CAN PROTOCOL-SPECIFIED DOSES OF CHEMOTHERAPY AND RADIOTHERAPY BE USEDAS A MEASURE OF TREATMENT ACTUALLY RECEIVED - A CCG NIH STUDY ON LONG-TERM SURVIVORS OF ACUTE LYMPHOCYTIC-LEUKEMIA/

In a cohort of 593 long-term survivors of acute lymphocytic leukemia i dentified through the Children's Cancer Group (CCG), treatment abstrac ts were obtained and compared to protocol information on radiation the rapy and intravenous chemotherapy. This was done in order to evaluate the actual compliance to protocol specified treatment, and assess if p rotocol specified doses can be used in studies of late effects of trea tment, The compliance to protocol specified type of treatment ranged b etween 95.3% (intrathecal methotrexate) and 98.6% (adriamycin) for che motherapy, and between 94.1% (cranial radiation) and 97.0% (extended h eld radiation) for radiation. Concordance with the protocol specified chemotherapy dose (+/- 25%) was 57.5% for adriamycin, 91.3% for daunom ycin, and 48.5% for cyclophosphamide. When concordance was low, most p atients received doses that were lower than expected. Concordance with chemotherapy was significantly lower for high dose regimens than for low dose regimens. Concordance with protocol specified radiation dose (+/- 10%) was 87.4% for cranial radiation, 87.8% for spinal radiation, and 85.7% for extended held radiation. Concordance with treatment did not differ by gender, relapse status, or age at diagnosis. In this co hort of leukemia survivors, the validity of type of treatment was grea ter than the validity of dosage. Great care should be used when drawin g conclusions about effects of treatment dosage. Although costly and t ime consuming, it appears that chart reviews are the most appropriate way to collect information about dose-related effects of therapy.