Outcomes of Breast Cancer Patients Treated with Chemotherapy, Biologic Therapy, Endocrine Therapy, or Active Surveillance During the COVID-19 Pandemic.

PURPOSE: Provide real-world data regarding the risk for SARS-CoV-2 infection and mortality in breast cancer (BC) patients on active cancer treatment. METHODS: Clinical data were abstracted from the 3778 BC patients seen at a multisite cancer center in New York between February 1, 2020 and May 1, 2020, including patient demographics, tumor histology, cancer treatment, and SARS-CoV-2 testing results. Incidence of SARS-CoV-2 infection by treatment type (chemotherapy [CT] vs endocrine and/or HER2 directed therapy [E/H]) was compared by Inverse Probability of Treatment Weighting. In those diagnosed with SARS-CoV-2 infection, Mann-Whitney test was used to a assess risk factors for severe disease and mortality. RESULTS: Three thousand sixty-two patients met study inclusion criteria with 641 patients tested for SARS-COV-2 by RT-PCR or serology. Overall, 64 patients (2.1%) were diagnosed with SARS-CoV-2 infection by either serology, RT-PCR, or documented clinical diagnosis. Comparing matched patients who received chemotherapy (n = 379) with those who received non-cytotoxic therapies (n = 2343) the incidence of SARS-CoV-2 did not differ between treatment groups (weighted risk; 3.5% CT vs 2.7% E/H, P = .523). Twenty-seven patients (0.9%) expired over follow-up, with 10 deaths attributed to SARS-CoV-2 infection. Chemotherapy was not associated with increased risk for death following SARS-CoV-2 infection (weighted risk; 0.7% CT vs 0.1% E/H, P = .246). Advanced disease (stage IV), age, BMI, and Charlson's Comorbidity Index score were associated with increased mortality following SARS-CoV-2 infection (P ≤ .05). CONCLUSION: BC treatment, including chemotherapy, can be safely administered in the context of enhanced infectious precautions, and should not be withheld particularly when given for curative intent.

Sex hormone receptors in breast cancer.

The dependency of certain breast cancers on estrogen is undeniably one of the most important observations in oncology. Since this early observation, there has been a tremendous effort to define the precise roles of the estrogen receptor (ER) in the pathogenesis of breast cancer. Estrogen signaling pathways can also be exploited as effective targets for cancer treatment. Both ligand-dependent and ligand-independent receptor activation pathways have been successfully blocked by hormonal therapies including selective ER modulators such as tamoxifen, by blocking and accelerating the degradation of ER (fulvestrant), and by depleting tissue levels of estrogen (aromatase inhibitors). Because of the immense prognostic and predictive value of the ER and PR receptor, accurately defining hormone dependency is also of paramount importance. Despite this avalanche of discovery and development resulting in improved outcome for the patient, resistance to these therapies, both intrinsic and acquired, is well known. Uncovering the various mechanisms of resistance has deepened scientific understanding of posttranslational modifications of these receptors, as well as their cross talk with other receptor families such as the HER-2/neu receptor. The recent discovery that orphan estrogen-related receptors may also play an important role in breast cancer is just starting to be appreciated. A clear understanding of the historical perspective and the intricacies of ER structure and function is required to improve current therapeutic strategies for breast cancer.