Metastatic nonfunctioning pancreatic neuroendocrine carcinoma to liver: Surgical treatment and outcomes

BACKGROUND: The surgical treatment of metastatic, nonfunctional pancreatic neuroendocrine carcinoma (nPNEC) is not well defined. Existing series are confounded by inclusion of patients with metastatic functional tumors or gastrointestinal carcinoid. Our hypothesis was that the surgical treatment of metastatic nPNEC provides favorable perioperative and oncologic outcomes. STUDY DESIGN: We performed a retrospective review of all patients undergoing surgical treatment of metastatic nPNEC to the liver from 1987 through 2008 at the Mayo Clinic. Data are presented as medians with ranges. RESULTS: Seventy-two patients were identified, with a median age of 57 years (range 28 to 77 years) and median body mass index (BMI) of 26 kg/m ² (range 18 to 40 kg/m ²). Operative intent of resection was curative in 39 (54%) or palliative (<90% tumor debulking) in 32 (44%). Median number of tumors treated and median tumor size were 8 (range 1 to 30) and 4.5 cm (range 0.3 to 20 cm), respectively. Tumor grade was 1 or 2 in 97%, and angioinvasion was identified in 55 (76%) patients. Postoperative morbidity and mortality were 50% and 0%, respectively. Among the 72 patients, overall survivals at 1, 5 and 10 years were 97.1%, 59.9%, and 45.0%, respectively. Among the 39 patients with a complete (R0) resection, the 1- and 5-year disease-free survivals were 53.7% and 10.7%, respectively. For patients undergoing debulking of <90% tumor burden, the 1- and 5-year survivals free of progression were 58.1% and 3.5%, respectively. CONCLUSIONS: Surgical treatment of metastatic nPNEC to the liver with curative intent or for palliative <90% debulking provides favorable oncologic outcomes. Despite a high incidence of tumor recurrence, 5-year survival rates are encouraging and appear to justify an aggressive surgical approach in these patients.