I read this announcement in the Johns Hopkins Kimmel Cancer Center "Kimmel Wire", an email newsletter that comes out several times a year. Seems as if Viagra and related drugs can have anti-cancer properties, as they increase the ability of the immune system's T-cells to locate and kill cancer cells. Of course, for men there is that "side effect" to deal with!

Note that at least in vitro (tissue studies) this worked with head and neck cancer as well as other types.

""ERECTILE DYSFUNCTION" DRUGS HEIGHTEN NATURAL ANTI-CANCER ACTIVITY

Sildenafil and other "impotence drugs" that boost the production of a gassy chemical messenger to dilate blood vessels and produce an erection now also show promise in unmasking cancer cells so that the immune system can recognize and attack them, say scientists at the Johns Hopkins Kimmel Cancer Center.

Tests at Hopkins on mice with implanted colon and breast tumors showed that tumor size decreased two- and threefold in sildenafil-treated animals, compared to mice that did not get the drug. In mice engineered to lack an immune system, tumors were unaffected, proof of principle, the scientists say, that the drug is abetting the immune system