Nielsen Matthew E, Makarov Danil V, Humphreys Elizabeth, Mangold Leslie, Partin Alan W, Walsh Patrick C
James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-2101, USA.
Urology. 2008 Aug;72(2):389-93; discussion 394-5. doi: 10.1016/j.urology.2007.10.053. Epub 2008 Feb 15.
The new American Society for Therapeutic Radiology and Oncology/Radiation Therapy Oncology Group consensus definition of biochemical failure after radiotherapy for prostate cancer is defined as a prostate-specific antigen level at or greater than the absolute nadir PSA level plus 2 ng/mL. Because this definition inevitably will be used to compare cancer control rates after radiotherapy to those after surgery, this study examined the effect of this comparison.
We reviewed the data from 2570 men who had undergone radical prostatectomy from 1985 to 2004. Biochemical failure was defined as any measurable PSA level of 0.2 ng/mL or greater. We evaluated how the nadir+2 definition affected the failure rate when applied to this series.
The actuarial 5, 10, and 15-year biochemical recurrence-free survival probability with failure defined as a PSA level of 0.2 ng/mL or more and a PSA level of 2 ng/mL or more was 88.6%, 81.2%, and 78.1% and 94.6%, 89.4%, and 84.3%, respectively (P <0.0001). The median time to biochemical progression was 2.8 years for the greater than 0.2 ng/mL definition and 7.9 years for the 2 ng/mL or more definition. The nadir+2 definition systematically overestimated the biochemical recurrence-free survival, even after stratifying patients into standard prognostic risk groups, especially in men who developed local recurrence.
When applied to a mature series of surgically treated patients with localized prostate cancer, the American Society for Therapeutic Radiology and Oncology "nadir+2" definition resulted in a systematic delay in the determination of biochemical failure. Because patients in this series who experienced a detectable PSA level took more than 5 years to progress to a PSA level of 2 ng/mL or greater, the 5-year biochemical control rates with the definition of 0.2 ng/mL or more should be compared with the 10-year biochemical control rates using the nadir+2 definition.
美国放射肿瘤学会/放射治疗肿瘤学组关于前列腺癌放疗后生化失败的新共识定义为前列腺特异性抗原水平等于或高于最低PSA水平绝对值加2 ng/mL。由于该定义将不可避免地用于比较放疗后与手术后的癌症控制率，本研究探讨了这种比较的影响。
我们回顾了1985年至2004年间2570例行根治性前列腺切除术的男性患者的数据。生化失败定义为任何可测量的PSA水平达到或超过0.2 ng/mL。我们评估了将最低值加2定义应用于该系列时对失败率的影响。
将失败定义为PSA水平达到或超过0.2 ng/mL和达到或超过2 ng/mL时，5年、10年和15年的精算无生化复发生存率分别为88.6%、81.2%和78.1%以及94.6%、89.4%和84.3%（P<0.0001）。对于大于0.2 ng/mL的定义，生化进展的中位时间为2.8年；对于2 ng/mL或更高的定义，为7.9年。即使将患者分层为标准预后风险组，最低值加2定义也系统性地高估了无生化复发生存率，尤其是在发生局部复发的男性中。
当应用于一组成熟的局部前列腺癌手术治疗患者时，美国放射肿瘤学会的“最低值加2”定义导致生化失败判定出现系统性延迟。由于该系列中PSA水平可检测到的患者需要超过5年时间才能进展到PSA水平达到或超过2 ng/mL，因此应将定义为0.2 ng/mL或更高时的5年生化控制率与使用最低值加2定义时的10年生化控制率进行比较。
