Table 6.

Reported findings of relevant studies for evaluating the potential cancer modulating activity of nicotine in xenograft studies.

Route/type/adequacy scoring	Number of (sub-)studies	Positive*	Negative*	Labs†
Inhalation
Total	0	0	0	0
Oral
Total	20	15	5	11
High score	7	4	3	4
Low score	13	11	2	7
Dermal
Total	1	1	0	1
High score	0	0	0	0
Low score	1	1	0	1
Other
Total	14	8	6	11
High score	4	2	2	3
Low score	10	6	4	8

Note: To facilitate comparisons, the (sub-)studies were grouped into high and low-adequacy scoring studies with overall scores subjectively set to >2 and ≤2, respectively.

*As judged by the authors of the respective studies, where “positive” indicates stimulating carcinogenesis and “negative” indicates a lack of carcinogenic effect.

†Number of different laboratories contributing studies.