Well-Differentiated Neuroendocrine Tumors (WDNETs) and Carcinoid Syndrome (CS): A Retrospective Analysis of 110 Patients from Istituto Nazionale Tumori Milano.

Introduction: CS is characterized by flushing, diarrhea and carcinoid heart disease (CHD) alone or in association. Aim(s): To assess the incidence, clinical features and survival of WDNETs pts with CS. Materials and methods: We retrospectively analyzed 700 NET pts, between 1979 to 2009. One-hundred and ten pts with Typical (T) or Atypical (A) CS were identified. Results: Incidence of CS was 15.7%, with a prevalence of 7.5/700 cases. Median age was 55.5 years, male/female = 59/51. All pts were WDNETs and 83% were GEP: Carcinoids/pNET= 66%/34%; Midgut/Foregut/ Hindgut= 44%/35.5%/3.3%. Liver involvement was found in 96%: synchronous (42%); metacronous (68%). Primary tumor resection was performed in 67% of midgut and in 33% of foregut. TCS was evident in 92/110 (83.3%), whilst ACS in 2/110 (2.2%). The most common symptoms were flushing/diarrhea/CHD in 72 %/64%/12 % of pts. CgA/NSE/HIAA levels were pathologic in 78%/22%/50%, respectively, mOS was 90 months (range 2-274), 5- and 10-year survival rates were 58% and 43% respectively. Significant difference in mOS was found between male/female 114/90 months; midgut/foregut 114/74 months; carcinoids/pNET 131/74 months (p<0.05). Primary tumor resection may be correlated with survival amelioration. Conclusion: The advanced stage and, in particular, the liver involvement could be the main factor related to the CS appearance. The status of functional or nonfunctional NET could be mostly correlated to tumor load involvement rather than to primary tumor site, which still remains the main prognostic factor. [ABSTRACT FROM AUTHOR]