Comparative carcinogenicity of cigarette mainstream and sidestream smoke condensates on the mouse skin

Abstract
The direct carcinogenic effects of sidestream (SS) and mainstream (MS) smoke condensates of a filtered commercial brand of blond cigarettes were compared using a lifetime mouse skin tumorigenicity assay on female NMRI mice. Each cigarette was smoked by a smoking machine under the standard conditions, and the separately collected SS and MS smoke condensates were extracted with acetone/methanol as described elsewhere. These were tested for carcinogenicity on an area of 1–1.5 cm shaved skin of mice on the lower back. The mice were treated with half of each dose (5, 10 or 15 mg) twice a week, for only 3 months. No substance was used as promoter or as an additional initiator of carcinogenicity. No statistically significant difference was found when the life spans of MS-treated and untreated animals were compared. In contrast, the life spans of SS-treated mice were significantly (PPP<0.001).