The risk of distant metastases in patients with clinical complete response managed by watch and wait after neoadjuvant therapy for rectal cancer: the influence of local regrowth in the International Watch and Wait Database

BACKGROUND: Nearly 30% of patients with rectal cancer develop local regrowth after initial clinical complete response managed by watch and wait. These patients might be at higher risk for distant metastases.OBJECTIVE: This study aimed to investigate risk factors for distant metastases using time-dependent analyses.DESIGN: Data from an international watch and wait database were retrospectively reviewed. Cox regression analysis was used to determine risk factors for worse distant metastases-free survival. Conditional survival modeling was used to investigate the impact of risk factors on the development of distant metastases.SETTING: Retrospective, multicenter database.PATIENTS: A total of 793 patients (47 institutions) with rectal cancer and clinical complete response to neoadjuvant treatment from the International Watch & Wait Database were included.MAIN OUTCOME MEASURES: Distant metastases-free survival.RESULTS: Of the 793 patients managed with watch and wait (median follow-up 55.2 mo)‚ 85 patients (10.7%) had distant metastases. Fifty-one of 85 patients (60%) had local regrowth at any time. Local regrowth was an independent factor associated with worse distant metastases-free survival in the multivariable model. Using conditional estimates, patients with local regrowth without distant metastases for 5 years (from decision to watch and wait) remained at higher risk for development of distant metastases for 1 subsequent year compared to patients without local regrowth (5-year conditional distant metastases-free survival 94.9% vs 98.4%).LIMITATIONS: Lack of information on adjuvant chemotherapy, salvage surgery for local regrowth, and heterogeneity of individual surveillance/follow-up strategies used may have affected results.CONCLUSIONS: In patients with clinical complete response managed by watch and wait, development of local regrowth at any time is a risk factor for distant metastases. The risk of distant metastases remains higher for 5 years after development of local regrowth.Surgical oncolog

Characteristics of Early-Onset vs Late-Onset Colorectal Cancer: A Review.

The incidence of early-onset colorectal cancer (younger than 50 years) is rising globally, the reasons for which are unclear. It appears to represent a unique disease process with different clinical, pathological, and molecular characteristics compared with late-onset colorectal cancer. Data on oncological outcomes are limited, and sensitivity to conventional neoadjuvant and adjuvant therapy regimens appear to be unknown. The purpose of this review is to summarize the available literature on early-onset colorectal cancer. Within the next decade, it is estimated that 1 in 10 colon cancers and 1 in 4 rectal cancers will be diagnosed in adults younger than 50 years. Potential risk factors include a Westernized diet, obesity, antibiotic usage, and alterations in the gut microbiome. Although genetic predisposition plays a role, most cases are sporadic. The full spectrum of germline and somatic sequence variations implicated remains unknown. Younger patients typically present with descending colonic or rectal cancer, advanced disease stage, and unfavorable histopathological features. Despite being more likely to receive neoadjuvant and adjuvant therapy, patients with early-onset disease demonstrate comparable oncological outcomes with their older counterparts. The clinicopathological features, underlying molecular profiles, and drivers of early-onset colorectal cancer differ from those of late-onset disease. Standardized, age-specific preventive, screening, diagnostic, and therapeutic strategies are required to optimize outcomes