Common p53 Gene Test Helps Predict Cancer Recurrence in Mastectomy Patients

A common blood protein test can predict which breast cancer patients are at risk for recurrence after mastectomy. The test may eventually help direct treatment decisions, speculate researchers from the University of Texas Health Sciences Center at San Antonio.

Texas investigator Richard Zellars, MD, and colleagues found that high levels of p53 protein accumulation were independently associated with a significant increase in the local recurrence rate in 1,530 breast cancer patients treated with mastectomy. In fact, patients who were were “p53-positive” were twice as likely to have a local recurrence of cancer.

Relapse Rate Higher for Recipients of Mastectomy Plus Radiation

Risk of relapse in patients treated with mastectomy only was 16.5% for p53-positive patients vs 9.1% for p53-negative patients. The recurrence rate was even higher for women who had been treated with mastectomy and radiation. In this subgroup, the risk of relapse for p53-positive patients was 21.5% vs 9.3% for p53-negative patients.

Most breast cancer patients undergo testing for p53 to help determine the likelihood of survival. However, this is the first study to assess its value in predicting local recurrence in breast cancer.

A p53 test “could become a valuable tool, like lymph-node involvement, to help make decisions on further treatment,” commented Dr. Zellars. The advance is important, he continued, because physicians know that 20% to 30% of lymph node–positive breast cancer patients will develop a locoregional recurrence after being treated by mastectomy, but they don’t know which patients are at highest risk. One-half of patients who experience recurrence will die of their disease.