Chemotherapy for early ovarian cancer

The treatment of early ovarian cancer has long been based on non-randomized studies and on a small number of randomized studies without sufficient power. Adjuvant chemotherapy is often given to high-risk patients, but the benefit of such an approach has never been proven and the definition of high-risk early ovarian cancer differs widely. Recently, the results of the two largest randomized clinical trials on early ovarian cancer became available. Both trials are discussed, and their results are related to the other relevant literature of the last three years.

A meta-analysis of over 1500 patients from the year 2001 confirmed tumor grade as a strong prognostic factor but it also demonstrated the adverse effect of capsule rupture before and during surgery. The Adjuvant Chemotherapy in Ovarian Neoplasm trial (European Organization for Research and Treatment of Cancer) randomized 448 patients to either adjuvant chemotherapy following surgery or observation. Adjuvant chemotherapy improved overall survival and disease-free survival in non-optimally staged patients but showed no benefit in optimally staged patients. The Medical Research Council International Collaborative Ovarian Neoplasm 1 trial randomized 477 patients in a similar way. Overall survival and disease-free survival were improved by adjuvant chemotherapy. It was argued that the study population of the International Collaborative Ovarian Neoplasm 1 trial probably represents non-optimally staged patients, and this hypothesis explains why the results of this trial were in accord with those of the Adjuvant Chemotherapy in Ovarian Neoplasm trial.

The implications of these data are that a complete surgical staging is of utmost importance and should be pursued. In cases of non-optimal staging and contraindications for restaging, adjuvant chemotherapy is indicated to deal with unnoticed residual tumor deposits that exist in approximately 25% of cases.