Management of a Refractory EIF3E-RSPO2 Fusion Positive Pilomatrical Cancer Patient with Encyclopedic Tumor Analysis Guided Treatment

Abstract

Pilomatrical carcinoma is an exceedingly rare, locally aggressive malignancy of the hair follicle. It may arise de novo as a solitary lesion or through malignant transformation from its pre-existing benign counterpart, pilomatrixoma. There are no standard treatment guidelines and wide surgical excision of the primary lesion followed by adjuvant radiotherapy remains principal treatment modality. However, high recurrence rate after primary treatment, presence of nodal and systemic metastases which is non-responsive to chemotherapy are major concerns in disease management. Here, we report a case of a 45-year-old female with recurrent pilomatrical carcinoma who opted for personalized treatment guidance based on Encyclopedic Tumor Analysis (ETA). Molecular analysis of tumor tissue identified a novel EIF3E-RSPO2 gene rearrangement, SETD2 mutation and overexpression of VEGFA and RET genes.These molecular alterations along with synchronous chemo-sensitivity assay on tumor derived cells helped in defining combinatorial off label therapy regimens which countered disease progression at each instance and led to the durable regression of primary as well as metastatic lesions. This personalized treatment management strategy described herein effectively addressed advanced, refractory disease for which current Standard of Care (SoC) options were unviable.