Introduction: Follicular lymphoma (FL) is an indolent, yet heterogeneous, B-cell lymphoproliferative disorder. Although most FL patients respond well to treatment, few with specific traits have a poor prognosis; the latter are difficult to define.
Patients and methods: We retrospectively analyzed data from 143 FL patients treated at the University of Debrecen since 2009 and investigated prognostic factors that may influence the survival of FL patients.
Results: A maximum standardized uptake value (SUVmax) cut-off of 9.85 at the staging positron emission tomography/computed tomography (PET/CT) (p = 0.0001, hazard ratio [HR]: 0.2535, 95% confidence interval [CI]: 0.1118-0.4878) and a lymphocyte/monocyte (Ly/Mo) ratio of 3.41 (p = 0.0027, HR: 2.997, 95% CI: 1.463-6.142), drawn at diagnosis, significantly predicted FL patients' progression-free survival (PFS). A staging SUVmax >9.85 with Ly/Mo <3.41 could delineate a high-risk group of FL patients (p<0.0001, HR: 0.0957, 95% CI: 0.03416-0.2685). Similarly, a significant difference was shown with an SUVmax cut-off of 3.15 at the interim PET/CT (p<0.0001, HR: 0.1614, 95% CI: 0.06684-0.3897). A staging SUVmax >9.85 in conjunction with interim SUVmax >3.15 predicted poor prognosis (p<0.0001, HR: 0.1037, 95% CI: 0.03811-0.2824). The PFS difference was translated into overall survival (OS) advantage (p = 0.0506, HR: 0.1187, 95% CI: 0.01401-1.005).
Conclusion: Biological prognostic factors, such as the Ly/Mo ratio, may improve the prognostic assessment of staging PET/CT. The survival advantage observed in PFS is translated into OS when determined using a combination of staging and interim SUVmax. We recommend investigating additional biological prognostic factors while highlighting the role of PET/CT in FL.