NEW THERAPEUTIC POSSIBILITIES IN PRIMARY INVASIVE BREAST-CANCER

Objective Current therapy for small invasive breast cancer, particular ly when discovered mammographically, was re-examined. Axillary dissect ion may be avoided when lymph node metastases incidence is low (< 10%) or when primary cancer features determine adjuvant therapy. Radiation therapy may be avoided when risk of recurrence is very low. Summary B ackground Data Recent studies by the Surveillance, Epidemiology, and E nd Results program (SEER) have shown increases in small invasive breas t cancers (< 1 cm) attributable to mammographic screening, The inciden ce of axillary metastases in mammographically discovered small cancers (< 1 cm) may be less than 1 0%. Follow-up data from the Breast Cancer Detection Demonstration Project (BCDDP) indicate a disease-free survi val rate exceeding 95% at 8 years if the cancer was discovered mammogr aphically. Methods Maximum diameter and lymph node metastases of invas ive breast cancers diagnosed between 1969 and 1988 were analyzed and c ompared to cases diagnosed between 1929 and 1968. One hundred thirty p atients have been treated without either axillary dissection or radiat ion therapy since 1980. Results The mean and median diameters of invas ive breast cancers decreased to 2.31 and 2.0 cm, respectively, between 1984 and 1988; 13% were less than 1 cm in diameter. Only 13% of patie nts had axillary metastases if the primary cancer was 1 cm or less in diameter in the last 1 0 years; 71 % had only 1 or 2 nodes involved. I solated local recurrence, total local recurrence, and distant metastas es were unchanged when radiated and nonirradiated patients were compar ed. Axillary nodal recurrence was decreased in irradiated patients bec ause the lower half of the axilla was treated. Conclusion In selected patients with very small invasive breast cancers detected by mammograp hy, breast conservation without axillary dissection or radiation thera py may be used. Entirely outpatient treatment markedly reduces morbidi ty and cost, and furthers the gains from screening programs.