Combined detection of sialic acid and hydroxyproline in diagnosis of ovarian cancer and its comparison with human epididymis protein 4 and carbohydrate antigen 125.

BACKGROUND

Elevated serum sialic acid (SA) and hydroxyproline (Hyp) concentrations have been found in a variety of malignant cancers. We simultaneously detect serum concentrations of SA and Hyp (SA&Hyp) in ovarian cancer, and compare its diagnostic value with classic tumor markers-human epididymis protein 4 (HE4) and carbohydrate antigen 125 (CA125).

METHODS

Serum concentrations of SA&Hyp, HE4 and CA125A were detected in a total of 767 serum samples collected from 484 patients with gynecologic diseases, 180 healthy individuals, 45 pregnant women and 58 patients with renal failure using chemical colorimetry and electrochemiluminescence immunoassay (ECLIA), respectively. Risk of ovarian malignancy algorithm (ROMA) was calculated based on HE4 and CA125 values.

RESULTS

Serum SA&Hyp concentrations were influenced significantly by renal failure and pregnancy but not age and menopausal status. The median concentrations of SA&Hyp, HE4 and CA125 in patients with ovarian cancer were 119.0 U/ml, 190.2 pmol/l and 366.0 pmol/l, which were significantly higher than concentrations in patients with benign gynecologic diseases (P<0.001). SA&Hyp showed a significantly higher AUC than HE4 and CA125 in the diagnosis of gynecologic malignancies (P<0.001), while no significance was found when compared with ROMA. Specially, SA&Hyp in 48.3% subjects (29/60) diagnosed as positive before primary surgery showed negative after surgery.

CONCLUSIONS

Renal failure and pregnancy are the main source for increased false positive of SA and Hyp. Compared with HE4 and CA125, SA&Hyp shows a better diagnosis value and can be used in the diagnosis and dynamic monitoring of gynecologic pelvic malignancies, while no statistical significance was found compared with ROMA.