There were significant modifications in breast cancer treatment due to the coronavirus disease 2019 (COVID-19) pandemic, such as high rates of neoadjuvant endocrine (NET) chemotherapy, genomic assay testing on core biopsies, and delays in planned surgeries, according to a study presented at the 2020 San Antonio Breast Cancer Symposium. However, these modifications are consistent with the prioritization and treatment recommendations made by the COVID-19 Pandemic Breast Cancer Consortium.

During the study, the researchers also observed that a majority of patients with triple-negative breast cancer (TNBC) and human epidermal growth factor receptor 2 (HER2)-positive disease received guideline concordant neoadjuvant chemotherapy (NCT).

To get a clearer understanding of the rapid care changes caused by the pandemic, the American Society of Breast Surgeons (ASBrS) Mastery COVID-19 developed a registry within the established HIPPA compliant Mastery of Breast Surgery Program to provide a snapshot of what has occurred in the field. Additionally, ASBrS developed the registry so that it could support ongoing data entry and analysis and enable understanding of the impact of the pandemic on long term breast cancer outcomes.

Significant changes have not only occurred in breast cancer treatment, as the pandemic has altered health care worldwide. As a result of the pandemic, many hospitals stopped some or all cancer surgery in order to save protective equipment and minimize exposures. This, in turn, forced oncologic providers to quickly adjust patient management approaches to adapt.

For these reasons, the researchers in this study intended to describe the breast cancer patient level changes that occurred in the initial months of the COVID-19 pandemic in the United States in order to understand its effects.

To assess these effects, the COVID-19 specific registry developed by ASBrS allowed surgeons the opportunity to enter patient demographic data and surgical and medical care. The data fields were then tracked in order to determine whether decisions made were usual for that practice or modified due to the pandemic.

Data were then entered by 154 surgeons between the period of March 1 and June 17, 2020, for 1781 patients. For the patients added to the registry, the mean age was 63 years, 78% were White, 10% were Black, and 6% were Hispanic. In terms of geographic distribution, 10.8% of patients were in the Northwest and 29.5% were in the Northeast.

For initial consultations, 94.8% occurred in-person and 5.2% took place on either video or telephone. During the study period, approximately 1% (14) of patients tested positive for COVID-19.

The mean invasive tumor size for patients was 21.2 mm, while 15.7% of the tumors were node positive. Among the 1445 invasive breast cancers observed, 75% (1081) were estrogen receptor(ER)-positive/HER2-negative, 13.5% were (195) HER2-positive, while 11.1% (160) were TNBC.

Of the cohort, ductal carcinoma in situ (DCIS) comprised 18.2% (325). In 267 cases of ER-positive DCIS, 49% (131) received primary surgery while 49% (130) received NET. However, 95% (124) of NET use was a result of COVID-19.

A significant number of (50/52) ER-negative DCIS underwent primary surgery, while NET due to COVID-19 was used in 45% (482), with only 5% (54) of NET being noted as a part of usual practice.

The researchers observed that age was not a significant factor in the use of NET (OR 0.99, 95% CI 0.97-1.01). They also found that patients in the Southwest and Northeast had the greatest use of NET as a result of COVID-19 compared with NET use as usual (ORs 14.4 and 4.6).

Among 216 patients observed in the study period, genomic assay testing was performed on the core biopsy, with 65% (141) of the tests conducted due to COVID-19. Of those patients who had genomic testing due to COVID-19, 116 (82%) had NET, 18 (13%) had NCT, while the rest received primary surgery. Surgery was delayed in 20% (96) of the 472 patients who received primary surgery due to COVID-19.

Among patients in the Northeast, there was a 2.1 greater likelihood of a surgery being delayed as a result of COVID-19 compared with patients in the Midwest. There were also changes made to surgical plans as a result of the pandemic. The most common changes made were converting from mastectomy to breast conservation 6% (27) and from mastectomy with reconstruction to mastectomy without reconstruction 7% (34).

REFERENCE
Wilke LG, et al. Impact of the COVID-19 pandemic on the multidisciplinary management of breast cancer: Initial analysis of the american society of breast surgeons mastery COVID-19 registry. Presented at: 2020 San Antonio Breast Cancer Symposium; virtual.