Background: The radiologic images of 1-14-mm invasive breast carcinomas can be classified into 5 separate categories. The use of these mammographic indicators to predict patient outcome has important prognostic and therapeutic implications.
Methods: To verify the results of previous studies conducted with smaller numbers of patients, the authors studied the 24-year survival of 714 women with 1-14-mm invasive breast carcinoma according to mammographic prognostic factors. The association of mammographic features with lymph node status, histologic malignancy grade, and 24-year survival in 714 women with invasive breast carcinomas that measured 1-14 mm also was evaluated. Adjustments were made for tumor characteristics and treatment factors in the survival analysis.
Results: The most common mammographic feature was a stellate lesion with no associated calcifications (420 women; 59%). Patients with stellate lesions had excellent long-term survival (95%). Casting-type calcifications were observed in 52 women (7%) and were associated significantly with a positive lymph node status (odds ratio [OR], 3.29; 95% confidence interval [95% CI], 1.41-7.67), poorer histologic grade (OR, 7.04; 95% CI, 3.77-13.16), and an increased risk of death from breast carcinoma (HR, 9.19; 95% CI, 4.18-20.17). Except for women who had tumors with associated casting-type calcifications, all other women with tumors < 10 mm in size had excellent survival regardless of lymph node status, histologic grade, or treatment. For women who had casting-type calcifications, survival was poorer even in the group with tumors that measured 1-9 mm (72% at 20 years). For women with 10-14-mm tumors, the 20-year survival rate was 52% for those who had casting calcifications and 86-100% those for those who had other mammographic features.
Conclusions: The subgroup of women who had small invasive breast carcinomas accompanied by casting-type calcifications had an unexpectedly poor prognosis for this tumor-size category. The process of neoductgenesis offers a possible explanation for the unexpectedly poor outcome. There is a need to develop treatment protocols for this group and to reevaluate the present TNM classification system for mammographically detected 1-14-mm breast carcinomas. After excluding women who had tumors associated with casting-type calcifications, the remaining women had an extremely good prognosis when they were treated with surgery alone. Due to their already excellent survival, adjuvant therapeutic regimens are unlikely to offer further benefit for these patients.