Reassessment of the 1997 TNM classification system for renal cell carcinoma - A 5-cm T1/T2 cutoff is a better predictor of clinical outcome
Reassessment of the 1997 TNM classification system for renal cell carcinoma - A 5-cm T1/T2 cutoff is a better predictor of clinical outcome
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DOI：
10.1002/cncr.11806
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发表时间：
2003-12-01
期刊：
影响因子：
6.2
通讯作者：
Sagalowsky, AI
中科院分区：
文献类型：
--
作者：
Elmore, JM;Kadesky, KT;Sagalowsky, AI
背景。1997年TNM对肾细胞癌（RCC）的分期分类将I期肿瘤定义为器官局限的肿瘤，大小不超过7cm。作者根据一系列可选择的大小临界值，通过评估I期RCC患者的生存来评估该临界值的有效性。此外，作者还确定了这些大小临界值如何影响非器官局限性肿瘤、局部淋巴结受累和转移性疾病的风险。对1960年至1991年间接受开放性根治性肾切除术的1324例肾细胞癌患者的数据库进行了评估。I期疾病患者以0.5 cm为单位，按2.5 ~ 7.0 cm的尺寸分割线分层。使用Kaplan-Meier方法估计5年疾病特异性生存率（DSS）。采用log-rank检验比较生存曲线。将肿瘤小于特定大小临界值的患者的生存与大于该临界值的患者的生存进行比较，并确定最具鉴别性的临界值。采用相同大小的临界值来比较所有肿瘤小于或等于7.0 cm的患者的局部非器官局限性、淋巴结阳性和转移性疾病的发生率。在544名可评估的患者中，351名患者的肿瘤小于或等于7.0厘米，其中233名患者为1997年I期（T1N0M0）疾病。当1997年I期肿瘤患者使用不同大小的分割线分离时，使用5.0 cm分割线的生存率差异最大。5厘米及以下的I期肿瘤患者与5.1-7厘米肿瘤患者的5年DSS率分别为94.6%和79.2% （P = 0.003）。此外，I期RCC患者的生存期为5.1-7.0 cm，与1997期（T2N0M0） RCC患者的生存期相同。局部非器官局限性疾病的概率差异也最大，临界值为5.0 cm。肿瘤小于5.0 cm的患者中有16.2%存在非器官局限性疾病，而肿瘤大小为5.1-7.0 cm的患者中有36.8%存在非器官局限性疾病。淋巴结阳性或转移性疾病的概率差异使用任何截断值都没有显著改变，尽管这两种可能性都随着肿瘤大小的增加而增加。对一大批接受根治性肾切除术的肾细胞癌患者的生存和疾病复发分析表明，1997年用于区分I期和II期疾病的TNM界限7.0 cm过高。在1997年器官受限的I期疾病患者中发现了与尺寸相关的生存差异，5.0 cm的临界值最好地划分了这种差异。这一发现与第六版美国癌症联合委员会癌症分期手册中所做的修改基本一致。肿瘤尺寸在5.1 cm至7.0 cm之间的患者与II期疾病患者的生存期相同。因此，将T1细分为T1a和T1b，如第6版AJCC癌症分期手册，可能不是最佳的。5厘米的分界线也能最好地分层发生非器官局限性疾病的风险。这一发现可能对某些患者的肾保留手术有影响。目前的研究结果，以及其他研究结果，支持I期RCC患者的上尺寸上限为4-5厘米。(C) 2003年美国癌症协会。
BACKGROUND. The 1997 TNM staging classification for renal cell carcinoma (RCC) defined Stage I tumors as organ-confined tumors measuring up to 7 cm in size. The authors evaluated the validity of this cutoff size by assessing the survival of patients with Stage I RCC according to a series of alternative size cutoff values. In addition, the authors determined how these size cutoffs affected the risk of having nonorgan-confined tumors, regional lymph node involvement, and metastatic disease.METHODS. A database containing the records of 1324 patients with RCC who underwent open radical nephrectomy between 1960 and 1991 was evaluated. Patients with Stage I disease were stratified by size cutoffs ranging from 2.5 to 7.0 cm in 0.5-cm increments. Five-year disease-specific survival (DSS) rates were estimated using the Kaplan-Meier method. The log-rank test was used to compare survival curves. The survival of patients with tumors smaller than a specified size cutoff was compared with the survival of patients with tumors larger than that cutoff and the most discriminating cutoff was identified. The same size cutoffs were used to compare the incidence of local nonorgan-confined, lymph node-positive, and metastatic disease for all patients with tumors 7.0 cm or smaller.RESULTS. Of 544 evaluable patients, 351 patients had tumors 7.0 cm or smaller and 233 of these patients had 1997 Stage I (T1N0M0) disease. When patients with 1997 Stage I tumors were separated using the various size cutoffs, survivals were most different using a 5.0-cm cutoff. The 5-year DSS rates for patients with Stage I tumors 5 cm or smaller versus those with tumors measuring 5.1-7 cm were 94.6% versus 79.2% (P = 0.003). Furthermore, the survival of patients with Stage I RCC lesions measuring 5.1-7.0 cm was the same as for patients with 1997 Stage II (T2N0M0) RCC. The difference in probability of having local nonorgan-confined disease was also greatest with a 5.0 cm cutoff value. Nonorgan- confined disease was reported to be present in 16.2% of the patients with tumors smaller than 5.0 cm compared with 36.8% of the patients with tumors measuring 5.1-7.0 cm in size. The difference in the probabilities of having lymph node-positive or metastatic disease did not change significantly using any of the cutoffs, although the probability of both of these increased with increasing tumor size.CONCLUSIONS. Survival and disease recurrence analysis in a large group of patients with RCC who underwent radical nephrectomy showed that the 1997 TNM cutoff of 7.0 cm used to separate Stage I from Stage II disease was too high. A size-related survival difference was found among patients with organ-confined 1997 Stage I disease and a 5.0-cm cutoff best stratified this difference. This finding was in general agreement with the changes made in the 6th edition of the American Joint Committee on Cancer cancer staging manual. Patients with tumors measuring between 5.1 cm and 7.0 cm were found to have the same survival as patients with Stage II disease. Thus, subclassification of T1 into T1a and T1b, as in the 6th edition of the AJCC cancer staging manual, may not be optimal. The 5-cm cutoff also best stratified the risk of developing nonorgan- confined disease. This finding may have an impact on nephron-sparing surgery in selected patients. The findings of the current study, as well as those of others, supported an upper size cutoff of 4-5 cm for patients with Stage I RCC. (C) 2003 American Cancer Society.