Conference Coverage

In metastatic breast cancer, primary resections on the decline


 

FROM SABCS 2021

The surgical resection rates of the primary tumor in metastatic breast cancer has declined in recent years, possibly reflecting changes in practice following randomized, controlled trials that have not consistently shown a survival benefit.

Dr. Sasha Douglas

Retrospective studies have suggested a possible benefit to resection, according to Sasha Douglas, MD, who presented the study (abstract PD7-06) at the 2021 San Antonio Breast Cancer Symposium. “Intuitively, you would think that you would want to get the primary tumor out even if it’s metastasized, so that it couldn’t metastasize more,” said Dr. Douglas, who is a surgical resident at the University of California, San Diego.

However, clinical trials have yielded mixed results, and the picture is complicated by the various molecular subtypes of breast cancer, metastatic sites, and other factors. “Different studies, whether it’s retrospective, and a really large database that has lots of numbers of patients, can give you a different answer than a smaller prospective randomized, controlled study in a different cohort of patients. So, we just thought it would be really interesting to look at all the trends over time at Commission on Cancer–accredited hospitals. Do they seem to be following what the latest literature is showing?” Dr. Douglas said in an interview.

The researchers used data from 87,331 cases from the National Cancer Database (NCDB) and examined rates of primary surgery as well as palliative care in women with metastatic breast cancer who had responded well to systemic therapy.

Between 2004 and 2009, the frequency of primary tumor resection remained near 35% (with a peak of 37% in 2009), then began a steady descent to 18% by 2017. The researchers found similar trends in estrogen receptor–positive/progesterone receptor–positive, HER2-negative (ER/PR+HERer2–); HER2-positive; and triple-negative subtypes.

In 2004, 48% of patients received only systemic therapy, while 37% received some combination of surgery and radiation to the primary tumor. By 2019, 69% received only systemic therapy and 20% received locoregional therapy (P < .001). “It seems that surgeons and providers and medical oncologists are becoming more selective about who they’re going to offer surgery to, and I think that’s very appropriate,” said Dr. Douglas.

But another finding suggests room for improvement: Just 21% of patients received palliative care. “I think that everybody with a major systemic illness like this would benefit from palliative care, just on a supportive basis. The palliative care team can really help people with quality of life, but I think it still has that stigma, and I think that’s what we’ve seen from our study,” said Dr. Douglas.

“We’re just postulating, [but] a lot of that could be from the stigma of thinking that palliative care means giving up. It doesn’t necessarily mean that. It means you’re dealing with a difficult chronic illness, and [palliative care] can be very, very helpful for patients,” said Dr. Douglas.

The study is limited by its retrospective nature, and palliative care might be underreported in the NCDB.

The study was funded by the National Cancer Institute and the University of California, San Diego. Dr. Douglas has no financial disclosures.