A randomized trial in ovarian cancer (OC) of early treatment of relapse based on CA125 level alone versus delayed treatment based on conventional clinical indicators (MRC OV05/EORTC 55955 trials)

Carolyn Vachani, RN, MSN, AOCN
Abramson Cancer Center of the University of Pennsylvania
Last Modified: June 8, 2009

Title: A randomized trial in ovarian cancer (OC) of early treatment of relapse based on CA125 level alone versus delayed treatment based on conventional clinical indicators (MRC OV05/EORTC 55955 trials)
Reviewer: Geoffrey Geiger MD
Presenter: G. J. Rustin, M. E. van der Burg
Affiliation: On behalf of the MRC and EORTC collaborators

Ovarian cancer is the second most common gynecological malignancy in the United Stages, with nearly 22,000 cases diagnosed annually. More than 15,000 of these patients will die of their disease, making ovarian cancer the fifth most common cause of cancer death in women in the United States. CA-125 is a glycoprotein whose blood levels are elevated in over 80% of women with ovarian cancer and is most sensitive for stage II or greater cancers.

For women receiving treatment for ovarian cancer, CA-125 levels often rise several months before they have symptoms or clinical signs of disease relapse. 80% of women ultimately relapse after treatment with first-line chemotherapy, but most will benefit from further therapy.

It is currently unclear whether chemotherapy should be started based on a rise in serum markers, or if one should wait for symptoms to be present. OV05/EORTC 55955 is a randomized trial examining whether benefit is derived in patients treated for suspected relapse based on their CA-125 levels as compared to patients whose treatment is delayed until symptoms are present.

The 527 participants had ovarian cancer (epithelial, fallopian tube or primary peritoneal carcinoma) that was in remission after chemotherapy with normal CA125 levels. The women who began treatment with a rise in CA125 began 2^nd line therapy 4.8 months sooner, and 3^rd line therapy 4.6 months sooner, than those who waited for symptoms to appear. Women treated in the immediate treatment arm received 12 more total cycles of chemotherapy on average (30 vs. 18 months in the immediate versus delayed treatment arms, respectively). There was no difference in the overall survival of the two groups. Most importantly, quality of life estimates revealed that women randomized to the immediate treatment arm had less time with a 'good' quality of life.

This study reveals strong evidence to eliminate the following of CA125 levels and use the development of symptoms as a measure of disease.

Also see Interpreting a Cancer Research Study