Low-grade prostate tumors can harbor signs of aggressive cancer

A prostate cancer tissue sample with low-grade (Gp3) and high-grade (Gp4) regions. Credit:  Adam Sowalsky.

When a patient undergoes a prostate cancer biopsy, the tumor is scored on its likely aggressiveness. Typically, a high score suggests that treatment is needed; in some cases, a low score may indicate that the patient can be safely managed with active surveillance. However, because there is a possibility that the biopsy may have missed a portion of the tumor that is more aggressive, clinicians need better ways to determine which biopsied tumors with low scores are truly low-risk and which may be part of a larger, more dangerous cancer.

In a study published January 24, 2017, in Clinical Cancer Research, Adam Sowalsky, Ph.D., Tenure Track Investigator in the Laboratory of Genitourinary Cancer Pathogenesis, and his colleagues investigated the genetic characteristics of prostate tumors. The team performed genomic analyses on prostate cancer tissue samples that included low- and high-grade regions. The researchers found that the two regions shared some mutations that are hallmarks of aggressive tumors, which likely arose early in the cancer’s development.

The results suggest that if a patient receives a low score on a biopsy, testing for mutations to specific genes could indicate whether the tumor is likely to be part of an unseen aggressive cancer. That information could help clinicians decide whether a follow-up biopsy should be performed to search for the high-grade region.

Summary Posted: Wed, 02/01/2017