Zagars G K, Ayala A G, von Eschenbach A C, Pollack A
Department of Radiotherapy, University of Texas, M. D. Anderson Cancer Center, Houston.
Int J Radiat Oncol Biol Phys. 1995 Jan 15;31(2):237-45. doi: 10.1016/0360-3016(94)00323-D.
It is common practice to histologically grade adenocarcinoma of the prostate using the Gleason system. Whereas the prognostic utility of this grading is well known, few studies have comprehensively evaluated it for patients undergoing definitive radiation therapy and generally accepted guidelines as to which Gleason grades should be "lumped" have not been established. This study reports the results of univariate and multivariate evaluation of the prognostic significance of Gleason grade in 648 patients followed for a median of 6.5 years after radiation therapy for T1 to T4, N0, or NX, MO prostate cancer.
The correlation between Gleason grade and local recurrence, metastatic relapse, any disease relapse, and patient survival was evaluated using univariate and multivariate methods. Analysis was also stratified according to whether the grading was assigned on a needle biopsy or on a transurethral resection specimen.
The large number of Gleason grades required grouping of grades for meaningful analysis and we found that a four-tier system (grades 2 and 3, 155 patients; grades 4-6, 290 patients; grade 7, 92 patients; and grades 8-10, 111 patients) correlated best with outcome. In univariate analysis, this four-tier grouping correlated significantly with local recurrence, distant metastases, any relapse, and survival. The incidences of distant metastasis at 10 years were: grades 2 and 3, 13%; grades 4-6, 34%; grade 7, 52%; and, grades 8-10, 63%. The survival rates at 10 years were: grades 2 and 3, 64%; grades 4-6, 60%; grade 7, 46%; and grades 8-10, 24%. In multivariate analysis, Gleason grade was the single most important determinant of outcome for each endpoint. These results applied equally to needle biopsy and transurethral resection specimens.
Tumor grade is the single most significant determinant of outcome following radiotherapy for clinically localized prostate cancer. The Gleason system is a valid method for grading tumors to be irradiated. A four-tier grouping into grades 2 and 3, grades 4-6, grade 7, and grades 8-10 appears to be adequate and simple.
采用Gleason系统对前列腺腺癌进行组织学分级是常见的做法。尽管这种分级的预后效用已广为人知，但很少有研究对接受根治性放射治疗的患者进行全面评估，且尚未确立关于哪些Gleason分级应“合并”的普遍接受的指南。本研究报告了对648例T1至T4、N0或NX、M0期前列腺癌患者进行放射治疗后中位随访6.5年的Gleason分级预后意义的单因素和多因素评估结果。
采用单因素和多因素方法评估Gleason分级与局部复发、远处转移复发、任何疾病复发以及患者生存之间的相关性。分析还根据分级是在穿刺活检还是经尿道切除标本上进行进行分层。
由于Gleason分级数量众多，需要对分级进行分组以进行有意义的分析，我们发现四级系统（2级和3级，155例患者；4 - 6级，290例患者；7级，92例患者；8 - 10级，111例患者）与结果的相关性最佳。在单因素分析中，这种四级分组与局部复发、远处转移、任何复发以及生存均显著相关。10年时远处转移的发生率分别为：2级和3级，13%；4 - 6级，34%；7级，52%；8 - 10级，63%。10年时的生存率分别为：2级和3级，64%；4 - 6级，60%；7级，46%；8 - 10级，24%。在多因素分析中，Gleason分级是每个终点结果的最重要单一决定因素。这些结果同样适用于穿刺活检和经尿道切除标本。
肿瘤分级是临床局限性前列腺癌放射治疗后结果的最重要单一决定因素。Gleason系统是对要接受放疗的肿瘤进行分级的有效方法。分为2级和3级、4 - 6级、7级以及8 - 10级的四级分组似乎足够且简单。
