But then there’s suramin. Suramin is not a standard chemotherapeutic drug— actually, it was originally used to eradicate internal parasites more than fifty years ago. Decades later, in the early 1980s, this synthetic compound was investigated as a potential treatment for AIDS. Doctors had discovered that suramin had a unique ability to invade cells and disturb their most basic elements. Suramin, they found, could hook itself up to various substances called growth factors—which serve as switches to activate processes that promote cell division—and upset their normal activities with the effect of a bull in a china shop.
Then doctors at the National Cancer Institute began wondering whether suramin could cause the same chaos in prostate cancer. They knew suramin was capable of thwarting the activity of such growth factors as basic fibroblast growth factor and epidermal growth factor—both believed to be important to sustaining and promoting the growth of prostate cancer cells. Spurred by such growth factors, these cancer cells somehow revert to a more primitive state, which encourages them to mass-produce.
The scientists also knew that suramin could inhibit growth in specific varieties of prostate cancer cells. And finally—a bonus—suramin also seemed to lower the level of adrenal androgens.
So suramin looked highly promising as the first drug with the potential not only to lower the adrenal androgens but to target the hormone-resistant cells that, so far, have successfully eluded every other attempt to kill them. Could suramin perform as expected—could it interrupt factors that feed cancer cells and make them grow? In other words, could it slow down the proliferation of cancer cells?
The jury is still out on suramin. The bottom line is that it has helped some men; it has not helped other men, and its effects don’t seem to be long-lasting. In one study, suramin caused reduction or “complete disappearance” of cancer metastases in soft tissue—masses in the pelvis, lymph nodes, and even nodules under the skin. However, in only a few men did the improvements last longer than three months. Only a few men showed an improvement in metastases to the bone, and these gains were slow in coming—it took about nine months or longer. In some men, bone metastases got better; in others, they got worse. Some men showed no change at all, and in other men, the cancer continued to progress. PSA levels dropped in some men, but in only a few of these men did this improvement last longer than three months.
A majority of the men in this study who had experienced severe bone pain found significant relief. However, this often happened within the first weeks of treatment and wasn’t accompanied by an obvious shrinking of the cancer. In fact, the doctors weren’t sure this was even due to suramin—it could have been the result of corticosteroid treatments, which are known to ease terrible bone pain.
Side Effects
In addition to inhibiting growth of cancer, suramin can also suppress the body’s immune system. Its side effects can include infection, particularly in the urinary tract; a reversible drop in the number of platelets in the blood; fatigue, decreased appetite; rash; and pain and weakness in the hands and feet.
*191\201\8*
