What’s The Odds: Beta-Human Chorionic Gonadotropin in Lung Cancer and Complete Response to Third Line Nivolumab
Ectopic secretion of β-hCG by lung cancer is rare, particularly regarding male patients. Here we describe a clinical case of a β-hCG-secreting lung squamous cell carcinoma who had an exceptional response to 3rd line therapy nivolumab.
A 52-year-old man, KPS score of 90, presented a 12-month history of intermittent right-sided testicular pain. No other positive findings were issued in the anamnesis and/or at physical examination. Despite β-hCG serum elevation, no other changes were observed on analytical studies. No abnormalities were described on scrotal ultrasonography. CT showed thoracic lymphadenopathies and a right adrenal gland mass. PET/CT showed abnormal FDG uptake in the referred lymphadenopathies and mass. EBUS-TBNA biopsy and pathology examination revealed a poor-differentiated squamous cell carcinoma positive for CK7 and p65. The patient was diagnosed with a stage IV NSCLC and initiated chemotherapy with cisplatin-gemcitabine. After two cycles a partial response was achieved at CT and there was a β-hCG decrease. Because of headache complaints a head MRI was performed, demonstrating a single metastatic lesion, which was surgically removed. The histopathologic results confirmed the primary pulmonary origin revealing that it was a poor-differentiated lung squamous cell carcinoma with positive p63 and β-hCG immunostaining. After holocranial RT, patient restarted the same chemotherapy scheme. Response assessment exams showed new multiple irregular cavities with thickened walls in the lung parenchyma, compatible with progressive lung disease. A retrospective assessment was carried out leading to the suspicion that the primary lung tumor was probably present since the first CT. At this time, patient KPS score was 70 and 2nd line treatment with docetaxel was started. After four cycles, the lung disease was still progressing. PD-L1 IHC 22C3 was quantified, obtaining a > 50% value. Nivolumab was started in 3rd line and after six months of treatment a complete metabolic response was achieved. Currently, the patient continues under nivolumab, having completed 17 months of therapy, with no signs of clinical, analytical or imaging progression.