Objective To investigate the role of serum inhibin A, inhibin pro-αC immunoreactivity, activin A, and follistatin in postmenopausal women with epithelial ovarian cancer.
Design Case-control study.
Sample Serum samples from 27 postmenopausal women with epithelial ovarian cancer and 54 controls from the general population participating in an ovarian cancer screening trial.
Results Women with epithelial ovarian cancer had significantly higher serum levels of pro-αC immunoreactivity (P= 0.03), activin A (P= 0.004) and follistatin (P= 0.04), but not inhibin A (P= 0.13). Using the 90th centile in the control group as the cut off, pro-αC levels were elevated in 41% of women with epithelial ovarian cancer, while inhibin A was elevated in only 15%. Using the 95th centile as the cut off, serum pro-αC was elevated in only 11% of women with epithelial ovarian cancer (3/27), while activin A was elevated in 48% (11/23). Follicle stimulating hormone levels were significantly lower in women with epithelial ovarian cancer (P= 0.01). Although, inhibin-related peptides can modulate follicle stimulating hormone levels, there was no correlation between inhibin A, pro-αC immunoreactivity, activin A or follistatin and follicle stimulating hormone.
Conclusion These data demonstrate that though there is preferential secretion of precursor forms of the α subunit rather than dimeric inhibin A by epithelial ovarian cancer, pro-αC is unlikely to be a useful tumour marker. Activin A is more commonly elevated in postmenopausal women with epithelial ovarian cancer and its role as a tumour marker in the diagnosis and screening of epithelial ovarian cancer warrants further evaluation.