Background

The importance of 2-yr postradiotherapy prostate biopsy status remains uncertain.

Objective

To assess the value of 2 year post treatment biopsies in a randomised trial of radiotherapy dose escalation.

Design, setting, and participants

Between 1998 and 2001, 843 men with localised prostate cancer were randomised to receive either control-64 Gy or escalated-74 Gy conformal radiotherapy (CFRT) in the MRC RT01 trial in combination with 3–6-mo neoadjuvant androgen deprivation therapy. Prostate biopsies were planned at 2 yr from start of CFRT in suitable men.

Outcome measurements and statistical analysis

Prostate biopsy results and prostate-specific antigen (PSA) levels performed at 2 yr post-CFRT were evaluated with long-term biochemical progression free survival (bPFS) and overall survival. Outcome measures were timed from the 2-yr biopsy using a landmark approach.

Results and limitations

A 2-yr biopsy was performed in 312/843 patients. One hundred and seventy-seven patients were included in the per-protocol group with median follow-up of 7.8 yr from biopsy. Median PSA at biopsy was 0.5 ng/ml. Sixty-four bPFS events were reported: 46/145 (32%) in patients with negative, 6/18 (33%) suspicious, and 12/14 (86%) positive biopsies. A positive biopsy was prognostic of worse bPFS, going forward, compared with negative and suspicious biopsies, hazard ratio (HR) = 4.81 (95% confidence interval [CI]: 2.50–9.26, p < 0.001). The estimate for survival was HR = 1.58 (95% CI: 0.52–4.78, p = 0.42). PSA values at 2 yr between 1.01 ng/ml and 2.09 ng/ml were also associated with subsequent PSA failures (HR = 2.71, 95% CI: 1.98–3.71), bPFS events (HR = 2.45, 95% CI: 1.81–3.32), and prostate cancer-specific survival (HR = 2.87, 95% CI: 1.08–7.64) compared with PSA ≤1.0 ng/ml.

Conclusions

Two-year postradiotherapy prostate biopsies have limited value in patients with PSA control but both positive biopsy and higher PSA status are strongly associated with future bPFS events. A policy of selected biopsy may provide an opportunity for early salvage interventions.

Patient summary

Routine 2-yr postradiotherapy biopsy is not recommended but can be considered in selected patients with unfavourable post-treatment prostate-specific antigen levels who are suitable for early salvage treatments.

中文翻译：

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两年放疗后活检：MRC RT01 试验的经验教训

 背景

放疗后 2 年前列腺活检状态的重要性仍不确定。

 客观的

评估放射治疗剂量递增随机试验中治疗后 2 年活检的价值。

设计、设置和参与者

1998 年至 2001 年间，MRC RT01 试验中，843 名患有局限性前列腺癌的男性被随机接受 64 Gy 对照放射治疗或 74 Gy 升级适形放射治疗 (CFRT)，并结合 3-6 个月新辅助雄激素剥夺治疗。计划在 CFRT 开始后 2 年对合适的男性进行前列腺活检。

结果测量和统计分析

CFRT 后 2 年进行的前列腺活检结果和前列腺特异性抗原 (PSA) 水平通过长期生化无进展生存期 (bPFS) 和总生存期进行评估。使用具有里程碑意义的方法从两年的活检开始测量结果。

 结果和局限性

对 312/843 名患者进行了为期 2 年的活检。 177 名患者被纳入符合方案组，活检中位随访时间为 7.8 年。活检时的中位 PSA 为 0.5 ng/ml。报告了 64 例 bPFS 事件：46/145 (32%) 活检结果阴性，6/18 (33%) 可疑，12/14 (86%) 阳性。与阴性和可疑活检相比，阳性活检预示 bPFS 更差，风险比 (HR) = 4.81（95% 置信区间 [CI]：2.50–9.26， p < 0.001）。生存率估计为 HR = 1.58（95% CI：0.52–4.78， p = 0.42）。 2 年 PSA 值在 1.01 ng/ml 至 2.09 ng/ml 之间也与随后的 PSA 失败（HR = 2.71，95% CI：1.98–3.71）、bPFS 事件（HR = 2.45，95% CI：1.81–3.32）相关) 和前列腺癌特异性生存率 (HR = 2.87, 95% CI: 1.08–7.64) 与 PSA ≤1.0 ng/ml 相比。

 结论

放疗后两年前列腺活检对于 PSA 控制的患者价值有限，但活检阳性和较高的 PSA 状态与未来的 bPFS 事件密切相关。选择性活检的政策可能为早期挽救干预提供机会。

 患者总结

不建议进行常规 2 年放疗后活检，但对于治疗后前列腺特异性抗原水平不利且适合早期挽救治疗的特定患者可以考虑进行。