Nonpalpable breast carcinomas: long-term evaluation of 1,258 cases.

Introduction: In recent decades, a steady improvement in imaging diagnostics has been observed together with a rising adherence to regular clinical breast examinations. As a result, the detection of small clinically occult (nonpalpable) lesions has progressively increased. At present in our institution some 20% of the cases are treated when nonpalpable. The aim of the present study is to analyze the characteristics and prognosis of such tumors treated in a single institution.
Methods: The analysis focused on 1,258 women who presented at the European Institute of Oncology with a primary clinically occult carcinoma between 2000 and 2006. All patients underwent radioguided occult lesion localization (ROLL), axillary dissection when appropriate, whole breast radiotherapy, or partial breast intraoperative irradiation and received tailored adjuvant systemic treatment.
Results: Median age was 56 years. Imaging showed a breast nodule in half of the cases and a breast nodule accompanied by microcalcifications in 9%. Microcalcifications alone were present in 17.1% of the cases, whereas suspicious opacity, distortion, or thickening represented the remaining 24.6%. Most tumors were characterized by low proliferative rates (68.9%), positive estrogen receptors (92.3%), and non-overexpressed Her2/neu (91.3%). After a median follow-up of 60 months, we observed 19 local events (1.5%), 12 regional events (1%), and 20 distant metastases (1.6%). Five-year overall survival was 98.6%.
Conclusions: Clinically occult (nonpalpable) carcinomas show very favorable prognostic features and high survival rates, showing the important role of modern imaging techniques.