Outcome and prognostic factors in Diffuse Large B-cell Lymphoma(DLBCL): An institutional experience of a tertiary care centre from India

Rohit Mahajan*, Budhi S Yadav, Ankita Gupta, Sushmita Ghoshal, Rakesh Kapoor, Narenrda kumar, S.C. Sharma Department of Radiotherapy and oncology, PGIMER . *Corresponding Author: Rohit Mahajan, Department of Radiotherapy and Oncology, MMIMSR, Mullana(Ambala), Email:rohit_ mahjn@yahoo.co.in, Tel: + 919914411178. Citation: Rohit Mahajan et al. Outcome and prognostic factors in Diffuse Large B-cell Lymphoma(DLBCL): An institutional experience of a tertiary care centre from India. Int J Cancer Epid & Res.1:1, 6-10 Copyright: © 2017, Rohit Mahajan et al. 2017, This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Introduction
Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma(NHL), accounting for approximately 30% of all new diagnoses. 1 The cyclophosphamide, doxorubicin, vincristine, and prednisolone(CHOP) chemotherapy regimen has been the mainstay of therapy since its development in the 1970s. 2 Over the past few decades, chemotherapy consisting of the anti-CD20 antibody rituximab combined most often with CHOP(R-CHOP) has been established as the standard of care for patients with DLBCL [3][4][5][6] . Western literature has shown 5-year overall survival (OS) rates for patients with DLBCL varies from 45%to 82% [7][8][9] . However, data from India is lacking. Thus, we conducted the retrospective study in our institution to analyze the main clinical features at diagnosis, response to therapy and the outcome of patients diagnosed with DLBCL.

Materials and methods
The retrospective study was conducted in our institution which enrolled 74 patients with histologically confi rmed diagnosis of DLBCL treated from January 2003-December 2014. A complete history was recorded and physical examination including local examination of disease. Baseline investigations like complete blood count, blood biochemistry, chest x-rays, bone marrow biopsy and histopathological examination was done. All patients were biopsy proven for DLBCL. All patients underwent neck, chest, abdominal and pelvic computed tomography(CT) scans or positron emission tomography(PET) scan. Staging was done with CT/PET scans. All patients were treated with chemotherapy with or without radiotherapy. Clinical features, treatment response and impact of different prognostic factors on clinical outcome was analyzed.

Discussion
In our study, we showed that there is marked improvement in local control of the disease with the addition of radiation to the CHOP/ R-CHOP chemotherapy. Despite the fact that R-CHOP is the standard chemotherapy regimen, we were able to give R-CHOP in only 21.6% patients due to poor affordability of most of the patients and thus, most of the patients(71.6%) received CHOP chemotherapy. Involved field radiotherapy with the dose of 30-40Gy was received in 58.1% patients after the chemotherapy     Table 3.
completion. At 2 years, overall survival(OS) and disease free survival(DFS) was 81.5% and 66% respectively. In the present study with a median follow-up time of 2 years, we found that disease free and overall survival estimates among patients treated with chemotherapy alone did not differ from those observed among patients treated with chemotherapy plus radiotherapy. In our study, 9.4% improvement in local control was seen with addition of radiation, however, it was not statistically significant. Of note, we observed a lack of difference in outcome for the 6 patients with bulky disease, a condition in which adjuvant radiotherapy is believed to optimally control local disease 10,11 ; however, this must be interpreted cautiously because of the small size of this subset of patients. An update of study by Miller et al with a longer followup showed that survival curves ultimately converged as a result of an excess of lymphoma relapses in the CHOP plus radiotherapy group. 12 Horning et al13 recently reported the results of a study with a median follow-up of 12 years in which patients with limitedstage aggressive lymphoma received consolidative radiotherapy after eight cycles of CHOP in which radiotherapy provided good local control which was similar in our study which showed improved local control of the disease by 9.4% with the addition of radiation although there was no significant benefit in OS. At 2 years estimated OS rates were 91% for CR patients consolidated with radiation 13 which was 81.5% in our study. Multiple prognostic factors were analyzed in our study where stage, International prognostic index (IPI), Supradiaphragmatic disease, number of sites, extranodal diasease and number of nodal sites involved were proven to be statistically significant factors having impact on local response, disease free survival (DFS) and overall survival (OS) whereas Bonnet et al in his study showed that overall survival was affected by stage II disease (p<0.001); and male sex (p<0.03) but not by bulky disease (p<0.3); event-free survival was affected only by stage II disease (p<0.001). Among the total of 576 patients, 5-year event-free and overall survival rates were 70% and 76% for patients with stage I disease, respectively, and 49% and 58% for patients with stage II disease, respectively.

Conclusion
This study represents the largest Indian experience to treat DLBCL. Stage, IPI, supradiaphragmatic disease, number of sites, extranodal disease and number of nodal sites came out to be the important prognostic factors for response, DFS and OS.