Among women undergoing induction (first-line treatment) chemotherapy for ovarian cancer, two specific measures of the protein CA-125 (CA-125 half-life and CA-125 nadir) provide information about prognosis. These results were published in the Annals of Oncology.
Elevated levels of the protein CA-125 in the blood have been associated with ovarian cancer. However, elevated levels of CA-125 in the blood do not always indicate the presence of ovarian cancer because CA-125 levels can be elevated in a number of other benign conditions and during the first trimester of pregnancy. Once a diagnosis of ovarian cancer has been established, the level of CA-125 in the blood is a useful indicator of cancer growth during or after treatment.
To evaluate patient outcomes in relation to two specific measures of CA-125, researchers in France conducted a study among 553 women with stage IIC to stage IV ovarian cancer. CA-125 was measured before and during induction chemotherapy. The focus of this study was CA-125 nadir (the lowest level to which CA-125 dropped), as well as CA-125 half-life (the time it took for CA-125 levels to drop by half).
- CA-125 half-life and CA-125 nadir were each independently linked with survival (they each predicted survival even after accounting for the other). Women with a shorter CA-125 half-life or a lower CA-125 nadir had improved survival.
- Other factors that influenced survival were cancer stage and the presence of residual tumor. Lower stage was linked with improved survival and the presence of residual tumor was linked with worse survival.
The researchers conclude that “Among well-established prognostic factors in ovarian cancers, CA-125 half-life and nadir concentration bear a strong and independent prognostic value.”
Reference: Riedinger JM, Wafflart J, Ricolleau G et al. CA 125 Half-life and CA 125 Nadir During Induction Chemotherapy are Independent Predictors of Epithelial Ovarian Cancer Outcome: Results of a French Multicentric Study. Annals of Oncology. 2006;17:1234-1238.