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Serum DNA methylation for monitoring response to neoadjuvant chemotherapy in breast cancer patients.

ABSTRACT: Patients with large or nonoperable breast cancers often receive neoadjuvant chemotherapy to facilitate full resection of the tumor and enable conservation of the breast. However, currently available methods for evaluation of response during therapy are limited and the actual effect of the treatment is only recognized at surgery upon completion of chemotherapy. Timely assessment of response could allow individual tailoring of the treatment and save noneffective drugs and unnecessary toxicity. Here, we suggest that tumor derived DNA methylation in the serum may reflect changes in tumor burden and allow early recognition of responders versus nonresponders. In this pilot study, we collected 7 consecutive serum samples from 52 patients with locally advanced breast cancer during neoadjuvant chemotherapy. We selected RASSF1, which was methylated in more than 80% of the tumors, for serum analysis. Using the "methylation sensitive PCR and high resolution melting," we detected RASSF1 methylation in the serum of 21 patients prior to therapy. In four patients who achieved complete pathological response, RASSF1 methylation in the serum became undetectable early during therapy. In contrast, in 17 patients that had partial or minimal pathological response, serum RASSF1 methylation persisted longer or throughout the treatment (complete versus partial response p = 0.02). These findings support further development of this assay for monitoring response during neoadjuvant therapy.

SUBMITTER: Avraham A

PROVIDER: S-EPMC3904188 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature

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Serum DNA methylation for monitoring response to neoadjuvant chemotherapy in breast cancer patients.

Avraham Ayelet A Uhlmann Ronit R Shperber Aino A Birnbaum Miriam M Sandbank Judith J Sella Avishay A Sukumar Saraswati S Evron Ella E

International journal of cancer 20120404 7

Patients with large or nonoperable breast cancers often receive neoadjuvant chemotherapy to facilitate full resection of the tumor and enable conservation of the breast. However, currently available methods for evaluation of response during therapy are limited and the actual effect of the treatment is only recognized at surgery upon completion of chemotherapy. Timely assessment of response could allow individual tailoring of the treatment and save noneffective drugs and unnecessary toxicity. Her ...[more]

PMID: 22407753

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Project description:Pathological response of breast cancer to chemotherapy is a prognostic indicator for long-term disease free and overall survival. Responses of locally advanced breast cancer in the neoadjuvant chemotherapy (NAC) settings are often variable, and the prediction of response is imperfect. The purpose of this study was to detect primary tumor responses early after the start of neoadjuvant chemotherapy using quantitative ultrasound (QUS), textural analysis and molecular features in patients with locally advanced breast cancer.The study included ninety six patients treated with neoadjuvant chemotherapy. Breast tumors were scanned with a clinical ultrasound system prior to chemotherapy treatment, during the first, fourth and eighth week of treatment, and prior to surgery. Quantitative ultrasound parameters and scatterer-based features were calculated from ultrasound radio frequency (RF) data within tumor regions of interest. Additionally, texture features were extracted from QUS parametric maps. Prior to therapy, all patients underwent a core needle biopsy and histological subtypes and biomarker ER, PR, and HER2 status were determined. Patients were classified into three treatment response groups based on combination of clinical and pathological analyses: complete responders (CR), partial responders (PR), and non-responders (NR). Response classifications from QUS parameters, receptors status and pathological were compared. Discriminant analysis was performed on extracted parameters using a support vector machine classifier to categorize subjects into CR, PR, and NR groups at all scan times.Of the 96 patients, the number of CR, PR and NR patients were 21, 52, and 23, respectively. The best prediction of treatment response was achieved with the combination mean QUS values, texture and molecular features with accuracies of 78%, 86% and 83% at weeks 1, 4, and 8, after treatment respectively. Mean QUS parameters or clinical receptors status alone predicted the three response groups with accuracies less than 60% at all scan time points. Recurrence free survival (RFS) of response groups determined based on combined features followed similar trend as determined based on clinical and pathology.This work demonstrates the potential of using QUS, texture and molecular features for predicting the response of primary breast tumors to chemotherapy early, and guiding the treatment planning of refractory patients.

Project description:BackgroundNeoadjuvant chemotherapy (NAC) is used in patients with breast cancer to reduce tumor focus, metastatic risk, and patient mortality. Monitoring NAC effects is necessary to capture resistant patients and stop or change treatment. The existing methods for evaluating NAC results have some limitations. The aim of this study was to assess the tumor response at an early stage, after the first doses of the NAC, based on the variability of the backscattered ultrasound energy, and backscatter statistics. The backscatter statistics has not previously been used to monitor NAC effects.MethodsThe B-mode ultrasound images and raw radio frequency data from breast tumors were obtained using an ultrasound scanner before chemotherapy and 1 week after each NAC cycle. The study included twenty-four malignant breast cancers diagnosed in sixteen patients and qualified for neoadjuvant treatment before surgery. The shape parameter of the homodyned K distribution and integrated backscatter, along with the tumor size in the longest dimension, were determined based on ultrasound data and used as markers for NAC response. Cancer tumors were assigned to responding and non-responding groups, according to histopathological evaluation, which was a reference in assessing the utility of markers. Statistical analysis was performed to rate the ability of markers to predict the final NAC response based on data obtained after subsequent therapeutic doses.ResultsStatistically significant differences (p<0.05) between groups were obtained after 2, 3, 4, and 5 doses of NAC for quantitative ultrasound markers and after 5 doses for the assessment based on maximum tumor dimension. Statistical analysis showed that, after the second and third NAC courses the classification based on integrated backscatter marker was characterized by an AUC of 0.69 and 0.82, respectively. The introduction of the second quantitative marker describing the statistical properties of scattering increased the corresponding AUC values to 0.82 and 0.91.ConclusionsQuantitative ultrasound information can characterize the tumor's pathological response better and at an earlier stage of therapy than the assessment of the reduction of its dimensions. The introduction of statistical parameters of ultrasonic backscatter to monitor the effects of chemotherapy can increase the effectiveness of monitoring and contribute to a better personalization of NAC therapy.

Dataset Information

Serum DNA methylation for monitoring response to neoadjuvant chemotherapy in breast cancer patients.

Publications

Serum DNA methylation for monitoring response to neoadjuvant chemotherapy in breast cancer patients.

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