Pollack A, Zagars G Z
Department of Radiotherapy, University of Texas MD Anderson Medical Center, Houston 77030, USA.
Semin Urol Oncol. 1996 May;14(2):86-95.
The role of radiotherapy for the treatment of clinical stage T3b transitional cell carcinoma of the bladder is controversial. The options range from definitive radiotherapy alone, to preoperative radiotherapy and cystectomy, to chemotherapy and radiation for bladder preservation. Our data show that long-term local control after definitive radiotherapy is only 27% and that death attributable to local-regional failure in this setting is 43%. Thus, definitive radiotherapy is only used in patients who are considered poor candidates for surgical and chemotherapy procedures. Preoperative radiotherapy (PREOP) has been studied in a number of randomized series, all of which failed to establish an improvement in patient outcome over those treated with radical cystectomy alone (CYST). However, these studies are subject to criticism, mostly because of poor patient accrual and low numbers of patients available for the analyses. A retrospective review of patients treated at MD Anderson Cancer Center indicates that local control is superior with PREOP as compared with CYST. An analysis of the impact of local control on distant metastasis rates in patients treated with CYST showed that local control was an independent correlate of distant metastasis and survival. Thus, preoperative radiotherapy may be beneficial to patients with late-stage muscle-invasive bladder cancer by securing local control and reducing distant metastasis rates as a result. The success of bladder preservation for stage T3b patients rests with the ability to select patients with radiosensitive tumors. To this end, the immunohistochemical staining status of tumor p53 and pRB was investigated in patients treated with PREOP. Abnormal pRB expression was very strongly related to radiation response, whereas altered p53 expression was associated with high distant metastasis-free and overall survival rates. These two molecular markers were complementary and show promise in facilitating the selection of late-stage patients for bladder preservation.
放射治疗在临床分期为T3b期膀胱移行细胞癌治疗中的作用存在争议。治疗方案从单纯根治性放疗,到术前放疗加膀胱切除术,再到化疗联合放疗以保留膀胱。我们的数据显示,根治性放疗后的长期局部控制率仅为27%,在此情况下因局部区域失败导致的死亡率为43%。因此,根治性放疗仅用于那些被认为不适合手术和化疗的患者。术前放疗(PREOP)已在多个随机系列研究中进行了探讨,所有这些研究均未能证实与单纯根治性膀胱切除术(CYST)相比患者预后有所改善。然而,这些研究受到了批评,主要原因是患者入组情况不佳且可供分析的患者数量较少。对在MD安德森癌症中心接受治疗的患者进行的回顾性研究表明,与CYST相比,PREOP的局部控制效果更佳。对接受CYST治疗的患者局部控制对远处转移率影响的分析表明,局部控制是远处转移和生存的独立相关因素。因此,术前放疗可能通过确保局部控制并降低远处转移率而对晚期肌层浸润性膀胱癌患者有益。T3b期患者保留膀胱的成功取决于选择对放疗敏感肿瘤患者的能力。为此,对接受PREOP治疗的患者的肿瘤p53和pRB免疫组化染色状态进行了研究。pRB表达异常与放疗反应密切相关,而p53表达改变与高无远处转移生存率和总生存率相关。这两个分子标志物具有互补性,在促进选择晚期患者进行膀胱保留方面显示出前景。