Detection and significance of occult axillary node metastases in patients with invasive breast cancer.

Blocks of axillary lymph nodes from 78 patients with invasive breast cancer, which after "routine" pathological examination were regarded as negative for metastases, were step-sectioned at 20 u intervals. Occult metastases were detected in 24% of the cases. A significant association between such metastases and a lack of or slight degree of an intraductal carcinomatous component of the dominant cancer was noted. There was no relationship between occult metastases and 15 other histopathological and 3 clinical features investigated, including an average 5 year survival rate. Similarly there was no correlation between any of the possible discriminants investigated in the 24% of patients who have died of their diseases or are living with recurrence regardless of the presence of occult metastases. Factors accounting for the lack of universal survival in patients with Stage I (and those with occult metastases that might be designated as stage 11/2) remain enigmatic. It is concluded that attempts to detect occult metastases by extending histopathological methods may be more academic than practical or therapeutically significant.