Synonym for cigarette. So name because they cause cancer.
I just smoked my last cancerstick.
Another term for the male genitalia, especially in gay culture. Likely stems from the word "fag" being another synonym for "cigarette." May also allude to the (apparently false) belief that semen contributes to oral cancer. Could also be an allusion to the verb "smoke" referencing oral sex on a male.
He spent the evening smoking his boyfriend's cancerstick