Presence of PAF-acether in human breast carcinoma: relation to axillary lymph node metastasis.

PAF-acether (PAF; formerly platelet-activating factor), a potent lipid mediator of inflammation, is involved in multiple cellular functions. To evaluate the role of PAF in human cancer, we obtained specimens from patients with localized breast carcinoma and assayed them for PAF. PAF was found in almost all carcinoma, although it was not detected in most of the matched, nontumor breast tissue samples. Intratumor PAF level was elevated when axillary lymph node involvement was low. Greater axillary extension (two or more positive lymph nodes) was associated with a decreased intratumor PAF level. These findings, along with the independence of other prognostic factors, indicate that PAF is a tumor marker of axillary lymph node involvement.