Endocrine Abstracts

Introduction: The histologic classification of lung carcinoids (LCs) as typical (TCs) and atypical (ACs) highlights its role as major prognostic factor for these patients. However, in the absence of sensitive biomarkers to effectively predict tumor behavior, long-term imaging surveillance is recommended for disease monitoring. Limited data suggest that progastrin-releasing peptide (ProGRP) may have diagnostic & monitoring utility in LCs.

Aim(s): To evaluate the possible role of ProGRP, in addition to chromogranin A (CgA), as a biomarker for LCs surveillance.

Materials and methods: Retrospective analysis of consecutive LCs patients treated in an ENETS Center of Excellence with regard to clinico-pathological parameters, treatment outcomes and their correlation with ProGRP and CgA.

Results: Thrity-five patients (pts) were studied (23 women; median age of 62y with a median follow up of 47 m). TCs and ACs were diagnosed in 43 and 57% of pts, respectively. 9 pts (26%) were defined as DIPNECH. The disease was localized in 31% & metastatic in 69% of cases. 71% of pts were already pretreated at the time of the first ProGRP evaluation. Disease status at first ProGRP measurement was: no evidence of disease (NED, 20%), stable disease (SD, 23%), progressive disease (PD, 57%). The NED group had normal ProGRP & CgA. In the SD group, ProGRP was increased in 62% vs 38% increase in CgA, while in the PD group 70% had increased ProGRP vs 35% with elevated CgA. Overall, ProGRP was increased in 50% of pts with evidence of disease, all with normal CgA.

Conclusion: ProGRP seems to be a valuable biomarker for monitoring patients with LCs, mainly when CgA is non-informative. Larger series including prospective long-term follow-up are needed to establish ProGRP’s specific role in monitoring disease activity in LCs pts.

Keywords: progrp, lung carcinoids, biomarkers.