Minimal breast cancer: advance or anachronism?

The author argues that minimal breast cancer does not represent a distinct disease entity but comprises three discrete components, each with unique characteristics. The natural history of lobular carcinoma in situ and intraductal cancer, two of the components of minimal breast cancer, is described. The dangers of relying on a data base established on the strength of retrospective anecdotal information is underscored. Lobular carcinoma in situ has a propensity for multicentricity and bilaterality. In 25% of patients with lobular carcinoma in situ, invasive breast cancer will develop subsequently, and the majority of these tumours will be of ductal origin. The average interval from the diagnosis of lobular carcinoma in situ to the development of subsequent invasive cancer is over 15 years and both breasts are at equal risk. Based on this information, the use of bilateral prophylactic mastectomy is unjustified. In contrast to lobular carcinoma in situ, 25% to 50% of patients with intraductal carcinoma will subsequently have infiltrating cancer, at an average of 10 years after the initial biopsy. Although the putative incidence of multicentricity is 50%, virtually all subsequent invasive cancers occur not only in the same breast but in the same quadrant as the initial lesion. In light of the momentum for breast-preserving operations in invasive cancer, clinical trials should be implemented to assess the propriety of conservative management with and without radiotherapy in patients with intraductal carcinoma.