An Outstanding Rapid Clinical Response to Olaparib in A Patient with gBRCA2m Fungating Breast Cancer: A Case Report

Abstract

Background: Breast cancer is a heterogeneous, phenotypically complex disease made up of various biologic subgroups with unique behaviors and therapeutic responses. Noted that despite lack of a cure for metastatic breast cancer (MBC), there have been appreciable advancements in survival that have occurred at the same time as newer systemic treatments. BRCA1 or BRCA2 mutations cause homologous recombination deficient (HRD) cells, which are vulnerable to PARPi agent treatment. Case Report: This case report presents a 40 years old single female, known case of multiple co-morbidities who was diagnosed with Bilateral breast cancer in June 2022. She has a Positive family history of malignancy; mother died from endometrial cancer and aunt from paternal side has breast cancer. She underwent needle core biopsy from her Right breast mass, which revealed Invasive high-grade ductal carcinoma with metaplastic features (foci of keratinizing squamous differentiation, and myxoid stromal change). DCIS, of intermediate and high grades and a solid pattern, was noted, focally suspicious for lymphovascular invasion, Triple negative (ER negative (<1%), PR negative (<1%) and her-2 (+2) FISH negative (Her-2 Low), KI 67= 70%. Left breast mass Biopsy done on 12/9/2022 showed Invasive Lobular carcinoma, grade 3, ER negative, PR negative, Her-2 +1, KI 67=70%, BRCA2 POSITIVE & PDL1 CPS score 10%. Staging positron emission tomography scan done on 10 October 2022. She had a Large hypermetabolic fungating right breast mass infiltrating the chest wall, consistent with biopsy-proven malignancy. Additional smaller FDG-avid lesions noted in the right breast. Moreover, she had FDG-avid right axillary and right internal mammary nodal metastases. Mildly FDG-avid left breast mass, consistent with biopsy-proven malignancy. FDG-avid liver and pleural metastases. She was started on PARP inhibitor (Olaparib) on 20/9/2022 after which she had amazing fast clinical response leading to falling off the large fungating mass. Conclusion: The chance of developing breast and ovarian cancer is extremely elevated if one possesses BRAC 1 or BRCA 2 mutation. In this situation, PARP inhibitors, mutation-targeted therapy, has better outcomes in reducing the morbidity and mortality associated with metastatic breast cancer (Olaparib).