Adjuvant chemotherapy in curatively resected rectal cancer: How valid are the data?

Table 1 Sample size and significance of the 21 studies included in the Cochrane meta-analysis

Ref.	ntot	nc	ni (type of intervention)	Weight (%)	Outcome
Grage et al[13] 1981	64	31	33 (adj. CTx)	1.4	S
Fisher 1988 (NSABP)	574	191	190 (adj. RT)	6.8	NS
			193(adj. CTx+RT)
Thomas 1988 (GTSG)	106	58	48 (adj. CTx)	3.5	NS
Hafström 1990	99	56	43 (adj. CTx)	2.6	NS
Krook et al[11] 1991 (NCCTG)	204	100 (adj. RT)	104 (adj. CTx + RT)	6.8	S
Matsuda 1991 (SGACCS)	1243	598	645 (adj. CTx)	7.8	NS
CCCSGJ[10] 1995	1004	335	323 (adj. CTx)	7.6	S
			346 (intra-art CTx + adj. CTx )
Kornek 1996	57	29	28 (adj. CTx)	0.9	NS
Ito 1996 (TSGHCFU)	77	40	37 (adj. CTx)	1.6	NS
Yasutomi 1997 (JFMTC7-2)	713	356	357 (adj. CTx)	6.9	NS
Kodaira 1998 (JFMTC 7-1)	794	398	396 (adj. CTx)	7.4	NS
Taal 2001 (NACCP)	299	150	149 (adj. CTx)	4.4	NS
Kato 2002 (TACSG)	143	72	71 (adj. CTx)	1.7	NS
Cafiero 2003	218	108	110 (adj. CTx+RT)	4.0	NS
Watanabe 2004 (JFMTC15-2)	391	122	269 (adj. CTx)	3.3	NS
Glimelius 2005 (NGTATG)	691	352	339 (adj. CTX)	9.2	NS
Bosset et al[16] 2006 (EORTC)	1011	252 (neoadj. RT)	253 (neoadj. RT + adj. CTx)	8.9	NS
		253 (neoadj. CTx + RT)	253 (neoadj. CTx and RT + adj. CTx)
Sakamoto 2007 (JFMTC 15-1)	447	229	218 (adj. CTx)	5.2	NS
Quasar[12] 2007	948	474	474 (adj. CTx)	7.0	S
Koda 2009	54	29	25 (adj. CTx)	0.3	NS
Hamaguchi et al[14] 2011	274	135	139 (adj. CTx)	2.9	S
Total	94111	43681	50431	100.22	5S vs 16NS

¹Following the description of the studies at pages 6-9 as well as the tables from page 24 to 37 of the original meta-analysis we obtain this total number of included patients which is different from the 9785 reported in the meta-analysis. Consequently, also the total number of patients that receive surgery alone and surgery plus chemotherapy is different;

²The sum of the assigned weight should be 100%. n_tot: Number of patients with rectal cancer included in the study; n_c: Number of patients included in the control group (surgery only); n_i: Number of patients included in the intervention group (operation and adj. chemotherapy or other interventions); Outcome: Results of the study (S: Study result significant for better OS in the intervention group vs control group; NS: Not significant). CTx: Chemotherapy; RT: Radiotherapy.