Case Report: Response to Immunotherapy and Anti-Androgen Therapy in Male Occult Triple-Negative Breast Cancer

Abstract

Male occult triple-negative breast cancer (TNBC) is an exceedingly rare form of breast cancer, and prospective information regarding its management is therefore lacking. Current treatment strategies are largely extrapolated from clinical trials of female breast cancer, leading to substantial knowledge gaps concerning the optimal management of male breast cancer. Here, we present a male patient with occult TNBC who responded to immunotherapy, with an obvious reduction in his tumor burden following antiandrogen therapy, after heavy treatment with several lines of chemotherapy. This case highlights the potential efficacy of immunotherapy in cases of male TNBC and suggests a role for antiandrogen therapy in managing patients with luminal androgen receptor-positive TNBC.

Keywords: antiandrogen therapy; case report; immunothearpy; male breast cancer; occult breast cancer.

Figure 1

Diagnosis of male occult TNBC. (A) Positron emission tomography-computed tomography scan of the entire body showing abnormal metabolism in the right axilla and supraclavicular lymph node at diagnosis. (B) Representative histopathological image (hematoxylin and eosin staining) of needle biopsy specimen of the lesion in the right axilla; ×200. (C) Immunohistochemistry staining showing positive expression of androgen receptor (AR) in carcinoma cell nuclei. The AR-positivity index was 80%; ×200.

Figure 2

Management flow and treatment response evaluation. (A) Schematic of course of disease management. (B) Tumor response assessment and follow-up. Computed tomography images of right axilla tumor (a) at baseline (October 2020), (b) after immunotherapy (March 2021), (c) under chemotherapy (July 2021), and (d) under antiandrogen therapy consisting of bicalutamide and goserelin (November 2021) 1L, first line; SD, stable disease; PR, partial response; AE, adverse events; PD, progressive disease.

Figure 3

Changes in breast cancer tumor biomarkers, carcinoembryonic antigen (CEA) and CA153. Normal range: CEA<5 mg/mL, CA153<31.3 U/mL.

Figure 4

Biomarker changes in relation to immunotherapy-related adverse events. Normal range: CK-MB< 7.2 ng/mL, Mb<154.9 ng/mL, hsTni<0.0342ng/mL CK-MB, creatine kinase-MB; Mb, myoglobin; hsTni, high-sensitivity troponin I; AE, adverse events.