Absolute Counts of Peripheral Lymphocyte Subsets Correlate with the Progression-Free Survival and Metastatic Status of Pancreatic Neuroendocrine Tumour Patients

PURPOSE: Pancreatic neuroendocrine tumours (panNETs) are rare tumours of pancreas. Lymphocyte subsets in the peripheral blood are reported to reflect tumour prognosis and progression. The objective of the study is to investigate the hypotheses that the levels of peripheral lymphocytes may reflect tumour progression and may predict the prognosis of pancreatic neuroendocrine tumours (panNETs). PATIENTS AND METHODS: A retrospective cohort study consisting of 73 patients diagnosed with panNETs was conducted. Kaplan–Meier methods and Log rank tests were used to compare the survival rates, and a Cox regression model was used to perform multivariate analyses. RESULTS: panNET patients with distant metastasis were associated with lower peripheral total T cell (p = 0.039) and CD4+ T cell (p = 0.006) counts. Lower peripheral B cells (p = 0.007) and higher peripheral NK cell (p = 0.001) counts indicated worse progression-free survival (PFS) in Log rank tests. In multivariate analyses, low B cell count (hazard ratio (HR): 6.769, 95% confidence interval (CI): 2.158 to 21.228, p = 0.001) and high NK cell count (HR: 3.715, 95% CI: 1.164 to 11.855, p = 0.027) were independent risk factors for progression. NK cells and B cells were also significantly associated with PFS following radical surgical resection. CONCLUSION: Peripheral total T cell and CD4+ T cell counts may reflect the distant metastasis status in panNET patients. The absolute count of peripheral B cells and NK cells may independently predict the progression of panNET patients, making them promising prognostic indicators and potential targets for treatment of panNETs.