Low risk for all-cause mortality among patients with lung neuroendocrine tumors co-diagnosed with pituitary adenomas

Lung neoplasms often co-occur with pituitary adenoma (PA). However, whether co-diagnosis of lung neuroendocrine tumors (LNETs) and PA constitute a unique entity and the impact of such co-diagnosis on patients' outcome is yet to be defined. The study objective was to compare patients' clinical characteristics with LNET to patients co-diagnosed with PA.

A Retrospective, case-control study based on the Surveillance, Epidemiology, and End Results (SEER) registry database between 2000 and 2016. A total of 2947 patients with LNET, including 2913 with LNET alone ("Sporadic") and 34 patients with both LNET and PA ("LNET-PA").

PA preceded LNET diagnosis in 85.3% of patients and had higher rates among LNET patients (34/2947) than with any cancer (p < 0.00001) and compared to patients with non-small cell lung cancer (NSCLC) (15/2378, p = 0.047). LNET-PA patients were younger at diagnosis compared with NSCLC patients and PA (p = 0.04). Among patients <60 years with LNET, co-diagnosis with PA was associated with lower all-cause mortality (ACM) risk (Log-rank test, p = 0.03). Adjusted ACM risk of patients with LNET-PA was lower than sporadic LNET (hazard ratio 0.553, 95% confidence interval 0.309-0.99, p = 0.046), especially among Caucasians, and lower overall-mortality risk in patients <60 years with borderline statistical significance (p = 0.071).

Patients with both LNET and PA constitute a distinct morbidity and mortality profile than sporadic LNET, possibly suggesting an undefined MEN syndrome. Additional studies to further investigate patients' natural course and genetic profile with these neoplasms are needed.