AXILLARY LYMPH-NODE DISSECTION FOR T1A BREAST-CARCINOMA

Background. Axillary dissection has been a routine part of breast canc er treatment for more than 100 years. Axillary node involvement is the single most important prognostic variable in patients with breast can cer. Recently, routine node dissection has been eliminated for intradu ctal carcinoma because so few patients had positive nodes. With the av ailability of numerous histologic prognosticators and the development of new immunochemical prognostic indicators, it is time to consider el iminating routine node dissection for lesions more advanced than duct carcinoma in situ (DCIS) but with extremely low likelihood of axillary involvement. Methods. Axillary node positivity, disease-free survival , and breast cancer-specific survival were determined for six breast c ancer subgroups by T category: Tis (DCIS), T1a, T1b, T1c, T2, and T3. Results. Nodal positivity for DCIS was 0%; for T1a lesions, 3%. A larg e increase in nodal positivity was seen in lesions larger than 5 mm. ( T1b, 17%; T1c, 32%; T2, 44%; T3, 60%). The rate of nodal positivity wa s statistically different as each T category was compared with the nex t more advanced T category. The disease-free survival and breast cance r-specific survival decreased with every increment in T value. Conclus ions. Axillary node positivity increases as the size of the invasive c omponent increases and is an excellent predictor of DSF and breast can cer-specific survival. Consideration should be given to eliminating ax illary node dissection for Tla lesions because of the low yield of pos itive nodes. Axillary node dissection should be performed routinely fo r T1b lesions and larger.