BREAST-CANCER REVEALED BY CLUSTER OF MICR OCALCIFICATIONS WITHOUT PALPABLE MASS - PROGNOSIS AND TREATMENT

Objectives: Routine screening mammography has greatly increased the nu mber of breast cancers detected in the form of clumped microcalcificat ions without a palpable tumour. Methods: From 1964 to 1989, 315 breast cancers revealed by microcalcifications without contralateral cancer, treated at the Institut Curie, Cancers were observed in 40% of the mi crocalcifications excised. Treatment was conservative in 57.5% of case s and mutilating in 42.5% of cases; these rates have changed only very slightly with time. Histologically, 50% of the tumours were intraduct al cancers, 25% were microinvasive, 24% were infiltrating and 1% were lobular in situ carcinomas. The therapeutic indication can be defined on the basis of the histological result of the initial tumour excision , as the initial examination underestimated the lesions in only 5.6% o f cases. Lymph node invasion was observed in 1.8% of intraductal cance rs, 5.3% of microinvasive cancers and 14.8% of invasive cancers. Resul ts: The overall survival was 99% at 5 years and 89.9% at 10 years. The prognosis of invasive cancer was less favourable than that of intradu ctal and microinvasive cancers (p = 0.03). Survival was not influenced by the radical or conservative nature of treatment. The presence of l ymph node invasion severely worsened the prognosis. The 5 year recurre nce rate was 4.2% for intraductal, 4.6% for microinvasive and 6.1% for invasive. The incomplete nature of the resection increased the local recurrence rate: 11.9% at 5 years instead of 5%. Conclusion: Conservat ive treatment of cancers revealed by microcalcifications without a pal pable tumour therefore appears to be justified provided the lesion is radiologically localized, with a histologically satisfactory resection and in the absence of residual microcalcifications on postoperative m ammography.