Factors associated with local breast cancer recurrence after lumpectomy alone: Postmenopausal patients

Background: We have been following a cohort of patients who underwent a lumpectomy without receiving adjuvant radiotherapy or adjuvant systemic therapy. We now report the experience of a postmenopausal subgroup. Methods: The postmenopausal subgroup included 244 patients accrued between 1977 and 1986 and followed up. The end point was ipsilateral local breast cancer recurrence. The factors studied were the patient’s age in years; tumor size (in mm); nodal status (N-, Nx, N+); estrogen and progesterone receptor status (<10, ≥10 fmol/mg protein); presence or absence of lymphovascular/perineural invasion; presence or absence, and type, of DCIS (none, non-comedo, comedo); percentage of DCIS; histological grade (1,2,3); and nuclear grade (1,2,3). Univariate analyses consisted of Kaplan-Meier plots and the Wilcoxon (Peto-Prentice) test statistic; the multivariate analyses were step-wise Cox and log-normal regressions. Results: The median follow-up of those patients still alive was 9.1 years, and the overall relapse rate was 24% (59/244). The univariate results indicated that the characteristics of smaller tumor size, negative nodes, positive ER status, and no lymphovascular or perineural invasion were associated with significantly (P<.05) lower relapse. From the multivariate analyses, the factors lymphovascular or perineural invasion, age, and amount of DCIS were all significantly associated with local relapse with both Cox and log-normal regressions. Additionally, there was weak evidence of an association between ER (P=.08 in the Cox regression and in the log-normal) and nodal status (P=.09 in the log-normal regression) with local relapse. We also are able to define a low-risk subgroup (N-, age ≥65, no comedo, ER positive, no emboli) with a crude 10-year local recurrence rate of 9%. Conclusion: With longer follow-up, and for postmenopausal patients, there continues to be support for the theory that local relapse is affected by the factors lymphovascular or perineural invasion, age, amount of DCIS, ER, and nodal status. A low risk subgroup has been identified. Presented at the 53rd Annual Meeting of the Society of Surgical Oncology, March 16–19, 2000, New Orleans.