Adjuvant chemotherapy for rectal cancer: Is it needed?

Table 1 Trials comparing adjuvant chemotherapy with observation after neoadjuvant treatment

	Sample size	Accrual period	Total mesorectal excision	Preoperative treatment	Adjuvant treatment	Adherence (%)	Overall survival (adjuvant vs observation)	Disease-free survival (adjuvant vs observation)	Local recurrence (adjuvant vs observation)
EORTC 22921	1011	1993-2003	36.80%	25 doses of 1.8 Gy and fluorouracil-based chemotherapy	Four courses every 3 wk of fluorouracil and folinic acid	42%	51.8% vs 48.4%, P = 0.32	47% vs 43.7%, P = 0.29	11.7% vs 11.8%
CHRONICLE	113	2004-2008	NR	45 Gy and fluorouracil-based chemotherapy	Six courses every 3 wk of oxaliplatin and oral capecitabine	48.10%	89% vs 88%, P = 0.75	78% vs 71%, P = 0.56	Not reported
PROCTOR-SCRIPT	437	2000-2013	All patients	25 doses of 1.8-2.0 Gy and fluorouracil-based chemotherapy	Six courses of fluorouracil and folinic acid OR 12 courses of fluorouracil and folinic acid OR eight courses every 3 wk of oral capecitabine	73.60%	80.4% vs 79.2%, P = 0.73	62.7% vs 55.4%, P = 0.13	7.8% vs 7.8%, P = 0.69
I-CNR-RT	634	1992-2001	NR	25 doses of 1.8 Gy and fluorouracil-based chemotherapy	Six courses of fluorouracil and folinic acid	58.50%	70% vs 69.1%, P = 0.77	62.8% vs 65.3%, P = 0.88	4.5% vs 6.4%
QUASAR	3239 (948 with rectal cancer)	1994-2003	NR	Radiotherapy (21%)	Thirty doses of intravenous FU with high or low dose folinic acid	58.00%	HR = 0.8 (0.6-1.07)1	HR = 0.69 (0.51-0.94)1	19.8% vs 27.2%

¹Hazard ratios were obtained from Cochrane review by Petersen et al[20]. HR: Hazard ratios; FU: Fluorouracil; NR: Not reported.