Fewer Women Need Chemotherapy for Breast Cancer

Less is more. When we find examples of that in medicine, we celebrate. In oncology – at least in fields like early breast cancer, where cure rates are high – the goal is to treat better, smarter – less – while maintaining high cure rates. In radiation oncology, strong scientific evidence has led to the widespread adoption of breast conserving surgery and radiation (less surgery) over mastectomy. Now, we have solid data that fewer women need chemotherapy as well.

It has taken a long time for that chemotherapy pendulum to swing back. In the 1980s, the prevailing mantra was high-dose chemotherapy for most women with breast cancer. Women even demanded and lobbied for the “right” to receive bone marrow transplants for aggressive breast cancers. My mother-in-law received a bone marrow transplant at an academic medical center in Lubbock, Texas. She stayed in the hospital for 30 days, much of that in the ICU, and nearly died from the treatment. Unfortunately, after recovering from the transplant she died from her cancer anyway. In retrospect, bone marrow transplant treatment for breast cancer can only be described as excessive, ineffective, and highly toxic. The scientific evidence just wasn’t there yet to support it.

Even putting aside bone marrow transplants, the promise of more and more chemotherapy that started around 1975 resulted in almost every woman with a cancer larger than a centimeter – not even a half inch – being recommended to get chemotherapy. That meant a lot of women were being treated with undeniably toxic chemotherapy who didn’t need it.

Thankfully, many advances along the way have helped determine who may or may not benefit from chemotherapy. Identification of receptors on an individual woman’s cancer for estrogen, progesterone, and HER2, for example, can guide certain treatment recommendations. In our modern era of often over-hyped personalized medicine, a test called Oncotype DX (developed in 2003) has actually revolutionized the way we decide for many women who gets chemotherapy and who doesn’t.

Oncotype DX is a 21-gene assay of a patient’s tumor that evaluates risk of recurrence with and without chemotherapy for women with early stage estrogen receptor-positive and HER2-negative breast cancer. The resultant individualized score quantifies the 10-year risk of distant recurrence and, therefore, the likelihood of chemotherapy benefit for that particular patient. Physicians receive a report indicating their patient is in a low risk, intermediate risk, or high risk group for recurrence. The practice until recently has been to offer chemotherapy in the high risk group and to consider it in the intermediate risk group as well.

On June 3, 2018, the prestigious New England Journal of Medicine published a practice-changing article that will have tens of thousands of women in the intermediate risk group celebrating each year, because they, too, won’t have to have chemotherapy. This is one of those game-changer moments when the news hype is real. The test is anticipated to spare nearly 70% of women from having to have chemotherapy who probably would have been recommended for it previously. One of the study’s authors estimated that around 60,000 women with breast cancer will benefit each year by not having to have chemotherapy.

In the US alone this year, about 266,000 new cases of breast cancer will be diagnosed in women, and there will be about 41,000 deaths. The 5-year relative survival for localized breast cancer is 99%! But women who won’t die from breast cancer don’t want to suffer through treatment they don’t need.

Breast cancer treatment remains quite complicated. There is not – and never will be – a one size fits all approach. Many women do need chemotherapy for breast cancer. Screening and early detection with mammography remain critically important to finding breast cancers earlier, when less aggressive treatments are much more likely to be recommended. Breast cancer treatment is an example where less can, indeed, be more.