Trastuzumab May Not Affect Reconstruction for Patients with HER-2 Breast Cancer

Patients with HER-2 positive breast cancer treated with trastuzumab (Herceptin) may not be at a higher risk of surgical complications during breast reconstruction immediately after a mastectomy, according to a study published by the Journal of the American College of Surgeons.

The new study is the first to explore the effects of trastuzumab on surgical complications and suggests that breast reconstruction does not need to be delayed due to adjuvant therapy, according to the authors.

However, the authors discovered that trastuzumab plus pertuzumab (Perjeta) may increase the risk of surgical complications after immediate reconstruction, according to the study. The investigators caution that patients treated with the combination therapy should finish the therapy before reconstruction.

“If a patient is otherwise fairly healthy and the surgery is straightforward, immediate breast reconstruction may be done even if she is receiving both therapies,” said principal author Scott Hollenbeck, MD, FACS. “If a patient has other risk factors and faces a potentially difficult operation, I would recommend waiting until the completion of pertuzumab therapy.”

Approximately 20% of breast cancers are HER-2 positive, which are typically more aggressive and metastasize faster than other subtypes of the disease.

Trastuzumab targets the HER-2 protein and has been found to increase overall survival when administered as a combination therapy, according to the study. Pertuzumab is also indicated as a combination therapy to treat HER-2 positive breast cancer.

Surgeons may be concerned that suppression of HER-2 through trastuzumab could alter the skin’s integrity and increase the risk of infection and surgical site complications, according to the study.

“During surgical reconstruction of the breast after mastectomy, the skin is saved and an implant or flap is inserted underneath. If the skin doesn’t heal or dies, the reconstruction could fail and require another operation,” Dr Hollenbeck said. “Trastuzumab and pertuzumab block the action of HER-2, which is associated with the epidermis or outer layer of the skin. Up to now, there haven’t been any studies of the outcomes after breast reconstruction in patients who received these agents. We conducted this study to determine whether trastuzumab alone or in combination with pertuzumab negatively affected breast reconstruction outcomes.”

Included in the study were 481 women who underwent breast reconstruction after mastectomy between 2006 and 2016. One group of patients received trastuzumab monotherapy or in combination with pertuzumab, while another cohort did not.

Overall, the investigators found that the prevalence of wound breakdown that called for additional surgery was greater among patients administered the combination therapy.

The authors found that trastuzumab monotherapy was not linked to surgical complications, including bleeding, swelling, coagulation or clotting, disruption of the skin around the incision, or cellular death in the mastectomy skin flap, according to the study.

“At the present time, there are no clear clinical guidelines on the optimal timing for breast reconstruction. While preliminary, this study may be helpful for guiding the decision by patients and surgeons,” Dr Hollenbeck said.

The authors concluded that larger studies are needed to validate the findings.

In the meantime, Dr Hollenbeck said that their findings “may help surgeons feel more comfortable performing immediate breast reconstruction on patients who receive trastuzumab and delaying the surgery for those on combination targeted HER-2 treatment.”