肺外小細胞癌例の検討―下咽頭小細胞癌例の報告とともに―

Abstract

Extrapulmonary small-cell carcinoma (EPSCC) is clinically underrecognized and optimal management remains illusive. Although head and neck EPSCC tends to involve early widespread dissemination and poor prognosis, recently reported favorable outcomes have used concurrent chemoradiotherapy in limited-stage disease. We report an EPSCC case of arising in the hypopharynx successfully treated by induction chemotherapy followed by concurrent chemoradiotherapy. To clarify EPSCC clinically, we retrospectively reviewed clinical courses of all EPSCC records between 1999 and 2008 in a single-institution series. The 14 subjects identified had primary sites at the gastrointestinal tract in 5, uterine cervix in 3, genitourinary system in 2 and at the gallbladder, liver, hypopharynx, and an unidentified primary lymph node in one case each. Of the 14, 2 cases had stage I, 2 cases had stage II, 4 cases had stage III, 5 cases had stage IV in tumor-node-metastasis (TNM) classification. Stage IV subjects usually underwent platinum-based chemotherapy, to which 25% showed partial response (PR) and 75% progressive disease (PD) with median overall survival (OS) of 114.0 days, or 16 weeks. Of stage III or lower subjects, 75% underwent surgery and 62.5% chemotherapy. OS was 1244.0 days or 3.7 years and 2-year survival rates was estimated at 87.5%. Survival duration differed significantly between those in stage III or lower and those in group IV. Age significantly affected survival time in the Cox proportional hazard regression model. Brain metastasis was uncommon in this series, despite the absence of prophylactic cranial radiation. Further studies are needed to improve and clarify the clinical EPSCC course.