Nearly a third of prostate biopsies resulted in a cancer diagnosis among a population of older men on Medicare. Men whose first biopsy did not find cancer often had multiple biopsies in the future, which increased the chance of a cancer diagnosis.
While PSA (prostate-specific antigen) tests have become widely used in prostate cancer screening, a biopsy is what actually determines the presence of prostate cancer. Nonetheless, it remains unclear whether or not PSA screening actually reduces prostate cancer mortality.
H. Gilbert Welch, M.D., of the Department of Veterans Affairs Medical Center in White River Junction, Vt., and colleagues estimated the proportion of prostate biopsies that result in a cancer diagnosis and the likelihood of finding cancer with subsequent biopsies after the first one was negative. The researchers analyzed the outcomes of 10,429 biopsies performed from 1993 to 2001 in 8,273 men aged 65 and older.
About one third of prostate biopsies detected cancer, and the proportion of biopsies that found cancer increased as men got older. Among men whose first biopsy did not show cancer, about one third of them had another biopsy within five years. Nearly half of men who had a second biopsy were diagnosed with cancer, and the chance of diagnosis increased with each subsequent biopsy.
Because the goal of screening is to reduce deaths from the disease and not simply to find more cancer, the utility of [repeated biopsies warrant] careful reassessment, the authors write.
Contact: H. Gilbert Welch, email@example.com, (802) 296-5178
Immune System Gene May Influence Lung Cancer Survival
Variations in a gene that influences the innate immune systemthe part of the immune system that provides short-term protection against infectionmay be associated with lung cancer survival.
Curtis Harris, M.D., of the National Cancer Institute in Bethesda, Md., and colleagues examined whether any of five variations of the MBL2 gene influenced survival among 558 white patients and 173 African-American patients with nonsmall-cell lung cancer.
Some gene variants were associated with improved survival among white patients, but not African-American patients. White patients who did not have the gene variants had poorer survival, particularly the heavy smokers.
This study may provide insight into the continued disparity in lung cancer survival between African-American and white patients, the authors write.
Contact: National Cancer Institute press office, firstname.lastname@example.org, (301) 496-6641
Virus Targets Brain Cancer Stem Cells
Brain cancer stem cells are susceptible to a cancer-killing virus, which caused the death of brain tumors cells in mice and in test cells.
To achieve long-term remission, a treatment for brain cancer must kill the brain tumor stem cells that are resistant to radiation and chemotherapy.
Hong Jiang, Ph.D., of the University of Texas M.D. Anderson Cancer Center in Houston and colleagues tested whether the virus could be targeted to brain tumor cells. They were able to infect four cancer stem cell lines with the virus, which caused the cells to die. Mice with brain tumors from the cancer stem cells lived longer when they were injected with the virus than those given an inactivated version.
Our data are important because brain tumor stem cells are the driving force sustaining tumor growth, and therefore developing therapies to target the brain tumor stem cells should be a more effective strategy than conventional treatments, the authors write.
Contact: Scott Merville, external communications office, M. D. Anderson Cancer Center, email@example.com, (713) 792-0661
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Journal of the National Cancer Institute