Recurrence and cancer‐specific death after adjuvant chemotherapy for Stage III colon cancer

• Published in: Colorectal disease Vol. 21; no. 2; pp. 164 - 173
• Main Authors: Chapuis, P. H., Bokey, E., Chan, C., Keshava, A., Rickard, M. J. F. X., Stewart, P., Young, C. J., Dent, O. F.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.02.2019
• Subjects: 5-Fluorouracil; Adenocarcinoma; Adjuvant chemotherapy; Aged; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; cancer‐specific death; Chemotherapy; Chemotherapy, Adjuvant; Colon cancer; Colonic Neoplasms - drug therapy; Colonic Neoplasms - mortality; Colonic Neoplasms - pathology; Colonic Neoplasms - surgery; Colorectal cancer; Colorectal carcinoma; competing risks; Death; Female; Health risks; Humans; Male; Middle Aged; Neoplasm Recurrence, Local - drug therapy; Neoplasm Recurrence, Local - mortality; Neoplasm Recurrence, Local - pathology; Neoplasm Staging; Oxaliplatin; Prospective Studies; recurrence; Risk Factors; Surgery; recurrence; competing risks; Adjuvant chemotherapy; colon cancer; cancer-specific death
• ISSN: 1462-8910; 1463-1318
• DOI: 10.1111/codi.14434

Aim The recommended standard of care for patients after resection of Stage III colon cancer is adjuvant 5‐fluorouracil based chemotherapy – FOLFOX (fluorouracil, leucovorin with oxaliplatin) – or CAPOX (capecitabine, oxaliplatin). This may be modified in older patients or depending on comorbidity. This has been challenged recently as the apparent benefit of adjuvant chemotherapy may arise from improvements in surgery or preoperative imaging or pathology staging. This study compares recurrence and colon‐cancer‐specific death between patients who received postoperative adjuvant chemotherapy and those who did not. Method Prospectively recorded data from 363 consecutive patients who had a resection for Stage III colonic adenocarcinoma between 1995 and 2010 inclusive were analysed. Surviving patients were followed for at least 5 years. The suitability of patients for chemotherapy was discussed routinely at multidisciplinary team meetings. The incidence of recurrence and colon‐cancer‐specific death was evaluated by competing risk methods. Results After adjustment for the competing risk of non‐colorectal cancer death, there was no significant difference in recurrence between the 204 patients who received chemotherapy and the 159 who did not [hazard ratio (HR) 0.94, 95% CI 0.66–1.32, P = 0.700) and no significant difference in colon‐cancer‐specific death (HR 0.73, 95% CI 0.50–1.04, P = 0.084; HR 0.88, 95% CI 0.57–1.36, P = 0.577 after adjustment for relevant covariates). Conclusion These findings question the routine use of chemotherapy after complete mesocolic excision for Stage III colon cancer. Recurrence and cancer‐specific death, assessed by competing risk methods, should be the standard outcomes for evaluating the effectiveness of adjuvant chemotherapy after potentially curative resection.