A case-control study was conducted on 143 case-control sets recruited from the 18 key hospitals/ institutes in Japan to identify risk factors for local recurrences and distant metastases after breast-conserving surgery in breast cancer patients: (1) positive surgical margin was a risk factor for local recurrences (relative risk (RR) = 16.70, p < 0.001) but not for distant metastases, (2) positive p53 immunostaining was a risk factor for both local recurrences (RR = 5.62, p = 0.003) and distant metastases (RR = 3.11, p = 0.034), (3) lymph node metastasis was a risk factor for distant metastases (RR = 9.28, p = 0.001) but not for local recurrences, (4) radiation therapy reduced local recurrences (RR = 0.13, p = 0.004) and (5) adjuvant chemotherapy (RR = 0.27, p = 0.120), endocrine therapy (RR = 0.21, p = 0.037), and chemoendocrine therapy (RR = 0.05, p = 0.013) reduced local recurrences.