A Study of Avastin (Bevacizumab) in Combination With mFOLFOX-6 or FOLFOXIRI in Patients With Metastatic Colorectal Cancer.

Following resective surgery, participants were evaluated for complete resection (R0) or the presence of microscopic (R1) or macroscopic (R2) residual tumor. The percentage of participants within each residual tumor classification was calculated as [number of participants with R0, R1, and/or R2 divided by the total number of participants] multiplied by 100. Associated 95% confidence intervals were calculated for one-sample binomial using the Clopper-Pearson method.

Time to resection was defined as the time from randomization to the date of first resective surgery. For participants who did not undergo resective surgery, time to resection was censored at Day 1. Time to resection was estimated by Kaplan-Meier analysis.

At the time of resective surgery, participants were evaluated for histopathological response as defined through pathologist review of the resected metastatic lesions, including assessment of margin status and tumor cell viability. Histopathological response classification was based upon the percentage of viable tumor cells, where 'Complete response' was considered for those with 0 percent (%) viable tumor cells, 'Major response' for those with 1% to 49% viable tumor cells, 'Minor response' for 50% to 99% viable tumor cells, and 'No response' for 100% viable tumor cells. The response could not be determined in some cases and was documented as 'Unknown.' The percentage of participants within each response category was calculated as [number of participants with a given response divided by the number of participants who completed the assessment] multiplied by 100.

At the time of resective surgery, participants were evaluated for histopathological response as defined through pathologist review of the resected metastatic lesions, including assessment of margin status and tumor cell viability. Histopathological response classification was based upon the percentage of viable tumor cells, as described previously. The collective percentage of participants assessed as having a complete or major response was calculated as [number of participants with complete or major response divided by the number of participants who completed the assessment] multiplied by 100. Associated 95% confidence intervals were calculated for one-sample binomial using the Clopper-Pearson method.

Among participants with curative resection (complete resection [R0] or microscopic residual tumor [R1]), relapse was defined as the first new occurrence of cancer or death. The percentage of participants who experienced relapse was calculated as [number of participants with a relapse event divided by the number of participants initially classified as R0 or R1 following resective surgery] multiplied by 100.

RFS was defined as the time from curative resection (complete resection [R0] or microscopic residual tumor [R1]) to the date of first diagnosis of relapse. For participants with curative resection and without relapse, RFS was censored at the last known relapse-free assessment. RFS was estimated by Kaplan-Meier analysis.

PD was defined, using Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0, as at least a 20% increase in the sum of the longest diameter of target lesions, or the appearance of one or more new lesions. The percentage of participants experiencing PD or death was calculated as [number of participants with event divided by the number of participants analyzed] multiplied by 100.

PFS was defined, using RECIST version 1.0, as the time from randomization to the date of first documented PD or death from any cause. PD was defined as at least a 20% increase in the sum of the longest diameter of target lesions, or the appearance of one or more new lesions. For participants without documented PD or death, PFS was censored at the time of last tumor assessment. PFS was estimated by Kaplan-Meier analysis.

OS was defined as the time from randomization to death from any cause. For participants without an event of death, OS was censored at the last-known alive date. OS was estimated by Kaplan-Meier analysis.

Using RECIST version 1.0, participants were considered to have achieved CR upon the disappearance of all target and non-target lesions. Participants who achieved PR demonstrated at least a 30% decrease in the sum of the largest diameter of target lesions, taking as reference the Screening sum largest diameter. Responses were confirmed by repeat assessments no less than 4 weeks after criteria for response were first met. The collective percentage of participants with confirmed best overall response of CR or PR was calculated as [number of participants meeting RECIST criteria for CR or PR divided by the number of participants analyzed] multiplied by 100. Associated 95% confidence intervals were calculated for one-sample binomial using the Clopper-Pearson method.

Time to response according to RECIST version 1.0 was defined as the time from randomization to the date of first documented CR or PR. Participants were considered to have achieved CR upon the disappearance of all target and non-target lesions. Participants who achieved PR demonstrated at least a 30% decrease in the sum of the largest diameter of target lesions, taking as reference the Screening sum largest diameter. Responses were confirmed by repeat assessments no less than 4 weeks after criteria for response were first met. For participants who did not complete a confirmatory tumor assessment, time to response was censored at the date of last tumor assessment, or if unavailable, at the date of first dose. Time to response was estimated by Kaplan-Meier analysis.

Complications related to the first resective surgery were evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 3.0, and classified according to severity. The NCI-CTCAE severity classification criteria are as follows: Grade 5 equals (=) resulting in death; Grade 4 = life-threatening; Grade 3 = severe; Grade 2 = moderate; and Grade 1 = mild. The percentage of participants experiencing a given adverse event (AE) by severity grade was calculated as [number of participants with an AE divided by the number of participants who underwent first resective surgery] multiplied by 100.

Complications related to the second resective surgery were evaluated using the NCI-CTCAE version 3.0, and classified according to severity. The NCI-CTCAE severity classification criteria are as follows: Grade 5 = resulting in death; Grade 4 = life-threatening; Grade 3 = severe; Grade 2 = moderate; and Grade 1 = mild. The percentage of participants experiencing a given AE by severity grade was calculated as [number of participants with an AE divided by the number of participants who underwent second resective surgery] multiplied by 100.