Bronchopulmonary Carcinoids causing Cushing Syndrome: Results from a Multicentric Study Suggesting a More Aggressive Behavior

Objective Cushing syndrome (CS) caused by bronchopulmonary carcinoids (BCs) is a very rare entity. The aim of this study was to revisit the features of a multicenter clinical series to identify significant prognostic factors. Methods From January 2002 to December 2013, the clinical and pathological data of 23 patients (treated in five different institutions) were retrospectively reviewed. Survival analysis was performed to explore the relative weight of potential prognostic factors. Results Median age and male/female ratio were 48 years and 14/9, respectively. Most (> 80%) of the patients presented with CS-related symptoms at diagnosis. Tumor location was peripheral in 13 patients (57%) and central in 10 (43%). All patients but two (treated with chemotherapy) underwent surgical resection with curative intent. Definitive cyto/histology was indicative of typical carcinoid (TC) in 16 cases (70%) and atypical carcinoid (AC) in 7 cases (30%). A complete remission of CS was obtained in 16 cases (70%). Lymph nodal involvement was detected in 11 cases (48%), with N2 disease occurring in 7 (∼ 30% of all cases). Four patients (22%) experienced a relapse of the disease after radical surgery. Overall 5-year survival (long-term survival, LTS) was 60%, better in TCs when compared with AC (LTS: 66 v s. 48%, p = 0.28). Log-rank analysis identified ECOG performance status, cTNM and cN staging, pTNM and pN staging, persistence of CS and relapses (local p = 0.006; distant p = 0.001) as significant prognostic factors in this cohort of patients. Conclusion BCs causing CS are characterized by a high rate of lymph-nodal involvement, a suboptimal prognosis (5-year survival = 60%, 66% in TCs) and a remarkable risk of relapse even after radical resection. Advanced stage, lymph-nodal involvement and the persisting of the CS after treatment correlate with a poor prognosis.