A retrospective study examining the influence of young age, defined as 30 years or less on the outcome of early-staged (American Joint Committee 1978-I, II) breast cancer was undertaken using patients treated between 1950 and 1970 to ensure a long follow-up period. Because of the era of treatment, radical mastectomy without systemic chemotherapy was the predominant treatment. Ninety-nine patients met study criteria, with a median follow-up of 11.4 years (range 0.5 to 41 years). The patient group was compared to patients of all ages, treated at Memorial Sloan-Kettering Cancer Center in 1960 (5 and 10 years) and to patients treated between 1940 and 1943 (30 year follow-up). At the 5, 10, and 30 year follow-up periods, patients in the young age group consistently had disease-specific survival 10-20% lower than their older counterparts. For young patients who survived their first cancer diagnosis, second primaries both in the contralateral breast and elsewhere, played a significant role in determining their subsequent life span. When compared to risks of second primary cancers in the National Cancer Institute's SEER (Surveillance, Epidemiology and End Results Program) Cancer Registry for all ages, the increased risk for very young breast cancer patients was significant (p = 0.000). With these two findings in mind, treatment for young patients with breast cancer should focus not on local therapy options alone but on the increased risk of both systemic disease and of second primaries.