Prophylactic mastectomy: pathologic findings in high-risk patients.

Area of Science:

• Oncology
• Surgical Oncology
• Genetics

Background:

• Prophylactic mastectomy (PM) is a surgical intervention aimed at preventing breast cancer in high-risk individuals.
• Published data suggests PM prevents approximately 90% of expected malignant neoplasms in women with a family history of breast cancer.

Purpose of the Study:

• To determine the frequency of high-risk lesions identified in prophylactic mastectomy specimens.
• To assess the occurrence of new primary breast cancers after prophylactic mastectomy.

Main Methods:

• A retrospective study reviewed medical charts and pathological findings of 35 patients undergoing bilateral prophylactic mastectomy between 1989 and 1996.
• Patients were stratified into three groups based on family history and presence of contralateral neoplasia, excluding those with prior bilateral breast cancer.
• Findings were compared to a control group of 10 women undergoing reduction mammoplasty.

Main Results:

• Among 9 patients with a positive family history and no known breast cancer, 33% had high-risk pathologic findings (atypical ductal or lobular hyperplasia).
• In patients with a positive family history and contralateral neoplasia, 15% had occult malignant neoplasms in the prophylactic mastectomy specimen.
• In patients with negative family history but contralateral neoplasia, 23.1% had high-risk lesions (atypical ductal or lobular hyperplasia).

Conclusions:

• A family history of breast cancer is associated with a 15.4% probability of simultaneous occult malignant neoplasms in the contralateral breast.
• Women with a strong family history but no current breast cancer show similar rates of proliferative disease in PM specimens as women with unilateral cancer and no significant family history.
• No new breast malignant neoplasms were observed in the 45 studied patients during a mean follow-up of 4.8 years.