Primary tumor site, size, patients age and axillary lymph nodes in breast cancers.

This study considers the correlations between some characteristics of the primary tumor and level of lymph node involvement in 185 primary breast cancers. The average number of lymph nodes was higher in N+ women than in N- women. Primary tumors with a diameter of more than 4 cm yielded the highest mean number of lymph nodes (17.5). The risk of developing lymph node metastases was fourfold in tumors with a diameter greater than 2 cm when compared to those with a diameter less than or equal to 2 cm. The most commonly metastasized lymph node level, in both large and small tumors, was the first; however, one-fifth of the patients had simultaneous lymph node metastasis in all three axillary levels. Although the left breast was the most affected (58.9%), there was no evidence of a different risk of metastasis between the two breasts; 34.1% of the tumors were multifocal. Lymph node involvement was higher in women under 50 years of age with a primary tumor larger than 2 cm.