Pancreatic Neuroendocrine Tumors With Involved Surgical Margins: Prognostic Factors and the Role of Adjuvant Radiotherapy

Journal Article · Sun Jul 01 00:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.12.068· OSTI ID:22058900

Arvold, Nils D ^[1]; Willett, Christopher G ^[2]; Fernandez-del Castillo, Carlos ^[3]; Ryan, David P ^[4]; Ferrone, Cristina R ^[3]; Clark, Jeffrey W; Blaszkowsky, Lawrence S ^[4]; Deshpande, Vikram ^[5]; Niemierko, Andrzej ^[6]; Allen, Jill N; Kwak, Eunice L; Wadlow, Raymond C; Zhu, Andrew X ^[4]; Warshaw, Andrew L ^[3]

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1. Harvard Radiation Oncology Program, Harvard Medical School, Boston, MA (United States)
2. Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)
3. Department of Surgery, Massachusetts General Hospital, Boston, MA (United States)
4. Department of Medicine, Massachusetts General Hospital, Boston, MA (United States)
5. Department of Pathology, Massachusetts General Hospital, Boston, MA (United States)
6. Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

Purpose: Pancreatic neuroendocrine tumors (pNET) are rare neoplasms associated with poor outcomes without resection, and involved surgical margins are associated with a worse prognosis. The role of adjuvant radiotherapy (RT) in these patients has not been characterized. Methods and Materials: We retrospectively evaluated 46 consecutive patients with positive or close (<1 mm) margins after pNET resection, treated from 1983 to 2010, 16 of whom received adjuvant RT. Median RT dose was 50.4 Gy in 1.8-Gy fractions; half the patients received concurrent chemotherapy with 5-fluorouracil or capecitabine. No patients received adjuvant chemotherapy. Cox multivariate analysis (MVA) was used to analyze factors associated with overall survival (OS). Results: Median age at diagnosis was 56 years, and 52% of patients were female. Median tumor size was 38 mm, 57% of patients were node-positive, and 11% had a resected solitary liver metastasis. Patients who received RT were more likely to have larger tumors (median, 54 mm vs. 30 mm, respectively, p = 0.002) and node positivity (81% vs. 33%, respectively, p = 0.002) than those not receiving RT. Median follow-up was 39 months. Actuarial 5-year OS was 62% (95% confidence interval [CI], 41%-77%). In the group that did not receive RT, 3 patients (10%) experienced local recurrence (LR) and 5 patients (18%) developed new distant metastases, while in the RT group, 1 patient (6%) experienced LR and 5 patients (38%) developed distant metastases. Of all recurrences, 29% were LR. On MVA, male gender (adjusted hazard ratio [AHR] = 3.81; 95% CI, 1.21-11.92; p = 0.02) and increasing tumor size (AHR = 1.02; 95% CI, 1.01-1.04; p = 0.007) were associated with decreased OS. Conclusions: Long-term survival is common among patients with involved-margin pNET. Despite significantly worse pathologic features among patients receiving adjuvant RT, rates of LR between groups were similar, suggesting that RT might aid local control, and merits further evaluation.

• OSTI ID: 22058900
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 83, Issue 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CHEMOTHERAPY
DIAGNOSIS
EVALUATION
FEMALES
HAZARDS
LIVER
MALES
METASTASES
MULTIVARIATE ANALYSIS
NEOPLASMS
PANCREAS
PATIENTS
RADIATION DOSES
RADIOTHERAPY
SURGERY
URACILS