Oncologic and survival outcomes in elderly patients with locally advanced rectal cancer receiving neoadjuvant chemoradiotherapy and total mesorectal excision

Abstract

Background: The efficacy of the addition of neoadjuvant chemotherapy to neoadjuvant chemoradiotherapy and total mesorectal excision for locally advanced rectal cancer in elderly patients has not been established.

Methods: A total of 3096 locally advanced rectal cancer patients who received neoadjuvant chemotherapy, along with neoadjuvant chemoradiotherapy and total mesorectal excision, with or without adjuvant chemotherapy, between January 2010 and December 2018, were studied retrospectively. Patients were divided into elderly (>75 years) and younger (≤75 years) groups, and propensity score matching was used to balance a potentially confounding clinical bias. Overall survival, cancer-specific survival, disease-free survival, distant metastasis-free survival and local recurrence-free survival rates for the two groups were compared. Hazard ratios (HR) with 95% confidence intervals (CI) for different clinicopathological variables were calculated to determine predictors of 3-year overall survival.

Results: Mean follow-up was 39.0 (range, 5-140) months. The overall 3-year overall survival, cancer-specific survival, disease-free survival, distant metastasis-free survival and locoregional relapse-free survival rates were 86.1, 87.6, 80.0, 82.4 and 95.4%, respectively. Only 3-year overall survival rates differed significantly between the elderly (77.2%) and younger (88.9%) groups (P = 0.01). Cancer-specific survival, disease-free survival, distant metastasis-free survival and locoregional relapse-free survival rates did not differ significantly between the two groups. Significant negative independent prognostic factors for 3-year overall survival were age >75 years (HR = 2.016, 95% CI 1.157-23.511, P = 0.01) and high pathologic TNM stage (yp stage III, P < 0.001).

Conclusion: For elderly locally advanced rectal cancer patients who have good health and performance status, the addition of neoadjuvant chemotherapy to neoadjuvant chemoradiotherapy and total mesorectal excision can result in disease-related survival rates and oncological outcomes similar to those experienced by younger patients. The decision to use this treatment approach in elderly patients should not be based solely on chronological age.

Keywords: elderly patients; locally advanced rectal cancer; neoadjuvant chemoradiotherapy; neoadjuvant chemotherapy; prognostic value.