human
***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 The role of surgery in small cell lung cancer ( SCLC ) is controversial . Survival outcomes for resection of stage I-IIIA SCLC compared to chemotherapy-based non-surgical treatment ( NST ) were examined using propensity matching . METHODS 29,994 clinical stage I-IIIA SCLC patients , including 2,619 undergoing surgery , were identified in the National Cancer Data base . Stage-specific propensity scores for receipt of surgery were created . Resected patients were matched 1:1 to those undergoing NST .  Overall survival ( OS ) was assessed using Kaplan-Meier and multivariable Cox models . A separate match was performed comparing Stage I/II patients aged < 85 with a Charlson score of 0 who underwent lobectomy with adjuvant chemotherapy ( and radiotherapy if node positive ) to those treated with multiagent chemotherapy and concurrent chest radiotherapy ( CRT ) of at least 40 gray . RESULTS 2,089 patients were matched , and cohorts were well balanced . Surgery was associated with longer survival for Stage I ( median OS 38.6 months vs. 22.9 months , HR 0.62 95%CI 0.57 - 0.69 , p<0.0001 ) , but survival differences were attenuated for Stage II ( median OS 23.4 months vs. 20.7 months , HR 0.84 95%CI 0.70 - 1.01 , p=0.06 ) and IIIA ( median OS 21.7 vs. 16.0 months , HR 0.71 95%CI 0.60 - 0.83 , p < 0.0001 ) . In analyses by T and N stage , longer OS was observed in resected patients with stage T3/T4 N0 ( median OS 33.0 vs. 16.8 months , p=0.008 ) and node positivity(N1 + 24.4 vs. 18.3 months p=0.03 ; N2 + 20.1 vs. 14.6 months p=0.007 ) . In the subgroup analysis , 507 stage I/II patients receiving lobectomy and adjuvant chemotherapy were matched to patients receiving concurrent CRT . In this cohort , lobectomy with adjuvant chemotherapy was associated with significantly longer survival ( median OS 48.6 vs. 28.7 months , p<0.0001 ) . CONCLUSIONS Surgical resection is associated with significantly longer survival for early SCLC . New r and omized trials should assess trimodality therapy in stages I/II , and in node negative disease Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more OBJECTIVE The role of surgery in limited SCLC is still a matter of controversy . Even though the response rates to chemotherapy are very high , prognosis of SCLC patients has remained poor with a median survival of only 12 - 14 months for limited disease . High incidence of local relapses after chemotherapy in limited-stage SCLC led to re assessment of the role of local treatment in the multimodality management of this tumor . METHODS We performed retrospective comparative analysis of survival in a series of 134 limited-stage SCLC patients treated between 1984 and 1996 with either complete resection followed by chemotherapy ( 67 patients ) , or with conventional non-surgical management ( 67 patients ) . In all patients who underwent resection , the diagnosis of SCLC was established only postoperatively . The control ( non-surgical ) group was selected using ' pair-matched case-control ' methodology , out of 176 limited-stage patients potentially suitable for surgery ( i.e. with no pleural effusion or other local advancement , no supraclavicular lymph node involvement and good performance status ) , but treated without resection . The major prognostic factors were well balanced between these two groups . Total series included 109 males and 25 females , 20 patients with T1 and 114 patients with T2 disease , 51 N0 , 43 N1 and 40 N2 disease . RESULTS Median survival in patients treated with and without surgery was 22 months and 11 months , respectively , ( P < 0.001 ) . The two-year and five-year survival probabilities were 43 and 27 % , respectively , in the surgical group , and 17 and 4 % , respectively , in the non-surgical group . Subset analysis confirmed significantly longer survival with surgery in all T and N categories , except for N2 disease . Local relapse occurred in 15 and 55 % of patients treated with and without surgery , respectively , ( P < 0.001 ) . Distant relapse probabilities were similar in both groups ( 36 and 40 % , respectively ) . The most common site of metastases in the entire series was brain , followed by liver , lymph nodes , bone , lung and skin . CONCLUSIONS Our results suggest a possible role of surgery in limited-stage SCLC . Thus , a r and omised study addressing this issue seems to be justified BACKGROUND For small-cell lung cancer confined to one hemithorax ( limited small-cell lung cancer ) , thoracic radiotherapy improves survival , but the best ways of integrating chemotherapy and thoracic radiotherapy remain unsettled . Twice-daily accelerated thoracic radiotherapy has potential advantages over once-daily radiotherapy . METHODS We studied 417 patients with limited small-cell lung cancer . All the patients received four 21-day cycles of cisplatin plus etoposide . We r and omly assigned these patients to receive a total of 45 Gy of concurrent thoracic radiotherapy , given either twice daily over a three-week period or once daily over a period of five weeks . RESULTS Twice-daily treatment beginning with the first cycle of chemotherapy significantly improved survival as compared with concurrent once-daily radiotherapy ( P=0.04 by the log-rank test ) . After a median follow-up of almost 8 years , the median survival was 19 months for the once-daily group and 23 months for the twice-daily group . The survival rates for patients receiving once-daily radiotherapy were 41 percent at two years and 16 percent at five years . For patients receiving twice-daily radiotherapy , the survival rates were 47 percent at two years and 26 percent at five years . Grade 3 esophagitis was significantly more frequent with twice-daily thoracic radiotherapy , occurring in 27 percent of patients , as compared with 11 percent in the once-daily group ( P<0.001 ) . CONCLUSIONS Four cycles of cisplatin plus etoposide and a course of radiotherapy ( 45 Gy , given either once or twice daily ) beginning with cycle 1 of the chemotherapy result ed in overall two- and five-year survival rates of 44 percent and 23 percent , a considerable improvement in survival rates over previous results in patients with limited small-cell lung cancer Three hundred twenty-eight patients with limited stage small cell lung cancer were enrolled in a trial to evaluate surgical treatment for such patients responding to chemotherapy . Cyclophosphamide , doxorubicin , and vincristine were administered every 21 days for five cycles . Patients achieving at least partial response who had confirmation of pure small cell histologic features by pathology review and who were fit enough for thoracotomy were r and omized to undergo or not to undergo pulmonary resection . All r and omized patients received radiotherapy to the chest and brain . Two hundred seventeen ( 66 % ) of the patients achieved objective response ( 90 complete response ; 127 partial response ) . One hundred forty-six patients were r and omized ( 66 % of responders , 44 % of all patients ): 70 to surgery and 76 to no surgery . Results of surgery were 83 % resection rate , 19 % pathologic complete remission rate , and 9 % with residual non-small cell histologic features only , for a total of 28 % eradication of small cell lung cancer . The survival curves for the two arms are not different ( log rank p = 0.78 ) . Median survivals were 12 months for all enrolled patients and 16 months for those who were r and omized . Actuarial 2-year survival is 20 % . The results of this trial do not support the addition of pulmonary resection to the multimodality treatment of small cell lung cancer A prospect i ve r and omized study of 80 cases of stage III lung cancer treated with different multimodality therapy  was carried out . Life table and Kaplan-Meir curve were employed to calculate survival rate . Log rank-multivariate analysis and time t test were used to evaluate statistical values of the 80 cases , 40 SCLC were r and omly treated with either chemotherapy (CT)-surgery-CT or CT-radiotherapy (RT)-CT . The year survival rates were better in the group treated with CT-surgery-CT , a statistical difference was observed in 2yr survival rate ( P < 0.05 ) . Thus , surgical resection for SCLC was better than RT after CT . The remaining 40 cases of NSCLC were r and omly treated with either CT-RT-CT or RT-CT .  Multivariate analysis showed a better statistical meaning in the 20 cases treated with CT-RT-CT than the other group , their 1 , 2 year survival rates were 27 % , 40 % and 22 % , 15 % , respectively . Thus preradiative CT was beneficial for survival Introduction : Current therapy for small-cell lung cancer ( SCLC ) relies on chemoradiation therapy , and the role of primary surgical resection in these patients remains controversial . A minority of SCLC patients present without metastatic disease and are c and i date s for surgery . This study investigates the role of surgical resection in select patients with SCLC , using a national cohort of approximately 2500 resected patients . Methods : A retrospective study of SCLC patients in the National Cancer Data Base ( NCDB ) was performed where patients were grouped for comparison by stage and treatment regimen . Survival was estimated by Kaplan – Meier methods and multivariate comparisons using Cox regression . Results : Of 28,621 cases of potentially resectable SCLC , 2476 patients ( 9 % ) underwent surgery of the primary site with curative intent . Five-year overall survival for patients after resection was 51 % , 25 % , and 18 % for clinical stages I , II , and IIIA , respectively . Addition of surgery to chemotherapy was associated with decreased likelihood of death ( hazard ratio : 0.57 , 95 % confidence interval : 0.47–0.68 ) , independent of age , stage , and comorbidity score . Lobectomy was associated with a 5-year overall survival of 40 % compared with 21 % and 22 % for sublobar resection and pneumonectomy , respectively . Hazard ratio for death after sublobar resections compared with lobectomy was 1.38 ( 95 % confidence interval : 1.12–1.71 ) . Conclusions : Patients with stages I , II , and III SCLC , who underwent surgical resection as part of initial treatment with chemotherapy had respectable OS . These data may warrant prospect i ve studies of including surgery in the multimodality treatment of SCLC in specific circumstances Abstract This report gives the 10-year results of controlled trial of a policy of surgery and a policy of radical radiotherapy in the treatment of patients with small-celled or oat-celled carcinoma of the bronchus diagnosed preoperatively on bronchial biopsy and thought likely to be operable . The analysis included 144 patients , 71 allocated at r and om to the surgery series and 73 to the radical-radiotherapy series . There were no 10-year survivors in the surgery series , but in the radiotherapy series 3 remained alive and well . The mean survival for the surgery series was 199 days and for the radical-radiotherapy series 300 days — a statistically significant difference ( P=0·04 ) . This reinforces the conclusion of the 5-year report that in this trial radical radiotherapy has given , in terms of survival , a somewhat better result than surgery in the treatment of patients with small-celled or oat-celled carcinoma of the bronchus diagnosed preoperatively on bronchial biopsy and judged to be operable We attempted to define the role of surgery in the treatment of small cell lung cancer ( SCLC ) . Of 81 patients with clinical ly localized SCLC , 36 underwent surgical resection : 19 underwent initial resection with postoperative chemotherapy , while the remaining 17 were treated initially with chemotherapy , then resection . The remaining 45 patients were treated with a combination of chemotherapy and radiotherapy . The 5-year survival for the 36 surgical patients was 38 % ; median survival time ( MST ) was 33 months . Nineteen patients treated with postoperative chemotherapy showed a 42 % 5-year survival , while 17 patients treated with preoperative chemotherapy showed a 33 % 5-year survival . This difference was not significant . However , stage III survival tended to be better in patients with preoperative chemotherapy ( MST , 29 months ) than in those who had had postoperative chemotherapy only ( MST , 17 months ) . Although survival of the 45 nonsurgical patients was poor , stage I and II patients , or those with complete remission showed a 25 % 5-year survival with an MST of 33 months , and a 21 % 5-year survival with an MST of 25 months , respectively . We thus concluded that initial resection combined with 
    Output:
    
agent
***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 The role of surgery in small cell lung cancer ( SCLC ) is controversial . Survival outcomes for resection of stage I-IIIA SCLC compared to chemotherapy-based non-surgical treatment ( NST ) were examined using propensity matching . METHODS 29,994 clinical stage I-IIIA SCLC patients , including 2,619 undergoing surgery , were identified in the National Cancer Data base . Stage-specific propensity scores for receipt of surgery were created . Resected patients were matched 1:1 to those undergoing NST .  Overall survival ( OS ) was assessed using Kaplan-Meier and multivariable Cox models . A separate match was performed comparing Stage I/II patients aged < 85 with a Charlson score of 0 who underwent lobectomy with adjuvant chemotherapy ( and radiotherapy if node positive ) to those treated with multiagent chemotherapy and concurrent chest radiotherapy ( CRT ) of at least 40 gray . RESULTS 2,089 patients were matched , and cohorts were well balanced . Surgery was associated with longer survival for Stage I ( median OS 38.6 months vs. 22.9 months , HR 0.62 95%CI 0.57 - 0.69 , p<0.0001 ) , but survival differences were attenuated for Stage II ( median OS 23.4 months vs. 20.7 months , HR 0.84 95%CI 0.70 - 1.01 , p=0.06 ) and IIIA ( median OS 21.7 vs. 16.0 months , HR 0.71 95%CI 0.60 - 0.83 , p < 0.0001 ) . In analyses by T and N stage , longer OS was observed in resected patients with stage T3/T4 N0 ( median OS 33.0 vs. 16.8 months , p=0.008 ) and node positivity(N1 + 24.4 vs. 18.3 months p=0.03 ; N2 + 20.1 vs. 14.6 months p=0.007 ) . In the subgroup analysis , 507 stage I/II patients receiving lobectomy and adjuvant chemotherapy were matched to patients receiving concurrent CRT . In this cohort , lobectomy with adjuvant chemotherapy was associated with significantly longer survival ( median OS 48.6 vs. 28.7 months , p<0.0001 ) . CONCLUSIONS Surgical resection is associated with significantly longer survival for early SCLC . New r and omized trials should assess trimodality therapy in stages I/II , and in node negative disease Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more OBJECTIVE The role of surgery in limited SCLC is still a matter of controversy . Even though the response rates to chemotherapy are very high , prognosis of SCLC patients has remained poor with a median survival of only 12 - 14 months for limited disease . High incidence of local relapses after chemotherapy in limited-stage SCLC led to re assessment of the role of local treatment in the multimodality management of this tumor . METHODS We performed retrospective comparative analysis of survival in a series of 134 limited-stage SCLC patients treated between 1984 and 1996 with either complete resection followed by chemotherapy ( 67 patients ) , or with conventional non-surgical management ( 67 patients ) . In all patients who underwent resection , the diagnosis of SCLC was established only postoperatively . The control ( non-surgical ) group was selected using ' pair-matched case-control ' methodology , out of 176 limited-stage patients potentially suitable for surgery ( i.e. with no pleural effusion or other local advancement , no supraclavicular lymph node involvement and good performance status ) , but treated without resection . The major prognostic factors were well balanced between these two groups . Total series included 109 males and 25 females , 20 patients with T1 and 114 patients with T2 disease , 51 N0 , 43 N1 and 40 N2 disease . RESULTS Median survival in patients treated with and without surgery was 22 months and 11 months , respectively , ( P < 0.001 ) . The two-year and five-year survival probabilities were 43 and 27 % , respectively , in the surgical group , and 17 and 4 % , respectively , in the non-surgical group . Subset analysis confirmed significantly longer survival with surgery in all T and N categories , except for N2 disease . Local relapse occurred in 15 and 55 % of patients treated with and without surgery , respectively , ( P < 0.001 ) . Distant relapse probabilities were similar in both groups ( 36 and 40 % , respectively ) . The most common site of metastases in the entire series was brain , followed by liver , lymph nodes , bone , lung and skin . CONCLUSIONS Our results suggest a possible role of surgery in limited-stage SCLC . Thus , a r and omised study addressing this issue seems to be justified BACKGROUND For small-cell lung cancer confined to one hemithorax ( limited small-cell lung cancer ) , thoracic radiotherapy improves survival , but the best ways of integrating chemotherapy and thoracic radiotherapy remain unsettled . Twice-daily accelerated thoracic radiotherapy has potential advantages over once-daily radiotherapy . METHODS We studied 417 patients with limited small-cell lung cancer . All the patients received four 21-day cycles of cisplatin plus etoposide . We r and omly assigned these patients to receive a total of 45 Gy of concurrent thoracic radiotherapy , given either twice daily over a three-week period or once daily over a period of five weeks . RESULTS Twice-daily treatment beginning with the first cycle of chemotherapy significantly improved survival as compared with concurrent once-daily radiotherapy ( P=0.04 by the log-rank test ) . After a median follow-up of almost 8 years , the median survival was 19 months for the once-daily group and 23 months for the twice-daily group . The survival rates for patients receiving once-daily radiotherapy were 41 percent at two years and 16 percent at five years . For patients receiving twice-daily radiotherapy , the survival rates were 47 percent at two years and 26 percent at five years . Grade 3 esophagitis was significantly more frequent with twice-daily thoracic radiotherapy , occurring in 27 percent of patients , as compared with 11 percent in the once-daily group ( P<0.001 ) . CONCLUSIONS Four cycles of cisplatin plus etoposide and a course of radiotherapy ( 45 Gy , given either once or twice daily ) beginning with cycle 1 of the chemotherapy result ed in overall two- and five-year survival rates of 44 percent and 23 percent , a considerable improvement in survival rates over previous results in patients with limited small-cell lung cancer Three hundred twenty-eight patients with limited stage small cell lung cancer were enrolled in a trial to evaluate surgical treatment for such patients responding to chemotherapy . Cyclophosphamide , doxorubicin , and vincristine were administered every 21 days for five cycles . Patients achieving at least partial response who had confirmation of pure small cell histologic features by pathology review and who were fit enough for thoracotomy were r and omized to undergo or not to undergo pulmonary resection . All r and omized patients received radiotherapy to the chest and brain . Two hundred seventeen ( 66 % ) of the patients achieved objective response ( 90 complete response ; 127 partial response ) . One hundred forty-six patients were r and omized ( 66 % of responders , 44 % of all patients ): 70 to surgery and 76 to no surgery . Results of surgery were 83 % resection rate , 19 % pathologic complete remission rate , and 9 % with residual non-small cell histologic features only , for a total of 28 % eradication of small cell lung cancer . The survival curves for the two arms are not different ( log rank p = 0.78 ) . Median survivals were 12 months for all enrolled patients and 16 months for those who were r and omized . Actuarial 2-year survival is 20 % . The results of this trial do not support the addition of pulmonary resection to the multimodality treatment of small cell lung cancer A prospect i ve r and omized study of 80 cases of stage III lung cancer treated with different multimodality therapy  was carried out . Life table and Kaplan-Meir curve were employed to calculate survival rate . Log rank-multivariate analysis and time t test were used to evaluate statistical values of the 80 cases , 40 SCLC were r and omly treated with either chemotherapy (CT)-surgery-CT or CT-radiotherapy (RT)-CT . The year survival rates were better in the group treated with CT-surgery-CT , a statistical difference was observed in 2yr survival rate ( P < 0.05 ) . Thus , surgical resection for SCLC was better than RT after CT . The remaining 40 cases of NSCLC were r and omly treated with either CT-RT-CT or RT-CT .  Multivariate analysis showed a better statistical meaning in the 20 cases treated with CT-RT-CT than the other group , their 1 , 2 year survival rates were 27 % , 40 % and 22 % , 15 % , respectively . Thus preradiative CT was beneficial for survival Introduction : Current therapy for small-cell lung cancer ( SCLC ) relies on chemoradiation therapy , and the role of primary surgical resection in these patients remains controversial . A minority of SCLC patients present without metastatic disease and are c and i date s for surgery . This study investigates the role of surgical resection in select patients with SCLC , using a national cohort of approximately 2500 resected patients . Methods : A retrospective study of SCLC patients in the National Cancer Data Base ( NCDB ) was performed where patients were grouped for comparison by stage and treatment regimen . Survival was estimated by Kaplan – Meier methods and multivariate comparisons using Cox regression . Results : Of 28,621 cases of potentially resectable SCLC , 2476 patients ( 9 % ) underwent surgery of the primary site with curative intent . Five-year overall survival for patients after resection was 51 % , 25 % , and 18 % for clinical stages I , II , and IIIA , respectively . Addition of surgery to chemotherapy was associated with decreased likelihood of death ( hazard ratio : 0.57 , 95 % confidence interval : 0.47–0.68 ) , independent of age , stage , and comorbidity score . Lobectomy was associated with a 5-year overall survival of 40 % compared with 21 % and 22 % for sublobar resection and pneumonectomy , respectively . Hazard ratio for death after sublobar resections compared with lobectomy was 1.38 ( 95 % confidence interval : 1.12–1.71 ) . Conclusions : Patients with stages I , II , and III SCLC , who underwent surgical resection as part of initial treatment with chemotherapy had respectable OS . These data may warrant prospect i ve studies of including surgery in the multimodality treatment of SCLC in specific circumstances Abstract This report gives the 10-year results of controlled trial of a policy of surgery and a policy of radical radiotherapy in the treatment of patients with small-celled or oat-celled carcinoma of the bronchus diagnosed preoperatively on bronchial biopsy and thought likely to be operable . The analysis included 144 patients , 71 allocated at r and om to the surgery series and 73 to the radical-radiotherapy series . There were no 10-year survivors in the surgery series , but in the radiotherapy series 3 remained alive and well . The mean survival for the surgery series was 199 days and for the radical-radiotherapy series 300 days — a statistically significant difference ( P=0·04 ) . This reinforces the conclusion of the 5-year report that in this trial radical radiotherapy has given , in terms of survival , a somewhat better result than surgery in the treatment of patients with small-celled or oat-celled carcinoma of the bronchus diagnosed preoperatively on bronchial biopsy and judged to be operable We attempted to define the role of surgery in the treatment of small cell lung cancer ( SCLC ) . Of 81 patients with clinical ly localized SCLC , 36 underwent surgical resection : 19 underwent initial resection with postoperative chemotherapy , while the remaining 17 were treated initially with chemotherapy , then resection . The remaining 45 patients were treated with a combination of chemotherapy and radiotherapy . The 5-year survival for the 36 surgical patients was 38 % ; median survival time ( MST ) was 33 months . Nineteen patients treated with postoperative chemotherapy showed a 42 % 5-year survival , while 17 patients treated with preoperative chemotherapy showed a 33 % 5-year survival . This difference was not significant . However , stage III survival tended to be better in patients with preoperative chemotherapy ( MST , 29 months ) than in those who had had postoperative chemotherapy only ( MST , 17 months ) . Although survival of the 45 nonsurgical patients was poor , stage I and II patients , or those with complete remission showed a 25 % 5-year survival with an MST of 33 months , and a 21 % 5-year survival with an MST of 25 months , respectively . We thus concluded that initial resection combined with 
    Output:
    