Ipsilateral breast tumor recurrence as a predictor of distant disease: implications for systemic therapy at the time of local relapse.

PURPOSE To evaluate the prognostic significance of ipsilateral breast tumor recurrence (IBTR) with respect to the subsequent development of distant metastasis. MATERIALS AND METHODS Between January 1970 and December 1989, 973 patients with invasive breast cancer were treated with conservative surgery and radiation therapy at Yale-New Haven Hospital. The median follow-up time as of December 1993 was 8.6 years. A number of prognostic factors were tested as possible predictors of distant metastases, including whether a patient experienced IBTR. IBTRs were broken down by time to recurrence to determine whether the breast recurrence-free interval had any prognostic relevance with respect to the development of distant metastasis. RESULTS As of December 1993, out of the entire population of 973 patients, 73 patients had developed IBTR and 134 had developed distant metastases. The overall actuarial survival rate at 10 years was .71 +/- .02, with a 10-year actuarial breast recurrence-free rate of .84 +/- .02 and a 10-year distant metastasis-free rate of .77 +/- .02. The overall distant metastasis rate was higher in patients who experienced IBTR compared with patients who had never experienced IBTR. Furthermore, the time to IBTR had a significant effect on distant metastases. Of 32 patients who developed an IBTR within 4 years of original diagnosis, 16 (50%) developed distant metastases. In contrast, of 41 patients who developed later breast relapses (> 4 years from original diagnosis), only seven (17%) developed distant metastases (P < .01). Of 32 patients who developed early breast relapse, the 5-year survival rate following breast relapse was .50 +/- .01, compared with a 5-year post-breast relapse survival rate of .78 +/- .10 among 41 patients with later breast relapses (P < .05). CONCLUSION It appears that early IBTR is a significant predictor for distant metastases. Whether early breast tumor relapse is a marker for or cause of distant metastases remains a controversial and unresolved issue. Implications for adjuvant systemic therapy at the time of breast relapse are discussed.