Modified Staging System for Pancreatic Neuroendocrine Tumors


Key Points

  • A modified ENETS system maintains ENETS T, N, and M definitions and adopts AJCC staging definitions.
  • The modified ENETS system improves patient distribution among stages and significantly differentiates survival outcomes by stage.

As reported in the Journal of Clinical Oncology, Luo et al found that a modified staging classification based on the European Neuroendocrine Tumor Society (ENETS) and the American Joint Committee on Cancer (AJCC) staging classifications may improve distinction among risk groups in pancreatic neuroendocrine tumors.

Study Details

The study involved application of the ENETS and AJCC staging systems to 2,529 patients in the SEER (Surveillance, Epidemiology, and End Results) registry and a multicentric series of 1,143 patients. A modified system was developed by maintaining the ENETS T, N, and M definitions and adopting the AJCC staging definitions; stage IV disease remained the same in all systems, defined as disease with distant metastases. For the modified system: stage IA = T1, N0, M0; stage IB = T2,N0,M0; stage IIA = T3,N0,M0; stage IIB =T1–3,N1,M0; stage III = T4, any N, M0; and stage IV = any T, any N, M1.

Problems Addressed by Modified Staging

The proportions of patients with AJCC stage III disease were low in both the SEER series (2.2%) and the multicentric series (2.1%). Patients with ENETS stage I disease had a similar prognosis compared with stage IIA disease, and those with stage IIIB disease had a lower hazard ratio for death compared with stage IIIA disease.

Under the modified system, patient distribution among stages was improved—eg, the proportion of patients with stage III disease was higher vs the AJCC system for both the SEER series (8.9% vs 2.2%) and the multicentric series (11.6% vs 2.1%). Furthermore, the hazard ratio for death for patients with stage III disease was higher vs stage IIB disease.

On multivariate analysis using the modified system, hazard ratios for death compared to stage I were 1.92, 3.26, and 5.36 (all P < .001) for stages II, III, and IV in the SEER database and 2.14, 3.48, and 6.91 (all P < .001), respectively, in the multicentric database.

The investigators concluded: “A [modified ENETS] staging classification is more suitable for pancreatic neuroendocrine tumors than either the AJCC or ENETS systems and can be adopted in clinical practice.”

The study was supported by the Natural Science Foundation of Shanghai, the National Natural Science Foundation, and the Prospective Clinical Trial Project, Shanghai Cancer Center.

Xianjun Yu, MD, of the Fudan University Shanghai Cancer Center, is the corresponding author of the Journal of Clinical Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.