nQuery Advisor + nTerim was used to calculate sample size in a study conducted at St James Hospital, Dublin. The study evaluated the dose intensity and toxicities experienced by patients of normal and increased body mass index BMI treated with FOLFOX chemo- therapy, and demonstrated that overweight patients may tolerate doses based on actual body weight.
The results of the study were recently published in the January edition of the European Journal of Oncology Pharmacy.
All patients who received FOLFOX 6 (+/− bevacizumab) between January 2006 and March 2010 were identified using Clinichemo. Clinichemo is the computerized system used for dispensing chemotherapy and has a record of each patient’s height and weight facilitating the calculation of BMI.
All patients who fitted into either the normal BMI group or the increased BMI group were stratified for age and gender. Randomised selection from each stratified group was employed. To calculate sample size nQuery Advisor + nTerim was used. A sample size of n = 17 was calculated to detect a significant difference between the two groups (CI 95%). Initially, 38 patients were included in each group to allow for loss to follow up. All statistics were analyzed using a power of 80% and significance level of 5% and there were 17 patients in each group.
The main findings from the study were that there was no statistically significant difference in the RDI percentage with which the patients of normal BMI and those with increased BMI were treated. The severity of toxicities between the groups also proved non-significant. However, a trend could be seen whereby the normal BMI group experienced more severe toxicities despite being treated with lower dose intensity than the increased BMI group.
Although the results seen in this study were not statistically significant, it can be seen that the increased BMI group suffered less grade 3 and 4 toxicities, completed more cycles on average than the normal BMI group, had less frequent dose reductions due to toxicity, spent less days in hospital due to toxicity and higher RDI percentage. The increased BMI group were initiated on a lower dose intensity percentage due to capping of the BSA at 21 they were tolerating a higher dose intensity percentage thannormal BMI group throughout treatment. This suggests, in line with the recent ASCO Guide- lines, that patients with an increased BMI can tolerate doses of FOLFOX based on actual body weight. In the future, clinical trials will need to address the impact of obesity on drug therapy. For more information CLICK HERE
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