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.

Microbiota in colorectal cancer related to liver metastasis.

The prevalence of colorectal cancer (CRC) is increasing annually and metastasis is the principal cause of death in patients with CRC, with the liver being the most frequently affected site. Many studies have shown a strong interplay between the gut flora, particularly Fusobacterium nucleatum (F. nucleatum), Escherichia coli, and Bacteroides fragilis, and the development of gut tumors. Some strains can induce gut inflammation and produce toxins that directly harm gut epithelial cells, ultimately accelerating the onset and progression of CRC. However, little clinical evidence exists on the specific interplay between the gut microflora and colorectal cancer liver metastasis (CRLM). Some research showed the existence of viable F. nucleatum in distant metastasis of CRC. Subsequently, gut microbiota products, such as lipopolysaccharides, sodium butyrate, and protein cathepsin K, were also found to affect the development of CRC. This article summarizes the mechanism and research status of the interplay between gut microflora and CRLM, discusses the importance of gut microflora in the treatment of CRLM, and proposes a new approach to understanding the mechanism of CRLM and potential treatments for the microbiome. It is anticipated that the gut microbiota will be a formidable therapeutic and prophylactic tool for treating and preventing CRLM.

Distinct clinical characteristics in stage III rectal cancer among different age groups and treatment outcomes after neoadjuvant chemoradiotherapy.

Background: There is a rapidly increasing incidence of early-onset colorectal cancer (EO-CRC) which threatens the survival of young people, while aging also represents a challenging clinical problem. Objectives: We aimed to investigate the differences in the clinical characteristics and prognosis in stage III rectal cancer (RC), to help optimize treatment strategies. Design and methods: This study included 757 patients with stage III RC, all of whom received neoadjuvant chemoradiotherapy and total mesorectal excision. The whole cohort was categorized as very early onset (VEO, ⩽30 years old), early onset (EO, >30 years old, ⩽50 years old), intermediate onset (IO, >50 years, ⩽70 years), or late onset (LO, >70 years old). Results: There were more female VEO patients than males, more mucinous adenocarcinoma, signet-ring cell carcinoma, pre-treatment cT4 stage, and higher pre-treatment serum carbohydrate antigen 19-9 compared with the other three groups. VEO patients had the worst survival with the highest RC-related mortality (34.5%), recurrence (13.8%), and metastasis (51.7%). LO patients had the highest non-RC-related mortality rate (16.6%). The Cox regression model showed VEO was a negative independent prognostic factor for disease-free survival [DFS, hazard ratio (HR): 2.830, 95% confidence interval (CI): 1.633-4.904, p < 0.001], distant metastasis-free survival (DMFS, HR: 2.969, 95% CI: 1.720-5.127, p < 0.001), overall survival (OS, HR: 2.164, 95% CI: 1.102-4.249, p = 0.025), and cancer-specific survival (CSS, HR: 2.321, 95% CI: 1.145-4.705, p = 0.020). LO was a negative independent factor on DFS (HR: 1.800, 95% CI: 1.113-2.911, p = 0.017), DMFS (HR: 1.903, 95% CI: 1.150-3.149, p = 0.012), OS (HR: 2.856, 95% CI: 1.745-4.583, p < 0.001), and CSS (HR: 2.248, 95% CI: 1.282-3.942, p = 0.005). VEO patients had better survival in the total neoadjuvant therapy-like (TNT-like) pattern on DFS (p = 0.039). IO patients receiving TNT-like patterns had better survival on DFS, OS, and CSS (p = 0.006, p = 0.018, p = 0.006, respectively). Conclusion: In stage III RC, VEO patients exhibited unique clinicopathological characteristics, with VEO a negative independent prognostic factor for DFS, DMFS, OS, and CSS. VEO and IO patients may benefit from a TNT-like treatment pattern.

Clinical factors of post-chemoradiotherapy as valuable indicators for pathological complete response in locally advanced rectal cancer

OBJECTIVES: Pathological complete response has shown a better prognosis for patients with locally advanced rectal cancer after preoperative chemoradiotherapy. However, correlations between post-chemoradiotherapy clinical factors and pathologic complete response are not well confirmed. The aim of the current study was to identify post-chemoradiotherapy clinical factors that could serve as indicators of pathologic complete response in locally advanced rectal cancer. METHODS: This study retrospectively analyzed 544 consecutive patients with locally advanced rectal cancer treated at Sun Yat-sen University Cancer Center from December 2003 to June 2014. All patients received preoperative chemoradiotherapy followed by surgery. Univariate and multivariate regression analyses were performed to identify post-chemoradiotherapy clinical factors that are significant indicators of pathologic complete response. RESULTS: In this study, 126 of 544 patients (23.2%) achieved pathological complete response. In multivariate analyses, increased pathological complete response rate was significantly associated with the following factors: post-chemoradiotherapy clinical T stage 0-2 (odds ratio=2.098, 95% confidence interval=1.023-4.304, p=0.043), post-chemoradiotherapy clinical N stage 0 (odds ratio=2.011, 95% confidence interval=1.264-3.201, p=0.003), interval from completion of preoperative chemoradiotherapy to surgery of >7 weeks (odds ratio=1.795, 95% confidence interval=1.151-2.801, p=0.010) and post-chemoradiotherapy carcinoembryonic antigen ≤2 ng/ml (odds ratio=1.579, 95% confidence interval=1.026-2.432, p=0.038). CONCLUSIONS: Post-chemoradiotherapy clinical T stage 0-2, post-chemoradiotherapy clinical N stage 0, interval from completion of chemoradiotherapy to surgery of >7 weeks and post-chemoradiotherapy carcinoembryonic antigen ≤2 ng/ml were independent clinical indicators for pathological complete response. These findings demonstrate that post-chemoradiotherapy clinical factors could be valuable for post-operative assessment of pathological complete response.