Efficacy and Cost-Effectiveness of Immediate Surgery versus a Wait-and-See Strategy for Sporadic Nonfunctioning T1 Pancreatic Endocrine Neoplasms.

Background: Whether patients with small (<2 cm), sporadic non-functioning pancreatic endocrine tumors (NF-PETs) should directly undergo pancreatic surgery or should be followed longitudinally to detect growth and malignancy still has to be defined. Study Design: Based on the pertinent literature of the past decade, a Markov model was developed to investigate this issue. In the wait-and-see strategy arm, surgery was performed if the tumor attained a size ≥2 cm or surpassed 20% of the initial size. In a Monte Carlo probabilistic analysis, 100 hypothetical patients undergoing a wait-and-see strategy were compared to 100 patients directly undergoing surgery, with the aim of investigating the efficacy and cost-effectiveness of the two strategies. Results: During the post-diagnostic lifetime, 63 NF-PETs in the wait-and-see group showed significant growth and underwent surgery: 38 were Stage I, 10 were Stage II, 15 were stage III and none were Stage IV. In the base-case scenario, the mean life expectancy and quality-adjusted life expectancy were found to be superior after immediate surgery (26.1 years and 11.8 quality-adjusted life-years [QALYs]) than with the wait-and-see strategy (22.1 years and 8.3 QALYs) as the consequence of ageing during the wait-and-see follow-up which increased mortality due to surgery, when surgery was needed. The model was sensitive to starting age and length of follow-up; in particular, for patients >65 years of age, the two strategies provided similar results but the wait-and-see strategy was more cost-effective. Conclusions: The wait-and-see strategy for NF-PETs <2 cm represents a reasonable approach only in patients over 65 years of age; otherwise, immediate surgery is preferable.