Objective  To investigate the incidence, prognostic value, and risk factors associated with progression of disease within 24 months (POD24) in patients with follicular lymphoma (FL).

  Methods  In Tianjin Medical University Cancer Institute and Hospital from January 2010 to December 2015, the clinical and follow-up data of 140 patients who were newly diagnosed with FL and received chemotherapy was collected.The expression levels of Myc, Bcl-2, Bcl-6, P53, CD10, MUM-1, and Ki-67 in tumor tissues from 75 patients before treatment were assessed with immunohistochemical (IHC) staining. Kaplan-Meier method and Cox regression model were applied to evaluate the effect of POD24 on the prognosis of FL. Logistic analysis was performed to identify the risk factors associated with POD24.

  Results  Among the 140 patients newly diagnosed with FL, 42 (30%) patients showed POD24. The results of Kaplan-Meier analysis revealed that patients with POD24 showed significantly reduced overall survival (OS) compared with patients without POD24 (P < 0.001). Univariate and multivariate Cox analysis indicated that POD24 is the most significant independent prognostic factor affecting the OS in patients with FL (HR=8.386, P < 0.001). Univariate Logistic analysis adjusted for first-line treatment regimen showed that splenic involvement, FLIPI ≥ 3, β2-MG >upper limit of normal, high Ki-67 expression, and positive MUM-1 expression were risk factors associated with POD24 (all P < 0.05). Furthermore, multivariate analysis showed that FLIPI ≥ 3 and positive MUM-1 expression were independent risk factors associated with POD24 (all P < 0.05). Upon comparing the predictive power of FLIPI and FLIPI combined with MUM-1 (FLIPI-M), we found that the latter has higher accuracy (71% vs. 69%) and sensitivity (80% vs. 68%), but low specificity (66% vs. 70%) to predict POD24.

  Conclusion  POD24 is a significant adverse prognostic factor for FL, which has an positive incidence of 30% in newly diagnosed FL patients at our hospital. Splenic involvement, FLIPI ≥ 3, β2-MG >upper limit of normal, high Ki-67 expression, and positive MUM-1 expression were risk factors associated with POD24. Moreover, FLIPI ≥ 3 and positive MUM-1 expression were independent risk factors associated with POD24. The sensitivity and accuracy of FLIPI combined with MUM-1 (FLIPI-M) in predicting POD24 were higher than that of FLIPI alone, and thus have high value in clinical practice.