The proportion of breast cancer patients who are eligible for breast conservation therapy, yet opt for mastectomy, is increasing, for reasons that include the desire to eliminate future screening and/or biopsy of the remaining breast tissue.

A new study led by researchers at the Icahn School of Medicine at Mount Sinai has determined that having a mastectomy does not completely eliminate the need for further breast imaging studies.

These results, published online in the Annals of Surgical Oncology, can help guide breast cancer patients and their physicians in their medical and surgical decision-making.

The study, titled "Defining the Need for Imaging and Biopsy After Mastectomy," is a retrospective review of all mastectomy cases, either one-sided or both sides, performed at The Mount Sinai Hospital's Dubin Breast Center. Post-mastectomy imaging and biopsy rates were determined. To the researchers' knowledge, this is the first study to describe the incidence and need for postoperative imaging and biopsy for patients who undergo mastectomy.

"Autonomy and choice in treatment are encouraged, and can be empowering for patients. But decision-making can also result in anxiety, fear, and distress. Some patients might choose more extensive surgery with the hope that this will reduce the need for breast imaging and biopsy later, when in fact this is not necessarily the medically beneficial course," said Soojin Ahn, MD, Assistant Professor of Breast Surgery, Mount Sinai St. Luke's.

The researchers identified 185 unilateral (one side) and 200 bilateral (both sides) mastectomy cases performed for breast cancer between 2009 and 2015. The average follow-up period was 30 months (the number of months ranged from 3 to 75).

Of the 185 unilateral patients, 19 (10 percent) underwent imaging on that side (all ultrasounds) for concerning physical examination findings, 11 (6 percent) underwent biopsy, and two (1 percent) showed malignant findings.

Of the 200 bilateral mastectomy patients, 31 (15.5 percent) required imaging (29 ultrasounds and 2 MRIs), with 76 percent of the ultrasounds performed on the side with previous cancer.

Subsequently, 16 (8 percent) of these patients had biopsy, with 11 (69 percent) of the 16 biopsies performed on the same side as the previous cancer.

Three (1.5 percent) of the biopsies done on this side demonstrated malignancy, whereas all five biopsies performed on the other side were benign.

Dr. Ahn and her colleagues concluded that for 10 percent to 15.5 percent of patients who undergo either a unilateral or bilateral mastectomy, subsequent imaging is required, and 6 to 8 percent ultimately undergo biopsy.

The rate of malignancy was found to be low, approximately 1 percent.

Nevertheless, enough cases were identified that the researchers concluded that mastectomies do not eliminate the need for imaging and biopsy.

"This information is critical for patient understanding and decision-making," said Elisa Port, MD, FACS, Chief of Breast Surgery and Co-Director of the Dubin Breast Cancer. "Physicians and their patients should make their surgical treatment decisions after careful consideration of various clinical factors and realistic expectations for post-operative follow up."

Source: The Mount Sinai Hospital