PROGNOSTIC ROLE OF LYMPH-NODE LEVEL INVOLVEMENT IN PATIENTS UNDERGOING AXILLARY DISSECTION FOR BREAST-CANCER

Aims. Clinical records of patients undergoing surgery for breast cance r were reviewed in order to evaluate the prognostic role of lymph-node level involvement. Methods. From 1982 to 1991, 1143 patients had radi cal mastectomy or conservative surgery with total axillary dissection: 461 patients of mean age 57.1 years (range: 25-89 years) were lymph-n ode positive (pN1); 369 patients (80%) had radical mastectomy; and 92 patients (20%) had conservative treatment plus post-operative radiothe rapy, with the same mean number (n = 16) of lymph nodes collected in t he surgical specimen. Data were analysed for the number of positive ly mph nodes and level of involvement. Results. Level I, Levels I+II and Levels I+II+III were involved in 44.9, 18 and 21.4% of patients, respe ctively; 'skip metastases' occurred in 72 of 461 pN1 patients (15.5%). A univariate analysis showed that prognosis was directly related to t he number of levels involved (P<0.001), and skip metastases had the sa me prognostic role as Level I involvement. The numbers of involved lym ph-node levels and metastatic lymph nodes were well correlated; multiv ariate analysis showed that involvement of Levels I and III was indepe ndently correlated with prognosis. After adjustment for age and number of positive lymph nodes, the number of involved lymph-node levels was an independent prognostic factor, with highest predictability when al l three lymph-node levels were positive (P=0.009). Conclusions. The pr ognostic value of lymph-node status should be defined not only by the number of metastatic lymph nodes, but also by the number of levels of involvement.