LOCAL RECURRENCE VERSUS NEW PRIMARY - CLINICAL ANALYSIS OF 82 BREAST RELAPSES AND POTENTIAL APPLICATIONS FOR GENETIC FINGERPRINTING

Purpose: The purpose of this study was to perform a detailed clinical pathological analysis of breast relapses in patients treated with cons ervative surgery and radiation therapy in an effort to classify those relapses as true local recurrences or second primary tumors, and to as sess the prognostic and therapeutic implications of such a classificat ion system. Methods and Materials: Of 990 patients treated with conser vative surgery and radiation therapy at our facilities prior to Decemb er 1987, 82 patients have experienced a relapse in the conservatively treated breast as the primary site of failure. Patients were classifie d as having new primary tumors if they fulfilled any one of the follow ing criteria: a) breast relapse occurring at a site distinctly removed from the original tumor; b) histology of the breast relapse compared with the original tumor consistent with a new primary; or c) DNA flow cytometry converting from an aneuploid primary to a diploid relapse. R esults: As of 2/92, with a median follow-up of 5.4 years from the time of breast relapse, the overall 5-year survival rate following breast relapse was 55%. Forty-seven patients were classified as true recurren ces and 33 patients were classified as new primaries. Patients classif ied as true recurrences had a shorter median time to breast relapse th an patients classified as new primaries (3.16 years vs.5.42 years, p < .05) and an inferior post breast recurrence survival rate compared to patients classified as new primaries (36% vs.89%, p < .05). Residual disease outside of the recurrent tumor bed was also noted to be more f requent in patients classified as true recurrences compared to patient s classified as new primaries (48% vs.16%, p < .05). Conclusion: Based on the clinical and pathological criteria outlined, it appears that a significant portion of patients experiencing a relapse in the conserv atively treated breast may have new primary tumors as opposed to true local relapses. Distinction between a true recurrence and a new primar y tumor may have significant prognostic implications. Uncertainties as sociated with the clinical and pathological criteria are presented and further investigations with genetic fingerprinting techniques to esta blish the clonality of breast relapses are presented and discussed.