Table 4b.

Relative risks (95% CI) for lung cancer by histologic type, from the polytomous logistic regression model #1 comparing risks associated with current and former smoking, Nurses’ Health Study, 1976-2002. B. Relative risks corresponding with 5, 10, and 15 years since quitting smoking^**

Histologic Type	Years Since Quitting
	5 years	10 years	15 years
Squamous Cell Carcinoma	0.57 (0.50, 0.63)	0.32 (0.25, 0.41)	0.18 (0.13, 0.26)
Small Cell Carcinoma	0.40 (0.34, 0.47)	0.16 (0.11, 0.22)	0.06 (0.04, 0.10)
Adenocarcinoma	0.67 (0.62, 0.72)	0.45 (0.39, 0.52)	0.30 (0.24, 0.38)
Large Cell Carcinoma	0.63 (0.53, 0.75)	0.40 (0.28, 0.56)	0.25 (0.15, 0.42)

^**Age, age at smoking initiation and cigs/day included in the model