Comparison of serum blocking factors on leucocyte adherence inhibition and PHA lymphocyte blastogenesis in breast cancer patients.

Specific and nonspecific serum blocking factors (SBF) in sera from 48 breast cancer patients were examined to evaluate the correlation of SBF to the tumor burden. Specific SBF in leucocyte adherence inhibition (LAI) assay was demonstrated in 15 of 21 patients with a recurrence, in five of 11 with local or regional involvement and in 3 of 16 with no evidence of the disease (NED). The difference between patients with recurrence and with NED was significant (P less than 0.005). SBF in LAI and lymphocyte blastogenesis correlated in 29 of 48 (60%) patients (both positive 9 of 48, both negative 20 of 48). However, SBF in LAI was demonstrated in 14 of 48 (29%) patients whose sera showed no SBF in lymphocyte blastogenesis. These results indicate that SBF in LAI and lymphocyte blastogenesis are either induced or derived from breast cancer tissue. SBF in LAI correlates closely with the tumor burden, more so than do SBF in lymphocyte blastogenesis. The blocking assays have a potential use for prognostication and a guide for clinical therapy.