Mammographic, pathologic, and treatment-related factors associated with local recurrence in patients with early-stage breast cancer treated with breast conserving therapy.

BACKGROUND

We retrospectively reviewed our institution's experience treating early-stage breast cancer patients with breast conserving therapy (BCT) to determine clinical, pathologic, mammographic, and treatment-related factors associated with outcome.

METHODS

Between January 1980 and December 1987, 400 cases of Stage I and II breast cancer were managed with BCT at William Beaumont Hospital, Royal Oak, Michigan. All patients underwent at least an excisional biopsy. Radiation treatment consisted of delivering 45-50 Gy to the whole breast, followed by a boost to the tumor bed to at least 60 Gy in all patients. The median follow-up in the 292 surviving patients is 118 months. Multiple clinical, pathologic, mammographic, and treatment-related factors were analyzed for an association with local recurrence and survival.

RESULTS

A total of 37 local recurrences developed in the treated breast, for a 5- and 10-year actuarial rate of 4% and 10%, respectively. On univariate analysis, patient age < or =35 years (25% vs. 7%, p = 0.004), and positive surgical margins (17% vs. 6%, p = 0.018) were associated with an increased risk of local recurrence at 10 years. On multivariate analysis, only age < or = 35 years remained significant. A subset analysis of 214 patients with evaluable mammographic findings was performed. On univariate analysis, age < or = 35 years (38% vs. 8%, p = 0.0029) and the presence of calcifications on preoperative mammography (22% vs. 6%, p = 0.0016) were associated with an increased risk of local recurrence. On multivariate analysis, both of these factors remained significant. The presence of calcifications on preoperative mammography did not affect the rates of overall survival, disease-free survival, and cause-specific survival.

CONCLUSION

In patients with early-stage breast cancer treated with BCT, age < or = 35 years and calcifications on preoperative mammography appear to be associated with an increased risk of local recurrence.