Mutant gene test may predict breast cancer return, spread

SAN ANTONIO Testing for a gene mutation may enable doctors topredict whether some breast cancer patients will have a relapse orwhether their cancer will spread, scientists said at a symposiumhere.

By detecting the presence of the mutated gene, doctors may beable to determine which breast cancer patients need strongchemotherapy and extensive surgery and which will survive withsurgery to remove only the tumor.

A German researcher at the meeting reported a related finding:By measuring certain substances produced by tumor cells, doctors maybe able to identify breast-cancer patients who are in danger ofrelapsing and treat them with chemotherapy.

The test for the mutant gene also may help low-risk people avoidthe unpleasant and often serious side effects of high doses ofchemotherapy, including hair loss, nausea, vomiting and infections,Dr. Ann D. Thor, of Harvard Medical School in Boston, said at the14th Annual San Antonio Breast Cancer Symposium.

With new laboratory techiques, this gene, called the p53 gene,can be easily studied and measured, and it is being implicated inmany types of human cancers, she said.

The normal p53 gene suppresses growth in all human cells. Butthrough mutation it loses its normal function and may promote cellgrowth.

In her study of 300 patients, Thor found that women who had themutant gene when their breast cancer was diagnosed had a much worseoutcome and survival rate.

Women with a family history of breast cancer were more likely tohave the mutated gene, Thor said.

Women who might benefit most from the new gene findings likelywill be those whose breast cancer has not invaded nearby lymph nodes, Thor said.

In the second breast cancer finding reported at the meeting, aGerman researcher described the role of two substances produced bytumor cells which he said can be used to predict how invasive breastcancer will be.

By measuring the substances, doctors can identify patients whoare in danger of relapsing and treat them with chemotherapy, whilesparing those who are not at high risk, said Dr. Fritz Jaenickeof theFrauenklinik/Women's Clinic of the Technical University of Munich inGermany.

About 45,000 American women are expected to die this year frombreast cancer, according to the American Cancer Society.