QUALITY-CONTROL OF END RESULTS IN A DANISH ADJUVANT BREAST-CANCER MULTICENTER STUDY

In a Danish multi-center study, qualify control was performed on off-s tudy data for high-risk breast cancer patients included in protocols o f adjuvant therapy. In the two protocols 4455 patients were randomized and 2477 were registered off-study. Data from these patients were val idated by reviewing the patients' records. Incorrect data were observe d in 16.2% of the cases who went off-study due to recurrence, other ma lignant disease or death. In 258 of 2133 patients unidentical location s were demonstrated. Of these, 104 showed a rime difference also. A ma jor difference in site of recurrence was found in 107 patients (5.0%), 43 of whom were upstaged from local to a distant recurrence and 64 we re downstaged. A time difference of more than 30 days was found in 192 patients (9.0%) and in 17 the difference exceeded 366 days. A time di fference only was found in 88 patients (4%). The major parameter in th e statistical analysis of the two protocols, i.e. recurrence-free surv ival, was not significantly influenced by the validation.