Background

Nonfunctional pancreatic neuroendocrine tumors (PNETs) ≤2 cm have uncertain malignant potential, and optimal treatment remains unclear. Objectives of this study were to better understand their malignant potential, determine whether extent of surgery or lymph node dissection is associated with overall survival (OS), and identify other factors associated with OS.

Methods

Patients with nonfunctional PNETs ≤2 cm were identified from the National Cancer Data Base (1998 to 2011). Descriptive statistics were used for patient characteristics and surgical resection patterns. Five-year OS was estimated using Kaplan-Meier analyses across extent of surgery and compared using the log-rank test. Cox proportional regression modeling was used to test the association between survival and extent of surgery.

Results

A total of 1854 patients with nonfunctional PNETs ≤2 cm were included. From 1998 to 2011, these tumors increased three-fold as a proportion of all PNETs. Among tumors ≤0.5 cm, 33 % presented with regional lymph node metastases and 11 % with distant metastases. Five-year OS for patients not undergoing surgery was 27.6 % vs. 83.0 % for partial pancreatectomy, 72.3 % for pancreaticoduodenectomy, and 86.0 % for total pancreatectomy (p < 0.01). Multivariate analysis demonstrated no difference in OS based on type of surgery or the addition of regional lymphadenectomy (p = 0.16). Younger age and later year of diagnosis were independently associated with improved survival.

Conclusions

Small nonfunctional PNETs represent an increasing proportion of all PNETs and have a significant risk of malignancy. Survival is improving over time despite older age at diagnosis. Type of surgical resection and the addition of lymph node resection were not associated with OS.

Background

Adrenocortical carcinoma (ACC) is a rare, aggressive disease with no apparent change in treatment or survival in the United States over the past two decades. Our objective was to determine whether treatment patterns or clinical outcomes vary by hospital case volume.

Methods

Patients with ACC were identified from the National Cancer Database (1998-2011). High-volume centers (HVCs) were defined by a case load of ≥4 cases of primary adrenal malignancy annually, which corresponded to the 90th percentile. All other facilities were considered low-volume centers (LVCs).

Results

A total of 2,765 ACC patients were treated across 1,046 facilities. Compared to patients treated at LVCs, patients treated at HVCs were younger (50 vs. 54 years), with larger tumors (11.2 vs. 10.5 cm), and underwent higher rates of surgery (78.8 vs. 73.4 %), radical resection (17.3 vs. 13.9 %), regional lymph node evaluation (23.2 vs. 18.8 %), and chemotherapy including mitotane (43.8 vs. 31.0 %, all p < 0.05).There were no significant differences in median length of stay (5 vs. 5 days), 30-day readmission rates (4.0 % for HVCs vs. 3.9 % for LVCs), or 30-day postoperative mortality rates (1.9 % for HVCs vs. 3.7 % for LVCs). Median overall survival was 2.0 years for HVCs and 1.9 years for LVCs, p = 0.53. After adjusting for patient and tumor characteristics, overall survival did not differ significantly between patients treated at HVCs versus LVCs [HR = 0.89 (95 % confidence interval 0.70, 1.12)].

Conclusions

Treatment at HVCs was associated with more aggressive surgical resection and chemotherapy use. Prognosis remained poor despite more aggressive treatment.