In reply to Dr. Cheung
2006; Elsevier BV; Volume: 66; Issue: 4 Linguagem: Inglês
10.1016/j.ijrobp.2006.07.006
ISSN1879-355X
Autores Tópico(s)Hepatocellular Carcinoma Treatment and Prognosis
ResumoDr. Cheung is absolutely correct. Using the so-called “Phoenix” definition (defined as nadir + 2 ng/mL) significantly changes the biochemical failure pattern compared with using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition (1Roach 3rd, M. Hanks G. Thames Jr., H. et al.Defining biochemical failure following radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer: Recommendations of the RTOG-ASTRO Phoenix Consensus Conference.Int J Radiat Oncol Biol Phys. 2006; 65: 965-974Abstract Full Text Full Text PDF PubMed Scopus (1971) Google Scholar). In addition to his retrospective studies, at least one Phase III randomized trial demonstrated that the use of the Phoenix definition could have an impact on the interpretation of dose–response data (2Cheung R. Tucker S.L. Lee A.L. et al.Assessing the impact of an alternative biochemical failure definition on radiation dose response for high-risk prostate cancer treated with external beam radiotherapy.Int J Radiat Oncol Biol Phys. 2005; 61: 14-19Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar, 3Cheung R. Tucker S.L. Lee A.K. et al.Dose–response characteristics of low- and intermediate-risk prostate cancer treated with external beam radiotherapy.Int J Radiat Oncol Biol Phys. 2005; 61: 993-1002Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar, 4Peeters S.T. Heemsbergen W.D. Koper P.C. et al.Dose–response in radiotherapy for localized prostate cancer: Results of the Dutch multicenter randomized phase III trial comparing 68 Gy of radiotherapy with 78 Gy.J Clin Oncol. 2006; 24: 1990-1996Crossref PubMed Scopus (786) Google Scholar). In the Dutch trial reported by Peeters et al. there was a highly significant difference in prostate-specific antigen failure favoring 78 over 70 Gy using the ASTRO definition. However, the dose–response relationship did not reach statistical significance using the nadir + 2 definition. As explained in our article, the Phoenix definition was chosen with an emphasis on specificity and its strong association with clinical endpoints. Of note, in an early draft, some of us favored employing the term “bioclinical” failure instead of “biochemical” failure when referring to a definition emphasizing clinical endpoints. Unfortunately (from my viewpoint), the consensus of our expert panel members was not to create such a distinction. In the consensus statement we did not recommend completely abandoning the ASTRO definition. When patients are treated with radiotherapy alone and follow-up is adequate, we consider it acceptable to use a stricter version of the ASTRO definition that requires citing results at a time point 2 years short of the median follow-up. For example, if the median follow-up was 3 years, only data out to 1 year would be considered adequate. In contrast, the Phoenix definition may be more useful when outcomes include patients treated with androgen deprivation therapy. For example, when whole pelvic radiotherapy is combined with neoadjuvant hormonal therapy, the Phoenix definition is more robust in identifying the benefits of treatment than using the ASTRO definition (unpublished data). The bottom line: there is no perfect definition. The work by Cheung and others reminds us of this fact. Crosby, Stills and Nash, The Isley Brothers, and Luther Vandross all sang “If you can’t be with the one you love, love the one you are with.” Until someone can develop an alternative definition that “we love”, and then get a panel of experts to reach a consensus on adopting it, I encourage the readers to try to love the one we are with. In regards to Roach et al. defining biochemical failure following radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer: Recommendations of the RTOG–ASTRO Phoenix Consensus Conference (Int J Radiat Oncol Biol Phys 2006;65:965–974)International Journal of Radiation Oncology, Biology, PhysicsVol. 66Issue 4PreviewI read with great interest the article by Roach et al. (1). The panel’s recommendation is to use the Phoenix (previously also called the current nadir + 2) definition as a new standard to define biochemical failure (1, 2). The ASTRO definition is recommended to continue be used with strict adherence to guidelines. As the debate on the most appropriate definition of biochemical failure is settling, I would like to draw attention to how much impact this change of definition may have on the radiation dose–response analysis of prostate cancer. Full-Text PDF Defining biochemical failure following radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer: Recommendations of the RTOG-ASTRO Phoenix Consensus ConferenceInternational Journal of Radiation Oncology, Biology, PhysicsVol. 65Issue 4PreviewIn 1996 the American Society for Therapeutic Radiology and Oncology (ASTRO) sponsored a Consensus Conference to establish a definition of biochemical failure after external beam radiotherapy (EBRT). The ASTRO definition defined prostate specific antigen (PSA) failure as occurring after three consecutive PSA rises after a nadir with the date of failure as the point halfway between the nadir date and the first rise or any rise great enough to provoke initiation of therapy. This definition was not linked to clinical progression or survival; it performed poorly in patients undergoing hormonal therapy (HT), and backdating biased the Kaplan-Meier estimates of event-free survival. Full-Text PDF
Referência(s)