Influence of complete administration of adjuvant chemotherapy cycles on overall and disease-free survival in locally advanced rectal cancer: post hoc analysis of a randomized, multicenter, non-inferiority, phase 3 trial

Abstract

BackgroundA randomized trial demonstrated that capecitabine is at least as effective as fluorouracil in the adjuvant treatment of patients with locally advanced rectal cancer. However, not all patients receive all planned cycles of chemotherapy. Therefore it is of interest how complete or partial administration of chemotherapy influences oncological outcome.MethodsA post hoc analysis of a trial with 401 randomized patients, nine being excluded because of missing data, was performed. 392 patients (197 - capecitabine, 195 - fluorouracil) could be analyzed regarding the number of administered adjuvant chemotherapy cycles. In the subgroup of 361 patients with an overall survival of at least six months, five-year overall and disease-free survival were analyzed in respect to completion (complete vs. incomplete) of chemotherapy cycles. Survival rates and curves were calculated and compared using the log-rank test. The effect of completion of chemotherapy was adjusted for relevant confounding factors.ResultsTwo hundred fifty-one (64.0%) of analyzed patients received all postoperative scheduled cycles. Five-year overall survival was significantly better in these patients compared to the incomplete group (76.0 vs. 60.6%, p < 0.0001). Of 361 patients with an overall survival of at least six months, 251(69.5%) patients received all cycles. Five-year overall survival was also significantly better than in the incomplete group (76.0 vs. 66.4%, p = 0.0073). Five-year disease free survival was numerically better (64.9 vs. 58.7%, p = 0.0646; HR [not all cycles vs. all cycles] = 1.42 95% CI: [0.98, 2.07]). Cox regression models show a non-significant better OS (p = 0.061) and DFS (p = 0.083), if chemotherapy cycles were administered completely.ConclusionComplete administration of chemotherapy cycles was associated with improved five-year overall and disease-free survival in patients with locally advanced rectal cancer.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-4309-6) contains supplementary material, which is available to authorized users.

Efficacy and Safety of Dual Anti-HER2 Blockade and Docetaxel With or Without Carboplatin as Neoadjuvant Regimen for Treatment of HER2-Positive Breast Cancer

“…25,32 Furthermore, because more patients in the TCHP group could not complete the NAT scheme, the antitumor effect may have been reduced. 33 Analysis of the factors influencing the patient's pCR rate showed that the HER2 immunohistochemical score significantly affected the patient's pCR rate. The proportion of patients who achieved pCR in the HER2 3+ population was significantly higher than that in the HER2 3+ population, which is similar to the results reported by Spring et al 24 More importantly, we found that tumor size significantly affected the pCR rate.…”

“… 25 , 32 Furthermore, because more patients in the TCHP group could not complete the NAT scheme, the antitumor effect may have been reduced. 33 …”

Neoadjuvant chemoradiotherapy with capecitabine based regimen in locally advanced rectal cancer: A retrospective study

“…It is consistent with another study that showed the value of adjuvant chemotherapy might be controversial. [ 24 ] However, Sandra-Petrescu et al [ 25 ] pointed that the complete administration of chemotherapy cycles after surgery were associated with improved the overall and disease-free survival at 5 years in patients with locally advanced rectal cancer.…”

A Retrospective Analysis of Locally Advanced Rectal Cancer Treated by Neoadjuvant Chemoradiotherapy Combined With Surgery

“…It is consistent with another study that showed the value of adjuvant chemotherapy might be controversial 23 . However, Sandra-Petrescu F et al pointed that the complete administration of chemotherapy cycles after surgery were associated with improved the overall and disease-free survival at 5 years in patients with locally advanced rectal cancer 24 .…”