Abstract SS2-06: Characterization of breast cancer management during the COVID 19 pandemic in a large integrated healthcare delivery system: Stage at diagnosis and timing/modality of first treatment

Abstract

Background: The COVID 19 pandemic has disrupted all aspects of healthcare, including the diagnosis and treatment of breast cancer. 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” (SiP) order began March 17, 2020, and both screening mammography and elective surgeries were stopped in a large, integrated health care system. We evaluated the impact of these operational changes on the presentation and treatment of breast cancer patients in our system.Methods:We performed a retrospective review of patients newly diagnosed between 3/17/20, the starting date of SiP, and 5/18/20, when elective operations resumed in our system. We compared this cohort to patients who were diagnosed between 3/17/19 and 5/18/19. Age, histology, anatomic staging features, grade, receptor status, and initial treatment were compared between the cohorts. For the patients who underwent surgery, we compared the time from biopsy to time to surgery (TTS) and the type of operation. Comparisons involving categorical variables were performed using the chi-square test. Normally-distributed continuous variables were compared using two sample-t-tests. P-values of <0.05 were considered statistically significant.Results: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% presented with T1c tumors in 2020 vs 26% in 2019, and 37% with T2 tumors in 2020 vs 30% in 2019 (p=0.03). A higher percentage of patients presented with distant metastatic disease at the time of diagnosis in 2020 (7% in 2020 vs 2% in 2019, p<0.001), although the absolute numbers of patients were similar (19 patients in 2020 vs 17 patients in 2019). Of patients with invasive breast cancer, a higher percentage of patients presented with grade 3 tumors in 2020 (35% in 2020 vs 24% in 2019, p=0.002), and triple negative tumors (15% vs 10%, p=0.02). Fewer patients underwent surgery first in 2020 (73% in 2020 vs 85% in 2019, p<0.001) and more underwent neoadjuvant chemotherapy (13% in 2020 vs 9% in 2019, p=0.03). Only 4% of the 2020 surgery group had been placed on neoadjuvant endocrine therapy while awaiting definitive surgery. The TTS for patients with surgery as the initial treatment was significantly shorter for the 2020 group (mean 22 days in 2020 vs 31 days in 2019, p<0.001).Conclusions: 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. Fewer patients underwent surgery first, and more underwent neoadjuvant chemotherapy. The TTS for breast cancer patients in 2020 was significantly shorter than in 2019, which we hypothesize was due to the availability of operating rooms since elective operations had been stopped. This study demonstrates the ability of a large, integrated health care system to deliver timely breast cancer care to patients presenting with symptomatic disease during the constraints of the COVID 19 pandemic, and highlights the importance of screening in the early detection of breast cancer. Citation Format: Sharon B. Chang, Alison C. Savitz, Brooke Vuong, Annie Tang, Margaret Mentakis, Amy M. Miller, Veronica C. Shim, Gillian E. Kuehner. Characterization of breast cancer management during the COVID 19 pandemic in a large integrated healthcare delivery system: Stage at diagnosis and timing/modality of first treatment [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SS2-06.

Assessing the impact of the COVID-19 pandemic on breast cancer screening and diagnosis rates: A rapid review and meta-analysis

“…Therefore, 33 reports consisting of 31 studies formed the basis of this review. 18 – 50 A PRISMA flow diagram outlining the screening process is presented in Figure 1 . The list of excluded studies with reasons of exclusion is reported in Supplementary Table S2.…”

“…Reductions in the diagnosis rate of breast cancer were observed in all but one study, by Vardhanabhuti et al, 48 with reported rates ranging from 36.0% reduction to a 0.5% increase among registry-based studies 26 , 27 , 40 , 48 , 50 and 64.7% to 3.0% reduction in non-registry-based studies. 19 , 21 – 23 , 28 – 34 , 37 – 39 , 42 , 43 , 45 – 47 Figure 3 displays the results of the meta-analysis of the diagnosis rate ratios. Similar to the changes in mammogram screening rates, we noted an estimated 18% (RR: 0.82, 95% CI: 0.63–1.06) and 29% (RR: 0.71, 95% CI: 0.63–0.80) reduction in diagnosis rates between 2019 and 2020 based on data derived from 4 registry-based and 18 non-registry-based studies respectively.…”

Impact of the COVID-19 Pandemic on the Diagnosis and Surgery of Breast Cancer: A Multi-Institutional Study

“…Fewer patients had hormone receptor-positive, HER2-negative breast cancer, whereas the rate of triple-negative breast cancer increased during the COVID-19 pandemic. The study results also showed that more symptomatic patients were diagnosed in 2020 [ 11 ]. However, this study did not compare the rate of patients with symptomatic breast cancer.…”

“…Accordingly, pathological stage and molecular subtype analyses were not performed. At the 2020 San Antonio Breast Cancer Symposium, a retrospective study reported that more patients had advanced and aggressive types of breast cancer at the beginning of the COVID-19 pandemic [ 11 ]. Fewer patients had hormone receptor-positive, HER2-negative breast cancer, whereas the rate of triple-negative breast cancer increased during the COVID-19 pandemic.…”

“…Due to the conditions that existed during the pandemic, it has become known that breast cancer diagnoses may have been delayed [ 11 12 ]. The risk of a delayed cancer diagnosis should be compared with serious complications or mortality from COVID-19.…”