A drug commonly used to overcome erectile dysfunction, Tadalafil, the generic form of Cialis, may help patients fight cancer. The results were outlined in a recent study published in Clinical Cancer Research, a publication of the American Association for Cancer Research.

The study, led by Dr. Donald T. Weed and Paolo Serafini, Ph.D., at the University of Miami, in conjunction with Johns Hopkins University, treated patients with HPV negative squamous cell cancers of the throat and mouth with Tadalafil before surgery.

For many patients with this disease, surgery remains a first-line treatment. While much of the tumor can be surgically removed, tiny microscopic cancer cells may be left behind. The cancer cells are able to hide from the immune system in part by suppressing the white blood cells that would normally attack them.

The suppressing cells are called myeloid derived suppressor cells (MDSCs) and regulatory T cells (Treg).

Tadalafil works by reducing the number of suppressor cells that help the cancer hide. That makes the cancer visible to the immune system, which can then create news cells, to fight the cancer.

Dr. Donald Weed tells FOX 13 that they were able to measure the immune system response in the patient's blood and surrounding the tumor.

Patients treated with Tadalafil had more specialized cancer fighting cells than patients who didn't get the drug.

Dr. Weed says, while these results are promising, he emphasizes that more study needs to be done before this treatment goes mainstream. For example, he says, the dose is extremely important.

If you use too much or too little, it could have negative consequences. He also said there is no evidence whatsoever to suggest that taking drugs like Cialis will prevent head and neck cancers.

The next step will be to combine Cialis with a vaccine, called anti MUC-1, a collaboration that will involve Olivera "Olja" Finn, Ph.D., at the University of Pittsburgh. It will be given to patients with head and neck cancer that has recurred as a stage 3 or 4 and who are undergoing surgery.

The goal will be to see if the two immune boosting treatments will help keep the cancer cells in check.

Dr. Weed tells me researchers are also working on newer generation Tadalafil-like drugs that pinpoint targets specific to cancer.