***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Cyclophosphamide , doxorubicin , vincristine , and prednisolone ( CHOP ) is used to treat patients with non-Hodgkin lymphoma . Interval decrease from 3 weeks of treatment ( CHOP-21 ) to 2 weeks ( CHOP-14 ) , and addition of rituximab to CHOP-21 ( R-CHOP-21 ) has been shown to improve outcome in elderly patients with diffuse large B-cell lymphoma ( DLBCL ) . This r and omised trial assessed whether six or eight cycles of R-CHOP-14 can improve outcome of these patients compared with six or eight cycles of CHOP-14 . METHODS 1222 elderly patients ( aged 61 - 80 years ) were r and omly assigned to six or eight cycles of CHOP-14 with or without rituximab . Radiotherapy was planned to sites of initial bulky disease with or without extranodal involvement . The primary endpoint was event-free survival ; secondary endpoints were response , progression during treatment , progression-free survival , overall survival , and frequency of toxic effects . Analyses were done by intention to treat . The trial is registered on National Cancer Institute website , number NCT00052936 and as EU-20243 . FINDINGS 3-year event-free survival was 47.2 % after six cycles of CHOP-14 ( 95 % CI 41.2 - 53.3 ) , 53.0 % ( 47.0 - 59.1 ) after eight cycles of CHOP-14 , 66.5 % ( 60.9 - 72.0 ) after six cycles of R-CHOP-14 , and 63.1 % ( 57.4 - 68.8 ) after eight cycles of R-CHOP-14 . Compared with six cycles of CHOP-14 , the improvement in 3-year event-free survival was 5.8 % ( -2.8 - 14.4 ) for eight cycles of CHOP-14 , 19.3 % ( 11.1 - 27.5 ) for six cycles of R-CHOP-14 , and 15.9 % ( 7.6 - 24.2 ) for eight cycles of R-CHOP-14 . 3-year overall survival was 67.7 % ( 62.0 - 73.5 ) for six cycles of CHOP-14 , 66.0 % ( 60.1 - 71.9 ) for eight cycles of CHOP-14 , 78.1 % ( 73.2 - 83.0 ) for six cycles of R-CHOP-14 , and 72.5 % ( 67.1 - 77.9 ) for eight cycles of R-CHOP-14 . Compared with treatment with six cycles of CHOP-14 , overall survival improved by -1.7 % ( -10.0 - 6.6 ) after eight cycles of CHOP-14 , 10.4 % ( 2.8 - 18.0 ) after six cycles of R-CHOP-14 , and 4.8 % ( -3.1 - 12.7 ) after eight cycles of R-CHOP-14 . In a multivariate analysis that used six cycles of CHOP-14 without rituximab as the reference , and adjusting for known prognostic factors , all three intensified regimens improved 3-year event-free survival ( eight cycles of CHOP-14 : RR [ relative risk ] 0.76 [ 0.60 - 0.95 ] , p=0.0172 ; six cycles of R-CHOP-14 : RR 0.51 [ 0.40 - 0.65 ] , p<0.0001 ; eight cycles of R-CHOP-14 : RR 0.54 [ 0.43 - 0.69 ] , p<0.0001 ) . Progression-free survival improved after six cycles of R-CHOP-14 ( RR 0.50 [ 0.38 - 0.67 ] , p<0.0001 ) , and eight cycles of R-CHOP-14 ( RR 0.59 [ 0.45 - 0.77 ] , p=0.0001 ) . Overall survival improved only after six cycles of R-CHOP-14 ( RR 0.63 [ 0.46 - 0.85 ] , p=0.0031 ) . In patients with a partial response after four cycles of chemotherapy , eight cycles were not better than six cycles . INTERPRETATION Six cycles of R-CHOP-14 significantly improved event-free , progression-free , and overall survival over six cycles of CHOP-14 treatment . Response-adapted addition of chemotherapy beyond six cycles , though widely practice d , is not justified . Of the four regimens assessed in this study , six cycles of R-CHOP-14 is the preferred treatment for elderly patients , with which other approaches should be compared BACKGROUND The role of rituximab in combination with different CHOP ( cyclophosphamide , doxorubicin , vincristine , and prednisone)-like chemotherapy regimens in young patients with good-prognosis diffuse large-B-cell lymphoma remains to be defined . We aim ed to compare CHOP-like chemotherapy and rituximab with CHOP-like chemotherapy alone in these patients . METHODS 824 patients who were from 18 countries ; aged 18 - 60 years ; and who had no risk factors or one risk factor according to age-adjusted International Prognostic Index ( IPI ) , stage II-IV disease , or stage I disease with bulk were enrolled . These patients were r and omly assigned to six cycles of CHOP-like chemotherapy and rituximab ( n=413 ) or to six cycles of CHOP-like chemotherapy alone ( n=411 ) . Bulky and extranodal sites received additional radiotherapy . The primary endpoint was event-free survival ; secondary endpoints were response , progression under therapy , progression-free survival , overall survival , and frequency of toxic effects . Analyses were done by intention to treat and per protocol . This trial is registered at http://www . clinical trials.gov , NCT 00064116 . FINDINGS After a median follow-up of 34 months ( range 0.03 - 61 ) , patients assigned chemotherapy and rituximab had increased 3-year event-free survival compared with those assigned chemotherapy alone ( 79 % [ 95 % CI 75 - 83 ] vs 59 % [ 54 - 64 ] ; difference between groups 20 % [ 13 - 27 ] , log-rank p<0.0001 ) , and had increased 3-year overall survival ( 93 % [ 90 - 95 ] vs 84 % [ 80 - 88 ] ; difference between groups 9 % [ 3 - 13 ] , log-rank p=0.0001 ) . Event-free survival was affected by treatment group , presence of bulky disease , and age-adjusted IPI : after chemotherapy and rituximab , a favourable subgroup ( ie , IPI=0 , no bulk ) could be defined from a less-favourable subgroup ( ie , IPI=1 or bulk , or both ) . Groups did not differ in the frequency of adverse events . INTERPRETATION Rituximab added to six cycles of CHOP is an effective treatment for young patients with good-prognosis diffuse large-B-cell lymphoma . The definition of two prognostic subgroups allows for a more refined therapeutic approach for these patients PURPOSE To compare low-dose ( 30 Gy ) radiotherapy ( RT ) with observation ( OBS ) in limited-stage aggressive lymphoma patients achieving complete remission ( CR ) after chemotherapy , and to measure conversion from partial response ( PR ) to CR with high-dose ( 40 Gy ) RT  . PATIENTS AND METHODS From 1984 to 1992 , stage I ( with risk factors ) and II adults with diffuse aggressive lymphoma in CR after eight cycles of cyclophosphamide , doxorubicin , vincristine , and prednisone ( CHOP ) were r and omly assigned to 30 Gy involved-field RT or OBS .  PR patients received 40 Gy RT . RESULTS Among 172 CR patients , the 6-year disease-free survival ( DFS ) was 73 % for low-dose RT versus 56 % for OBS ( two-sided P = .05 ) . Failure-free survival ( two-sided P = .06 ) , and time to progression ( two-sided P = .06 ) also favored RT . Intent-to-treat analyses yielded similar results . No survival differences were observed . Three RT versus 15 OBS patients relapsed in initial disease sites . At 6 years , failure-free survival was 63 % in PR patients ; conversion to CR did not significantly influence clinical outcome . CONCLUSION For patients in CR after CHOP , low-dose RT prolonged DFS and provided local control , but no survival benefit was observed . The majority of PR patients were event-free at 6 years despite residual radiographic abnormalities . Future efforts should be directed toward improved imaging and more effective systemic therapies PURPOSE Chemoradiotherapy has been considered st and ard treatment for patients with limited-stage aggressive lymphoma on the basis of trials conducted before the introduction of the International Prognostic Index . To evaluate this approach in elderly patients with low-risk localized lymphoma , we conducted a trial comparing chemoradiotherapy with chemotherapy alone . PATIENTS AND METHODS Previously untreated patients older than 60 years with localized stage I or II histologically aggressive lymphoma and no adverse prognostic factors of the International Prognostic Index were r and omly assigned to receive either four cycles of cyclophosphamide , doxorubicin , vincristine , and prednisone ( CHOP ) plus involved-field radiotherapy ( 299 patients ) or chemotherapy alone with four cycles of CHOP ( 277 patients ) . RESULTS With a median follow-up time of 7 years , event-free and overall survival did not differ between the two treatment groups ( P = .6 and P = .5 , respectively ) . The 5-year estimates of event-free survival were 61 % for patients receiving chemotherapy alone and 64 % for patients receiving CHOP plus radiotherapy ; the 5-year estimates of overall survival were 72 % and 68 % , respectively . In a multivariate analysis , overall survival was affected by stage II disease ( P < .001 ) and male sex ( P = .03 ) . CONCLUSION In this large prospect i ve study , CHOP plus radiotherapy did not provide any advantage over CHOP alone for the treatment of low-risk localized aggressive lymphoma in elderly patients Abstract The impact of radiotherapy in aggressive NHL is not well defined . In the NHL B-94 trial of the DSHNHL , an irradiation of bulky disease areas was done after completing 6 cycles of CHOP/CHOEP chemotherapy . In the entire patient group , including those patients with extranodal disease and those who did not receive the complete chemotherapy , bulky disease was a significant independent prognostic factor concerning recurence-free survival ( 66.1 % ( no bulk ) vs. 53.5 % ( bulk ) , p=0.0001 ) . Out of 366 patients with nodal disease only and 6 cycles of chemotherapy according to the protocol , 84 of 91 patients with bulky disease were irradiated with 36 Gy . In this group of patients the prognostic impact of bulky disease could not be shown any longer ( recurrence-free survival 77.3 % ( no bulk ) vs. 74.1 % ( bulk ) . Localized radiotherapy of bulky disease areas may therefore have contributed to an improvement in outcome in this high-risk group Diffuse large B-cell lymphoma ( DLBCL ) is the most common subtype of non-Hodgkin lymphoma in the United States . Historically , radiation therapy ( RT ) was the primary treatment for patients with localized disease . Several r and omized trials have demonstrated that the addition of systemic therapy improves outcomes . Additional r and omized trials have shown that the combination of RT and systemic therapy is superior to systemic therapy alone . The role of RT in advanced-stage DLBCL has not been firmly established , but some prospect i ve phase III trials , as well as retrospective studies , suggest a benefit for advanced disease also . For patients with relapsed or primary refractory disease , autologous stem cell transplantation is the treatment of choice . Here too , consolidation RT appears to improve outcomes compared with autologous stem cell transplant alone . Finally , for patients with advanced DLBCL who are no longer responsive to systemic therapy , RT may provide rapid and durable palliation of local lymphoma-related symptoms PURPOSE The purpose of this study was to evaluate the possible effect of adjunctive involved field ( IF ) radiotherapy on long-term local control for patients with Ann Arbor Stage I-III diffuse large cell lymphoma ( DLCL ) who achieved a complete remission on a combined modality program which included cyclophosphamide , doxorubicin , vincristine , prednisone , and Bleomycin ( CHOP-Bleo ) .  METHODS AND MATERIAL S One hundred and ninety patients with Ann Arbor Stage I-III DLCL were treated with CHOP-Bleo and radiotherapy . Analyses were undertaken to determine ( a ) response to treatment according to stage , extent of maximum local disease , and irradiation dose either < 40 Gy or > or = 40 Gy and ( b ) relapse patterns . RESULTS A complete remission ( CR ) was achieved in 162 patients . Among 
    Output:
    
Limited evidence shows benefits of consolidation RT in advanced aggressive NHL .