Remarkable Results: Some Patients With Breast Cancer May Be Treated Without Surgery

“Remarkable” results from a small study suggest that some women with breast cancer may be treated without surgery.

For more than 130 years, surgery has remained the mainstay of breast cancer treatment. Other treatments are given to shrink tumors before surgery, reduce recurrence risk afterward, or extend survival and relieve symptoms in advanced cancer. This new study, however, seriously raises for the first time the possibility that some patients with early or locally advanced breast cancer may be fully treated without surgery.

These results are based on women with a neoadjuvant (presurgical tumor-shrinking) systemic treatment response classified as a pathological complete response (pCR), who had early-stage triple-negative or HER2-positive breast cancer; there were 31 such women. 

Surgery would normally follow neoadjuvant treatment in breast cancer. These women, however, did not undergo surgery and instead received standard whole-breast radiotherapy directly. Omitting surgery appeared safe. The researchers reported that, after a median follow-up of 26.4 months, not a single patient had a local or distant cancer recurrence. The study was published on October 25, 2022 in Lancet Oncology and received substantial coverage in international mainstream media, including The New York Times  and Fox News .

What Is a Pathological Complete Response?

The effectiveness of treatment given before surgery is shown by the pathology findings from breast cancer surgery. If no cancer cells are found in the surgical pathology after neoadjuvant treatment, this is called a pathological complete response . Patients who achieve a pathological complete response have a substantially lower likelihood of cancer recurrence.

Lead investigator Dr. Henry Kuerer, a breast cancer surgeon at MD Anderson Cancer Center in Texas, described the results as “remarkable and very promising” in a press release. However, he added: “Much longer follow-up and further studies are necessary before this approach can be incorporated into routine breast cancer care.”

Experts not involved in the study were similarly cautious.

Response to Neoadjuvant Treatment Is Key to Long-Term Outcomes

New treatments for early-stage triple-negative and HER2-positive breast cancers have brought pathological complete response rates after neoadjuvant therapy to 60-70%. This multicenter, single-arm phase II study builds on the increasing success of neoadjuvant therapy in recent years.

Enrolled patients had tumors smaller than 5 cm (cT1-2) and, at most, level I-II positive axillary lymph nodes (N0-1). There were 21 patients with triple-negative and 29 with HER2-positive breast cancer. The median age was 62.

Response to neoadjuvant treatment was assessed using a relatively new biopsy technique, vacuum-assisted biopsy .

Vacuum-assisted biopsy found a complete treatment response in 31 of 50 patients (62%). These women omitted surgery and received standard whole-breast radiotherapy. They were closely monitored for recurrence, including mammograms every 6 months. Nine patients subsequently underwent additional biopsies.

The study allowed node-positive disease, but women could have no more than three abnormal lymph nodes on ultrasound. These nodes were marked with metal clips before chemotherapy to ensure that the correct nodes were removed.

There were no serious biopsy-related adverse events or treatment-related deaths.

Long-Term Results Are Still Needed 

Although this new approach could make a difference and change practice, concerns remain about how it would perform in real-world care.

For example, oncology teams may not be equally successful at using vacuum-assisted biopsy to detect residual disease. Having interventional radiologists experienced in oncology at cancer centers is important in this context.

Some women may indeed question whether avoiding surgery is a meaningful alternative, particularly if they face a straightforward breast-conserving operation. They may ask, “Is avoiding surgery worth the stress of closer follow-up?”

Furthermore, pathological complete response rates after neoadjuvant treatment were higher in this study than in some previous reports, suggesting that the current follow-up is not yet “mature” enough for a definitive decision.

In conclusion, this study demonstrated for the first time that newer systemic treatments may make nonsurgical treatment an option for some patients with early-stage breast cancer. Incorporating nonsurgical approaches into early breast cancer care requires accurate prediction of residual disease/pathological complete response after neoadjuvant treatment, and techniques such as vacuum-assisted biopsy must be feasible at different cancer centers. This phase II study should provide important motivation for larger randomized clinical trials.