Prognostic value of soluble MUC1 and anti-MUC1 antibody levels in patients with diffuse large B-cell lymphoma

6586 Background: A soluble form of mucin MUC1 (sMUC1) as well as antibodies anti-MUC1 can be found in peripheral blood (PB) of patients with MUC1+ carcinoma or myeloma. MUC1 is expressed in 80% of diffuse large cell lymphoma (DLCL). Methods: sMUC1 level was evaluated in 80 VBD (Volunteer Blood Donor) and 95 DLCL pts using an immunoassay that detects the MUC1 CA27.29 epitope. All DLCL pts were treated on study with the same anthracyclins-containing regimen at MD Anderson between 1993 and 1996. IgM and IgG antibodies against MUC1 were quantified using an immunoassay with a 60aa peptide part of MUC1 tandem repeat. The median level of sMUC1, anti-MUC1-IgG and anti-MUC1-IgM found in VBD was used as a cutoff to separate the patients in two groups. Results: The sMUC1 level was significantly higher in DLCL (mean 25.4 ± 11.3 U/ml) than in VBD (mean value 15.6 ± 9.1 U/ml) (p < .0001, Mann-Whitney). The level of circulating anti-MUC1-IgG was also significantly higher in DLCL (1.211 ± 0.959 Arb, U/ml) than in VBD (1.015 ± 0.667 Arb, U/ml) (p=. 0041, Mann-Whitney), but not for anti-MUC1-IgM. There was no statistical correlation between the levels of sMUC1 and the presence of anti-MUC1 antibodies. The 10-year failure-free survival (FFS) was 87.1% for pts with low sMUC1 vs. 56.7% for pts with high sMUC1 (p = .026; log-rank test.). The same correlation was seen with overall survival (P < .05). In addition sMUC1 remained an independent prognostic variable for FFS. The level of circulating anti-MUC1-IgG or anti-MUC1-IgM did not correlate with either FFS or OS. Conclusions: A high level of circulating of sMUC1 is associated with a poor outcome in patients with DLCL. The level of circulating anti-MUC1 antibody was not found predictive of survival in DLCL patients in our study. No significant financial relationships to disclose.