Contributions
Abstract: PB1774
Type: Publication Only
Background
Primary mediastinal large B-cell lymphoma (PMLBCL) is a rare subtype of diffuse large B-cell lymphoma. The most standard approaches include a combination of immunochemotherapy and mediastinal radiotherapy (RT).
Aims
Because mediastinal RT is associated with significant long-term toxicities, it was necessary the development of effective therapeutic strategies (rituximab with increased dose intensity regimens) that changed the need for routine RT.
Methods
Fifteen patients with diagnosis of PMLBCL between 2005-2015 were treated according to protocol R-DA- EPOCH (infusional dose-adjusted etoposide, doxorubicin and cyclophosphamide with vincristine, prednisone and rituximab).
Patients were classified into 3 risk groups (according to presence of pleural/pericardial effusion and IPI high/intermediate-risk or high-risk).
Residual disease (RD) was evaluated by FDG-PET scan and defined as score 2 according to Deauville Criteria and partial response (PR) defined as score 4-5 with a reduction >50% in size of mass.
Results
Median age at diagnosis was 29 (21-43) years, 86.7% of patients were aged <40 years (n=13).
Eleven patients (78.6%, n=14) had bulky disease (tumor mass ≥10 cm) and 6 (42.9%, n=14) had superior vena cava syndrome (SVCS) at presentation. Presence of pleural/pericardial effusion in 7 patients (53.8%, n=13) and pulmonary involvement in 5 (38.5%, n=13). According to the prognostic score, two patients (15.4%) were classified as high risk (2 adverse factors), five (38.5%) in intermediate risk (1 factor) and six (42.2%) in low risk (0 factors). All patients were treated with 6 cycles of immunochemotherapy.
Seven patients (46.7%) achieved complete response (CR), confirmed by FDG-PET in five. Another 3 (20%) had RD. All patients who achieved CR/RD did not perform RT with an event-free survival (EFS) of 100%.
PR was attained in 3 patients (20%), two had high-risk disease. All patients in PR were submitted to RT, reaching CR (confirmed by FDG-PET) without relapse during the follow-up time.
Progressive/stable disease was observed in 2 patients (13.3%). They were submitted to autologous stem cell transplant reaching CR.
With a median follow-up of 64 (26-128) months, an overall survival/EFS of 100% was reached without evidence of disease. No cardiac events or secondary tumors were observed, so far.
Conclusion
The use of therapeutic approaches with rituximab and increased dose intensity regimens (like R-DA-EPOCH) has shown excellent efficacy and challenge the need for mediastinal radiation (5-years OS and EFS >90%, according to data from several studies).
In conclusion, our results indicate that patients who had CR/RD evaluated by FDG-PET after treatment with R-DA-EPOCH, attained an EFS was 100% with a median follow up of 64 months. In these patients, the use of R-DA-EPOCH obviated the need for routine mediastinal RT. In patients with persistent disease after treatment, RT is a necessary approach though.
Session topic: 21. Aggressive Non-Hodgkin lymphoma - Clinical
Keyword(s): chemotherapy, lymphoma, Radiotherapy
Abstract: PB1774
Type: Publication Only
Background
Primary mediastinal large B-cell lymphoma (PMLBCL) is a rare subtype of diffuse large B-cell lymphoma. The most standard approaches include a combination of immunochemotherapy and mediastinal radiotherapy (RT).
Aims
Because mediastinal RT is associated with significant long-term toxicities, it was necessary the development of effective therapeutic strategies (rituximab with increased dose intensity regimens) that changed the need for routine RT.
Methods
Fifteen patients with diagnosis of PMLBCL between 2005-2015 were treated according to protocol R-DA- EPOCH (infusional dose-adjusted etoposide, doxorubicin and cyclophosphamide with vincristine, prednisone and rituximab).
Patients were classified into 3 risk groups (according to presence of pleural/pericardial effusion and IPI high/intermediate-risk or high-risk).
Residual disease (RD) was evaluated by FDG-PET scan and defined as score 2 according to Deauville Criteria and partial response (PR) defined as score 4-5 with a reduction >50% in size of mass.
Results
Median age at diagnosis was 29 (21-43) years, 86.7% of patients were aged <40 years (n=13).
Eleven patients (78.6%, n=14) had bulky disease (tumor mass ≥10 cm) and 6 (42.9%, n=14) had superior vena cava syndrome (SVCS) at presentation. Presence of pleural/pericardial effusion in 7 patients (53.8%, n=13) and pulmonary involvement in 5 (38.5%, n=13). According to the prognostic score, two patients (15.4%) were classified as high risk (2 adverse factors), five (38.5%) in intermediate risk (1 factor) and six (42.2%) in low risk (0 factors). All patients were treated with 6 cycles of immunochemotherapy.
Seven patients (46.7%) achieved complete response (CR), confirmed by FDG-PET in five. Another 3 (20%) had RD. All patients who achieved CR/RD did not perform RT with an event-free survival (EFS) of 100%.
PR was attained in 3 patients (20%), two had high-risk disease. All patients in PR were submitted to RT, reaching CR (confirmed by FDG-PET) without relapse during the follow-up time.
Progressive/stable disease was observed in 2 patients (13.3%). They were submitted to autologous stem cell transplant reaching CR.
With a median follow-up of 64 (26-128) months, an overall survival/EFS of 100% was reached without evidence of disease. No cardiac events or secondary tumors were observed, so far.
Conclusion
The use of therapeutic approaches with rituximab and increased dose intensity regimens (like R-DA-EPOCH) has shown excellent efficacy and challenge the need for mediastinal radiation (5-years OS and EFS >90%, according to data from several studies).
In conclusion, our results indicate that patients who had CR/RD evaluated by FDG-PET after treatment with R-DA-EPOCH, attained an EFS was 100% with a median follow up of 64 months. In these patients, the use of R-DA-EPOCH obviated the need for routine mediastinal RT. In patients with persistent disease after treatment, RT is a necessary approach though.
Session topic: 21. Aggressive Non-Hodgkin lymphoma - Clinical
Keyword(s): chemotherapy, lymphoma, Radiotherapy