目的:前列腺放疗后第二次癌症的风险增加是一个有争议的临床问题。该研究的目的是根据文献分析评估前列腺放射治疗后发生第二种癌症的风险,并确定解释研究结果差异的潜在因素。
方法:对文献进行了综述,比较所有前列腺癌患者的第二癌症的发生,治疗或不接受辐射。
结果:本综述包括30项研究,报告了2,112,000例接受局部前列腺癌治疗或监测的患者中第二癌症的发生。包括1,111,000的外部放射治疗和103,000的近距离放射治疗。关于外部放射治疗,平均随访时间为7.3年。大多数研究(80%)涉及外部放射治疗,与没有外部放射治疗相比,显示第二次癌症的风险增加,风险比在1.13至4.9之间,具体取决于随访的持续时间。外部放疗后这些第二种癌症发生的中位时间为4至6年。在52%和85%的研究中观察到第二次直肠癌和膀胱癌的风险增加,分别。考虑到辐照后10年以上的审查期,57%和100%的研究发现直肠癌和膀胱癌的风险增加,对总生存率没有任何影响。近距离放射治疗的研究未显示出第二次癌症的风险增加。然而,这些比较研究,最常见的是旧的和回顾性的,有许多方法论上的偏见。
结论:尽管存在许多方法学偏见,前列腺外放射治疗似乎与第二盆腔癌的风险适度增加有关,特别是膀胱癌,而不影响生存。近距离放射治疗不会增加第二次癌症的风险。
OBJECTIVE: The increased risk of second cancer after prostate radiotherapy is a debated clinical concern. The objective of the study was to assess the risk of occurrence of second cancers after prostate radiation therapy based on the analysis the literature, and to identify potential factors explaining the discrepancies in results between studies.
METHODS: A review of the literature was carried out, comparing the occurrence of second cancers in patients all presenting with prostate cancer, treated or not by radiation.
RESULTS: This review included 30 studies reporting the occurrence of second cancers in 2,112,000 patients treated or monitored for localized prostate cancer, including 1,111,000 by external radiation therapy and 103,000 by brachytherapy. Regarding external radiation therapy, the average follow-up was 7.3years. The majority of studies (80%) involving external radiation therapy, compared to no external radiation therapy, showed an increased risk of second cancers with a hazard ratio ranging from 1.13 to 4.9, depending on the duration of the follow-up. The median time to the occurrence of these second cancers after external radiotherapy ranged from 4 to 6years. An increased risk of second rectal and bladder cancer was observed in 52% and 85% of the studies, respectively. Considering a censoring period of more than 10 years after irradiation, 57% and 100% of the studies found an increased risk of rectal and bladder cancer, without any impact in overall survival. Studies of brachytherapy did not show an increased risk of second cancer. However, these comparative studies, most often old and retrospective, had many methodological biases.
CONCLUSIONS: Despite numerous methodological biases, prostate external radiation therapy appears associated with a moderate increase in the risk of second pelvic cancer, in particular bladder cancer, without impacting survival. Brachytherapy does not increase the risk of a second cancer.