In the first 2 months after California issued a shelter-in-place order to reduce the spread of COVID-19, new patients diagnosed at a large integrated health care system presented with more advanced and aggressive breast cancers than during the same period in 2019, a researcher told colleagues at the 2020 San Antonio Breast Cancer Symposium (Abstract SS2-06).
Without screening mammography, newly diagnosed patients also had more distant metastatic cancer, as well as more grade 3 tumors than during the corresponding period in 2019, said lead author Sharon Chang, MD, Surgical Oncology Specialist at Kaiser Permanente, Fremont Medical Center in California.
"COVID-19 pandemic has disrupted all aspects of health care, including the diagnosis and treatment of breast cancer," she said. "We evaluated the impact of these operational changes on the presentation and treatment of breast cancer patients in our system."
Of patients with invasive breast cancer, 35 percent of patients diagnosed between March and May 2020 had grade 3 tumors versus 24 percent in 2019, as well as more triple-negative tumors (15% vs. 10%).
In March 2020, the Society of Surgical Oncology, the American College of Surgeons, and the American Society of Breast Surgeons issued guidelines regarding the timing of surgery for cancer patients to preserve hospital resources and minimize exposure of patients and staff to COVID-19. Recommendations included delaying breast cancer surgery, if possible, and using neoadjuvant chemotherapy or neoadjuvant endocrine therapy to treat selected patients while waiting for definitive surgery.
In California, the "shelter in place" order began March 17, 2020, and both screening mammography and elective surgeries were halted at Kaiser, a large, integrated health care system.
Study Details
Chang and her colleagues conducted a retrospective review of patients newly diagnosed between the shelter-in-place order and May 2020, when elective operations resumed. Age, histology, anatomic staging features, grade, receptor status, and initial treatment were compared between patient groups. For the patients who underwent surgery, the investigators compared the time from biopsy to time to surgery and the type of operation.
There were 790 patients in the 2019 cohort and 279 in the 2020 cohort. There were no significant differences in age at presentation, histologic subtypes, nodal status, or operation type between the two groups.
The T-stages at presentation of the 2020 group were higher than those of the 2019 group; 29 percent presented with T1c tumors in 2020 versus 26 percent in 2019, and 37 percent with T2 tumors in 2020 versus 30 percent in 2019.
A higher percentage of patients presented with distant metastatic disease at the time of diagnosis in 2020 (7% in 2020 vs. 2% in 2019), although the absolute numbers of patients were similar (19 patients vs. 17 patients in 2019).
Fewer patients underwent surgery first in 2020 (73% in 2020 versus 85% in 2019), and more underwent neoadjuvant chemotherapy (13% in 2020 versus 9% in 2019). Only 4 percent of the 2020 surgery group had been placed on neoadjuvant endocrine therapy while awaiting definitive surgery.
Notably, the time to surgery for patients with surgery as the initial treatment was significantly shorter in the 2020 group (mean 22 days in 2020 vs. 31 days in 2019). The researchers hypothesized that this was due to the availability of operating rooms since all elective operations had been halted.
Without screening mammography, newly diagnosed patients in a large, integrated health care system during the COVID-19 pandemic presented with more advanced and aggressive breast cancers as compared to the equivalent time period in 2019.
"Our study demonstrates the ability of a large, integrated health care system to deliver timely breast cancer care during the constraints of the COVID-19 pandemic, and highlights the importance of screening in early breast cancer detection," Chang noted.
Kurt Samson is a contributing writer.