Oral Presentation Clinical Oncology Society of Australia 2014 Annual Scientific Meeting

Survival outcomes following adjuvant fluoropyrimidine-containing chemotherapy for resected early stage rectal adenocarcinoma (#97)

Rebecca Y Tay 1 , Murtaza Jamnagerwalla 2 , Malcolm Steel 2 , Wong Hui-Li 3 4 , Joe J McKendrick 1 5 , Ian Faragher 6 , Suzanne Kosminder 7 , Ian Hastie 8 , Jayesh Desai 9 , Michael Harold 4 , Peter Gibbs 3 4 7 9 , Rachel Wong 1 5
  1. Department of Medical Oncology, Eastern Health, Melbourne, VIC, Australia
  2. Department of Surgery, Eastern Health, Melbourne, VIC, Australia
  3. University of Melbourne, Melbourne, VIC, Australia
  4. Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
  5. Eastern Health Clinical School, Monash University, Melbourne, VIC, Australia
  6. Department of Surgery, Western Health, Melbourne, VIC, Australia
  7. Department of Medical Oncology, Western Health, Melbourne, VIC, Australia
  8. Department of Surgery, Royal Melbourne Hospital, Melbourne, VIC, Australia
  9. Department of Medical Oncology, Royal Melbourne Hospital, Melbourne, VIC, Australia

Background:

Recent data have created uncertainty regarding the benefit of the current standard of care adjuvant fluoropyrimidine-containing chemotherapy following preoperative chemoradiotherapy and surgical resection for locally advanced rectal cancer. In particular, patients with a pathologic complete response may derive no benefit from adjuvant chemotherapy. 

Methods:

This is a retrospective analysis of patients with early stage rectal adenocarcinoma, diagnosed between 1 January 2003 and 30 June 2013 at three Melbourne health services (Eastern Health, Royal Melbourne Hospital and Western Health). Patients were identified from a search of the ACCORD (Australian Comprehensive Cancer Outcomes and Research Database) database, where a defined data set is prospectively collected on consecutive patients. Patient demographics, pre-treatment staging, post-operative treatment, recurrence and survival were analysed.

Results:

A total of 580 patients with localised rectal cancer were identified, of whom 451 had received neoadjuvant long course chemoradiation followed by resection of the primary tumour. 369 patients (82%) subsequently received adjuvant 5-fluorouracil. At a median follow-up of 45.9 months, 63 (19%) patients in the adjuvant chemotherapy group and 21 (29%) in the surveillance only group had relapsed. Median relapse-free survival (RFS) has not been reached in either group; 3-year RFS was 81% in the adjuvant chemotherapy group compared to 71% in the surveillance only group (p=0.034). Five-year overall survival was 83% in the adjuvant chemotherapy group compared to 71% in the surveillance only group (p=0.038). The impact of age, surgical complications, treatment-related toxicity and pathological complete response post neoadjuvant therapy on the uptake of post-operative chemotherapy and on survival are being evaluated. 

Conclusions:

A high proportion of patients in routine practice receive adjuvant chemotherapy following neoadjuvant treatment and surgery for early stage rectal cancer. Adjuvant chemotherapy was associated with a significant improvement in 3-year relapse-free and 5-year overall survival.