Breast Cancer through the Ages

More than 100 years ago, before the founding of the American College of Surgeons or Commission on Cancer (CoC), William Stewart Halsted revolutionized the treatment of breast cancer with surgical innovation that became known as the “Halsted radical mastectomy.” This treatment was based on anatomic considerations and what was known about local and regional spread of breast cancer. Dr. Halsted was also the first to appreciate the role that estrogen played in breast cancer progression, and the potential benefit of oophorectomy. This remained the hallmark of breast cancer treatment for 70 years. When I entered Harvard Medical School in 1971, the Halsted radical mastectomy was still being performed. I still remember my patients with severe arm lymphedema and very limited arm mobility or strength due to removal of muscle and regional axillary nodes, but within a few years the field changed dramatically.

In the 1970s, mammography screening was shown to reduce mortality in the Health Insurance Plan of New York study, and adjuvant hormonal and chemotherapy approaches were introduced for women who had undergone mastectomy and were found to have involved axillary lymph nodes, resulting in improved survival.

And in the late 1970s modified radical mastectomy replaced the Halsted radical mastectomy, and patients were first treated with segmental mastectomy, or lumpectomy, followed by breast radiation. In the decades that followed advances were made in surgical techniques for both lumpectomy and mastectomy, and especially reconstruction post-mastectomy. Improvements in post-lumpectomy radiation resulted in much better cosmetic outcomes and systemic therapies, based on an ever deeper understanding of the molecular biology of breast cancer, had dramatic effects on overall survival. Newer hormonal approaches with aromatase inhibitors and fulvestrant, along with modifying drugs such as the CDK 4/6 inhibitors, made significant contributions to outcomes and targeted therapies against HER2 revolutionized the prognosis for these patients. More recently, immunotherapies with check point inhibitors have impacted patients with the most resistant biologic subtype of breast cancer, those with so-called triple negative disease. Screening with mammography and MRI have shifted the stage distribution of patients coming for care, leading to better options for surgery, systemic therapy and radiation, and ever-improving survival.

These advances have required greater involvement and integration not only of the three clinical specialties, breast surgery, medical oncology and radiation oncology, but also of our colleagues in radiology and pathology. A modern tumor board routinely brings these five specialists (and sometimes plastic surgery) together to collectively tailor the best therapeutic options for patients. These advances required continual data analysis to know where opportunities for continued improvement were, and to be certain that these more effective approaches were reaching all of our cancer programs and therefore all of our patients. The CoC has played a major role in advancing and focusing our efforts in this regard. CoC required programs to have tumor boards, established standards for synoptic pathology reports, and five of its initial quality metrics were focused on aspects of breast cancer care. When operative standards, required for accreditation, were introduced in 2020, two were focused on axillary surgery for breast cancer.

In 1950, the estimated five-year survival for patients with breast cancer was 55 percent (though we had less complete population statistics then), and now nearly 90 percent of breast cancer patients in the US will be alive five years after diagnosis, and with far fewer short and long-term toxicities, resulting in not only better survival, but better quality of life.

For those of us who have been caring for breast cancer patients since the 1970s, the improvements in all aspects of care are truly astounding, but we still lose too many patients—an estimated 40,000 patients per year in the U.S. So our work is not done but we can be optimistic that through hard work we will continue to advance the field and continue to improve the outcomes for our patients.