Concerning nicotine, and protection with aspirin:
"The results suggest that stimulation of COX-2 and VEGF expression can contribute as important factors in the tumorigenic action of nicotine in oral cancer progression."
" Pretreatment with celecoxib [an NSAID like aspirin] inhibited nicotine-induced change in the expression of VEGF and COX-2."
The above caused me to wonder about aspirin:
"Observational and also some randomized trials suggest that regular long-term use of aspirin (acetylsalicylic acid) might reduce the risk of colorectal carcinomas by 15-40%. "
"Inhibition of COX-1 and/or COX-2 is most likely involved. "
"Furthermore, aspirin and sodium salicylate inhibited COX-2 expression stimulated by VEGF. These findings indicate that aspirin and other salicylate drugs at pharmacological concentrations inhibit colon cancer-induced angiogenesis which is correlated with COX-2 suppression."
"tumor growth in the subcutaneous tissues was also suppressed by aspirin, COX-2 selective inhibitors, and the VEGF antibody, but not by the COX-1 inhibitor."