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

Background: We have been following a cohort of patients who underwent a lum pectomy without receiving adjuvant radiotherapy or adjuvant systemic therap y. 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 c ancer recurrence. The factors studied were the patient's age in years; tumo r size (in mm); nodal status (N-, Nx, N+); estrogen and progesterone recept or status (<10, greater than or equal to 10 fmol/mg protein); presence or a bsence of lymphovascular/perineural invasion; presence or absence, and type , of DCIS (none, non-comedo, comedo); percentage of DCIS; histological grad e (1,2,3); and nuclear grade (1,2,3). Univariate analyses consisted of Kapl an-Meier plots and the Wilcoxon (Peto-Prentice) test statistic; the multiva riate 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 indic ated that the characteristics of smaller tumor size, negative nodes, positi ve 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 greater than or equal to 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 c ontinues to be support for the theory that local relapse is affected by the factors lymphovascular or perineural invasion, age, amount of DCIS, ER, an d nodal status. A low risk subgroup has been identified.