A phase III randomised trial on the addition of a contact X-ray brachytherapy boost to standard neoadjuvant chemo-radiotherapy for organ preservation in early rectal adenocarcinoma: 5 year results of the OPERA trial.

We report the results after 5 years of follow-up.

我们报告了5年随访后的结果。

patients_and_methods

OPERA was a multicentre, phase III trial that included operable patients (pts), with cT2-cT3b low-mid rectal ADK, tumours <5 cm, cN0 or cN1 <8 mm.

OPERA 是一项多中心、III 期临床试验，纳入了可手术的患者（pts），这些患者患有 cT2-cT3b 低-中分化直肠腺癌，肿瘤 <5 cm，cN0 或 cN1 <8 mm。

All pts received external beam radiotherapy (EBRT): 45 Gy in 25 fractions with concurrent capecitabine.

所有患者均接受了体外放射治疗（EBRT）：45 Gy，分25次照射，同时使用卡培他滨。

Pts were randomly assigned (1:1) to receive a boost of EBRT in group A (9 Gy/5 fractions) or a boost with CXB (90 Gy/3 fractions) in group B.

患者被随机分配（1:1），在A组接受电子束放射治疗（EBRT）增强剂量（9 Gy/5次）或在B组接受碳离子放射治疗（CXB）增强剂量（90 Gy/3次）。

The primary end point was OP rate.

主要终点是手术成功率（OP率）。

Results

Out of 148 patients randomised, 141 were eligible.

在随机分组的148名患者中，有141名患者符合入选标准。

Between week 14-24, a clinical complete (or near) response was observed in 44 pts in group A (64%) versus 66 in group B (92%); P < 0.001.

在第14至24周之间，观察到A组中有44名患者（64%）和B组中有66名患者（92%）实现了临床完全（或接近完全）缓解；P < 0.001。

The 3-year OP rate was 59% in group A versus 81% in group B (P = 0.003).

A组的3年总生存率为59%，而B组为81%（P = 0.003）。

After update the median follow-up was 61.1 months [56.8-64.5].

更新后，中位随访时间为61.1个月[56.8-64.5]。

The 5-year local regrowth was 39% in group A and 17% in group B (P = 0.1).

A组5年局部复发率为39%，B组为17%（P = 0.1）。

The difference in OP was still highly significant between both groups: A 56% versus B 79% (P = 0.004).

两组在总体生存率上的差异仍然具有高度显著性：A组为56%，B组为79%（P = 0.004）。

The difference was more significant if tumours <3 cm, with an OP rate of 93% in group B compared to 54% in group A.

如果肿瘤小于3厘米，差异更为显著，B组的总生存率为93%，而A组为54%。

Of the 28 local regrowths, 3 occurred after 3 years of follow-up.

在28例局部复发中，有3例发生在随访3年后。

Rectal bleeding (grade 1-2), which was the most prevalent toxicity during follow-up, disappeared most of the time after three years.

直肠出血（1-2级），这是随访期间最常见的毒性反应，大多数情况下在三年后消失。

Bowel function was not worsened by the CXB boost.

CXB增强并未导致肠功能恶化。

Conclusions

The OPERA trial was the first trial to demonstrate that CXB dose escalation was increasing the OP rate with good bowel function at 3 years.

OPERA试验是首个证明CXB剂量递增能提高3年时的OP率并保持良好肠道功能的试验。

At 5 years, these results are sustained, especially in small early-stage tumours.

在5年时，这些结果得到了维持，特别是在小的早期肿瘤中尤为显著。

The occurrence of some local regrowth after 3 years necessitates close surveillance of these pts during the 5-year period.

在3年后出现一些局部复发的情况，需要在5年期间密切监测这些患者。