DEAR DR. ROACH: My brother was just diagnosed with a rare form of prostate cancer, called small cell. What I’ve read doesn’t sound encouraging. Are there any new treatments? — Anon.
ANSWER: Most prostate cancers start from cells that form part of the prostate gland, whose primary job is to secrete prostatic fluid. One of the components of prostatic fluid is an enzyme that liquifies mucus. It’s called gamma-seminoprotein, but is more commonly known as prostate-specific antigen — or PSA.
Cancer cells normally continue some of the jobs that the normal cells they derive from are supposed to do, and the PSA test is a way to both screen for and monitor progression of the common form of prostate cancer during treatment. Regular prostate cancer varies from a slow-growing, indolent form that is easy to treat in its early stages to a much more aggressive form.
Small cells, in contrast, are derived from stem cells. Small cell cancers most commonly show up in the lung, but are also rarely found in the bladder, stomach, gallbladder and other sites, including the prostate. Only 1% of prostate cancers are small cell cancers, and unfortunately, they do have a poor prognosis. Although most cancers do initially respond to platinum-based chemotherapy, chemotherapy can’t quite kill all the cancer cells, so the promising early treatment is commonly followed by a relapse.
I did a search at ClinicalTrials.gov and found many ongoing trials that recruit people with small cell prostate cancer, which is your brother’s best way to get involved with the newest treatments. Since this is a rare cancer, people are needed to identify what promising new treatments will work.
