Abstract Topic: 19. Aggressive Non-Hodgkin lymphoma - Clinical
Background: Diffuse large B-cell lymphoma (DLBCL) is the most frequent type of non-Hodgkin’s lymphoma. The response to treatment and the survival of DLBCL patients is highly variable depending on many prognostic factors. Some studies have reported a correlation between DLBCL, platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII) before treatment.
Aims: In our country, there is no study examining SII, PLR and NLR as a prognostic factor in DLBCL. Thus, this study aims to assess the use of these factors as prognostic markers for DLBCL.
Methods: This is a retrospective study, including patients diagnosed with DLBCL, performed at the clinical university hematology department of Monastir, over a period of 9 years (2013- 2021).
Results: Seventy-six patients were included. The median age was 55 years (range 18 – 86 years). Sex- ratio was 0.76. Advanced stage disease was found in 36 patients (47%).Poor PS (≥ 2) noted in 15 patients (19.7%). Most patients belonged to low and low-intermediate risk groups according to aaIPI (80%). R-CHOP was the chemotherapy regimen used for all our patients. At the time of diagnosis, the median values of absolute neutrophil counts, absolute lymphocyte counts, absolute platelet counts were 4.21 G/L (1.2-22.4 G/L), 1.7 G/L (0.4-3.2 G/L) and 253 G/L (15-892 G/L). Complete remission was achieved in 69.7% of patients, while relapse after response occurred in 3 cases. Nineteen patients died before the end of the follow-up period.
According to the ROC curve, the optional cutoff points of SII, NLR and PLR were 1054.7, 3.76 and 218.23. The area under the ROC curves for SII, NLR and PLR were 0.6, 0.577 and 0.654, respectively, demonstrating that the prognostic value of PLR was better than that of SII and NLR (Figure 1)
Patients were divided according to the cut-off values of SII, PLR and NLR: 54 patients had low SII and 20 patients had high SII, 49 patients had low PLR and 25 patients had high PLR and 51 patients had low NLR and 23 patients had high NLR.
Through kaplan-Meier analysis, the 3-year OS and 3-year EFS of the whole group were 75.9% and 69% respectively.
The patients who have low PLR experienced superior OS (P= 0.011) and EFS (P=0.003) than the patients with a high PLR. The 3-year OS rates were 83.3% in the PLR<218.23 group, and 54.5% in the PLR ≥218.23 group. Correspondingly, the 3-year EFS rates were 78.8% in the PLR<218.23 group and 44% in the PLR≥218.23 group.
The 3-year OS rates and EFS rates were higher in low SII and NLR groups but these results were statistically not significant. By carrying out univariate Khi-2 test, we found that independent predictor factors of OS were stage, ECOG-PS, aaIPI, LDH, extranodal sites nombre, response at the interim evaluation, and PLR(P=0.01).For the Independent predictor factors of EFS, they were stage, aaIPI score, response at interim evaluation and PLR (P=0.005). The multivariate analysis revealed that aaIPI score, LDH, extranodal sites nombre, response at the interim evaluation and PLR (P=0.03) were statically significant to predict OS. Also, it revealed that aaIPI score, stage, response at the interim evaluation, SII (P= 0.05) and PLR (P=0.03) were statistically significant predictor factors for the EFS.
Summary/Conclusion: Our study demonstrated that PLR was independent prognostic factors for EFS and OS in DLBCL. Given the low cost and availability of this prognostic index, it can be combined with other common prognostic factors to better discriminate patient prognosis and improve therapeutic management. However, further large-scaled studies are needed to confirm our results
Keywords: Diffuse large B cell lymphoma