Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

Abstract

BackgroundFor rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.MethodsThe study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan–Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).ResultsOf 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.ConclusionAdjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Effect of adjuvant chemotherapy on the oncological outcome of rectal cancer patients with pathological complete response

“…A total of 29 [ 15 – 19 , 26 , 28 – 31 , 33 – 52 ]. studies, including 9 [ 18 , 26 , 29 , 31 , 35 , 38 , 39 , 43 , 47 ].…”

“…For the pooled analysis, we only included the most recently published studies from this database. Given the 18 [ 16 , 17 , 19 , 28 , 30 , 33 , 34 , 36 , 37 , 40 – 42 , 44 – 46 , 50 – 52 ]. studies with reporting on the effect of ACT on the hazard ratio of OS in patients with rectal cancer in pCR, the pooled analysis showed that ACT improved overall survival (HR = 0.803, 95% CI 0.678–0.952, P = 0.011) without any observed heterogeneity ( I 2 = 0%, χ 2 = 14.66, P = 0.620) (Fig.…”

“…2 A). Additionally, 19 [ 15 – 17 , 19 , 28 , 30 , 33 , 34 , 36 , 37 , 40 – 42 , 45 , 46 , 49 , 51 , 52 , 54 ]. studies reported on the 5-year OS rate, and the analysis revealed that patients with pCR who underwent ACT had a higher 5-year OS rate than those who did not receive ACT (OR = 1.605, 95% CI 1.183–2.177, P = 0.002).…”

“…Thirteen [ 15 – 17 , 28 , 33 , 34 , 37 , 40 , 44 , 48 , 50 – 52 ]. studies compared the effect of ACT and non-ACT on DFS in rectal cancer patients who achieved a pCR.…”

“…3 A). Furthermore, 11 [ 15 – 17 , 28 , 33 , 34 , 37 , 40 , 48 , 51 , 52 ]. studies examined the effect of ACT on the 5-year DFS rates in patients with pCR.…”