Testing for mutations of the ataxia telangiectasia gene in radiosensitive breast cancer patients.

BACKGROUND AND PURPOSE

To determine if clinical radiosensitivity in breast cancer patients is related to mutations of the ataxia telangiectasia gene (ATM).

MATERIALS AND METHODS

Fifteen patients who had developed a severe late reaction to a standard radiotherapy schedule were examined for evidence of increased in vitro radiosensitivity using the MTT assay. Mutation analysis was performed using a protein truncation assay.

RESULTS

No mutations were detected in the 15 patients despite evidence of increased in vitro radiosensitivity.

CONCLUSIONS

Testing for the ATM gene is unlikely to be useful for predicting clinical response to radiotherapy in breast cancer patients.