乳腺癌新辅助化疗的研究进展

乳腺癌是一种女性最常见的恶性肿瘤,近年来我国乳腺癌的发病率呈逐年上升趋势。研究证实,新辅助化疗不仅可使不能手术的晚期乳腺癌患者获得手术机会,而且也增加了部分患者的保乳概率,但是约20%的乳腺癌患者不能从新辅助化疗中获益,并影响后续治疗效果。因此,制定合理的、个体化的新辅助化疗方案对于提高乳腺癌患者的生存质量和改善其预后尤为重要。目前,研究已发现的NCT相关的预测因子主要包块肿瘤类型、分子分型、ER、PR、Ki67等,而HER2、TOP2A、P53、PRAP单独作为预测因子的还存在争议。本文主要对乳腺癌新辅助化疗的现状、各种预测因子的作用及其不足之处进行了综述。     

新辅助化疗在局部晚期宫颈癌治疗中的疗效观察

目的：探讨新辅助化疗联合手术治疗较传统手术治疗Ib2、IIa2局部晚期宫颈癌的临床疗效。方法：选取2008年6月～2011年12月在黑龙江省哈尔滨医科大学附属第三医院初治宫颈癌患者120例,临床分期为Ib2期、IIa2期,术前均经病理证实为宫颈鳞癌,将其分为两组：研究组（新辅助化疗联合手术治疗组）;对照组（单纯手术治疗组）。研究组给予1～2个疗程的新辅助化疗后评估其化疗疗效,有效者化疗结束后行广泛性子宫切除＋盆腔淋巴结清扫术;对照组直接行手术治疗。结果：新辅助化疗能够使肿瘤体积较化疗前缩小或消失,临床有效率高达81.43%,从而降低了宫颈癌的临床分期,提高手术的切除率,扩大手术适应征,降低术后病理高危因素,同时手术治疗能保留卵巢功能,提高年轻宫颈癌患者生活质量。结论：术前新辅助化疗可以提高手术治疗局部晚期宫颈癌的临床疗效。     

Exploratory Cost-Effectiveness Analysis of Response-Guided Neoadjuvant Chemotherapy for Hormone Positive Breast Cancer Patients

PurposeGuiding response to neoadjuvant chemotherapy (guided-NACT) allows for an adaptative treatment approach likely to improve breast cancer survival. In this study, our primary aim is to explore the expected cost-effectiveness of guided-NACT using as a case study the first randomized controlled trial that demonstrated effectiveness (GeparTrio trial).ResultsOur exploratory CEA predicted that guided-NACT as proposed by the GeparTrio, costs additional €110, but results in 0.014 QALYs gained per patient. This scenario of guided-NACT was considered cost-effective at any willingness to pay per additional QALY. At the prevailing Dutch willingness to pay threshold (€80.000/QALY) cost-effectiveness was expected with 78% certainty.ConclusionThis exploratory CEA indicated that guided-NACT (as proposed by the GeparTrio trial) is likely cost-effective in treating HR+ EBC women. While prospective validation of the GeparTrio findings is advisable from a clinical perspective, early CEAs can be used to prioritize further research from a broader health economic perspective, by identifying which parameters contribute most to current decision uncertainty. Furthermore, their use can be extended to explore the expected cost-effectiveness of alternative guided-NACT scenarios that combine the use of promising imaging techniques together with personalized treatments.     

Endoscopic Gold Fiducial Marker Placement into the Bladder Wall to Optimize Radiotherapy Targeting for Bladder-Preserving Management of Muscle-Invasive Bladder Cancer: Feasibility and Initial Outcomes

ResultsBetween 1/2007 and 7/2012, a total of 89 markers (3–5 per tumor site) were placed into 18 patients of mean age 73.6 years. Two patients elected cystectomy before starting treatment; 16/18 completed chemo-radiotherapy. All (100%) markers were visible with all on-table (portal, cone-beam CT), fluoroscopy, plain-film, and CT-scan imaging. In two patients, 1 of 4 markers placed at the tumor site fell-out (voided) during the second half of radiotherapy. All other markers (80/82, 98%) were present through the end of radio-therapy. No intraoperative (e.g. uncontrolled bleeding, collateral injury) or post-operative complications (e.g. stone formation, urinary tract infection, post-TUR hematuria >48 hours) occurred. Use of micro-tined fiducial tumor-site markers afforded a 2 to 6-fold reduction in bladder-area targeted with high-dose radiation.DiscussionPlacement of the micro-tined fiducial markers into the bladder was feasible and associated with excellent retention-rate and no complications. All markers were well-visualized during radiotherapy with all imaging modalities. Bladder fiducial markers improve targeting accuracy, and may increase treatment efficacy and reduce morbidity from collateral radiation.     

Modulation of Mutational Landscape in HER2-Positive Breast Cancer after Neoadjuvant Chemotherapy

IntroductionIn early-stage HER2 positive breast cancer (BC) patients, tumor response to neoadjuvant chemotherapy (NACT) predict survival outcomes. Patients achieving less than pathological complete response (pCR) have a worse prognosis, however, this group is heterogeneous. Nowadays limited data on predictive/prognostic biomarkers in patients with residual cancer disease are available.MethodsUsing next-generation sequencing technology, we evaluated a panel of 21 cancer genes in a group of HER2 positive BC patients with residual disease after NACT. A control group of patients who achieved the pCR was selected too. The BC mutational profile was analyzed on both the tumor diagnostic biopsy and matched residual disease.ResultsOverall, the detection rate of mutations was 79% in the No-pCR group versus 90% in the pCR cohort and 98% in the residual BC. The most mutated genes were TP53 and PIK3CA. No correlations between single gene mutations and survival outcomes were found. In no-pCR cohort, 52% of patients had different mutational profile after NACT, 69% of them had an increased in the number of mutated genes. Mutational profile changes from diagnostic biopsy to residual BC were a negative prognostic factor in term of relapse free survival: recurrence probability in different gene profile sub-group was 42% vs 0% in the same profile one (P = .019).ConclusionsTreatment selective pressure on tumor cells due to NACT changed the gene mutational profile in more than half of BC patient with residual tumor disease. Treatment-induced gene mutations significantly increase the risk of relapse. Profiling primary and residual BC is a major step in order to further personalized adjuvant treatment strategy.     

不同给药途径的新辅助化疗在晚期上皮性卵巢癌的疗效观察

目的:探讨新辅助化疗中不同给药方式在晚期上皮性卵巢癌的临床疗效及意义。方法:选取132例初治上皮性卵巢癌患者,临床分期为Ⅲc一Ⅳ期。随机平均分为4组(A组:单纯紫杉醇静脉化疗B组:单纯卡铂腹腔灌注C组:紫杉醇静脉联合卡铂腹腔D组:直接手术)。A、B、C三组给予1个疗程新辅助化疗后评估其疗效,行卵巢癌肿瘤细胞减灭术;D组直接手术治疗,比较各组治疗情况。结果:4组的满意肿瘤减灭率分别为78.8%、75.7%、87.9%、63.6%;化疗A、B与C组间、化疗各组与D组间在减灭术成功率、手术时间、术中出血量、术后排气时间上比较均有统计学意义(P0.05);新辅助化疗各组不良反应可耐受,均顺利完成手术,其中骨髓抑制及神经毒性以C组发生率较高(P0.01)。结论:1新辅助化疗可降低手术风险,有效提高满意的减灭术的成功率,改善生存质量。2静脉联合腹腔灌注较单途径用药的临床疗效好,毒副作用略高但可耐受。     

CD133 Is a Useful Surrogate Marker for Predicting Chemosensitivity to Neoadjuvant Chemotherapy in Breast Cancer

Background

Neoadjuvant chemotherapy (NAC) is a standard care regimen for patients with breast cancer. However, the pathologic complete response (pCR) rate remains at 30%. We hypothesized that a cancer stem cell marker may identify NAC-resistant patients, and evaluated CD133 and ALDH1 as a potential surrogate marker for breast cancer. The aim of this study was to find a surrogate maker to predict chemosensitivity of NAC for breast cancer.

Methodology/Findings

A total of 102 patients with breast cancer were treated with NAC consisting of epirubicin followed by paclitaxel. Core needle biopsy (CNB) specimens and resected tumors were obtained from all patients before and after NAC, respectively. Chemosensitivity and prognostic potential of CD133 or ALDH1 expression was evaluated by immunohistochemistry. Clinical CR (cCR) and pCR rates were 18% (18/102) and 29% (30/102), respectively. Forty-seven (46%) patients had CD133-positive tumors before NAC, and CD133 expression was significantly associated with a low pCR rate (p = 0.035) and clinical non-responders. Multivariate analysis revealed that CD133 expression was significantly (p = 0.03) related to pCR. Recurrence was more frequent in patients with CD133-positive tumors (21/47, 45%) than that in patients with CD133-negative tumors (7/55, 13%). The number of patients with CD133-positive tumors (62%) after NAC was higher than that (46%) before NAC. Furthermore, most patients with CD133-positive tumors before NAC maintained the same status after NAC.

Conclusion/Significance

CD133 before NAC might be a useful marker for predicting the effectiveness of NAC and recurrence of breast cancer after NAC.     

宫颈癌患者新辅助化疗前后miR-138的表达及与化疗敏感性的关系研究

目的:研究宫颈癌患者新辅助化疗前后微小RNA-138(mi R-138)的表达及与化疗敏感性的关系。方法:选取2016年2月至2018年7月我院收治的宫颈癌患者18例为研究对象。所有患者均给予新辅助化疗,并根据治疗后的效果分为化疗有效组与化疗无效组。采用微阵列芯片技术分别检测两组患者化疗前后的mi R-138表达水平,同时采用Western blot技术检测mi R-138基因靶蛋白γH2AX的表达情况,分析患者化疗后mi R-138表达水平与临床病理特征的关系。结果:化疗有效组化疗后mi R-138△Ct值明显低于化疗前,且明显低于化疗无效组(P0.05),而化疗无效组化疗后mi R-138△Ct值与化疗前比较差异无统计学意义(P0.05)。化疗后两组靶蛋白γH2AX相对表达量均明显低于化疗前(P0.05),化疗有效组靶蛋白γH2AX相对表达量的差值显著低于化疗无效组(P0.05)。宫颈癌患者新辅助化疗后组织中mi R-138△Ct差值与肿瘤分化程度、浸润深度和淋巴结转移密切相关(P0.05),与年龄、FIGO临床分期无关(P0.05)。结论:新辅助化疗可以改变宫颈癌患者的mi R-138表达水平,且mi R-138的表达水平可能与化疗药物敏感性密切相关。     

Utilization of Neoadjuvant Chemotherapy Varies in the Treatment of Women with Invasive Breast Cancer

Background

Treatment with neoadjuvant chemotherapy (NAC) has made it possible for some women to be successfully treated with breast conservation therapy (BCT ) who were initially considered ineligible. Factors related to current practice patterns of NAC use are important to understand particularly as the surgical treatment of invasive breast cancer has changed. The goal of this study was to determine variations in neoadjuvant chemotherapy use in a large multi-center national database of patients with breast cancer.

Methods

We evaluated NAC use in patients with initially operable invasive breast cancer and potential impact on breast conservation rates. Records of 2871 women ages 18-years and older diagnosed with 2907 invasive breast cancers from January 2003 to December 2008 at four institutions across the United States were examined using the Breast Cancer Surgical Outcomes (BRCASO) database. Main outcome measures included NAC use and association with pre-operatively identified clinical factors, surgical approach (partial mastectomy [PM] or total mastectomy [TM]), and BCT failure (initial PM followed by subsequent TM).

Results

Overall, NAC utilization was 3.8%l. Factors associated with NAC use included younger age, pre-operatively known positive nodal status, and increasing clinical tumor size. NAC use and BCT failure rates increased with clinical tumor size, and there was significant variation in NAC use across institutions. Initial TM frequency approached initial PM frequency for tumors >30-40mm; BCT failure rate was 22.7% for tumors >40mm. Only 2.7% of patients undergoing initial PM and 7.2% undergoing initial TM received NAC.

Conclusions

NAC use in this study was infrequent and varied among institutions. Infrequent NAC use in patients suggests that NAC may be underutilized in eligible patients desiring breast conservation.     

The Prognostic Value of BRCA1 mRNA Expression Levels Following Neoadjuvant Chemotherapy in Breast Cancer

Background

A fraction of sporadic breast cancers has low BRCA1 expression. BRCA1 mutation carriers are more likely to achieve a pathological complete response with DNA-damage-based chemotherapy compared to non-mutation carriers. Furthermore, sporadic ovarian cancer patients with low levels of BRCA1 mRNA have longer survival following platinum-based chemotherapy than patients with high levels of BRCA1 mRNA.

Methodology/Principal Findings

Tumor biopsies were obtained from 86 breast cancer patients who were candidates for neoadjuvant chemotherapy, treated with four cycles of neoadjuvant fluorouracil, epirubicin and cyclophosphamide. Estrogen receptor (ER), progesterone receptor (PR), HER2, cytokeratin 5/6 and vimentin were examined by tissue microarray. HER2 were also assessed by chromogenic in situ hybridization, and BRCA1 mRNA was analyzed in a subset of 41 patients for whom sufficient tumor tissue was available by real-time quantitative PCR. Median time to progression was 42 months and overall survival was 55 months. In the multivariate analysis for time to progression and overall survival for 41 patients in whom BRCA1 could be assessed, low levels of BRCA1 mRNA, positive PR and negative lymph node involvement predicted a significantly lower risk of relapse, low levels of BRCA1 mRNA and positive PR were the only variables associated with significantly longer survival.

Conclusions/Significance

We provide evidence for a major role for BRCA1 mRNA expression as a marker of time to progression and overall survival in sporadic breast cancers treated with anthracycline-based chemotherapy. These findings can be useful for customizing chemotherapy.     

FOLFOX4和XELOX两周方案用于进展期胃癌新辅助化疗的随机对照研究

目的:观察FOLFOX4和XELOX新辅助化疗方案治疗局部进展期胃癌的疗效和毒副作用。方法:68例初治确诊为局部进展期胃癌的患者,随机分为两组,每组各34例,分别采用XELOX和FOLFOX4化疗方案行术前两个疗程的化疗治疗。结果:XELOX组总有效率为47.06%,FOLFOX4组总有效率为41.08%,两组间无显著性差异。不良反应方面,FOLFOX4组恶心、呕吐,白细胞减少和口腔黏膜炎发生率较高,而XELOX组手足综合症发生率较高。结论:XELOX方案作为胃癌新辅助化疗方案,疗效与FOLFOX4方案相似,但XELOX方案副作用较轻且均可控制,化疗时间短,对机体损伤小,易于接受,值得在临床工作中进一步研究和推广。     

Evaluation of Neoadjuvant Chemotherapy Response in Women with Locally Advanced Breast Cancer Using Ultrasound Elastography

PURPOSE: Ultrasound elastography is a new imaging technique that can be used to assess tissue stiffness. The aim of this study was to investigate the potential of ultrasound elastography for monitoring treatment response of locally advanced breast cancer patients undergoing neoadjuvant therapy. METHODS: Fifteen women receiving neoadjuvant chemotherapy had the affected breast scanned before, 1, 4, and 8 weeks following therapy initiation, and then before surgery. Changes in elastographic parameters related to tissue biomechanical properties were then determined and compared to clinical and pathologic tumor response after mastectomy. RESULTS: Patients who responded to therapy demonstrated a significant decrease (P < .05) in strain ratios and strain differences 4 weeks after treatment initiation compared to non-responding patients. Mean strain ratio and mean strain difference for responders was 81 ± 3% and 1 ± 17% for static regions of interest (ROIs) and 81 ± 3% and 6 ± 18% for dynamic ROIs, respectively. In contrast, these parameters were 102±2%, 110±17%, 101±4%, and 109±30% for non-responding patients, respectively. Strain ratio using static ROIs was found to be the best predictor of treatment response, with 100% sensitivity and 100% specificity obtained 4 weeks after starting treatment. CONCLUSIONS: These results suggest that ultrasound elastography can be potentially used as an early predictor of tumor therapy response in breast cancer patients.     

动脉介入新辅助化疗对宫颈癌细胞增殖及凋亡的影响

目的:探讨动脉介入新辅助化疗对宫颈癌细胞增殖及凋亡的影响,为中晚期宫颈癌的临床治疗提供依据。方法:选择2012年8月-2015年5月在我院确诊为中晚期宫颈癌并行动脉介入化疗的患者60例作为研究对象。分别在入院时和动脉介入化疗后收集患者肿瘤组织标本,应用免疫组化法检测肿瘤细胞增殖指数(LI),TUNEL法检测肿瘤细胞凋亡指数(AI)。结果:经动脉介入化疗后,宫颈癌细胞的增殖指数显著降低,而凋亡指数显著提高,与化疗前比较,差异具有统计学意义(P0.05)。宫颈癌细胞增殖指数LI随临床分期的增加而升高,而凋亡指数AI随临床分期的增加而降低,差异具有统计学意义(P0.05);介入化疗后,同一临床分期宫颈癌细胞的增殖指数LI均低于化疗前,而凋亡指数AI则高于化疗前,差异具有统计学意义(P0.05)。结论:动脉介入新辅助化疗能够抑制中晚期宫颈癌细胞的增殖,并促进其凋亡,为患者创造手术切除的机会。     

新辅助化疗配合手术治疗中晚期乳腺癌的临床效果分析

目的:观察新辅助化疗配合手术治疗中晚期乳腺癌的临床效果,为临床研究提供参考。方法:选取我院2009年5月-2011年4月收治的中晚期乳腺癌患者107例,根据治疗方法的不同,将患者分为新辅助化疗组和对照组。新辅助化疗组采取术前辅助化疗,而对照组术前不接受化疗。观察新辅助化疗组患者的近期临床疗效、毒副反应发生率;比较两组患者的手术时间、术中出血量等;术后随访三年,记录两组患者的肿瘤局部复发率及远处转移率。结果:新辅助化疗组患者治疗的总有效率为79.66%,毒副反应的发生率为33.89%;新辅助化疗组的平均手术时间、术中出血量均低于对照组,差异具有统计学意义(P0.05)。新辅助化疗组患者的局部复发率为5.08%,远处转移率为6.78%;对照组患者局部复发率为12.50%,远处转移率为18.75%。新辅助化疗组患者的肿瘤复发转移率低于对照组,差异具有统计学意义(P0.05)。结论:在中晚期乳腺癌的临床治疗中,术前对患者实施新辅助化疗具有明显的效果,患者近期疗效良好,毒副反应可耐受,且手术后的复发转移率相对较低,值得推广应用。     

探究新辅助化疗对胃癌细胞Bcl-2和p53基因表达的影响

胃癌在中国的发病率和死亡率居恶性肿瘤前列,现在胃癌的治疗主要以手术和化疗为主的综合治疗,新辅助化疗是胃癌综合治疗的重要组成部分,通过新辅助化疗能够有效抑制癌细胞增殖、缩小肿瘤体积等优点,从而为手术切除创造条件。本研究用新辅助化疗处理患胃癌的小鼠,并检测了新辅助化疗处理前后胃癌细胞内p53和Bcl-2 (细胞凋亡相关因子)基因在组织内的表达变化情况,以及与对照相比新辅助化疗对肿瘤大小的影响。结果表明,新辅助化疗可以减缓肿瘤的增长,显著上调小鼠胃癌组织内细胞凋亡因子p53的表达,并且显著下调Bcl-2抗凋亡因子的表达,从而有效地抑制胃癌细胞的增殖。这一结果可能为新辅助化疗对胃癌的治疗分子机制提供一些理论支持。     

DNA Damage and Repair Biomarkers in Cervical Cancer Patients Treated with Neoadjuvant Chemotherapy: An Exploratory Analysis

Cervical cancer cells commonly harbour a defective G₁/S checkpoint owing to the interaction of viral oncoproteins with p53 and retinoblastoma protein. The activation of the G₂/M checkpoint may thus become essential for protecting cancer cells from genotoxic insults, such as chemotherapy. In 52 cervical cancer patients treated with neoadjuvant chemotherapy, we investigated whether the levels of phosphorylated Wee1 (pWee1), a key G₂/M checkpoint kinase, and γ-H2AX, a marker of DNA double-strand breaks, discriminated between patients with a pathological complete response (pCR) and those with residual disease. We also tested the association between pWee1 and phosphorylated Chk1 (pChk1), a kinase acting upstream Wee1 in the G₂/M checkpoint pathway. pWee1, γ-H2AX and pChk1 were retrospectively assessed in diagnostic biopsies by immunohistochemistry. The degrees of pWee1 and pChk1 expression were defined using three different classification methods, i.e., staining intensity, Allred score, and a multiplicative score. γ-H2AX was analyzed both as continuous and categorical variable. Irrespective of the classification used, elevated levels of pWee1 and γ-H2AX were significantly associated with a lower rate of pCR. In univariate and multivariate analyses, pWee1 and γ-H2AX were both associated with reduced pCR. Internal validation conducted through a re-sampling without replacement procedure confirmed the robustness of the multivariate model. Finally, we found a significant association between pWee1 and pChk1. The message conveyed by the present analysis is that biomarkers of DNA damage and repair may predict the efficacy of neoadjuvant chemotherapy in cervical cancer. Further studies are warranted to prospectively validate these encouraging findings.     

Multi-Site Clinical Evaluation of DW-MRI as a Treatment Response Metric for Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy

Purpose

To evaluate diffusion weighted MRI (DW-MR) as a response metric for assessment of neoadjuvant chemotherapy (NAC) in patients with primary breast cancer using prospective multi-center trials which provided MR scans along with clinical outcome information.

Materials and Methods

A total of 39 patients with locally advanced breast cancer accrued from three different prospective clinical trials underwent DW-MR examination prior to and at 3–7 days (Hull University), 8–11 days (University of Michigan) and 35 days (NeoCOMICE) post-treatment initiation. Thirteen patients, 12 of which participated in treatment response study, from UM underwent short interval (<1hr) MRI examinations, referred to as “test-retest” for examination of repeatability. To further evaluate stability in ADC measurements, a thermally controlled diffusion phantom was used to assess repeatability of diffusion measurements. MRI sequences included contrast-enhanced T1-weighted, when appropriate, and DW images acquired at b-values of 0 and 800 s/mm². Histogram analysis and a voxel-based analytical technique, the Parametric Response Map (PRM), were used to derive diffusion response metrics for assessment of treatment response prediction.

Results

Mean tumor apparent diffusion coefficient (ADC) values generated from patient test-retest examinations were found to be very reproducible (|ΔADC|<0.1x10^-3mm²/s). This data was used to calculate the 95% CI from the linear fit of tumor voxel ADC pairs of co-registered examinations (±0.45x10^-3mm²/s) for PRM analysis of treatment response. Receiver operating characteristic analysis identified the PRM metric to be predictive of outcome at the 8–11 (AUC = 0.964, p = 0.01) and 35 day (AUC = 0.770, p = 0.05) time points (p<.05) while whole-tumor ADC changes where significant at the later 35 day time interval (AUC = 0.825, p = 0.02).

Conclusion

This study demonstrates the feasibility of performing a prospective analysis of DW-MRI as a predictive biomarker of NAC in breast cancer patients. In addition, we provide experimental evidence supporting the use of sensitive analytical tools, such as PRM, for evaluating ADC measurements.     

Association Between Background Parenchymal Enhancement and Pathologic Complete Remission Throughout the Neoadjuvant Chemotherapy in Breast Cancer Patients

PURPOSE: To retrospectively investigate the quantitative background parenchymal enhancement (BPE) of the contralateral normal breast in patients with unilateral invasive breast cancer throughout multiple monitoring points of neoadjuvant chemotherapy (NAC) and to further determine whether BPE is associated with tumor response, especially at the early stage of NAC. MATERIALS AND METHODS: A total of 90 patients with unilateral breast cancer who then received six or eight cycles of NAC before surgery were analyzed retrospectively. BPE was measured in dynamic contrast-enhanced MRI at baseline and after 2nd, 4th, and 6th NAC, respectively. Correlation between BPE and tumor size was analyzed, and the association between pathologic complete remission (pCR) and BPE was also analyzed. RESULTS: The BPE of contralateral normal breast showed a constant reduction throughout NAC therapy regardless of the menopausal status (P < .001 in all). Both the BPEs and the changes of BPE in each of the three monitoring points were significantly correlated with those in tumor size (P < .05 in all), and the reduction of BPE after 2nd NAC had the largest diagnostic value for pCR (AUC = 0.726, P < .001), particularly in hormonal receptor (HR)-negative patients (OR = 0.243, 95%CI = 0.083 to 0.706, P = .009). CONCLUSION: The BPE of contralateral normal breast had a constant decreased tendency similar to the change of tumor size in NAC. Reduction of BPE at the early stage of NAC was positively associated with pCR, especially in HR-negative status.     

Effect of Imaging Parameter Thresholds on MRI Prediction of Neoadjuvant Chemotherapy Response in Breast Cancer Subtypes

The purpose of this study is to evaluate the predictive performance of magnetic resonance imaging (MRI) markers in breast cancer patients by subtype. Sixty-four patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy were enrolled in this study. Each patient received a dynamic contrast-enhanced (DCE-MRI) at baseline, after 1 cycle of chemotherapy and before surgery. Functional tumor volume (FTV), the imaging marker measured by DCE-MRI, was computed at various thresholds of percent enhancement (PE_t) and signal-enhancement ratio (SER_t). Final FTV before surgery and percent changes of FTVs at the early and final treatment time points were used to predict patients’ recurrence-free survival. The full cohort and each subtype defined by the status of hormone receptor and human epidermal growth factor receptor 2 (HR+/HER2-, HER2+, triple negative) were analyzed. Predictions were evaluated using the Cox proportional hazard model when PE_t changed from 30% to 200% in steps of 10% and SER_t changed from 0 to 2 in steps of 0.2. Predictions with high hazard ratios and low p-values were considered as strong. Different profiles of FTV as predictors for recurrence-free survival were observed in each breast cancer subtype and strong associations with survival were observed at different PE_t/SER_t combinations that resulted in different FTVs. Findings from this retrospective study suggest that the predictive performance of imaging markers based on FTV may be improved with enhancement thresholds being optimized separately for clinically-relevant subtypes defined by HR and HER2 receptor expression.