Exploratory Analysis of TP53 Mutations in Circulating Tumour DNA as Biomarkers of Treatment Response for Patients with Relapsed High-Grade Serous Ovarian Carcinoma: A Retrospective Study.
Exploratory Analysis of TP53 Mutations in Circulating Tumour DNA as Biomarkers of Treatment Response for Patients with Relapsed High-Grade Serous Ovarian Carcinoma: A Retrospective Study.
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DOI：
10.1371/journal.pmed.1002198
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发表时间：
2016-12
期刊：
影响因子：
15.8
通讯作者：
Brenton JD
中科院分区：
文献类型：
--
作者：
Parkinson CA;Gale D;Piskorz AM;Biggs H;Hodgkin C;Addley H;Freeman S;Moyle P;Sala E;Sayal K;Hosking K;Gounaris I;Jimenez-Linan M;Earl HM;Qian W;Rosenfeld N;Brenton JD
携带肿瘤特异性序列改变的循环肿瘤DNA（ctDNA）可能提供一种微创手段来动态评估癌症患者的肿瘤负荷和治疗反应。体细胞 TP53 突变是高级别浆液性卵巢癌 (HGSOC) 的一个定义特征。我们测试了这些突变是否可以用作个性化标记物来监测肿瘤负荷和早期变化，作为反应和进展时间（TTP）的预测因子。我们对 40 名接受不同标准护理治疗的 HGSOC 患者的常规临床就诊期间收集的系列血浆样本进行了回顾性分析。针对福尔马林固定、石蜡包埋的患者肿瘤 DNA 中鉴定出的 31 种独特突变，开发了患者特异性 TP53 检测方法。这些测定通过微流控数字 PCR 定量 318 个血浆样本中的 ctDNA。将 TP53 突变等位基因分数 (TP53MAF) 与血清 CA-125（当前血液中 HGSOC 的金标准反应标记物）进行比较，并通过体积分析与计算机断层扫描上的疾病体积进行比较。将一个治疗周期后的变化与 TTP 进行比较。 51 个复发治疗疗程中治疗前的中位 TP53MAF 为 8%（四分位距 [IQR] 1.2%–22%），而 7 名未经治疗的新诊断 IIIC/IV 期患者的TP53MAF 中值为 0.7%（IQR 0.3%–2.0%）。 TP53MAF 与体积测量相关（Pearson r = 0.59，p < 0.001），并且当排除腹水患者时，这种相关性得到改善（r = 0.82）。复发患者的 TP53MAF 与疾病体积的比率（0.04%/cm3）高于未治疗患者（0.0008%/cm3，p = 0.004）。在几乎所有疾病体积 > 32 cm3 的复发患者中，每毫升血浆检测到 ctDNA ≥20 个可扩增拷贝。在 49 个复发性疾病治疗过程中，治疗前 TP53MAF 浓度（而非 CA-125）与 TTP 相关。 ctDNA 对化疗的反应较早，达到最低点的中位时间为 37 天（IQR 28-54），而 CA-125 达到最低点的中位时间为 84 天（IQR 42-116）。在 32 个可评估一个化疗周期后反应的复发治疗疗程中，多变量分析显示 TP53MAF 下降 >60% 是 TTP 的独立预测因子（风险比 0.22，95% CI 0.07-0.67，p = 0.008）。相反，TP53MAF 降低≤60% 与反应不佳相关，并且识别出 TTP < 6 个月的病例，敏感性为 71%（95% CI 42%–92%），特异性为 88%（95% CI 64%–99%）。当排除近期腹水引流的患者时，特异性得到提高。腹水引流导致TP53MAF浓度降低。这项研究的局限性包括回顾性设计、样本量小以及队列内治疗的异质性。在这项回顾性研究中，我们证明 ctDNA 与 HGSOC 女性治疗开始时的疾病体积相关，并且一个化疗周期后 TP53MAF 下降 ≤60% 与较短的 TTP 相关。这些结果提供了证据，表明 ctDNA 有潜力成为 HGSOC 中高度特异性的早期分子反应标记物，并值得在接受统一治疗的更大群体中进行进一步研究。 James Brenton 及其同事通过高级别浆液性卵巢癌的循环 DNA 分析揭示了肿瘤负荷和预后的相关性。用于测量接受高级别浆液性卵巢癌 (HGSOC) 化疗的女性反应的标准临床血液测试是血清蛋白癌抗原 125 (CA-125)。 CA-125 很敏感，但缺乏检测卵巢癌的特异性，并且在对化疗的反应中，CA-125 水平的变化不够快，如果化疗无效，在一两个周期后建议改变治疗。需要更好的肿瘤标记物，而循环肿瘤 DNA (ctDNA) 是一个有希望的候选者。 ctDNA 是源自肿瘤细胞的无细胞 DNA，可在血液中检测到； ctDNA 可用作高度特异性标记物，因为它携带癌症特有的突变。 HGSOC 是测试 ctDNA 作为生物标志物的理想癌症，因为 99% 的患者存在 TP53 基因突变。我们为 40 名 HGSOC 患者的回顾性研究设计了患者特异性 TP53 检测，并用于量化化疗前、化疗期间和化疗后收集的 318 份血浆样本中的 ctDNA 含量。我们询问 ctDNA 水平是否与化疗前存在的疾病数量相关，化疗治疗前使用 CT 图像的 3D 体积重建进行测量，作为常规护理的一部分。我们还询问化疗治疗一个周期后 TP53 ctDNA 的下降是否可以预测哪些患者的癌症会在六个月内出现进展。 ctDNA 水平（而非 CA-125 水平）与疾病总量密切相关。一个化疗周期后ctDNA水平下降>60%的患者比ctDNA水平下降60%或更少的患者的进展时间明显更长。 TP53 ctDNA 有潜力成为一种临床上有用的血液测试，用于评估 HGSOC 女性的预后和治疗反应。这项回顾性研究的反应结果应该在采用统一治疗的更大规模的前瞻性研究中得到证实。如果这些发现得到证实，TP53 ctDNA 可用于 HGSOC 临床试验和常规实践，以更早确定治疗是否有效。
Circulating tumour DNA (ctDNA) carrying tumour-specific sequence alterations may provide a minimally invasive means to dynamically assess tumour burden and response to treatment in cancer patients. Somatic TP53 mutations are a defining feature of high-grade serous ovarian carcinoma (HGSOC). We tested whether these mutations could be used as personalised markers to monitor tumour burden and early changes as a predictor of response and time to progression (TTP). We performed a retrospective analysis of serial plasma samples collected during routine clinical visits from 40 patients with HGSOC undergoing heterogeneous standard of care treatment. Patient-specific TP53 assays were developed for 31 unique mutations identified in formalin-fixed paraffin-embedded tumour DNA from these patients. These assays were used to quantify ctDNA in 318 plasma samples using microfluidic digital PCR. The TP53 mutant allele fraction (TP53MAF) was compared to serum CA-125, the current gold-standard response marker for HGSOC in blood, as well as to disease volume on computed tomography scans by volumetric analysis. Changes after one cycle of treatment were compared with TTP. The median TP53MAF prior to treatment in 51 relapsed treatment courses was 8% (interquartile range [IQR] 1.2%–22%) compared to 0.7% (IQR 0.3%–2.0%) for seven untreated newly diagnosed stage IIIC/IV patients. TP53MAF correlated with volumetric measurements (Pearson r = 0.59, p < 0.001), and this correlation improved when patients with ascites were excluded (r = 0.82). The ratio of TP53MAF to volume of disease was higher in relapsed patients (0.04% per cm3) than in untreated patients (0.0008% per cm3, p = 0.004). In nearly all relapsed patients with disease volume > 32 cm3, ctDNA was detected at ≥20 amplifiable copies per millilitre of plasma. In 49 treatment courses for relapsed disease, pre-treatment TP53MAF concentration, but not CA-125, was associated with TTP. Response to chemotherapy was seen earlier with ctDNA, with a median time to nadir of 37 d (IQR 28–54) compared with a median time to nadir of 84 d (IQR 42–116) for CA-125. In 32 relapsed treatment courses evaluable for response after one cycle of chemotherapy, a decrease in TP53MAF of >60% was an independent predictor of TTP in multivariable analysis (hazard ratio 0.22, 95% CI 0.07–0.67, p = 0.008). Conversely, a decrease in TP53MAF of ≤60% was associated with poor response and identified cases with TTP < 6 mo with 71% sensitivity (95% CI 42%–92%) and 88% specificity (95% CI 64%–99%). Specificity was improved when patients with recent drainage of ascites were excluded. Ascites drainage led to a reduction of TP53MAF concentration. The limitations of this study include retrospective design, small sample size, and heterogeneity of treatment within the cohort. In this retrospective study, we demonstrated that ctDNA is correlated with volume of disease at the start of treatment in women with HGSOC and that a decrease of ≤60% in TP53MAF after one cycle of chemotherapy was associated with shorter TTP. These results provide evidence that ctDNA has the potential to be a highly specific early molecular response marker in HGSOC and warrants further investigation in larger cohorts receiving uniform treatment. James Brenton and colleagues reveal tumour burden and prognosis correlations from circulating DNA analysis in high grade serous ovarian carcinoma. The standard clinical blood test for measuring response in women receiving chemotherapy for high-grade serous ovarian cancer (HGSOC) is the serum protein cancer antigen 125 (CA-125). CA-125 is sensitive but it lacks specificity for detection of ovarian cancer, and in response to chemotherapy, CA-125 level does not change rapidly enough to suggest change in treatment after one or two cycles if chemotherapy treatment is ineffective. Better tumour markers are required, and circulating tumour DNA (ctDNA) is a promising candidate. ctDNA is cell-free DNA derived from tumour cells that can be detected in the bloodstream; ctDNA can be used as a highly specific marker because it carries mutations unique to the cancer. HGSOC is an ideal cancer to test ctDNA as a biomarker because 99% of patients have a mutation in the TP53 gene. We designed patient-specific TP53 assays for a retrospective study of 40 patients with HGSOC, and these were used to quantify the amount of ctDNA in 318 plasma samples collected before, during, and after chemotherapy. We asked if ctDNA level was correlated with the amount of disease present before chemotherapy treatment measured using 3-D volume reconstruction from CT images taken as part of routine care. We also asked if the decrease in TP53 ctDNA after one cycle of chemotherapy treatment could predict which patients would have progression of their cancer within six months. ctDNA level, but not CA-125 level, was strongly correlated with the total volume of disease. Patients whose ctDNA level exhibited a decrease of >60% after one cycle of chemotherapy had a significantly longer time to progression than those whose ctDNA level decreased by 60% or less. TP53 ctDNA has the potential to be a clinically useful blood test to assess prognosis and response to treatment in women with HGSOC. The response findings from this retrospective study should be confirmed in larger, prospective studies with uniform treatment. If these findings are confirmed, TP53 ctDNA could be used in HGSOC clinical trials and routine practice to identify earlier whether treatment is effective.
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影响因子：
7.3
作者：
Ahmed, Ashour Ahmed;Etemadmoghadam, Dariush;Temple, Jillian;Lynch, Andy G.;Riad, Mohamed;Sharma, Raghwa;Stewart, Colin;Fereday, Sian;Caldas, Carlos;DeFazio, Anna;Bowtell, David;Brenton, James D.
通讯作者：
Brenton, James D.
影响因子：
8.4
作者：
Eisenhauer, E. A.;Therasse, P.;Verweij, J.
通讯作者：
Verweij, J.
影响因子：
4.7
作者：
Eng KH;Hanlon BM;Bradley WH;Szender JB
通讯作者：
Szender JB
DOI：
10.1093/jnci/djr282
发表时间：
2011-09-01
期刊：
JOURNAL OF THE NATIONAL CANCER INSTITUTE
影响因子：
--
作者：
Lee, Chee K.;Friedlander, Michael;Simes, R. John
通讯作者：
Simes, R. John
影响因子：
45.3
作者：
MARKMAN, M;ROTHMAN, R;LEWIS, JL
通讯作者：
LEWIS, JL