[Clinical characteristics and prognosis analysis in patients with bone marrow invasive follicular lymphoma]

Objective: This study aimed to summarize the clinical characteristics and prognosis of patients with bone marrow invasive follicular lymphoma (FL) and discuss the treatment modalities. Methods: This study included 183 consecutive patients with FL accompanied by bone marrow invasion and receiving regular treatment at the Hospital of Hematology, Chinese Academy of Medical Sciences, from January 2013 to December 2022. Clinical data were retrospectively collected and analyzed, and single and multifactorial analyses of survival prognosis were conducted with the Kaplan-Meier method and Cox regression model. Results: The median age was 48 (range: 19 - 78) years, and the male-to-female ratio was 0.9∶1. All of the patients had bone marrow invasion, 27.8% had increased lactate dehydrogenase levels, 42.1% had lymphocyte counts of >5×10(9)/L, 18.4% had abnormal chromosomal karyotypes, and 48.6% had Ki-67 index of ≥30% in lymphoid tissue. Comparison of different subgroups: lymphocyte counts of >5×10(9)/L, number of lymph nodes of ≥5 involved, and proportion of bone marrow chromosomal abnormalities occurring were higher in the anthracycline-intensive treatment group than in the rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) protocol and the nucleoside analog (including CD20 monoclonal antibody in combination with fludarabine and bendamustine) groups (all P<0.05). The complete remission rate was 39.1% in the conventional R-CHOP group, which was lower and statistically significant than that in the intensive treatment group (55.1%) and the nucleoside analog group (62.5%) (P=0.042). The multivariate analysis for survival analysis revealed high risk of FLIPI (HR= 1.910, 95% CI 1.036 - 3.522, P=0.036), chromosomal abnormalities karyotype (HR=2.666, 95% CI 1.333-5.331, P=0.006), and conventional R-CHOP treatment (HR=2.287, 95% CI 1.140-4.591, P=0.020) were the independent adverse prognostic factors affecting progression-free survival (PFS), whereas POD24 was the only independent adverse prognostic factor affecting overall survival (OS) adverse prognostic factor (HR=9.581, 95% CI 3.000 - 30.593, P<0.001) . Conclusions: The clinical presentations of patients with bone marrow invasive FL were easy to combine the clinical features, including increased lymphocyte count, chromosomal abnormalities, and Ki-67 index in lymphoid tissues. The FLIPI score, chromosomal abnormal karyotype, and high-lymphoid-tissue Ki-67 index were the poor prognostic factors influencing PFS. R-CHOP therapy demonstrated a poor prognosis in this group of patients.