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17p12 deletion in breast cancer predicts resistance to neoadjuvant chemotherapy.

ABSTRACT: Numerous studies have attempted to identify gene expression profiles which can be utilized to predict responses to neoadjuvant chemotherapy (NAC), but their findings are not clinically applicable at present. In the present study, we sought to determine DNA copy number alterations (CNAs) in breast cancer tissues which are associated with the response to NAC. Frozen tumor tissues from 63 breast cancer patients were obtained using core needle biopsy prior to NAC (3 cycles of docetaxel plus adriamycin) and were microdissected. Array comparative genomic hybridization (array CGH) with 4,045 bacterial artificial chromosome (BAC) probes was performed to identify the CNAs. Changes in tumor size in response to NAC were measured via magnetic resonance imaging. Fluorescence in situ hybridization (FISH) was conducted to verify array CGH results and for independent validation studies. CNAs at eight chromosomal loci encompassing 24 clones were correlated with changes in tumor size after NAC (p<0.05; t-test). Two CNAs were selected, 17p12 deletion and 17q21.32-33 gain, which were significantly associated with a smaller reduction in tumor size following NAC, via prioritization of the regions containing the candidate genes. In an independent validation set of samples from 39 patients, FISH assay further showed that the 17p12 deletion was markedly associated with smaller changes in tumor size (p=0.006), while the 17q21.32-33 gain was not significant (p=0.309). In conclusion, we successfully identified a 17p12 deletion in breast cancer tissue which can be applied in predicting tumor resistance to NAC.

SUBMITTER: Han W

PROVIDER: S-EPMC3440692 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature

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17p12 deletion in breast cancer predicts resistance to neoadjuvant chemotherapy.

Han Wonshik W Woo Jung Hoon JH Jeon Yoon Kyung YK Yang Song-Ju SJ Cho Jihyoung J Ko Eunyoung E Kim Tae-You TY Im Seock-Ah SA Oh DO-Youn DY Park In-Ae IA Hwang Ki-Tae KT Moon Hyeong-Gon HG Yang Kap-Seok KS Noh Dong-Young DY

Experimental and therapeutic medicine 20110629 5

Numerous studies have attempted to identify gene expression profiles which can be utilized to predict responses to neoadjuvant chemotherapy (NAC), but their findings are not clinically applicable at present. In the present study, we sought to determine DNA copy number alterations (CNAs) in breast cancer tissues which are associated with the response to NAC. Frozen tumor tissues from 63 breast cancer patients were obtained using core needle biopsy prior to NAC (3 cycles of docetaxel plus adriamyc ...[more]

PMID: 22977578

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Project description:BackgroundNeoadjuvant chemotherapy is a key component of breast cancer treatment regimens and pathologic complete response to this therapy varies among patients. This is presumably due to differences in the molecular mechanisms that underlie each tumor's disease pathology. Developing genomic clinical assays that accurately categorize responders from non-responders can provide patients with the most effective therapy for their individual disease.MethodsWe applied our previously developed E2F4 genomic signature to predict neoadjuvant chemotherapy response in breast cancer. E2F4 individual regulatory activity scores were calculated for 1129 patient samples across 5 independent breast cancer neoadjuvant chemotherapy datasets. Accuracy of the E2F4 signature in predicting neoadjuvant chemotherapy response was compared to that of the Oncotype DX and MammaPrint predictive signatures.ResultsIn all datasets, E2F4 activity level was an accurate predictor of neoadjuvant chemotherapy response, with high E2F4 scores predictive of achieving pathologic complete response and low scores predictive of residual disease. These results remained significant even after stratifying patients by estrogen receptor (ER) status, tumor stage, and breast cancer molecular subtypes. Compared to the Oncotype DX and MammaPrint signatures, our E2F4 signature achieved similar performance in predicting neoadjuvant chemotherapy response, though all signatures performed better in ER+ tumors compared to ER- ones. The accuracy of our signature was reproducible across datasets and was maintained when refined from a 199-gene signature down to a clinic-friendly 33-gene panel.ConclusionOverall, we show that our E2F4 signature is accurate in predicting patient response to neoadjuvant chemotherapy. As this signature is more refined and comparable in performance to other clinically available gene expression assays in the prediction of neoadjuvant chemotherapy response, it should be considered when evaluating potential treatment options.

Project description:BackgroundPathologic complete response (pCR) after neoadjuvant chemotherapy (NACT) is associated with improved overall survival (OS) in patients with breast cancer, but it is unclear how post-NACT response influences radiation therapy administration in patients presenting with node-positive disease. We sought to determine whether nodal pCR is associated with likelihood of receiving nodal radiation and whether radiation therapy among patients experiencing nodal pCR is associated with improved OS.Methods and materialsClinical N1 (cN1) female breast cancer patients diagnosed during 2010 to 2015 who were ypN0 (ie, nodal pCR; n = 12,341) or ypN1 (ie, residual disease; n = 13,668) after NACT were identified in the National Cancer Database. Multivariate logistic regression was used to identify factors associated with receiving radiation therapy. Cox proportional hazards modeling was used to estimate the association between radiation therapy and adjusted OS.ResultsThe study included 26,009 patients; 43.9% (n = 5423) of ypN0 and 55.3% (n = 7556) of ypN1 patients received nodal radiation. Rates of nodal radiation remained the same over time among ypN0 patients (trend test, P = .29) but increased among ypN1 patients from 49% in 2010 to 59% in 2015 (trend test, P < .001). After adjusting for covariates, nodal pCR (vs no stage change) was associated with decreased likelihood of nodal radiation after mastectomy (∼20% decrease) and lumpectomy (∼30% decrease; both P < .01). After mastectomy, nodal (vs no) radiation conferred no significant survival benefit in ypN0 patients, but it approached significance for ypN1 patients (hazard ratio [HR], 0.83; 95% confidence interval [CI], 0.69-0.99, P = .04; overall P = .11). After lumpectomy, nodal radiation was associated with improved adjusted OS for ypN0 (HR, 0.38; 95% CI, 0.22-0.66) and ypN1 patients (HR, 0.44; 95% CI, 0.30-0.66; both P < .001), but this improvement was not significantly greater than that associated with breast-only radiation.ConclusionsypN0 patients were less likely to receive nodal radiation than ypN1 patients were, suggesting that selective omission already occurs and, in the context of limited survival data, could potentially be appropriate for select patients.

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17p12 deletion in breast cancer predicts resistance to neoadjuvant chemotherapy.

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17p12 deletion in breast cancer predicts resistance to neoadjuvant chemotherapy.

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