Contributions
Abstract: PB2334
Type: Publication Only
Background
Bone marrow (BM) is one of the most frequent extranodal sites of follicular lymphoma (FL). BM involvement is an unfavorable prognostic factor in FL included in FLIPI2. Detection of B-cell clonality in the BM suggests a specific BM involvement, but is not sufficient to confirm of the BM involvement in a tumor process.
Aims
To characterize morphological and molecular (B-cell clonality) features of BM involvement in FL 3 grade and assess their prognostic value in patients who received chemotherapy with R-CHOP-21.
Methods
In this retrospective analysis 89 primary patients with FL3 (median age was 54 years, range 21 - 78 years, f:m=1:1,5) were observed in the «National Research Center for Hematology» Moscow, Russian Federation (2001-2016) were included. BМ involvement in FL3 was studied by histological slides of bone marrow biopsy (BMC) with staining H&E in 48 patients. Three variants of the tumor lymphoid cells in the BM were determined in 46 available speciments: a) small-cell (BM infiltration predominantly centrocytes); b) large-cell (BM infiltration predominantly centroblasts); c) mixed-cell (BM infiltration by centrocytes and centroblasts in different ratios). B-cell clonality was studied in 49 patients. A multivariate analysis was performed in groups of patients with R-CHOP-21 chemotherapy. The analysis included a number of clinical and laboratory parameters - age, gender, stage by Ann-Arbor, FLIPI and others, including histological (n = 54) or molecular (n = 32) BM involvement.
Results
BМ involvement in FL3 was detected by BMB in 48 (54%) of 89 patients – 54% in FL3A, 39% in FL3B, 56% in FL 3(A+B) grade. Small-cell BM involvement detected in 22 (48%) patients, large-cell – in 14 (30%) patients, mixed-cell – in 10 (22%). Large-cell BM involvement was more common in FL3B in comparison with FL3A (57% vs. 20%, p=0,06). Patients with BM involvement had more often involvement of other extranodal sites besides BM (79% vs. 54%, p=0,01), three times more often had thrombocytopenia (p=0,07), four times more often had monoclonal secretion of paraprotein (in blood and/or urine, p=0,06) than patients without BM involvement. By multivariate analysis we did not reveal an unfavorable prognostic value of BM involvement by histological study (р=0,058). B-cell clonality was detected in 21 (43%) of 49 patients. According to the multivariate analysis the detection of B-cell clonality in the BM had an independent unfavorable prognostic value for the overall (HR-10,367, p = 0,001) and event-free survival (HR-8,0, p = 0,001) (picture 1), Me 30 мес.
Conclusion
There are 3 morphological variants of BM involvement in FL3. BM involvement in FL3 is associated with other extranodal sites tumor involvement. Detection of B-cell clonality in the BM is independent unfavorable prognostic factor for the overall and event-free survival (on R-CHOP-21 therapy).
Session topic: 19. Non-Hodgkin lymphoma Biology & Translational Research
Keyword(s): Clonality, Follicular lymphoma, Prognostic factor, Bone marrow involvement
Abstract: PB2334
Type: Publication Only
Background
Bone marrow (BM) is one of the most frequent extranodal sites of follicular lymphoma (FL). BM involvement is an unfavorable prognostic factor in FL included in FLIPI2. Detection of B-cell clonality in the BM suggests a specific BM involvement, but is not sufficient to confirm of the BM involvement in a tumor process.
Aims
To characterize morphological and molecular (B-cell clonality) features of BM involvement in FL 3 grade and assess their prognostic value in patients who received chemotherapy with R-CHOP-21.
Methods
In this retrospective analysis 89 primary patients with FL3 (median age was 54 years, range 21 - 78 years, f:m=1:1,5) were observed in the «National Research Center for Hematology» Moscow, Russian Federation (2001-2016) were included. BМ involvement in FL3 was studied by histological slides of bone marrow biopsy (BMC) with staining H&E in 48 patients. Three variants of the tumor lymphoid cells in the BM were determined in 46 available speciments: a) small-cell (BM infiltration predominantly centrocytes); b) large-cell (BM infiltration predominantly centroblasts); c) mixed-cell (BM infiltration by centrocytes and centroblasts in different ratios). B-cell clonality was studied in 49 patients. A multivariate analysis was performed in groups of patients with R-CHOP-21 chemotherapy. The analysis included a number of clinical and laboratory parameters - age, gender, stage by Ann-Arbor, FLIPI and others, including histological (n = 54) or molecular (n = 32) BM involvement.
Results
BМ involvement in FL3 was detected by BMB in 48 (54%) of 89 patients – 54% in FL3A, 39% in FL3B, 56% in FL 3(A+B) grade. Small-cell BM involvement detected in 22 (48%) patients, large-cell – in 14 (30%) patients, mixed-cell – in 10 (22%). Large-cell BM involvement was more common in FL3B in comparison with FL3A (57% vs. 20%, p=0,06). Patients with BM involvement had more often involvement of other extranodal sites besides BM (79% vs. 54%, p=0,01), three times more often had thrombocytopenia (p=0,07), four times more often had monoclonal secretion of paraprotein (in blood and/or urine, p=0,06) than patients without BM involvement. By multivariate analysis we did not reveal an unfavorable prognostic value of BM involvement by histological study (р=0,058). B-cell clonality was detected in 21 (43%) of 49 patients. According to the multivariate analysis the detection of B-cell clonality in the BM had an independent unfavorable prognostic value for the overall (HR-10,367, p = 0,001) and event-free survival (HR-8,0, p = 0,001) (picture 1), Me 30 мес.
Conclusion
There are 3 morphological variants of BM involvement in FL3. BM involvement in FL3 is associated with other extranodal sites tumor involvement. Detection of B-cell clonality in the BM is independent unfavorable prognostic factor for the overall and event-free survival (on R-CHOP-21 therapy).
Session topic: 19. Non-Hodgkin lymphoma Biology & Translational Research
Keyword(s): Clonality, Follicular lymphoma, Prognostic factor, Bone marrow involvement