Gene mutations tied to less invasive breast cancer

Mutations in the BRCA1 or BRCA2 gene have been linked to invasive forms of breast cancer, and new research suggests that they are also found with ductal carcinoma in situ (DCIS), a less invasive form of the disease.

BRCA mutations are associated with hereditary forms of breast cancer as well as ovarian cancer. The new research suggests that like invasive breast cancer, DCIS is a part of the cancer syndromes defined by these mutations, Dr. Elizabeth B. Claus from Yale University School of Medicine in New Haven, Connecticut, and colleagues note.

The researchers came to these conclusions based on telephone interviews and BRCA mutation testing performed on 369 women who were diagnosed with DCIS between 1994 and 1998. Their findings appear in the Journal of the American Medical Association.

The rate of BRCA1 and BRCA2 mutations in the study group was 0.8 and 2.4 percent, respectively. One DCIS patient was noted to a have mutation in both BRCA1 and BRCA2.

BRCA1 mutation rates in women with invasive breast cancer, according to recent estimates, range from 0.4 to 2.6 percent. The corresponding rate for BRCA2 is about 1.5 percent.

Compared with other women, those with a BRCA mutation were more likely to have a family history of breast cancer and a personal history of ovarian cancer. Moreover, BRCA mutations were associated with breast cancer diagnosis at an earlier age - for both the patient and for first-degree relatives.

"These findings," the researchers conclude, "suggest that patients with breast cancer with an appropriate personal or family history of breast and/or ovarian cancer should be screened and followed according to high-risk protocols, regardless of whether they are diagnosed with in situ or invasive breast cancer."

SOURCE: Journal of the American Medical Association, February 23, 2005.