Multimodality therapy in metastatic pancreas cancer with a BRCA mutation and durable long-term outcome: biology, intervention, or both?

Metastatic pancreatic adenocarcinoma (PDAC) is a rapidly lethal disease, with less than half of patients surviving 12 months, and 5-year survival approximately 3%. These outcomes are in large part due to a lack of effective medical and surgical therapies for metastatic PDAC. Herein, we present the case of a patient with oligometastatic liver recurrence of BRCA2-mutated PDAC following a curative-intent resection. Through a combination of systemic chemotherapy, metastasectomy, radiotherapy, and subsequent targeted therapy with olaparib, the patient is asymptomatic four years following metastatic diagnosis with stable low-volume disease. This patient's excellent outcome is attributable to the multi-disciplinary care received, all aspects of which were informed by new evidence surrounding metastasectomy for metastatic PDAC, the unique biology and medical treatment of BRCA-mutated PDAC, and the role of radiotherapy in controlling locoregional recurrence. We provide a review of this evidence, while highlighting the importance of evaluating disease biology through somatic and germline genetic testing as well as monitoring response to systemic chemotherapy.

Early evidence of anti-PD-1 activity in enzalutamide-resistant prostate cancer.

While programmed cell death 1 (PD-1) inhibitors have shown clear anti-tumor efficacy in several solid tumors, prior results in men with metastatic castration resistant prostate cancer (mCRPC) showed no evidence of activity. Here we report unexpected antitumor activity seen in mCRPC patients treated with the anti-PD-1 antibody pembrolizumab. Patients with evidence of progression on enzalutamide were treated with pembrolizumab 200 mg IV every 3 weeks for 4 doses; pembrolizumab was added to standard dose enzalutamide. Three of the first ten patients enrolled in this ongoing phase II trial experienced rapid prostate specific antigen (PSA) reductions to ≤ 0.2 ng/ml. Two of these three patients had measurable disease upon study entry; both achieved a partial response. There were three patients with significant immune-related adverse events. One had grade 2 myositis, one had grade 3 hypothyroidism, and one had grade 2 hypothyroidism. None of these patients had a response. Two of the three responders had a baseline tumor biopsy. Immunohistochemistry from those biopsies showed the presence of CD3+, CD8+, and CD163+ leukocyte infiltrates and PD-L1 expression. Genetic analysis of the two responders revealed markers of microsatellite instability in one. The surprising and robust responses seen in this study should lead to re-examination of PD-1 inhibition in prostate cancer.