Rebecca Y Tay1, Murtaza Jamnagerwalla2, Malcolm Steel2, Hui-Li Wong3, Joseph J McKendrick4, Ian Faragher5, Suzanne Kosmider5, Ian Hastie6, Jayesh Desai6, Mark Tacey6, Peter Gibbs7, Rachel Wong8. 1. Department of Medical Oncology, Eastern Health, Box Hill, Australia. 2. Department of Surgery, Eastern Health, Box Hill, Australia. 3. Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia; University of Melbourne, Melbourne, Australia. 4. Department of Medical Oncology, Eastern Health, Box Hill, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia. 5. Western Health, Footscray, Australia. 6. The Royal Melbourne Hospital, Parkville, Australia. 7. Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia; University of Melbourne, Melbourne, Australia; Western Health, Footscray, Australia; The Royal Melbourne Hospital, Parkville, Australia. 8. Department of Medical Oncology, Eastern Health, Box Hill, Australia; Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia. Electronic address: Rachel.Wong@monash.edu.
Abstract
BACKGROUND: Recent data has created uncertainty regarding the benefit of adjuvant fluoropyrimidine-containing chemotherapy following preoperative chemoradiotherapy and surgical resection for locally advanced rectal cancer (LARC). In particular, patients with a pathologic complete response (pCR) may derive no benefit from adjuvant chemotherapy. PATIENTS AND METHODS: This is a retrospective analysis of patients with LARC, diagnosed between January 1, 2003 and December 31, 2014 at 3 Melbourne health services. Patients were identified from the Australian Comprehensive Cancer Outcomes and Research Database, where a defined data set is prospectively collected on consecutive patients. Patient demographics, pCR rates, postoperative treatment, recurrence, and survival were analyzed. RESULTS: A total of 717 patients with LARC were identified, of whom 555 (77%) had received preoperative long-course chemoradiation followed by surgery. Four hundred fifty-two of 555 patients (81%) subsequently received adjuvant fluoropyrimidine-based chemotherapy. At a median follow-up of 45.9 months, 95 (21%) patients in the adjuvant chemotherapy group and 20 (19%) in the surveillance group had relapsed. Five-year relapse-free survival was 77% in the adjuvant chemotherapy group and 71% in the surveillance group with no significant difference on univariate analysis (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.58-1.51; P = .780). No significant impact on relapse-free survival was seen for either pCR or non-pCR patients. Five-year overall survival (OS) was 85% in the adjuvant chemotherapy group and 74% in the surveillance group with a nonsignificant trend towards OS benefit (HR, 0.62; 95% CI, 0.37-1.05; P = .074). A significant OS benefit favoring adjuvant chemotherapy was seen in the non-pCR subset of patients (HR, 0.49; 95% CI, 0.28-0.86; P = .014). CONCLUSION: A high proportion of patients in this routine practice cohort received adjuvant chemotherapy following preoperative treatment and surgery for LARC. Adjuvant chemotherapy administration was associated with a significant improvement in 5-year OS only in the patients with a non-pCR.
BACKGROUND: Recent data has created uncertainty regarding the benefit of adjuvant fluoropyrimidine-containing chemotherapy following preoperative chemoradiotherapy and surgical resection for locally advanced rectal cancer (LARC). In particular, patients with a pathologic complete response (pCR) may derive no benefit from adjuvant chemotherapy. PATIENTS AND METHODS: This is a retrospective analysis of patients with LARC, diagnosed between January 1, 2003 and December 31, 2014 at 3 Melbourne health services. Patients were identified from the Australian Comprehensive Cancer Outcomes and Research Database, where a defined data set is prospectively collected on consecutive patients. Patient demographics, pCR rates, postoperative treatment, recurrence, and survival were analyzed. RESULTS: A total of 717 patients with LARC were identified, of whom 555 (77%) had received preoperative long-course chemoradiation followed by surgery. Four hundred fifty-two of 555 patients (81%) subsequently received adjuvant fluoropyrimidine-based chemotherapy. At a median follow-up of 45.9 months, 95 (21%) patients in the adjuvant chemotherapy group and 20 (19%) in the surveillance group had relapsed. Five-year relapse-free survival was 77% in the adjuvant chemotherapy group and 71% in the surveillance group with no significant difference on univariate analysis (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.58-1.51; P = .780). No significant impact on relapse-free survival was seen for either pCR or non-pCR patients. Five-year overall survival (OS) was 85% in the adjuvant chemotherapy group and 74% in the surveillance group with a nonsignificant trend towards OS benefit (HR, 0.62; 95% CI, 0.37-1.05; P = .074). A significant OS benefit favoring adjuvant chemotherapy was seen in the non-pCR subset of patients (HR, 0.49; 95% CI, 0.28-0.86; P = .014). CONCLUSION: A high proportion of patients in this routine practice cohort received adjuvant chemotherapy following preoperative treatment and surgery for LARC. Adjuvant chemotherapy administration was associated with a significant improvement in 5-year OS only in the patients with a non-pCR.