RESUMO
OBJECTIVES: In the past two decades, nonpalpable breast cancer incidence has greatly increased by routine screening mammography. Microcalcifications are the most frequent radiological feature. METHODS: Between 1964 and 1994, 789 breast cancers revealed by clustered microcalcifications without palpable mass were treated at Institut Curie. Patients who had a past history of breast cancer or a contralateral cancer were eliminated like those with lobular carcinoma in situ. The definitive treatment was decided on the margins of the initial excision and the presence of microcalcifications on postoperative mammograms. RESULTS: Mean follow-up of the patients was 77 months (9-358). The treatment was conservative in 49.5% and radical in 50.5%. Histologically, 43.5% of the lesions were intraductal carcinoma, 25.5% were microinvasive and 31% were infiltrating cancers. Five and ten years overall survival were 98% and 92.5% respectively, 50% of the patients died from their breast cancer. This survival was identical for intraductal, microinvasive and invasive carcinomas without lymph node metastasis, but was less favorable in patients with node metastasis. There were no survival differences for the two treatment modalities, although local recurrences were more frequent in the conservative one. The 5-year recurrence rate was 3.5% for intraductal subtype, 4.4% for microinvasive and 6% for invasive cancers. The difference was not statistically significant. CONCLUSION: Under the impact of mammographic screening, sizable proportions of breast cancer patients are being seen in a totally nonpalpable state with either a very small invasive, microinvasive or intraductal breast cancer. These lesions have an excellent prognosis, and can benefit from less aggressive treatments. In the case of diffuse microcalcifications, where a radical treatment is indicated, skin sparing mastectomy can be easily done followed by immediate reconstructive surgery.
