The aim of the present study was to investigate the therapeutic outcome of early-stage breast cancer (pT1aN0M0) and to identify prognostic factors for secondary primary contralateral breast cancer (CBC). A total of 85 patients with mammary carcinomas were included. All patients had undergone breast surgery and adjuvant treatment between January 2001 and December 2008 at the Central Hospital of Grenoble University (Grenoble, France). The primary end-points were disease-free survival and secondary CBC, and the potential prognostic factors were investigated. During a median follow-up of 60 months, 10 of the 85 patients presented with secondary primary cancer, of which six suffered with CBC. No patient mortalities were reported. The rates of CBC were 2.35, 3.53 and 7.06% at one, two and five years, respectively. The cumulative univariate analysis showed that microinvasion and family history are potential risk factors for newly CBC. The current study also demonstrated that secondary CBC was more likely to occur in patients with microinvasion or a family history of hte dise. In addition, the systematic treatment of secondary CBC should include hormone therapy.