Consistent signatures in the human gut microbiome of old- and young-onset colorectal cancer.

The incidence of young-onset colorectal cancer (yCRC) has been increasing in recent decades, but little is known about the gut microbiome of these patients. Most studies have focused on old-onset CRC (oCRC), and it remains unclear whether CRC signatures derived from old patients are valid in young patients. To address this, we assembled the largest yCRC gut metagenomes to date from two independent cohorts and found that the CRC microbiome had limited association with age across adulthood. Differential analysis revealed that well-known CRC-associated taxa, such as Clostridium symbiosum, Peptostreptococcus stomatis, Parvimonas micra and Hungatella hathewayi were significantly enriched (false discovery rate <0.05) in both old- and young-onset patients. Similar strain-level patterns of Fusobacterium nucleatum, Bacteroides fragilis and Escherichia coli were observed for oCRC and yCRC. Almost all oCRC-associated metagenomic pathways had directionally concordant changes in young patients. Importantly, CRC-associated virulence factors (fadA, bft) were enriched in both oCRC and yCRC compared to their respective controls. Moreover, the microbiome-based classification model had similar predication accuracy for CRC status in old- and young-onset patients, underscoring the consistency of microbial signatures across different age groups.

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.

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 pelvic exenterations for gynecological malignancies: a single-center retrospective cohort study.

BACKGROUND: Recently, with the advancement of medical technology, the postoperative morbidity of pelvic exenteration (PE) has gradually decreased, and it has become a curative treatment option for some patients with recurrent gynecological malignancies. However, more evidence is still needed to support its efficacy. This study aimed to explore the safety and long-term survival outcome of PE and the feasibility of umbilical single-port laparoscopic PE for gynecologic malignancies in a single medical center in China. PATIENTS AND METHODS: PE for gynecological cancers except for ovarian cancer conducted by a single surgical team in Sun Yat-sen University Cancer Center between July 2014 and December 2019 were included and the data were retrospectively analyzed. RESULTS: Forty-one cases were included and median age at diagnosis was 53 years. Cervical cancer accounted for 87.8% of all cases, and most of them received prior treatment (95.1%). Sixteen procedures were performed in 2016 and before, and 25 after 2016. Three anterior PE were performed by umbilical single-site laparoscopy. The median operation time was 460 min, and the median estimated blood loss was 600 ml. There was no perioperative death. The years of the operations was significantly associated with the length of the operation time (P = 0.0018). The overall morbidity was 52.4%, while the severe complications rate was 19.0%. The most common complication was pelvic and abdominal infection. The years of surgery was also significantly associated with the occurrence of severe complication (P = 0.040). The median follow-up time was 55.8 months. The median disease-free survival (DFS) was 17.9 months, and the median overall survival (OS) was 25.3 months. The 5-year DFS was 28.5%, and the 5-year OS was 30.8%. CONCLUSION: PE is safe for patient who is selected by a multi-disciplinary treatment, and can be a curative treatment for some patients. PE demands a high level of experience from the surgical team. Umbilical single-port laparoscopy was a technically feasible approach for APE, meriting further investigation.

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.

Screening and Management of Lynch Syndrome: The Chinese Experience.

Lynch syndrome (LS), caused by germline mutations in the mismatch repair genes, is the most common hereditary colorectal cancer. While LS is also associated with various cancers, early detection of the proband is meaningful for tumor prevention, treatment, and familial management. It has been a dramatic shift on the screening approaches for LS. As the rapid development of the molecular biological methods, a comprehensive understanding of the LS screening strategies will help to improve the clinical care for this systematic disease. The current screening strategies have been well validated but mainly by evidence derived from western population, lacking consideration of the ethnic heterogeneity, which hampers the universality and clinical application in China. Hence, this review will focus on the Chinese experience in LS screening, aiming to help better understand the ethnic diversity and further optimize the screening strategies.

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).

Locally advanced rectal cancer with dMMR/MSI-H may be excused from surgery after neoadjuvant anti-PD-1 monotherapy: a multiple-center, cohort study.

Objective: Examine patients with locally advanced rectal cancer (LARC) with deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-H) who received neoadjuvant immunotherapy (nIT), and compare the outcomes of those who chose a watch-and-wait (WW) approach after achieving clinical complete response (cCR) or near-cCR with those who underwent surgery and were confirmed as pathological complete response (pCR). Methods: LARC patients with dMMR/MSI-H who received nIT were retrospectively examined. The endpoints were 2-year overall survival (OS), 2-year disease-free survival (DFS), local recurrence (LR), and distant metastasis (DM). The efficacy of programmed cell death protein-1 (PD-1) inhibitor, immune-related adverse events (irAEs), surgery-related adverse events (srAEs), and enterostomy were also recorded. Results: Twenty patients who received a PD-1 inhibitor as initial nIT were examined. Eighteen patients (90%) achieved complete response (CR) after a median of 7 nIT cycles, including 11 with pCR after surgery (pCR group), and 7 chose a WW strategy after evaluation as cCR or near-cCR (WW group). Both groups had median follow-up times of 25.0 months. Neither group had a case of LR or DM, and the 2-year DFS and OS in each group was 100%. The two groups had similar incidences of irAEs (P=0.627). In the pCR group, however, 2 patients (18.2%) had permanent colostomy, 3 (27.3%) had temporary ileostomy, and 2 (18.2%) had srAEs. Conclusion: Neoadjuvant PD-1 blockade had high efficacy and led to a high rate of CR in LARC patients with dMMR/MSI-H. A WW strategy appears to be a safe and reliable option for these patients who achieve cCR or near-cCR after nIT.

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.

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.

Surgical Outcome and Long-Term Survival of Conversion Surgery for Advanced Gastric Cancer.

BACKGROUND: The present study aims to report the surgical outcome and long-term survival of conversion surgery and clarify its role in advanced gastric cancer. PATIENTS AND METHODS: A total of 95 primary advanced gastric adenocarcinoma patients who underwent systemic chemotherapy and conversion surgery were reviewed retrospectively. The survival of conversion surgery was analyzed by Cox regression and the Kaplan-Meier method. Surgical outcomes were analyzed according to the Clavien-Dindo classification. RESULTS: The median survival time (MST) of the 95 patients was 26.8 months, and the postoperative MST was 19.3 months. The MSTs of the patients in categories 1, 2, 3, and 4 were 28.8, 25.5, 43.6, and 11.3 months, respectively. The MSTs of the patients who underwent R0 resection (47 cases) and R1/2 resection (48 cases) were 49.3 months and 21.9 months, respectively. The MST of patients treated with total gastrectomy was shorter (21.9 months) than that of patients who underwent proximal (55.0 months) or distal (46.3 months) gastrectomy. Patients who received more than 6 cycles of induction chemotherapy had a longer MST than patients who received 3-5 cycles or 1-2 cycles (MST: 55.0 months versus 21.1 months versus 21.7 months). The incident postoperative complications and postoperative mortality rates were 10.5% and 1.1%, respectively. CONCLUSIONS: Advanced gastric cancer patients may obtain a survival benefit from conversion surgery, except category 4. Performing a sufficient number of cycles of induction chemotherapy (usually ≥ 6 cycles) is recommended. Surgical oncologists should perform R0 resection and avoid total gastrectomy.

Correction: Control of PD-L1 expression by miR-140/142/340/383 and oncogenic activation of the OCT4-miR-18a pathway in cervical cancer.

In Fig. 2d, the Western blot panels representing GAPDH endogenous loading controls were improperly cropped, leading to four lanes of GAPDH endogenous loading controls for five lanes of PD-L1 protein expressions. The authors apologize for any confusion that this error may have caused. This has now been corrected in both the PDF and HTML versions of the article.

Control of PD-L1 expression by miR-140/142/340/383 and oncogenic activation of the OCT4-miR-18a pathway in cervical cancer.

PD-L1, a key inhibitory immune receptor, has crucial functions in cancer immune evasion, but whether PD-L1 promotes the malignant properties of cervical cancer (CC) cells and the mechanism by which PD-L1 is regulated in CC remains unclear. We report that PD-L1 is overexpressed in CC, and shRNA-mediated PD-L1 depletion suppresses the proliferation, invasion, and tumorigenesis of CC cells. Loss of miR-140/142/340/383 contributes to PD-L1 upregulation. miR-18a enhances PD-L1 levels by targeting PTEN, WNK2 (ERK1/2 pathway inhibitor), and SOX6 (Wnt/ß-catenin pathway inhibitor and p53 pathway activator) to activate the PI3K/AKT, MEK/ERK, and Wnt/ß-catenin pathways and inhibit the p53 pathway, and miR-18a also directly suppresses the expression of the tumor suppressors BTG3 and RBSP3 (CTDSPL). miR-18a overexpression in CC cells is triggered by OCT4 overexpression. Our data implicate PD-L1 as a novel oncoprotein and indicate that miR-140/142/340/383 and miR-18a are key upstream regulators of PD-L1 and potential targets for CC treatment.