Node-negative breast cancer treated by modified radical mastectomy without adjuvant therapies: variables associated with disease recurrence and survivorship.

The present study attempts to identify poor prognosis subgroups of women with node-negative breast cancer that might benefit from systemic adjuvant therapy. The cases were collected through a cooperative effort of 57 surgeons at eight hospitals in the Detroit area and coordinated by the Michigan Cancer Foundation where data collection and analyses were completed. The primary treatment of all patients was a modified radical mastectomy. Of the 1,078 cases accessioned between October 1975 and April 1983, 537 were found to have no microscopic lymph node involvement and 462 of these cases received no adjuvant antineoplastic therapy. The period of follow-up of these cases (alive, n = 358) has been 78.75 +/- 24.6 months (mean +/- SD). Overall, the cumulative 6-year recurrence rate as calculated by life table analysis was 26%, with 16.8% dying of their disease. Tumor size was an important prognostic factor; the recurrence rate was 16.2% for those with primaries measuring less than or equal to 1 cm, with only a 6....