By Sharan Sharma

CA 125 has been used as a tumour marker in epithelial ovarian cancer. The predictive and prognostic values of CA125 are well described in all phases of epithelial ovarian cancer management. The rate of normalisation of CA125 during primary chemotherapy serves as a useful sign of increased progression free survival and overall survival. Similarly, its value after the completion of front line therapy predicts progression free survival. But, what is the role of the rate of rise of CA1125? A recent study published in European Journal of Cancer revealed that doubling time of CA125 is an independent prognostic factor for survival in patients with ovarian cancer relapsing after first-line chemotherapy.

Ovarian cancer accounts for 4.2% of all cancer deaths worldwide and is the leading cause of death from gynaecological cancer in Western countries. The researchers identified 296 patients of ovarian cancer treated in The Royal Marsden Hospital, London, UK, from 1994 to 2003 and found out the median doubling time of CA125 of 40 days. Patients with CA125 doubling time of 40 days or less were found to have median survival of 10.6 compared to 22.1 for those with doubling time of more than 40 days. In a univariate analysis, different factors like age, high-grade, suboptimal cytoreduction, short CA125 doubling time were significantly associated with poor survival, but in a multivariate analysis, a short CA125 doubling time of 40 days or less and a short time to disease progression were the only independent adverse prognostic factors (p = 0.001). The correlation between doubling time of CA125 and survival is independent of the time to disease progression. The researchers suggest "The management of ovarian cancer relapsing with first-line chemotherapy require more focused approach on the individualised care decision and certainly doubling time of CA125 could be a key in that decision".