An Observational Study on Bevacizumab (Avastin) as First-Line Treatment in Colorectal Cancer Participants With Potentially Resectable Liver Metastases

Secondary resection involves removal of all detectable metastases at surgery including participants with missing metastases left in place. Percentage of participants without detectable metastatic disease after secondary resection removing all detectable metastases at surgery (including participants with disappeared metastases left in place [missing metastases]) was reported. Metastases was detected using computed tomography (CT) scan or magnetic resonance imaging (MRI).

The percentage of participants with no detectable metastatic disease after a complete response without surgery (missing metastasis) was reported.

Percentage of participants who had any concurrent disease (comorbidity) at Day 0 was reported. Comorbidities included gastrointestinal disease, hypertension, other cardiovascular disease, and other medical history and comorbidities (other than those specified above). Same participant may be counted in more than one category.

Previous therapies included neoadjuvant treatment (chemotherapy or chemotherapy + radiotherapy) and adjuvant treatment (FOLFOX [folinic acid+5-fluorouracil+oxaliplatin], LV5FU2 [leucovorin+5-Fluorouracil], capecitabine, or any other adjuvant treatment). Only participants who received neoadjuvant treatment and adjuvant treatment was reported.

Percentage of participants who had any concurrent disease (comorbidity) was reported. Comorbidities included gastrointestinal disease, other cardiovascular disease, and other medical history and comorbidities (other than those which are specified above). Same participant may be counted in more than one category.

Disease progression is defined at least a 20 percent (%) increase in the sum of diameters of target lesions, and the sum must also demonstrate an absolute increase of at least 5 millimeter (mm) or persistence of non-target lesions, or appearance of one or more new lesions.

Progression-free survival defined as the time elapsed between the Avastin start date and the date of first progressive disease (PD) or death. Kaplan-Meier estimate was used for evaluation. PD: At least a 20% increase in the sum of diameters of target lesions, and the sum must also demonstrate an absolute increase of at least 5 mm or persistence of non-target lesions or appearance of one or more new lesions.

Relapse was defined as the presence of metastases post last surgery removing all detectable metastases (A1 criterion [participants without detectable metastatic disease {DMD} after secondary resection removing all detectable metastases at surgery {including participants with missing metastases}]) and the date of first PD or death. PD: At least a 20% increase in the sum of diameters of target lesions, and the sum must also demonstrate an absolute increase of at least 5 mm or persistence of non-target lesions, or appearance of one or more new lesions.

RFS was defined as the time elapsed between the last surgery removing all detectable metastases (A1 criterion [participants without DMD after secondary resection removing all detectable metastases at surgery {including participants with missing metastases}]) and the date of first PD or death. PD: At least a 20% increase in the sum of diameters of target lesions, and the sum must also demonstrate an absolute increase of at least 5 mm or persistence of non-target lesions, or appearance of one or more new lesions.

OS time is defined as time between start of therapy and date of death. Kaplan-Meier estimate was used for evaluation.

For the non-detectable liver and lung metastases the categorization based on rate of viable cells were as follows (no viable cells =0%, minimum =1 to 49%, maximum =50 to 100%).