A new study has said that breast cancer patients having a specific wild-type gene may be benefited by taking tamoxifen as compared to women not carrying the gene.
The study showed that women carrying Cytochrome P450 2D6 (CYP2D6), genes are likely to benefit more from tamoxifen.
The team of researchers led by Dr Rinaa Punglia, of the Dana-Farber Cancer Institute in Boston created a mathematical model to assess the benefits.
The researchers used estimates about the risk of recurrence from past randomized trials that showed that breast cancer survivors who take aromatase inhibitors reduce their risk of recurrence more than those taking tamoxifen.
They calculated that women with wild-type CYP2D6 who take tamoxifen would have approximately the same reduction in the risk of recurrence as was seen for the whole population of women who took aromatase inhibitors in the clinical trial.
Therefore, women with wild-type CYP2D6 genotype may derive as much benefit from tamoxifen as from aromatase inhibitors.
"Our model raises the possibility that tailored therapy based on pharmacogenomics could be considered for such women," write the authors.
The accompanying editorial written by Daniel Hayes, M.D., of the University of Michigan Comprehensive Cancer Centre in Ann Arbor and colleagues commented that the findings have brought the field of pharmacogenomics to the attention of breast cancer physicians. However, the analysis was based on limited data and on modeling assumptions and must be viewed with caution.
"We do not recommend routine CYP2D6 genotyping for all patients who are considering tamoxifen, although we recognize that there are already selected circumstances in which such knowledge might be helpful," they write.