Serum IgG against Candida predict survival in patients with metastatic renal cell carcinoma

Abstract

Background and aim: In contrast to hematologic malignancies, little is known about the role of fungi in the development and progression of solid tumors. This prompted us to analyze and correlate serum levels of different fungal IgG with survival of patients with metastatic renal cell carcinoma.

Patients and methods: Serum IgG to Candida sp., Saccharomyces cerevisiae and Aspergillus fumigatus were measured in a cross-sectional study in 64 patients with advanced disease. Univariate and multivariate analyses were chosen to study serum IgG as prognostic indicators.

Results: Median follow-up was 29.0 months (range 0.3-122). Median overall survival of patients, which tested negative for Candida IgG, was significantly increased (median not reached, >29 months) compared with Candida IgG positive patients (17.8 months, P = 0.002). Median survival of Saccharomyces IgG negative patients was 33.1 months as opposed to 19.4 months in Saccharomyces IgG positive patients, although this difference was not significant (P = 0.281). No difference in overall survival was found between Aspergillus IgG positive patients (28.0 months) and Aspergillus IgG negative patients (29.1 months) (P = 0.181). Cox backward-stepwise regression confirmed Candida IgG as the strongest predictor of survival in metastatic renal cell carcinoma patients (risk ratio 3.27, P = 0.001, [95% CI 1.86-5.73]).

Conclusion: Our findings suggest that IgG antibodies directed against yeast fungi and particularly against Candida but not against mold fungi have prognostic relevance.

Fig. 1

Kaplan–Meier survival plot in relation to fungal IgG. Plot a shows a significant difference between Candida IgG positive (continuous line) and negative patients (broken line). Plot b and c illustrate Saccharomyces cerevisiae and Aspergillus fumigatus cutoffs with no statistically significant difference between positive (continuous line) and negative patients (broken line)