An ingredient present in a common cough suppressant has been found to be effective in the treatment of advanced prostate cancer, according to a new study.
The collaborative study revealed that noscapine, which has been used in cough medication for nearly 50 years, reduced tumour growth in mice by 60 percent and limited the spread of tumours by 65 percent without causing harmful side effects.
While prostate cancer is slow growing in most men, it is considered advanced when it spreads beyond the prostate. There is no known cure.
The laboratory study was a joint effort by Dr. Israel Barken of the Prostate Cancer Research and Educational Foundation, Moshe Rogosnitzky of MedInsight Research Institute, and Dr. Jack Geller of The University of California San Diego.
Noscapine has previously been studied as a treatment for breast, ovarian, colon, lung and brain cancer and for various lymphomas, chronic lymphocytic leukemia and melanoma. However, this is the first study to demonstrate its effectiveness in treating prostate cancer.
Noscapine is a naturally-occurring substance, a non-addictive derivative of opium. As a natural substance, noscapine cannot be patented, which has limited the potential for clinical trials.
Since noscapine is approved for use in many countries as a cough suppressant, however, it is available to doctors to prescribe for other uses as well. This common practice is known as "off-label" prescription. Noscapine is increasingly being used off-label to treat a variety of cancers.
Barken used noscapine to treat a handful of prostate cancer patients before retiring from clinical practice.
Barken is encouraging academic institutions to follow up this successful laboratory research with a human clinical trial.
Rogosnitzky pointed out the significant advantages that noscapine could present as a treatment for prostate cancer.
"Noscapine is effective without the unpleasant side effects associated with other common prostate cancer treatments. Because noscapine has been used as a cough-suppressant for nearly half a century, it already has an extensive safety record. This pre-clinical study shows that the dose used to effectively treat prostate cancer in the animal model was also safe," he said.
Currently, hormone therapy and chemotherapy, along with radiation and surgery, are used to slow the progression of advanced prostate cancer. Side effects resulting from these treatments include impotence, incontinence, fatigue, anemia, brittle bones, hair loss, reduced appetite, nausea and diarrhea.
However, no toxic side effects were observed in the laboratory study of noscapine.
The study was published in the latest issue of the European medical journal Anticancer Research