Bevacizumab in Stage II-III Colon Cancer: 5-Year Update of the National Surgical Adjuvant Breast and Bowel Project C-08 Trial
ABSTRACT PURPOSEThe National Surgical Adjuvant Breast and Bowel Project trial C-08 was designed to investigate the safety and efficacy of adding bevacizumab to fluorouracil, leucovorin, and oxaliplatin (FOLFOX6) for the adjuvant treatment of patients with stage 2-3 colon cancer. Our report summarizes the primary and secondary end points of disease-free and overall survival, respectively, with 5 years median follow-up time.Patients And methodsPatients received modified FOLFOX6 once every 2 weeks for a 6-month period (control group) or modified FOLFOX6 for 6 months plus bevacizumab (5 mg/kg) once every 2 weeks for a 12-month period (experimental group). The primary end point of the study was disease-free survival (DFS) and overall survival (OS) was a secondary end point.ResultsOf 2,673 analyzed patients, demographic factors were well-balanced by treatment. With a median follow-up of 5 years, the addition of bevacizumab to mFOLFOX6 did not result in an overall significant increase in DFS (hazard ratio [HR], 0.93; 95% CI, 0.81 to 1.08; P = .35). Exploratory analyses found that the effect of bevacizumab on DFS was different before and after a 1.25-year landmark (time-by-treatment interaction P value <.0001). The secondary end point of OS was no different between the two study arms for all patients (HR, 0.95; 95% CI, 0.79 to 1.13; P = .56) and for those with stage 3 disease (HR, 1.0; 95% CI, 0.83 to 1.21; P = .99). CONCLUSION
Bevacizumab for 1 year with modified FOLFOX6 does not significantly prolong DFS or OS in stage 2-3 colon cancer. We observed no evidence of a detrimental effect of exposure to bevacizumab. A transient effect on disease-free survival was observed during bevacizumab exposure in the study's experimental arm.
- Journal of Clinical Oncology 01/2014; 33(2):133-135. DOI:10.1200/JCO.2014.58.1298 · 17.88 Impact Factor
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ABSTRACT: Given the paucity of information on dose intensity, the objective of this study is to describe the use of adjuvant chemotherapy for stage III colon cancer, focusing on relative dose intensity (RDI), overall survival (OS) and disease-free survival (DFS). Retrospective cohort of 367 patients diagnosed with stage III colon cancer in 2003-2008 and treated at 19 VA medical centers. Kaplan-Meier curves summarize 5-year OS and 3-year DFS by chemotherapy regimen and RDI, and multivariable Cox proportional hazards regression was used to model these associations. 5-fluorouracil/leucovorin (FU/LV) was the most commonly initiated regimen in 2003 (94.4%) and 2004 (62.7%); in 2005-2008, a majority of patients (60%-74%) was started on an oxaliplatin-based regimen. Median RDI was 82.3%. Receipt of >70% RDI was associated with better 5-year OS (p < 0.001) and 3-year DFS (P = 0.009) than was receipt of ≤70% RDI, with 5-year OS rates of 66.3% and 50.5%, respectively and 3-year DFS rates of 66.1% and 52.7%, respectively. In the multivariable analysis of 5-year OS, oxaliplatin + 5-FU/LV (versus 5-FU/LV) (HR = 0.55; 95% CI = 0.34-0.91), >70% RDI at the first year (HR = 0.58; 95% CI = 0.37-0.89) and married status (HR = 0.66; 95% CI = 0.45-0.97) were associated with significantly decreased risk of death, while age ≥75 (versus 55-64) (HR = 2.06; 95% CI = 1.25-3.40), Charlson Comorbidity Index (HR = 1.17; 95% CI = 1.06-1.30), T4 tumor status (versus T1/T2) (HR = 5.88; 95% CI = 2.69-12.9), N2 node status (HR = 1.68; 95% CI = 1.12-2.50) and bowel obstruction (HR = 2.32, 95% CI = 1.36-3.95) were associated with significantly increased risk. Similar associations were observed for DFS. Patients with stage III colon cancer who received >70% RDI had improved 5-year OS. The association between RDI and survival needs to be examined in studies of adjuvant chemotherapy for colon cancer outside of the VA.BMC Cancer 12/2015; 15(1):1038. DOI:10.1186/s12885-015-1038-y · 3.32 Impact Factor
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ABSTRACT: In this issue of Cancer, Castonguay et al highlight problems with reliably estimating the median OS in the control arm of clinical trials in ovarian cancer. This suggests that more careful reflection is generally required concerning how clinically relevant differences are determined and highlights further issues with the selection of overall survival as a primary endpoint. The article also raises questions regarding the prevalent standard statistical approach used to design and analyze studies with time to event outcomes.Cancer 10/2014; 121(3). DOI:10.1002/cncr.29031 · 4.90 Impact Factor