A small trial headed by MD Anderson Cancer Center, Houston, has helped to further identify women who can safely skip surgery after neoadjuvant therapy for early breast cancer.
Among 50 women in the study with cT1-2N0-1M0 triple negative or HER2-positive disease, 31 (62%) had a complete pathologic response (pCR) to neoadjuvant therapy on image-guided vacuum-assisted core biopsy (VACB).
They went onto whole breast radiation with a boost, but given their response to neoadjuvant treatment and the accuracy of VACB, the women did not have surgery.
So far, it seems to have been the right call: At 3 years, there’s been no tumor recurrences and disease-free and overall survival are both 100%.
Eliminating “breast surgery in highly-selected patients with image-guided VACB-determined pCR following” neoadjuvant systemic therapy has “very promising 3-year results,” lead investigator Henry M. Kuerer, MD, PhD, a breast cancer surgeon at MD Anderson, who presented the findings at the European Society for Medical Oncology (ESMO) 2023 annual meeting.
With the success of modern systemic therapy, “it’s only natural that we think this way,” said Ava Kwong, PhD, chief of breast surgery at the University of Hong Kong, who discussed Dr. Kuerer’s presentation at the meeting.
“This study is really important,” she said. “It’s addressing a very important question whether we can omit surgery in certain groups of patients ... We do want to deescalate surgery,” and the study results are “very good,” she said.
However, larger trials with longer follow-up are needed to draw any firm conclusions, she said.
Dr. Kuerer agreed. He and his team will continue to follow the study subjects, and they have opened up a new trial with 100 patients. A similar study is ongoing in Korea, as well, he noted.
Study details
Women in the trial were a median of 60.4 years old; 58% had HER2-positive and the rest triple-negative unicentric breast cancer. Mean baseline tumor size was 2.8 cm. Just 12% of the participants had lymph node involvement. Neoadjuvant systemic therapy was clinician’s choice.
Breast lesions had to shrink to less than 2 cm on imaging after systemic therapy to be eligible for the study, and a minimum of 12 cores had to be obtained on VACB.
The 38% of women in the study with residual disease after systemic treatment went on to surgery.
Two patients were circulating tumor cell (CTC)-positive at baseline, two were positive at 6 months, and one at 12 months. No patients had CTCs detected at more than one timepoint.
The work was funded by the National Cancer Institute. Dr. Kuerer is an adviser for Merck. Dr. Kwong is an adviser/speaker/reviewer/author for Stryker, AstraZeneca, Merck, and Roche. She also disclosed research funding from Merck, Roche, and Gilead and funding for genetic testing from AstraZeneca.