Cost-effective treatment of women with advanced ovarian cancer by cytoreductive surgery and chemotherapy directed by an in vitro assay for drug resistance

PURPOSE Epithelial ovarian cancer is the fourth leading cruise of cancer-related de ath in women. Five-year survival is about 25%, and new approaches to the tr eatment of this disease are dearly warranted. This study was designed to de termine the feasibility of using an in vitro assay fbr drug resistance to g uide treatment after cytoreductive surgery. We present preliminary results of this study after a median follow-up of 24 months. MATERIALS AND METHODS We treated 66 patients with advanced ovarian cancer by use of a combination of cytoreductive surgery and chemotherapy. Patient inclusion criteria incl uded histologic confirmation of epithelial ovarian cancer, International Fe deration of Gynecology and Obstectrics (FIGO) stage III, no prior chemother apy or radiation therapy, no coexisting neoplasm, and optimal residual dise ase (< 2 cm), Malignant tissue from the involved ovary of each patient was tested in vitro for drug resistance, and chemotherapy was directed individu ally by assay results. On the basis of the assay we treated 19 patients wit h platinum/paclitaxel (TP) and 47 with platinum/cyclophosphamide (CP). RESULTS Three-year survival (Kaplan-Meier estimate) was 69%; the 95% confidence int erval was 58% to 80%. There was no difference in 3-year survival between th e 13 patients treated with TP (66%) and the 47 patients treated with CP (74 %). The cost-effectiveness of each treatment option was determined It cost $4615 to achieve 3-year survival for patients receiving CP and $17,988 to o btain a similar survival with TP, The cost-effectiveness of assay-directed therapy was $9768, DISCUSSION Because of the high recurrence rate and the poor long-term survival of wome n with advanced ovarian cancer, improved therapies for this disease are nee ded. After surgical debulking, we used results of an in vitro assay for dru g resistance to individually select chemotherapy for the patients in this s tudy. Although the 3-year survival of 69% obtained in the present study app ears good compared with previously published studies of optimally debulked patients, the results must be viewed with caution. Patients were not ramdom ized, and differences in prognostic factors, such as tumor grade, patient a ge, and performance status, could account in part for the higher survival f ound in the current study compared with previously published studies. Treat ment with either CP or TP resulted in equivalent 3-year survival. The cost to achieve 3-year survival with this protocol, including the cost of the drug resistance assay, was $9768. We believe that consideration of c osts avoided by the elimination of ineffective treatments, needless toxicit y, and loss of quality of life would likely increase the cost-effectiveness of assay-directed therapy compared with conventional therapy. This study d emonstrates that it is feasible to use an in vitro assay in routine clinica l practice to eliminate ineffective chemotherapeutic agents.