National data analyzing health insurance claims of breast cancer diagnosis and treatment showed a decrease of diagnoses with an increase of preoperative therapy while highlighting the disproportionate impact on certain groups of people. This information was based on research presented at the 2021 San Antonio Breast Cancer Symposium by lead author Jennifer L. Caswell-Jin, MD, Assistant Professor of Medicine (Oncology) at Stanford University, Stanford Hospital and Clinics.
"Our aim was to understand the impact of the pandemic in the U.S. on breast cancer diagnosis, as well as the 'first treatment over time' across geography and by race and ethnicity," said Caswell-Jin, who explained the analysis of new diagnoses of early-stage invasive breast cancers, Stage I, II, and III tumors, as inferred from insurance claims data. "We did not, however, include new diagnoses of presumed Stage 0 (in situ) or Stage IV (metastatic) breast cancers in these analyses, as these are managed differently."
Guidelines that were issued early on in the pandemic suggested the consideration of neoadjuvant endocrine therapy for many estrogen receptor-positive (ER+) HER2 breast cancers, she noted. Primary endpoints were incidence of breast cancer diagnosis and first treatment (surgery vs. neoadjuvant systemic therapy).
Diagnoses & First Treatment
Based on the national study of insured U.S. patients, which included 30 million adult health plan enrollees between February 1, 2017, and January 31, 2021, new breast cancer diagnosis decreased by 12.3 percent during February-May 2020 compared to the same period in the previous 3 years.
"Research showed that the drop in incidence of breast cancer diagnosis was most prominent in April and May 2020, when diagnoses decreased by about 40 percent compared to the pre-pandemic baseline," said Caswell-Jin, noting there was some recovery in June with full recovery in July.
"Notably, those missing diagnoses from April and May were still not fully accounted for by early 2021 when our data ended," she stated.
"In our second endpoint, the rise in the use of neoadjuvant endocrine therapy [began] with patients diagnosed in February 2020 with preoperative endocrine therapy given to one-third of patients at the peak in March 2020, versus ~5 percent of patients prior to the pandemic," Caswell-Jin explained. "The impact of the pandemic on 'choice of first treatment' differed by geographic area, but not by race/ethnicity or income in this insured population.
The data also showed the use of preoperative therapy, primarily endocrine which increased by 2.7-fold. "Many early-stage invasive breast cancers are treated with both surgery and systemic treatment, which can include chemotherapy, endocrine therapy (blocking the effects of estrogen), or both," she said.
During the early months of the pandemic, more patients received systemic therapy prior to surgery. "This trend applied to both preoperative chemotherapy and endocrine therapy, but was especially driven by endocrine therapy," said Caswell-Jin. "Presumably, giving systemic treatment allowed oncologists to treat the tumor when cancer surgeries were delayed by limited operating room capacity during the early months of the pandemic.
"We saw differential use of preoperative therapy across geographic regions, with the greatest increase in the Middle Atlantic and New England regions," she noted. "These geographic differences were likely driven in part by varying COVID incidence rates in the early pandemic."
Distribution of the first treatment returned to its pre-pandemic normal (baseline) by July 2020.
While people of all categories of race/ethnicity suffered a drop in breast cancer diagnoses in the early pandemic, breast cancer incidence did not recover in the Hispanic population as it did in the other groups, Caswell-Jin explained.
"There is no question the pandemic has had a disproportionate impact on certain groups of people. Our hope would be that better understanding the post-pandemic landscape will help direct public health efforts to improve equity of access and care," she said.
The team studied data through January 2021 in order to see some of the recovery after the acute changes in diagnosis and treatment in the early months.
"We should continue to monitor post-pandemic cancer diagnoses across races/ethnicities to understand whether efforts to improve equity in access to cancer screening and treatment are being met with success," Caswell-Jin noted. "Ultimately, we will follow up with the claims data to assess the longer-term impact of these pandemic-related changes on treatment patterns, cost, and patient outcomes."
Amy Gallagher is a contributing writer.