ABSTRACT
Background:In a previous retrospective audit from our institution we reported that patients had limited access to HER2-targeted therapy due to financial constraints. Subsequently, the advent of biosimilar versions of trastuzumab and philanthropic support has potentially changed this situation. Herein, we reanalyzed and reported access to HER2-targeted therapy in a more recent cohort of patients. Methods: Medical records of new breast cancer patients registered in one calendar year were retrospectively reviewed, supplemented by online pharmacy data to extract information on receptor status, use of HER2-targeted therapy, and other relevant variables. Since not all HER2 immunohistochemistry (IHC) 2+ tumors underwent fluorescent in-situ hybridization (FISH) testing, we estimated the probable HER2 amplified from this group based on a FISH amplified fraction in those HER2 2+ tumors who did undergo FISH. Results: Between January 2016 and December 2016, 4717 new BC patients were registered at our institution, of whom 729 (20.04%) had HER2 IHC 3+ tumors while 641 (17.62%) had HER2 IHC 2+ tumors. The final number of HER2 overexpressing/amplified tumors was estimated to be 928 (729 HER2 IHC 3+, 105 known FISH amplified, and 94 estimated FISH amplified), of whom 831 received treatment at our institution. Overall 474 (57.03%, 95% confidence interval [CI] 53.6–60.4) of these 831 patients received trastuzumab for durations ranging from 12 weeks to 12 months in the (neo)adjuvant setting or other durations in metastatic setting compared to 8.61% (95% CI 6.2–11.6) usage of HER2-targeted therapy in the 2008 cohort. Conclusion: Access to HER2-targeted therapy has substantially increased among patients treated at a public hospital in the past decade, likely due to the advent of biosimilars, the use of shorter duration adjuvant regimens, and philanthropic support. However, further efforts are required to achieve universal access to this potentially life-saving treatment.
ABSTRACT
Background: This study was undertaken to document the pattern of expression of estrogen (ER), progesterone (PR) and human epidermal growth factor receptor-2 (HER2) and the usage of HER2-targeted therapy in a large tertiary care hospital in India in the year 2008. Materials and Methods: The histopathology reports of all breast cancer patients registered in the hospital in 2008 were extracted from the electronic medical record system. All the cases were immunohistochemically evaluated for estrogen and progesterone receptor status (ER and PR), and c-erbB-2 protein (HER2) expression using standard immunoperoxidase method. The use of HER2-targeted therapies was evaluated by extracting relevant information from the database of the hospital pharmacy and case charts of patients enrolled in ongoing approved trials. Results: A total of 2001 new patients of invasive breast cancers with available pathology reports were registered in the hospital in the year 2008. ER and/or PR expression was positive in tumors of 1025 (51.2%) patients. HER2 3+ expression by immunohistochemistry (IHC) was found in 335 (16.7%) and HER2 2+ in 163 (8.1%). The triple negative phenotype was found in 596 (29.8%) patients. An estimated 441 patients were eligible to receive HER2-targeted therapy based on their HER2 status. Of these 38 (8.6%) patients received some form of HER2-targeted therapy; 20 patients (4.5%) as part of ongoing clinical trials and 18 (4.1%) as part of routine care. Conclusions: The overwhelming majority of patients eligible for HER2-targeted therapy in our institution are unable to receive it because of financial constraints and limited access to health insurance. There is a higher fraction of patients with the triple negative phenotype compared to the Western population.