Xiaozhou Ma MD, Presenter: Nothing to Disclose

Mengye Guo, Abstract Co-Author: Nothing to Disclose

Jeffrey T. Yap PhD, Abstract Co-Author: Researcher, Novartis AG Researcher, GlaxoSmithKline plc Researcher, Bristol-Myers Squibb Company Researcher, Infinity Pharmaceuticals, Inc Researcher, Pfizer Inc

Jyothipriya Jagannathan MBBS, Abstract Co-Author: Nothing to Disclose

Mizuki Nishino MD, Abstract Co-Author: Nothing to Disclose

Nikhil H. Ramaiya MD, Abstract Co-Author: Nothing to Disclose

William B. Hanlon, Abstract Co-Author: Nothing to Disclose

Gordon J. Harris PhD, Abstract Co-Author: Medical Advisory Board, Fovia, Inc

Annick D. Van Den Abbeele MD, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

To compare the prognostic value of the tumor marker Cancer Antigen 125 (CA 125) with the Response Evaluation Criteria in Solid Tumors (RECIST) in patients with ovarian cancer receiving chemotherapy.

CT scans of patients entered in two IRB-approved and closed phase II randomized trials using systemic chemotherapy in ovarian cancer were retrospectively reviewed. The patients with baseline and at least one more radiological assessments were included for evaluation. The radiological results and the corresponding CA 125 values obtained within a two-week period were compared after 2 cycles of chemotherapy. The CA 125 analysis was based on criteria of 20% increase and 30% decrease relative to the baseline defining progressive disease and partial response respectively, and otherwise stable disease. The radiological analysis was based on RECIST criteria. Statistical analysis was performed using McNemar’s test.

Of 28 patients enrolled in two closed trials, 18 patients had 2 to 13 follow-up CT scans that met our inclusion criteria. After two cycles of chemotherapy, CA 125/RECIST criteria diagnosed partial response (PR) in 7(38.9%)/6(33.3%), stable disease (SD) in 3(16.7%)/8(44.4%), and progressive disease (PD) in 8(44.4%)/4(22.2%) patients respectively. The response criteria for CA 125 and RECIST were concordant in 14 (78%) patients (95% CI [52.4%, 93.6%]), and discordant in 4(22.0%) patients (95% CI [6.4%, 47.6%] (p>0.05). Of the 4 patients with discordant CA125/RECIST, 2 were classified as progressors (PD) by CA 125 after 2 cycles of chemotherapy which only become evident by RECIST after 4 chemotherapy cycles, and the other 2 patients were classified as responders (PR+SD) by RECIST after 2 cycles of chemotherapy while a decrease in CA 125 was only seen after 6 cycles of chemotherapy.

Evaluation of therapeutic response based on CA 125 and RECIST criteria show concordant results in 78% of patients after two cycles of chemotherapy. With regards to prognostic value, radiological response by RECIST may have a superior performance than biochemical response in early detection of response to chemotherapy, while in non-responders, CA 125 may be more sensitive in detecting early progression.

Biochemical (CA 125) and radiological (RECIST) responses are two important prognostic indicators for predicting response to therapy in patients with ovarian cancer undergoing chemotherapy.

Ma, X, Guo, M, Yap, J, Jagannathan, J, Nishino, M, Ramaiya, N, Hanlon, W, Harris, G, Van Den Abbeele, A, et al, 0, The Comparison of Radiological Response versus Biochemical Response in Ovarian Cancer Patients Receiving Chemotherapy during Phase II Trials.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8011316.html