Association between cigarette smoking, APCmutations and the risk of developing sporadic colorectal adenomas and carcinomas

Table 3 Distribution of selected smoking characteristics for adenoma and carcinoma cases divided by APC truncation-mutation status.

	Cases*
	Adenomas		Carcinomas
Characteristics^a	APC⁺ (n = 18)	APC^- (n = 25)	APC⁺ (n = 27)	APC^- (n = 57)
Ever smoked	59% (10/17)	84% (22/26)	68% (17/25)	68% (37/54)
Mean no. cigarettes per day	10,5 ± 5,3	14.5 ± 7,4	11,3 ± 10,0	13,5 ± 8,4
Mean years smoking	39,2 ± 4,6	30,9 ± 11,5	32,4 ± 15,2	34,2 ± 15,1
Mean years since started smoking	40,3 ± 4,8	38,9 ± 6,9	48,9 ± 6,2	46,3 ± 9,8
Starting smoking ≥ 40 years ago	60% (6/10)	45% (10/22)	100%(17/17)	69% (25/36)

*Uncertain APC truncation mutation status for one or more of the sequenced fragments gave rise to diminished numbers of CRC and adenoma cases, compared to the study population in Table 1.
^aNone of the smoking parameters were significantly different within the adenoma group. Within the CRC group only "starting smoking ≥ 40 years ago" yielded a significant difference, P = 0.010.

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