The CancerWeb Report, What's New In Cancer: December, 1996
Prostate Cancer

• A gene on a specific chromosome implicated in susceptibility to prostate cancer - Researchers from Johns Hopkins University and the University of Michigan in the US, and Umea University in Sweden claim, in the November 22, 1996 issue of Science, to have identified a gene involved in prostate cancer. Genetic susceptibility accounts for only about 9% of all prostate cancers, but more than 40% of the disease with an early onset. In a combined study of 91 families at high risk for prostate cancer, they produced evidence for a susceptibility gene located on chromosome 1. This gene is not the only one involved in hereditary disease, but it does appear to be critical in at least one third of the cases, and it may also play a role in non-hereditary forms of the cancer. The gene has not yet been identified and cloned, but it appears to be a cancer-promoting oncogene rather than a tumor-suppressor gene. (Smith, Science 274:1371, 1996)

  ---

• PSA is not a good indicator of metastases in patients with hormone-refractory disease - Numerous studies have demonstrated a relationship between metastatic disease and serum PSA measurements in newly diagnosed patients with prostate cancer. As a result, PSA has come to play an important role in patient work-up, and values below 10 ng/mL in newly-diagnosed patients are generally taken as an adequate reason for not performing bone scans, or evaluating lymph node or other soft tissue involvement. PSA production is poorly understood, but it is known to be androgen-dependent, and this raises the issue of how well its levels correlate with metastatic disease in patients with hormone-refractory cancer who mostly have bone disease. Researchers at the Walter Reed Army Medical Center in Washington, DC evaluated 177 patients with hormone-refractory prostate cancer with PSA measurements, abdominal/pelvic CT scans, and bone scans. All had bone disease and 19% had measurable soft tissue metastases. Their findings, published in Cancer Investigation, Volume 14, Number 6, 1996 clearly showed that PSA levels were not correlated with the presence or the extent of soft-tissue metastatic disease, in contrast to the situation in newly-diagnosed, hormone-responsive patients. (Figg, Cancer Invest 14:513, 1996)