***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 Concurrent chemoradiotherapy ( CCRT ) has been shown to improve outcomes for stage III-IV nasopharyngeal carcinoma ( NPC ) patients compared with radiotherapy ( RT ) alone , but the effectiveness of the combined therapy for stage II NPC patients is unknown . METHODS Patients with Chinese 1992 stage II NPC were r and omly assigned to receive either RT alone ( n = 114 ) or CCRT ( n = 116 ) . The CCRT patients were given concurrent cisplatin ( 30 mg/m(2 ) on day 1 ) weekly during RT . The primary endpoint was overall survival ( OS ) . Secondary endpoints were progression-free survival ( PFS ) , distant metastasis-free survival , and locoregional relapse-free survival . All patients were analyzed by the intent-to-treat principle . The Cox proportional hazards model was used to calculate hazard ratios ( HRs ) with 95 % confidence intervals ( CIs ) and in multivariable analyses to test the independent statistical significance of treatment intervention . Toxic effects and the response to treatment were analyzed using the χ(2 ) test . All statistical tests were two-sided . RESULTS With a median follow-up of 60 months , adding chemotherapy statistically significantly improved the 5-year OS rate ( 94.5 % vs 85.8 % ; HR of death = 0.30 , 95 % CI = 0.12 to 0.76 ; P = .007 ) , PFS ( 87.9 % vs 77.8 % ; HR of progression = 0.45 , 95 % CI = 0.23 to 0.88 ; P = .017 ) , and distant metastasis-free survival ( 94.8 % vs 83.9 % ; HR of distant relapse = 0.27 , 95 % CI = 0.10 to 0.74 ; P = .007 ) ; however , there was no statistically significant difference in the 5-year locoregional relapse-free survival rate ( 93.0 % vs 91.1 % ; HR of locoregional relapse = 0.61 , 95 % CI = 0.25 to 1.51 ; P = .29 ) . Multivariable analysis showed that the number of chemotherapy cycles was the only independent factor that was associated with OS , PFS , and distant control in stage II NPC . The CCRT arm experienced statistically significantly more acute toxic effects ( P = .001 ) , although the rate of late toxic effects did not increase statistically significantly . CONCLUSION Concurrent chemotherapy and radiotherapy is associated with a considerable survival benefit for patients with stage II NPC Objectives : To evaluate the treatment outcome of patients with stage IIB nasopharyngeal carcinoma ( NPC ) after definitive intensity-modulated radiotherapy ( IMRT ) without concurrent chemotherapy .  Methods : Between August 2003 and December 2006 , 107 patients with T1N1M0 ( 8 % ) , T2N0M0 ( 13 % ) , or T2N1M0 ( 79 % ) NPC were definitively treated with IMRT . Sixty-one received IMRT only , and 46 patients had various strategies of systemic treatment , consisting of abbreviated neoadjuvant ( 38 patients ) , concurrent ( 8 patients ) , or adjuvant ( 16 patients ) chemotherapy . Radiation doses prescribed to the planning tumor volume of the gross disease , high-risk clinical tumor volume , and low-risk clinical tumor volume were 66 to 70 Gy , 54 to 60 Gy , and 50–54 Gy , respectively . Results : With a median follow-up of 39 months ( range , 7–77 months ) , 6 patients had locoregional relapse : 1 local only , 1 locoregional , and 4 regional only . Five patients had distant failure . Five of 6 total deaths were cancer related . The 3-year estimated local control , regional control , metastasis-free survival , disease-free survival , and overall survival were 96.5 % , 98 % , 94.8 % , 90.7 % , and 95.8 % , respectively . No significant difference in treatment outcome was demonstrated in patients treated with or without chemotherapy of any schedule . Conclusions : IMRT without concurrent chemotherapy provides good outcome for patients with stage IIB NPC with acceptable toxicity . Neoadjuvant chemotherapy did not appear to provide significant additional benefit for this patient subgroup . Further investigation in the prospect i ve setting is warranted to explore the role of systemic agents in the treatment of NPC with limited primary disease and cervical lymphadenopathy when IMRT is used PURPOSE To investigate the feasibility of intensity-modulated radiation therapy ( IMRT ) with or without chemotherapy , and to assess toxicities , failure patterns , and survivals in patients with nasopharyngeal carcinoma ( NPC ) . PATIENTS AND METHODS Radiation consisted of 70 Gy given to the planning target volumes of primary tumor plus any N+ disease and 59.4 Gy given to sub clinical disease , delivered over 33 treatment days . Patients with stage T2b or greater or with N+ disease also received concurrent cisplatin ( 100 mg/m(2 ) ) on days 1 , 22 , and 43 followed by adjuvant cisplatin ( 80 mg/m(2 ) ) on day 1 ; fluorouracil ( 1,000 mg/m(2)/d ) on days 1 through 4 administered every 4 weeks for three cycles . Tumor , clinical status , and acute/late toxicities were assessed . The primary objective was to test the transportability of IMRT to a multi-institutional setting . RESULTS Between February 2003 and November 2005 , 68 patients with stages I through IVB NPC ( of which 93.8 % were WHO types 2 and 3 ) were enrolled . Prescribed IMRT ( target delineation ) was given to 83.8 % , whereas 64.9 % received chemotherapy per protocol . The estimated 2-year local progression-free ( PF ) , regional PF , locoregional PF , and distant metastasis-free rates were 92.6 % , 90.8 % , 89.3 % , and 84.7 % , respectively . The estimated 2-year PF and overall survivals were 72.7 % and 80.2 % , respectively . Acute grade 4 mucositis occurred in 4.4 % , and the worst late grade 3 toxicities were as follows : esophagus , 4.7 % ; mucous membranes , 3.1 % ; and xerostomia , 3.1 % . The rate of grade 2 xerostomia at 1 year from start of IMRT was 13.5 % . Only two patients complained of grade 3 xerostomia , and none had grade 4 xerostomia . CONCLUSION It was feasible to transport IMRT with or without chemotherapy in the treatment of NPC to a multi-institutional setting with 90 % LRPF rate reproducing excellent reports from single institutions . Minimal grade 3 and lack of grade 4 xerostomia were encouraging Abstract The objective of this study was to evaluate the necessity of concurrent chemotherapy in T1 - 2N1 nasopharyngeal carcinoma ( NPC ) patients treated with intensity-modulated radiation therapy (IMRT).The  retrospective analysis was conducted using the paired comparison method . We matched cases to controls using the greedy matching algorithm with 1:1 control to case ratio . Controls were matched to cases by factors including age , gender , T stage , and duration of RT . The control group included patients received IMRT alone . In another group , concurrent chemotherapy ( DDP 40 mg/m2/w ) was administrated to each paired patient . From Jan 2009 to Dec 2011 , a total of 86 well-balanced T1 - 2N1 ( 2002 UICC staging system ) NPC patients were retrospectively analyzed . Half of them ( 43 patients ) received radical IMRT alone and another 43 received concurrent chemotherapy with IMRT ( CCRT ) . Median follow-up is 37.4 months ( 4.8–66.2 months ) . All patients received a radiation dose of 66Gy/30Fx . In the CCRT group , all patients received a cumulative dose of ≥200 mg/m2 . The differences of 3-year overall survival ( OS ) , 3-year progression-free survival ( PFS ) , 3-year relapse-free survival ( RFS ) , and 3-year metastasis-free survival ( MFS ) between 2 groups were not significant ( P > 0.05 ) . The most frequently increased toxicities related to chemotherapy were mild to moderate leukopenia ( P = 0.003 ) and mild anemia ( P = 0.008).Omission of weekly cisplatin chemotherapy result ed in comparable survival outcomes to CCRT in IMRT population s. More data from future r and omized trials are warranted to further confirm it OBJECTIVES To evaluate the long-term survival and the role of chemotherapy in nasopharyngeal carcinoma ( NPC ) patients in Stage II treated by intensity-modulated radiation therapy ( IMRT ) .  METHODS Three hundred and eleven NPC patients in Stage II were review ed . All were treated with IMRT with or without chemotherapy , with 191 , 20 and 100 patients being defined as T1N1M0 , T2N0M0 and T2N1M0 stage , respectively . RESULTS At a median follow-up of 57 months , the 5-year overall survival , disease-specific survival , distant metastasis-free survival , loco-regional relapse-free survival ( LRRFS ) and progression-free survival were 91.1 , 93.5 , 90.6 , 95.9 and 87.6 % , respectively . T2N1 patients had significant poorer survival outcomes than T1N1 patients , with T2N0 patients in between . Further analysis showed that the addition of chemotherapy could only improve LRRFS [ hazard ratio ( HR ) 0.263 , 95 % confidence interval ( CI ) 0.083 - 0.839 , P = 0.024 ] , especially for T1N1 patients ( HR 0.209 , 95 % CI 0.046 - 0.954 , P = 0.043 ) . For those in the T2N1M0 group , chemotherapy , as used in our series , added no benefit to any endpoint . CONCLUSIONS IMRT in NPC patients in Stage II was quite therapeutic ; however , different subgroups have distinct survival outcomes . Distant metastasis was the main failure pattern , especially for those with T2N1 disease , and the chemotherapy currently in use failed to treat sub clinical metastatic foci effectively . Further prospect i ve study is warranted to find out the role and the optimal schedule of chemotherapy in this subgroup of patients To evaluate the long term impact of concurrent chemoradiotherapy ( CCRT ) compared to radiotherapy ( RT ) alone in patients with T2N1M0 nasopharyngeal carcinoma ( NPC ) retrospectively . Three hundred and ninety-two patients with T2N1M0 NPC according to the AJCC 2002 stage classification system were analyzed . Among them , 211 patients were treated with RT alone and the rest of 181 patients were treated with CCRT .  A planned dose of 70 Gy was delivered in 2.0 Gy per fraction over 7 weeks to the primary tumor with 6-MV photons or (60)Cobalt γ-ray . The chemotherapy regimen of cisplatin with a dose of 100mg/m(2 ) was delivered for 2 - 3 cycles . With a median follow-up of 66 months ( range 2.4 - 117.1 months ) , the 5-year overall survival ( OS ) and disease-free survival ( DFS ) rates was higher in CCRT group compared to RT alone group , though they failed to reach statistical significance ( 80.2 % vs. 76.6 % , P=0.778 and 70.5 % vs. 64.2 % , P=0.413 , respectively ) . A significant improvement was detected in 5-year relapse-free survival ( RFS ) rate in CCRT group than RT alone group ( 91.5 % vs. 77.3 % , P=0.008 ) . Moreover , chemotherapy was the only independent prognostic factor for the 5-year RFS ( P=0.007 ) . Concurrent chemoradiotherapy appeared to improve the 5-year RFS rate for patients with T2N1M0 NPC . Large prospect i ve , r and omized clinical studies are needed to confirm its therapeutic gain PURPOSE Early-stage nasopharyngeal carcinoma ( NPC ) continues to carry a failure rate of 15 % to 30 % when treated with radiotherapy alone ; the benefit of concomitant radiotherapy and chemotherapy ( CCRT ) in early-stage NPC is unclear . The purpose of this report is to describe our efforts to improve treatment outcome in early-stage NPC after CCRT . PATIENTS AND METHODS Of 189 newly diagnosed NPC patients without evidence of distant metastases who were treated in our institution between 1990 and 1997 , 44 presented with early-stage ( stage I and II ) disease according to the American Joint Committee on Cancer ( AJCC ) 1997 NPC staging system . Twelve of these patients were treated with radiotherapy alone and 32 with CCRT . Each patient 's head and neck area was evaluated by magnetic resonance 
    Output:
    
Adding concurrent chemotherapy to IMRT led to no survival benefit and increased acute toxicity reactions for stage II nasopharyngeal carcinoma