Some breast cancer patients with a high response to chemotherapy may not need surgery

Patients with early-stage breast cancer who had a pathologic complete response (pCR) to nonadjuvant chemotherapy can skip surgery and receive standard radiation treatment with a low chance of disease recurrence, according to a new study by researchers at the University of Texas MD Anderson Cancer Center.

Trial Phase II results, published today Art Lancet Oncology, evaluated the probability of breast cancer recurrence in patients in complete remission after chemotherapy and radiation without surgery. Each of the 31 patients had a complete response to chemotherapy, and none had breast tumor recurrence after a median follow-up of 26.4 months.

“The ultimate form of breast-conserving therapy is complete avoidance of breast surgery for invasive disease,” said principal investigator Henry Currer, MD, professor of surgical breast oncology. “This study adds to the body of evidence that, in some cases, new drugs can completely eradicate cancer, and very early results show that we can safely rule out surgery in this select group of women with breast cancer.”

This is the first modern prospective study of omitting surgery in patients with early stage breast cancer which respond favorably to chemotherapy. High responses indicate state-of-the-art breast imaging techniques using vacuum core biopsy (VACB). These results build on Currer’s previous research using a biopsy protocol developed by Anderson, MD, to accurately identify patients who achieved PCR after chemotherapy. These patients, known as “exceptional patients,” have a lower risk of breast cancer recurrence and are candidates for avoiding breast surgery.

Improved chemotherapy drugs have greatly increased pCR rates, and patients with triple-negative or HER2-positive breast cancer now achieve a pCR in 60-80% of cases. The combination of these high response rates with selective image-guided VACB and rigorous histological processing has improved physicians’ ability to identify which patients may not require surgery.

The multicenter study involved 50 women over the age of 40 with triple-negative or HER2-positive early-stage breast cancer and a residual breast lesion of less than 2 centimeters, as determined by imaging after standard chemotherapy. Patients had a single image-guided VACB. If no disease was found on biopsy, breast surgery was not performed and patients proceeded to standard whole-breast radiation therapy.

The average age of the participants was 60.4 years; 21 patients had triple negative breast cancer and 29 had HER2-positive breast cancer. Thirty-eight participants were White, 10 were Black, and 2 were of other ethnicities/races. VACB determined pCR in 31 patients. No serious biopsy-related adverse events or treatment-related deaths occurred.

“At this point, standard breast cancer surgery is still necessary,” Currer said. “While these results are great and promising, it’s important for patients to know that this is just the beginning of a new type of treatment for individual patients. Much longer follow-up and further research will be needed before this approach can be integrated into routine breast cancer care.”

The investigators will continue to follow the trial participants for long-term results. As a secondary aim of the study, the researchers are also measuring minimal residual disease from liquid biopsies to determine if they correlate with pCR.

Although this was a small non-randomized study, it shows the feasibility of this approach. A larger randomized trial is needed to directly compare treatments before any changes in standards of care are considered.