Factors Implicated for Delay of Adjuvant Chemotherapy in Colorectal Cancer: A Meta-analysis of Observational Studies.

Abstract

The survival benefit of administering adjuvant chemotherapy (AC) in colorectal cancer is well established, as is the impact of its timing. Although various factors have been associated with treatment delay, their implications remain controversial. We determined clinicopathological factors associated with delay in transition to AC via systematic review and meta-analysis. Studies assessing factors for delay in initiating AC were identified from MEDLINE, EMBASE, and Cochrane Databases. Studies were included only if relevant clinicopathological factors were adequately described and appropriate comparative groups were balanced. For each study, the odds ratio (OR) and 95 % confidence interval (CI) were estimated, regarding response to early versus delayed AC initiation. We identified 15 eligible studies involving 67,537 patients. Twelve studies were multicentre studies and three were single-center cohort studies. Meta-analysis demonstrated age >75 years [4 studies, OR = 1.44 (95 % CI 1.32-1.58)], marital status-single [3 studies, OR = 1.32 (95 % CI 1.20-1.44)], low socioeconomic status (SES) [7 studies, OR = 1.67 (95 % CI 1.32-2.12)], worse comorbidity status [5 studies, OR = 1.47 (95 % CI 1.14-1.90)], low tumour grade [7 studies, OR = 1.06 (95 % CI 1.02-1.11)], prolonged length of stay [3 studies, OR 2.37 (95 % CI 2.10-2.68)], and readmission [3 studies, OR = 3.23 (95 % CI 1.66-6.26)] were significant predictors of delayed initiation of AC. Laparoscopy compared to an open surgical approach was a significant predictor of earlier AC initiation [5 studies, OR = 0.70 (95 % CI 0.51-0.97)]. Laparoscopy is associated with earlier initiation of AC, encouraging its increased adoption. Social isolation and low SES merit consideration of approaches that counter the lack of social support and deprivation to improve cancer outcomes.