Drugs used for treatment of erectile dysfunction and pulmonary arterial hypertension as anti-cancer agents
A few days ago, a new paper from one of my favorite organisations (AntiCancerFunds) published a review paper on the anti cancer potential of drugs used typically for treatment of erectile dysfunction and pulmonary arterial hypertension. Example of drugs discussed in this paper are sildenafil, tadalafil, vardenafil, avanafil and udenafil. Thir anti cancer mechanisms seems to be related to one or more of the following: immune modulation (MDSC- and Treg- reduction), multi drug resistance reduction, Tumour hypoxia reduction, aromatase inhibition. Most of these actions seem to be related to the PDE5 inhibition capabilities of these drugs. As a result these drugs have been shown to be effective against multiple types of cancers in the lab such as Chronic lymphocytic leukaemia, Prostate, Colorectal, Brain, Breast, Melanoma, Multiple myeloma, Lung, Lymphoma, Liver, Head and neck, Rhabdomyosarcoma, Ehrlich ascites carcinoma. However these results were achieved in a pre-clinical setting. In humans, these drugs have been already shown to add value for patients with macroglobulinemia, penile squamous cell carcinoma, MM. Based on the evidence, the authors at AntiCancerFunds concluded the following:
"The data are strongest for clinical trials of PDE5 inhibitors, in combination with other agents, in the following cancer types (a) HNSCC (b) Glioblastoma (c) Pancreatic cancer (d) Medulloblastoma (e) Waldenstrom’s macroglobulinemia (f) Melanoma. The perioperative use of PDE5 inhibitors in combination with other perioperative therapies is also of interest in the following cancers: (a) Colorectal cancer (b) Breast cancer (c) HNSCC"
What I like the most here is that these drugs can lower MDSC, since this is an important point in cancer and there are not many drugs available to do this.