In reply to the letter by Gevaert et al.

✍ Scribed by Jozien Helleman; Maurice P.H.M. Jansen; Maria E.L. van der Burg; Els M.J.J. Berns

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: French
• Weight: 40 KB
• Volume: 119
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.21984

✦ Synopsis

raised an important issue about the implementation in clinical practice of the 9-gene set for platinum resistance of ovarian cancer patients. They also stated that nonplatinum containing regimens are suboptimal in the treatment of ovarian cancer.

In our study 1 we have included specimens of 96 primary ovarian adenocarcinoma patients from 2 Dutch Medical Centres. All patients were treated with platinum-based chemotherapy and 14 patients showed resistance whereas 82 responded to platinumbased chemotherapy. In our search for genes, a discovery set of 24 specimens was profiled in duplicate in which 69 genes were found to be differentially expressed between the nonresponders (n 5 5) and the responders (n 5 19). An algorithm was constructed to identify the predictive genes in this 69-gene discovery set. This resulted in 16 genes, of which 9 genes were confirmed with quantitative (q) RT-PCR. An independent validation was performed using qRT-PCR on a set of 72 specimens (9 nonresponders, 63 responders). The 9-gene set predicted platinum resistance in these 72 tumours with a sensitivity of 89% (95% CI, 0.68-1.09) and a specificity of 59% (95% CI, 0.47-0.71) (OR 5 0.09, p 5 0.026).

We agree with Gevaert et al. that the specificity is not optimal and that the profile is not yet ready for clinical practice. In fact, we have stated in the Abstract (last line) and Discussion (last paragraph) that further validation, including multicentre (retrospective) studies and prospective clinical trials, are needed before implementation in the clinical practice is warranted.