy (DFS: HR=0.464, 95% CI: 0.233-0.921, P=0.029 and OS: (HR=0.476, 95% CI: 0.223-1.017, P=0.049). CONCLUSIONS: Intraoperative chemotherapy showed no significant extra prognostic benefit in total colorectal cancer patients who underwent radical surgical resection; however, in colon cancer patients with abnormal pretreatment serum CEA levels (> 5 ng/ml), intraoperative chemotherapy could improve long-term survival.

Effect of neoadjuvant chemoradiotherapy with or without PD-1 antibody sintilimab in pMMR locally advanced rectal cancer: A randomized clinical trial.

Neoadjuvant chemoradiotherapy (NACRT) was the standard treatment for patients with locally advanced rectal cancer (LARC) with proficient mismatch repair (pMMR) proteins. In this randomized phase 2 trial (ClinicalTrial.gov: NCT04304209), 134 pMMR LARC patients were randomly (1:1) assigned to receive NACRT or NACRT and the programmed cell death protein 1 (PD-1) antibody sintilimab. As the primary endpoint, the total complete response (CR) rate is 26.9% (18/67, 95% confidence interval [CI] 16.0%-37.8%) and 44.8% (30/67, 95% CI 32.6%-57.0%) in the control and experimental arm, respectively, with significant difference (p = 0.031 for chi-squared test). Response ratio is 1.667 (95% CI 1.035-2.683). Immunohistochemistry shows PD-1 ligand 1 (PD-L1) combined positive score is associated with the synergistic effect. The safety profile is similar between the arms. Adding the PD-1 antibody sintilimab to NACRT significantly increases the CR rate in pMMR LARC, with a manageable safety profile. PD-L1 positivity may help identify patients who might benefit most from the combination therapy.

Is early surveillance with CT scan necessary in patients with stage II/III colorectal cancer: a retrospective study.

BACKGROUND AND OBJECTIVES: This analysis aims to evaluate the value of early surveillance within 6 months after resection for stage II/III colorectal cancer (CRC). METHODS: Patients with stage II/III CRC who received surgery with curative intent for CRC were included. CT scans of the chest, abdomen, and pelvis performed within 6 months after surgery were evaluated. RESULTS: Among 150 patients included in the study, 10 patients (1 occurred in stage II disease and 9 occurred in stage III) were diagnosed as recurrence within 6 months after surgery. The proportion of patients diagnosed as recurrence was significantly higher in stage III disease than in stage II disease (P = 0.01). The likelihood of recurrence within 6 months was associated with the extent of lymph node metastases (r = 0.205, P = 0.012). Three patients with recurrent disease underwent salvage resection with curative intent. CONCLUSIONS: Early surveillance with CT scan within 6 months after curative resection may not be necessary for stage II disease. Although, the strategy may be helpful for stage III disease considering the high incidence of salvage surgery for recurrence disease, the early detection of recurrence could not be translated into survival benefit.

[Expression of molecular markers detected by immunohistochemistry and risk of lymph node metastasis in stage T1 and T2 colorecrectal cancers].

OBJECTIVE: To study the molecular risk factors of lymph node metastasis in stage T1 and T2 colorectal cancers by tissue microarray and immunohistochemistry techniques. METHODS: Two hundred and three patients with stage T1 and T2 colorectal carcinoma who underwent radical surgery from 1999 to 2010 in our department were included in this study. Their clinicopathological data were retrospectively analyzed. Expression of the following 14 molecular markers were selected and assayed by tissue microarray and immunohistochemistry: VEGFR-3, HER2, CD44v6, CXCR4, TIMP-1, EGFR, IGF-1R, IGF-2, IGFBP-1, ECAD, MMP-9, RKIP, CD133, MSI. Chi-squared test and logistic regression were used to evaluate the variables as potential risk factors for lymph node metastasis. RESULTS: The positive expression rates of biomarkers were as following: VEGFR-3 (44.3%), EGFR (30.5%), HER-2 (28.1%), IGF-1R (63.5%), IGF-2 (44.8%), IGFBP-1 (70.9%), ECAD (45.8%), CD44v6 (51.2%), MMP-9 (44.3%), TIMP-1 (41.4%), RKIP (45.3%), CXCR4 (40.9%), and CD133 (49.8%). The positive rate of MSI expression was 22.2%. Both univariate and multivariate analyses showed that VEGFR-3, HER-2, and TIMP-1 were significant predictors of lymph node metastasis. Univariate analysis showed that CD44v6 and CXCR4 were significant significant predictors of lymph node metastasis. CONCLUSIONS: VEGFR-3, HER2 and TIMP-1 are independent factors for lymph node metastasis in stage T1 and T2 colorectal cancers.

Neoadjuvant PD-1 blockade with sintilimab in mismatch-repair deficient, locally advanced rectal cancer: an open-label, single-centre phase 2 study.

BACKGROUND: The current standard treatment for locally advanced rectal cancer is neoadjuvant chemoradiotherapy followed by radical surgery, but this approach can lead to multiple complications. We aimed to investigate the clinical activity and safety of neoadjuvant therapy with sintilimab, a single-agent PD-1 antibody, in patients with mismatch-repair deficient locally advanced rectal cancer. METHODS: This open-label, single-arm, phase 2 study was done at the Sun Yat-sen University Cancer Center, Guangzhou, China. Patients aged 18-75 years with mismatch-repair deficient or microsatellite instability-high locally advanced rectal cancer were enrolled and received neoadjuvant sintilimab monotherapy (200 mg by intravenous infusion) every 21 days. After an initial four cycles of treatment, patients and clinicians could choose one of the following options: total mesorectal excision surgery, followed by four cycles of adjuvant sintilimab with or without CapeOX chemotherapy (capecitabine 1000 mg/m2, orally administered twice daily on days 1-14; oxaliplatin 130 mg/m2, intravenously administered on day 1 every 3 weeks), determined by clinicians; or another four cycles of sintilimab followed by radical surgery or observation (only for patients with a clinical complete response; also known as the watch and wait strategy). The primary endpoint was the complete response rate, which included both a pathological complete response after surgery and a clinical complete response after completion of sintilimab treatment. Clinical response was evaluated by digital rectal examination, MRI, and endoscopy. Response was assessed in all patients who received treatment at least until the first tumour response assessment, after the first two cycles of sintilimab. Safety was analysed in all patients who received at least one dose of treatment. This trial is closed to enrolment and is registered with ClinicalTrials.gov (NCT04304209). FINDINGS: Between Oct 19, 2019, and June 18, 2022, 17 patients were enrolled and received at least one dose of sintilimab. The median age was 50 years (IQR 35-59) and 11 (65%) of 17 patients were male. One patient was excluded from efficacy analyses because they were lost to follow-up after the first sintilimab cycle. Of the remaining 16 patients, six underwent surgery, of whom three had a pathological complete response. Nine other patients had a clinical complete response and chose the watch and wait strategy. One patient had a serious adverse event and discontinued treatment; this patient did not have a complete clinical response and refused to undergo surgery. A complete response was thus noted for 12 (75%; 95% CI 47-92) of 16 patients. One of the three patients who underwent surgery but did not have a pathological complete response showed an increase in tumour volume after the initial four cycles of sintilimab (at which point they underwent surgery); this patient was deemed to have primary resistance to immune checkpoint inhibitors. After a median follow-up of 17·2 (IQR 8·2-28·5) months, all patients were alive and none had disease recurrence. Only one (6%) patient had a grade 3-4 adverse event, which was deemed a serious adverse event (grade 3 encephalitis). INTERPRETATION: The preliminary results of this study suggest that anti-PD-1 monotherapy is effective and tolerable for patients with mismatch-repair deficient locally advanced rectal cancer and could potentially spare some patients from radical surgery. Longer treatment courses might be needed to achieve maximum effects in some patients. Longer follow-up is also needed to observe the duration of response. FUNDING: The National Natural Science Foundation of China, CAMS Innovation Fund for Medical Sciences, Science and Technology Program of Guangzhou, and Innovent Biologics.

Phosphorylated NFS1 weakens oxaliplatin-based chemosensitivity of colorectal cancer by preventing PANoptosis.

Metabolic enzymes have an indispensable role in metabolic reprogramming, and their aberrant expression or activity has been associated with chemosensitivity. Hence, targeting metabolic enzymes remains an attractive approach for treating tumors. However, the influence and regulation of cysteine desulfurase (NFS1), a rate-limiting enzyme in iron-sulfur (Fe-S) cluster biogenesis, in colorectal cancer (CRC) remain elusive. Here, using an in vivo metabolic enzyme gene-based clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 library screen, we revealed that loss of NFS1 significantly enhanced the sensitivity of CRC cells to oxaliplatin. In vitro and in vivo results showed that NFS1 deficiency synergizing with oxaliplatin triggered PANoptosis (apoptosis, necroptosis, pyroptosis, and ferroptosis) by increasing the intracellular levels of reactive oxygen species (ROS). Furthermore, oxaliplatin-based oxidative stress enhanced the phosphorylation level of serine residues of NFS1, which prevented PANoptosis in an S293 phosphorylation-dependent manner during oxaliplatin treatment. In addition, high expression of NFS1, transcriptionally regulated by MYC, was found in tumor tissues and was associated with poor survival and hyposensitivity to chemotherapy in patients with CRC. Overall, the findings of this study provided insights into the underlying mechanisms of NFS1 in oxaliplatin sensitivity and identified NFS1 inhibition as a promising strategy for improving the outcome of platinum-based chemotherapy in the treatment of CRC.

FTO downregulation mediated by hypoxia facilitates colorectal cancer metastasis.

Fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) demethylase, participates in tumor progression and metastasis in many malignancies, but its role in colorectal cancer (CRC) is still unclear. Here, we found that FTO protein levels, but not RNA levels, were downregulated in CRC tissues. Reduced FTO protein expression was correlated with a high recurrence rate and poor prognosis in resectable CRC patients. Moreover, we demonstrated that hypoxia restrained FTO protein expression, mainly due to an increase in ubiquitin-mediated protein degradation. The serine/threonine kinase receptor associated protein (STRAP) might served as the E3 ligase and K216 was the major ubiquitination site responsible for hypoxia-induced FTO degradation. FTO inhibited CRC metastasis both in vitro and in vivo. Mechanistically, FTO exerted a tumor suppressive role by inhibiting metastasis-associated protein 1 (MTA1) expression in an m6A-dependent manner. Methylated MTA1 transcripts were recognized by an m6A "reader", insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), which then stabilized its mRNA. Together, our findings highlight the critical role of FTO in CRC metastasis and reveal a novel epigenetic mechanism by which the hypoxic tumor microenvironment promotes CRC metastasis.

Elevated preoperative neutrophil to lymphocyte ratio predicts risk of recurrence following curative resection for stage IIA colon cancer.

BACKGROUND AND OBJECTIVES: Adjuvant chemotherapy for stage II colon cancer remains controversial but may be considered for patients with high-risk features. Recent studies have shown that elevated neutrophil to lymphocyte ratio (NLR) is a worse prognostic factor and a predictor of response to chemotherapy in patients with advanced colorectal cancer. The purpose of this study was to evaluate whether NLR predicts risk of recurrence in patients with stage IIA colon cancer undergoing curative resection without adjuvant chemotherapy. METHODS: We retrospectively reviewed 141 consecutive patients with stage IIA colon cancer treated with curative surgery alone from 2002 to 2006. NLR, as well as demographics, clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were conducted to identify prognostic factors associated with recurrent-free survival (RFS). RESULTS: Cox's regression analysis demonstrated that elevated NLR (>4) (hazard ratio, 4.88; P < 0.01) and less lymph node sampling (<15 lymph nodes; hazard ratio, 3.80; P < 0.05) were adverse prognostic factors for RFS. The 5-year RFS was 91.4% (95% CI, 88.6-94.2%) for patients with normal NLR and 63.8% (51.1-76.3%) for patients with elevated NLR. The 5-year RFS for patients with 0, 1, and 2 of the identified risk factors was 95.1%, 87.4%, and 33.3%, respectively (P < 0.001). CONCLUSIONS: Elevated preoperative NLR is an independent predictor of worse RFS for patients with stage IIA colon cancer and a potential biomarker to identify candidates for adjuvant chemotherapy.

Germline mutational profile of Chinese patients under 70 years old with colorectal cancer.

BACKGROUND: Inherited susceptibility accounts for nearly one-third of colorectal cancer (CRC) predispositions and has an 80%-100% lifetime risk of this disease. However, there are few data about germline mutations of hereditary CRC-related genes in Chinese patients with CRC. This study aimed to assess the prevalence of gene mutations related to cancer susceptibility among Chinese patients with CRC, differences between Chinese and Western patients, and the phenotype-genotype correlation. METHODS: We retrospectively collected tumor samples from 526 patients with CRC under 70 years old who underwent hereditary CRC genetic testing. A series of bioinformatic analyses, as well as statistical comparisons, were performed. RESULTS: We found that 77 patients (14.6%) harbored functional variants of the 12 genes. The mutation frequencies of the top 5 mutated genes were 6.5% for MutL homolog 1 (MLH1), 5.1% for MutS homolog 2 (MSH2), 1.0% for MSH6, 0.8% for PMS1 homolog 2 (PMS2), and 0.8% for APC regulator of the WNT signaling pathway (APC). Our data showed much higher rates of mutations of MSH6 and PMS2 genes among all mismatch repair (MMR) genes as compared with those in Western populations. Mutations in MLH1, MSH2, and MSH6 were found to be mutually exclusive. Patients with MLH1 or MSH2 mutations had higher frequencies of personal history of cancer (MLH1: 20.6% vs. 8.7%; MSH2: 25.9% vs. 8.6%) and family history of cancer than those without these mutations (MLH1: 73.5% vs. 48.4%; MSH2: 70.4% vs. 48.9%), and the lesions were more prone to occur on the right side of the colon than on the left side (MLH1: 73.5% vs. 29.3%; MSH2: 56.0% vs. 31.0%). The proportion of stage I/II disease was higher in patients with MLH1 mutations than in those without MLH1 mutations (70.6% vs. 50.7%), and the rate of polyps was higher in patients with APC mutations than in those with wild-type APC (75.0% vs. 17.4%). CONCLUSION: These results provide a full-scale landscape of hereditary susceptibility over 12 related genes in CRC patients and suggest that a comprehensive multi-gene panel testing for hereditary CRC predisposition could be a helpful analysis in clinical practice.

Efficacy of adjuvant cytokine-induced killer cell immunotherapy in patients with colorectal cancer after radical resection.

Adjuvant chemotherapy after surgery is the standard treatment modality for stage III and part of stage II or stage IV colorectal cancer (CRC) patients. However, the 5-year overall survival (OS) rate remains unsatisfactory. Thus, developing combination therapies is essential to improve the prognosis of patients with CRC. The present study aimed to determine the effect of a sequential combination of cytokine-induced killer cell (CIK) infusion and chemotherapy for patients with CRC. 122 patients with CRC treated with postoperative adjuvant chemotherapy were retrospectively included in this study. Among them, 62 patients received adjuvant chemotherapy only (control group), while the other 60 patients, with similar demographic and clinical characteristics, received adjuvant chemotherapy and sequential CIK cell immunotherapy (CIK group). Survival analysis showed significantly improved disease free survival (DFS) and OS rates in the CIK group compared with the control group (log-rank test, P = .0024; P = .008, respectively). Univariate and multivariate analyses indicated that sequential CIK cell treatment was an independent prognostic factor for patients' DFS and OS. Subgroup analyses showed that sequential CIK cell treatment significantly improved the DFS and OS of patients with high-risk T4 stage and insufficient chemotherapy duration. In conclusion, these data indicate that sequential adjuvant CIK cell treatment combined with chemotherapy is an effective therapeutic strategy to prevent disease recurrence and prolong survival of patients with CRC, particularly for patients with high-risk T4 stage and insufficient chemotherapy duration.

Cutoff value of carcinoembryonic antigen and carbohydrate antigen 19-9 elevation levels for monitoring recurrence in patients with resectable gastric adenocarcinoma.

BACKGROUND: The aim of this longitudinal study was to try and improve the specificity of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in monitoring tumor recurrence in patients with resectable gastric adenocarcinoma by setting suitable elevation levels. METHODS: One hundred eighty-one patients with resectable gastric adenocarcinoma were considered. Serum samples were obtained preoperatively and every 3 months postoperatively. RESULTS: Preoperative CEA and CA19-9 positivity rates were 19.9% and 18.2%. The specificity and sensitivity of CEA elevation to monitor recurrence were 92.9% and 23.4% versus 76.5% and 78.9% in CEA-negative versus CEA-positive patients, respectively. For CA19-9 the specificity and sensitivity were 95.0% and 18.8% versus 60.0% and 83.3% in CA19-9-negative versus CA19-9-positive patients, respectively. When we set the elevation level of CEA at 5 ng/mL, the specificity of CEA elevation to monitor recurrence increased to 94.1% for CEA-positive patients. The specificity increased to 93.3% for CA19-9-positive patients when the CA19-9 elevation level was set at 100 U/mL. CONCLUSIONS: For CEA- or CA19-9-positive patients with resectable gastric adenocarcinoma we can increase the specificity of CEA and CA19-9 by setting the elevation level of CEA at 5 ng/mL and CA19-9 at 100 U/mL.

The association between weight stability and parenteral nutrition characteristics and survival in patients with colorectal cancer.

OBJECTIVE: Knowledge about the impact of metabolic disturbances and parenteral nutrition (PN) characteristics on the survival of cancer patients receiving PN is limited. We aimed to assess the association between clinical and PN characteristics and survival in colorectal-cancer patients receiving PN support. METHODS: Our study included 572 consecutive colorectal-cancer patients who had received PN support between 2008 and 2013. Patient characteristics, body mass index, weight, medical/surgical history, indication for PN, PN data and survival were recorded. Associations between clinical and PN characteristics and survival were analysed with important confounding factors. RESULTS: The final cohort included 437 evaluable patients, with a mean age of 57 years. Eighty-one percent of the study population had advanced stage of colorectal cancer. Unstable weight (weight change ≥2.5%) prior to PN initiation [hazard ratio (HR) = 1.41, P = 0.023] was adversely associated with survival after adjusting for multiple factors including cancer stage. Bowel obstruction (HR = 1.75, P = 0.017) as a PN indication was associated with worse survival when compared with without bowel obstruction. Higher PN amino acid by ideal body weight (g•kg-1) (HR = 0.59, P = 0.029) was associated with longer survival, whereas a higher percentage of non-PN intravenous calories (HR = 1.04, P = 0.011) was associated with shorter survival independently of confounding factors. CONCLUSIONS: Body mass index and weight stability can be useful nutritional indices for survival prediction in cancer patients receiving PN. PN planning should take into account of non-PN calories to achieve optimal energy support and balance. Future research is needed to define optimal PN amino-acid requirement and energy balance.