Serum YKL-40 as a marker for cervical adenocarcinoma

Background: The current study examined the clinical usefulness of YKL-40 in detection and prognosis of uterine cervical cancer. Patients and methods: Serum levels of YKL-40, cancer antigen 125 (CA 125), carbohydrate antigen 19-9 (CA19-9), and squamous cell carcinoma (SCC) antigen were determined by enzyme-linked immunosorbent assay in women with benign gynecologic disease (n = 24), cervical malignancy (SCC, n = 104; adenocarcinoma, n = 37), and age-matched healthy controls (n = 45). Immunohistochemical analysis for local YKL-40 expression was carried out on 28 adenocarcinomas. Results: Receiver operating characteristic curve analysis showed that YKL-40 [area under the curve (AUC) = 0.882] was significantly better at discriminating adenocarcinoma from healthy control than SCC antigen, CA 125, and CA19-9. For SCC, YKL-40 (AUC = 0.898) carried out similarly to SCC antigen and was better than CA 125 and CA19-9. Using a cut-off YKL-40 value of 92.2 ng/ml, sensitivity of YKL-40 in stage I adenocarcinoma (68%) was higher than that of the other three markers (11%-21%). Tumor-associated macrophages showed immunoreactivity for YKL-40 in 2 of 28 adenocarcinoma tissue samples, but adenocarcinoma cells themselves were nonimmunoreactive in all samples. Multivariate Cox regression analysis revealed that elevated pretreatment YKL-40 levels predicted unfavorable prognosis, independent of International Federation of Gynecology and Obstetrics stage and age at diagnosis. Conclusions: Pretreatment serum YKL-40 level is a possible prognosticator of cervical adenocarcinoma.