AXILLARY LYMPH-NODE DISSECTION IN NON-PAL PABLE BREAST CANCERS

The study concerns 265 patients with axillary lymph node dissection fo r non-palpable breast cancer. The mammographically detected breast tum ors were: 36 ductal carcinomas in situ (DCIS), 23 microinvasive carcin omas, 206 invasive carcinomas of which 179 were invasive ductal cancer s (IDC), 25 invasive lobular cancers (ILC) and 2 mucinous invasive car cinomas. The histologic size of the invasive component was less than o r equal to 5 mm in 38 cases, 6-10 mm in 84 cases, 11-15 mm in 53 cases , 16-20 mm in 16 cases, > 20 mm in 15 cases, Axillary dissection was p erformed immediately during the initial surgical procedure in 209 pati ents (79%) or secondarily in 56 (21%) according to the results of intr aoperative examination of surgical specimens on frozen sections. Axill ary lymph node involvement was not found in DCIS, microinvasive carcin omas or invasive carcinomas less than or equal to 5 mm in size. Among all 206 invasive breast carcinomas, lymph node involvement was found i n 7.8% (16/206) of cases. There were 9/84 (10.7%) in tumors > 10 mm, 7 /122 (5.8%) in tumors less than or equal to 10 mm. Thus, it is conclud ed that lymph node involvement is unlikely to be found in patients wit h non palpable breast cancers, specially those with carcinoma in situ, microinvasive breast tumors and invasive breast cancer with less than 5 mm maximum diameter size. Axillary dissection may be avoided in the se patients. However, the use of new prognostic factors of lymph node involvement may help in the definition of patient group.