Due to COVID-19, NET was used to treat an additional 554 patients (36%) who would otherwise have had surgery first between March 1 and October 28, 2020, the study found. Subsequent results through March 2021 bring the total to 31%.
NET was also used in 6.5% to 7.8% of patients in the registries who would normally have received this treatment, the study authors said in an ASBrS press release.
The patterns found in the registry are what cancer experts discussed early in the pandemic, said Dr. Tari King, chief of breast surgery at Dana-Farber/Brigham and Women’s Cancer Center in Boston, who was not involved in the study.
“We had good data to support that this would be a reasonable strategy for the majority of patients with ER+ breast cancer that we could use this as a bridge to surgery without negatively impacting their outcomes,” King said.
Several clinical studies had already validated the approach, which is more common in Europe.
Endocrine anti-estrogen therapy blocks or decreases the ability of hormones to grow certain types of cancer cells. In the United States, it’s most commonly used in postmenopausal women with larger tumors, Wilke said.
The study also found that there were fewer immediate breast reconstruction surgeries because shorter surgery times prioritized cancer removal.
About 24% of patients had genetic mutation testing on tumor tissue biopsy, the study found.
Dana-Farber/Brigham and Women’s Cancer Center already used core biopsy for these genomic studies to determine which women needed chemotherapy prior to surgery, King said.
In places like Boston, cancer treatment returned to normal in the late fall, she noted.
King said many of the patients who started preoperative endocrine therapy at the center didn’t stay on treatment as long as they normally would if the goal had been to shrink the tumor, because they were already candidates for a lumpectomy.
While this change of treatment was temporary, King said it challenges researchers to think more broadly about which patients might benefit from NET in the future. It shrinks tumors as well as chemo, but it takes longer to do that, she said.