Department of Urology, Erasmus University Medical Centre Cancer Institute, Rotterdam, The Netherlands.
Department of Oncology and Haemato-oncology, Università degli Studi di Milano. Radiation Oncology 1, Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
Prostate Cancer Prostatic Dis. 2021 Dec;24(4):1048-1054. doi: 10.1038/s41391-021-00343-2. Epub 2021 Apr 8.
The reduction of overtreatment by active surveillance (AS) is limited in patients with low-risk prostate cancer (PCa) due to high rates of patients switching to radical treatment. MRI improves biopsy accuracy and could therewith affect inclusion in or continuation of AS. We aim to assess the effect of MRI with target biopsies on the total rate of patients discontinuing AS, and in particular discontinuation due to Grade Group (GG) reclassification.
Three subpopulations included in the prospective PRIAS study with GG 1 were studied. Group A consists of patients diagnosed before 2009 without MRI before or during AS. Group B consists of patients diagnosed without MRI, but all patients underwent MRI within 6 months after diagnosis. Group C consists of patients who underwent MRI before diagnosis and during follow-up. We used cumulative incidence curves to estimate the rates of discontinuation.
In Group A (n = 500), the cumulative probability of discontinuing AS at 2 years is 27.5%; GG reclassification solely accounted for 6.9% of the discontinuation. In Group B (n = 351) these numbers are 30.9 and 22.8%, and for Group C (n = 435) 24.2 and 13.4%. The three groups were not randomized, however, baseline characteristics are highly comparable.
Performing an MRI before starting AS reduces the cumulative probability of discontinuing AS at 2 years. Performing an MRI after already being on AS increases the cumulative probability of discontinuing AS in comparison to not performing an MRI, especially because of an increase in GG reclassification. These results suggest that the use of MRI could lead to more patients being considered unsuitable for AS. Considering the excellent long-term cancer-specific survival of AS before the MRI era, the increased diagnostic accuracy of MRI could potentially lead to more overtreatment if definitions and treatment options of significant PCa are not adapted.
由于低危前列腺癌（PCa）患者转为根治性治疗的比例较高，主动监测（AS）的过度治疗减少受到限制。MRI 提高了活检的准确性，因此可能会影响 AS 的纳入或继续。我们旨在评估 MRI 联合靶向活检对终止 AS 总患者比例的影响，特别是因 GG 重新分类而终止 AS 的比例。
研究了前瞻性 PRIAS 研究中包括的三个亚组，GG1 患者。A 组包括 2009 年前诊断且 AS 期间或之前未行 MRI 的患者。B 组包括未行 MRI 但所有患者在诊断后 6 个月内行 MRI 的患者。C 组包括诊断前和随访期间行 MRI 的患者。我们使用累积发生率曲线估计终止率。
A 组（n=500）中，2 年内终止 AS 的累积概率为 27.5%；仅 GG 重新分类占终止的 6.9%。B 组（n=351）分别为 30.9%和 22.8%，C 组（n=435）分别为 24.2%和 13.4%。三组未行随机分组，但基线特征高度可比。
在开始 AS 前进行 MRI 检查可降低 2 年内终止 AS 的累积概率。在已经进行 AS 后进行 MRI 检查会增加与不进行 MRI 检查相比终止 AS 的累积概率，尤其是因为 GG 重新分类的增加。这些结果表明，MRI 的使用可能导致更多患者不适合 AS。考虑到 MRI 时代之前 AS 的长期癌症特异性生存率极佳，如果不调整有意义的 PCa 的定义和治疗选择，MRI 的诊断准确性提高可能会导致更多的过度治疗。
