One intersting thing here Moeburn.....you mentioned you were trying to find out the connection (if any) If you don't mind, I will add my experience here and you can decide for yourself whether it's an argument FOR or AGAINST cannabais and smoking.

Smoked for 35 years; smoked pot for the 20; took ten years off pot then picked it up again (smoking). One year and ONE MONTH after I quit smoking cigerettes i was diagnosed with small cell lung cancer .......one of the cancers KNOWN to be related to smoking.

A.....Did quitting cigs but not pot make this worse?
B....You can bet your ass I don't put ANYTHING in my lungs now
C....Cannabis obviously played no POSITIVE ROLE in my cancer ARISING......in other words it did not prevent it in any way. I quit smoking cannabis when I had so damn much trouble breathing.......which turned out to be 2 softball sized tumors in my chest.
I did continue to eat it in cookies and my capsules.
D.....With conventional chemo therapy I've SO FAR (knock on wood) have experienced EXCELLENT results with tumor shrinkage. Something like in the top 16% because my type is very aggressive and fast.

E....last question.......did cannabis play a role in my tumors shrinking? I eat or use capsules the equivelant of several grams a day. I can't say.......could totally be coincdence.......but interesting isn't it?