You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
FOLFIRI followed by FOLFOX6 or the reverse sequence in advanced colorectal cancer: a randomized GERCOR study.
Abstract 1:
PURPOSE In metastatic colorectal cancer , phase III studies have demonstrated the superiority of fluorouracil ( FU ) with leucovorin ( LV ) in combination with irinotecan or oxaliplatin over FU + LV alone . This phase III study investigated two sequences : folinic acid , FU , and irinotecan ( FOLFIRI ) followed by folinic acid , FU , and oxaliplatin ( FOLFOX6 ; arm A ) , and FOLFOX6 followed by FOLFIRI ( arm B ) . PATIENTS AND METHODS Previously untreated patients with assessable disease were r and omly assigned to receive a 2-hour infusion of l-LV 200 mg/m(2 ) or dl-LV 400 mg/m(2 ) followed by a FU bolus 400 mg/m(2 ) and 46-hour infusion 2,400 to 3,000 mg/m(2 ) every 46 hours every 2 weeks , either with irinotecan 180 mg/m(2 ) or with oxaliplatin 100 mg/m(2 ) as a 2-hour infusion on day 1 . At progression , irinotecan was replaced by oxaliplatin ( arm A ) , or oxaliplatin by irinotecan ( arm B ) . RESULT Median survival was 21.5 months in 109 patients allocated to FOLFIRI then FOLFOX6 versus 20.6 months in 111 patients allocated to FOLFOX6 then FOLFIRI ( P = .99 ) . Median second progression-free survival ( PFS ) was 14.2 months in arm A versus 10.9 in arm B ( P = .64 ) . In first-line therapy , FOLFIRI achieved 56 % response rate ( RR ) and 8.5 months median PFS , versus FOLFOX6 which achieved 54 % RR and 8.0 months median PFS ( P = .26 ) . Second-line FOLFIRI achieved 4 % RR and 2.5 months median PFS , versus FOLFOX6 which achieved 15 % RR and 4.2 months PFS . In first-line therapy , National Cancer Institute Common Toxicity Criteria grade 3/4 mucositis , nausea/vomiting , and grade 2 alopecia were more frequent with FOLFIRI , and grade 3/4 neutropenia and neurosensory toxicity were more frequent with FOLFOX6 . CONCLUSION Both sequences achieved a prolonged survival and similar efficacy . The toxicity profiles were different


Title 2:
Correlation of progression-free and post-progression survival with overall survival in advanced colorectal cancer.
Abstract 2:
BACKGROUND Polychemotherapy and biological drugs have increased therapeutic options and outcomes of advanced colorectal cancer ( CRC ) . We examined the relation between progression-free survival ( PFS ) , post-progression survival ( PPS ) and overall survival ( OS ) in trials of  modern ( oxaliplatin- and irinotecan-based ) chemotherapy alone or with targeted therapies for advanced CRC . We also evaluated surrogacy of PFS and OS . PATIENTS AND METHODS A PubMed search identified 34 r and omized trials . We split the OS , PFS and PPS and evaluated the correlation between OS and either PFS or PPS . RESULTS The median PPS and PFS were 10.75 and 8.4 months , respectively . For all trials , PPS was strongly associated with OS [ regression coefficient (R2)=0.8 ; Spearman 's rank correlation coefficient (r)=0.88 ] , whereas PFS was moderately associated with OS (R2)=0.43 ; r=0.64 ) . In trials with targeted therapies , the correlation of PPS with OS was 0.88 . However , across all trials , correlation between differences in median PFS ( ΔPFS ) and median OS ( ΔOS ) is 0.59 ( P=0.0007 ) , confirming PFS/OS surrogacy . CONCLUSION Our findings indicate that in recent first-line , phase III , trials , OS becomes more associated with PPS than PFS . However , improvements in PFS are strongly associated with improvements in OS . In this setting so , PFS may be an appropriate surrogate for OS


Title 3:
Bevacizumab plus infusional 5-fluorouracil, leucovorin and irinotecan for advanced colorectal cancer that progressed after oxaliplatin and irinotecan chemotherapy: a pilot study.
Abstract 3:
AIM To evaluate the combination of bevacizumab with infusional 5-fluorouracil ( 5-FU ) , leucovorin ( LV ) and irinotecan ( FOLFIRI ) in patients with advanced colorectal cancer ( CRC ) pretreated with combination regimens including irinotecan and oxaliplatin .  METHODS Fourteen patients ( median age 56 years ) with advanced CRC , all having progressed after oxaliplatin- and irinotecan-based combination chemotherapy  , were enrolled in this study . Patients were treated with 2 h infusion of irinotecan 150 mg/m2 on d 1 , plus bevacizumab 5 mg/kg iv infusion for 90 min on d 2 , and iv injection of LV 20 mg/m2 followed by a bolus of 5-FU 400 mg/m2 and then 22 h continuous infusion of 600 mg/m2 given on two consecutive days every 14 d. RESULTS The median number of cycles of chemotherapy was six ( range 3 - 12 ) . The response rate was 28.5 % , one patient had a complete response , and three patients had a partial response . Eight patients had stable disease . The median time to progression was 3.9 mo ( 95 % CI 2.0 - 8.7 ) , and the median overall survival was 10.9 mo ( 95 % CI 9.6 - 12.1 ) . Grade 3/4 neutropenia occurred in five patients , and two of these developed neutropenic fever . Grade 3 hematuria and hematochezia occurred in one . Grade 2 proteinuria occurred in two patients . However , hypertension , bowel perforation or thromboembolic events did not occur in a total of 90 cycles . CONCLUSION Bevacizumab with FOLFIRI is well tolerated and a feasible treatment in patients with heavily treated advanced CRC


Title 4:
Sequential versus combination chemotherapy for the treatment of advanced colorectal cancer (FFCD 2000-05): an open-label, randomised, phase 3 trial.
Abstract 4:
BACKGROUND The optimum use of cytotoxic drugs for advanced colorectal cancer has not been defined . Our aim was to investigate whether combination treatment is better than the sequential administration of the same drugs in patients with advanced colorectal cancer . METHODS In this open-label , r and omised , phase 3 trial , we r and omly assigned patients ( 1:1 ratio ) with advanced , measurable , non-resectable colorectal cancer and WHO performance status 0 - 2 to receive either first-line treatment with bolus ( 400 mg/m(2 ) ) and infusional ( 2400 mg/m(2 ) ) fluorouracil plus leucovorin ( 400 mg/m(2 ) ) ( simplified LV5FU2 regimen ) , second-line LV5FU2 plus oxaliplatin ( 100 mg/m(2 ) ) ( FOLFOX6 ) , and third-line LV5FU2 plus irinotecan ( 180 mg/m(2 ) ) ( FOLFIRI ) or first-line FOLFOX6 and second-line FOLFIRI . Chemotherapy was administered every 2 weeks . R and omisation was done central ly using minimisation ( minimisation factors were WHO performance status , previous adjuvant chemotherapy , number of disease sites , and centre ) . The primary endpoint was progression-free survival after two lines of treatment . Analyses were by intention-to-treat . This trial is registered at Clinical Trials.gov , NCT00126256 . FINDINGS 205 patients were r and omly assigned to the sequential group and 205 to the combination group . 161 ( 79 % ) patients in the sequential group and 161 ( 79 % ) in the combination group died during the study . Median progression-free survival after two lines was 10·5 months ( 95 % CI 9·6 - 11·5 ) in the sequential group and 10·3 months ( 9·0 - 11·9 ) in the combination group ( hazard ratio 0·95 , 95 % CI 0·77 - 1·16 ; p=0·61 ) . All six deaths caused by toxic effects of treatment occurred in the combination group . During first-line chemotherapy , significantly fewer severe ( grade 3 - 4 ) haematological adverse events ( 12 events in 203 patients in sequential group vs 83 events in 203 patients in combination group ; p<0·0001 ) and non-haematological adverse events ( 26 events vs 186 events ; p<0·0001 ) occurred in the sequential group than in the combination group . INTERPRETATION Upfront combination chemotherapy is more toxic and is not more effective than the sequential use of the same cytotoxic drugs in patients with advanced , non-resectable colorectal cancer . FUNDING Sanofi-Aventis France
FOLFIRI-B is a reasonable and effective option for stage IV CRC pretreated with oxaliplatin and not exposed to B during first-line treatment .
Its activity seems better than historical FOLFIRI-based second-line trials