Morgan Peter B, Hanlon Alexandra L, Horwitz Eric M, Buyyounouski Mark K, Uzzo Robert G, Pollack Alan
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111-2497, USA.
Cancer. 2007 Jul 1;110(1):68-80. doi: 10.1002/cncr.22755.
The relation of prostate cancer risk-group stratification and the timing of biochemical failure (BF) and distant metastasis (DM) is not well defined. The authors hypothesized that early failures due to subclinical micrometastasis at presentation could be differentiated from late failures due to local persistence.
A total of 1833 men with clinically localized prostate cancer treated with 3D-conformal radiotherapy with or without short-term androgen deprivation were retrospectively analyzed. By using American Society for Therapeutic Radiology and Oncology (ASTRO) and Phoenix (Nadir+2) definitions (developed at the ASTRO-RTOG [Radiation Therapy Oncology Group] consensus meeting, Phoenix, Arizona, January 21, 2005), the interval hazard rates of BF and DM were determined for men with low-risk, intermediate-risk, and high-risk disease.
Median follow-up was 67 months. Multivariate analysis showed that increasing risk group was independently associated with higher ASTRO BF (P < .0001) and Nadir+2 BF (P < .0001). The preponderance (87%) of ASTRO BF occurred <or=4 years after radiotherapy, whereas Nadir+2 BF was more evenly spread over Years 1-12, with 43% at >4 years. The hazard of Nadir+2 BF persisted in Years 8-12 in all risk groups. The interval hazard function for DM appeared to be biphasic (early peak followed by a drop and late increase) for intermediate-risk and high-risk patients, but no distinct early wave was evident for low-risk patients.
Because of backdating, ASTRO BF underestimates late BF. Local persistence of disease is suggested by delayed Nadir+2 BF and subsequent late DM in every risk group. The paucity of early DM among those with low-risk tumors supports the hypothesis that occult micrometastases contributed to the early wave.
前列腺癌风险分组分层与生化复发（BF）及远处转移（DM）发生时间之间的关系尚未明确界定。作者推测，就诊时因亚临床微转移导致的早期复发可与因局部残留导致的晚期复发相区分。
对1833例接受三维适形放疗联合或不联合短期雄激素剥夺治疗的临床局限性前列腺癌男性患者进行回顾性分析。采用美国放射肿瘤学会（ASTRO）和凤凰城（最低点+2）定义（在2005年1月21日于亚利桑那州凤凰城召开的ASTRO-放射肿瘤学组[RTOG]共识会议上制定），确定低风险、中风险和高风险疾病患者的BF和DM间隔风险率。
中位随访时间为67个月。多因素分析显示，风险分组增加与更高的ASTRO BF（P <.0001）和最低点+2 BF（P <.0001）独立相关。ASTRO BF的大多数（87%）发生在放疗后≤4年，而最低点+2 BF在1至12年分布更为均匀，43%发生在>4年。最低点+2 BF的风险在所有风险分组的第8至12年持续存在。中风险和高风险患者的DM间隔风险函数似乎呈双相性（早期峰值后下降，后期上升），但低风险患者未见明显的早期波峰。
由于回溯问题，ASTRO BF低估了晚期BF。各风险分组中延迟的最低点+2 BF及随后的晚期DM提示疾病的局部残留。低风险肿瘤患者中早期DM较少，支持隐匿性微转移导致早期波峰的假说。
