Sex, Drugs, and Cancer?

March 11, 2008 -- Certain head and neck cancers may be tied to sexual activity, marijuana use, and human papillomavirus ( HPV) type 16.

That news comes from Johns Hopkins University's Maura Gillison, MD, PhD, and colleagues, who studied 240 people with head and neck squamous cell carcinomas (head and neck cancers). Some of their cancers tested positive for HPV 16; others were negative for HPV 16.

The patients answered questions about their lifestyle. For comparison, 322 cancer-free people answered the same lifestyle questions.

Here's what the researchers learned:

• Head and neck cancers that were positive for HPV 16 were associated with having more oral sex partners and smoking more marijuana.
• Head and neck cancers that were negative for HPV 16 weren't linked to sex or marijuana. Instead, they were tied to smoking tobacco, drinking alcohol, and having poor oral hygiene.

Because the study was observational, it's not clear if those risk factors caused cancer.

Based on the findings, Gillison's team argues that HPV 16-negative and HPV 16-positive head and neck squamous cell carcinomas should be considered two different types of cancer.

The study appears in today's advance online edition of the Journal of the National Cancer Institute.