Chemoradiotherapy Response In Patients Research Articles

Apparent diffusion coefficient histogram analysis for predicting neoadjuvant chemoradiotherapy response in patients with rectal cancer.

PURPOSE This study aimed to retrospectively evaluate the apparent diffusion coefficient (ADC) histograms in predicting chemoradiotherapy (CRT) response in patients with locally advanced rectal cancer (LARC). METHODS A total of 51 patients who underwent surgery in our institution for rectal cancer following neoadjuvant CRT between November 2013 and July 2019 were enrolled. Conventional magnetic resonance (MR) and diffusion-weighted images obtained before and after CRT were evaluated retrospectively. All tumor-containing regions of interests were drawn in 3 selected axial images, and special software for histogram analysis was used to evaluate ADC distribution. ADC cutoff values from post-CRT ADC histogram were calculated from receiver operating characteristic (ROC) analysis for evaluating CRT response. RESULTS In histopathological analysis, 5 patients (9.8%) had minimal response (group 1), 31 patients (60.8%) had partial response (group 2), and 15 patients (29.4%) had complete or almost complete response (group 3). In the ADC histogram, minimum, maximum, 10th, 25th, 50th, 75th, and 90th percentile, mean ADC values, and skewness values of groups 2 and 3 showed significant changes before and after CRT, but no difference was found within group 1 values. The mean, 25th, 50th, 75th percent ADC values after CRT and skewness, and kurtosis values were significantly different between group 1 and group 3. Skewness value from the ADC histogram in postCRT magnetic resonance imaging had the best diagnostic performance with an area under the ROC curve of 0.851 (P =.003) for detecting group 3. The skewness cutoff calculated from the ROC analysis was 0.210 for evaluating CRT response. The sensitivity and specificity of the cut-off value were 100% and 61.4%, respectively. CONCLUSION The ADC histogram analysis seems to have potential application in predicting response to neoadjuvant CRT in patients with locally advanced rectal cancer.

1214P Prognostic value of 68Ga-FAPI PET/CT in esophageal squamous cell carcinoma: A pilot study

The prognostic value of 68Ga-FAPI PET/CT has not been evaluated in any cancer type. We aimed to investigate the association between patients’ survival and 68Ga-FAPI PET/CT-derived parameters in ESCC. We hypothesized that parameters derived from baseline 68Ga-FAPI PET/CT might be used for evaluating the prognostic value of chemoradiotherapy response in patients with ESCC.

Multiparametric MRI Radiomics for the Early Prediction of Response to Chemoradiotherapy in Patients With Postoperative Residual Gliomas: An Initial Study.

PurposeTo evaluate whether multiparametric magnetic resonance imaging (MRI)-based logistic regression models can facilitate the early prediction of chemoradiotherapy response in patients with residual brain gliomas after surgery.Patients and MethodsA total of 84 patients with residual gliomas after surgery from January 2015 to September 2020 who were treated with chemoradiotherapy were retrospectively enrolled and classified as treatment-sensitive or treatment-insensitive. These patients were divided into a training group (from institution 1, 57 patients) and a validation group (from institutions 2 and 3, 27 patients). All preoperative and postoperative MR images were obtained, including T1-weighted (T1-w), T2-weighted (T2-w), and contrast-enhanced T1-weighted (CET1-w) images. A total of 851 radiomics features were extracted from every imaging series. Feature selection was performed with univariate analysis or in combination with multivariate analysis. Then, four multivariable logistic regression models derived from T1-w, T2-w, CET1-w and Joint series (T1+T2+CET1-w) were constructed to predict the response of postoperative residual gliomas to chemoradiotherapy (sensitive or insensitive). These models were validated in the validation group. Calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA) were applied to compare the predictive performances of these models.ResultsFour models were created and showed the following areas under the ROC curves (AUCs) in the training and validation groups: Model-Joint series (AUC, 0.923 and 0.852), Model-T1 (AUC, 0.835 and 0.809), Model-T2 (AUC, 0.784 and 0.605), and Model-CET1 (AUC, 0.805 and 0.537). These results indicated that the Model-Joint series had the best performance in the validation group, followed by Model-T1, Model-T2 and finally Model-CET1. The calibration curves indicated good agreement between the Model-Joint series predictions and actual probabilities. Additionally, the DCA curves demonstrated that the Model-Joint series was clinically useful.ConclusionMultiparametric MRI-based radiomics models can potentially predict tumor response after chemoradiotherapy in patients with postoperative residual gliomas, which may aid clinical decision making, especially to help patients initially predicted to be treatment-insensitive avoid the toxicity of chemoradiotherapy.

407P Neoadjuvant chemo-radiotherapy response in patients affected by mismatch repair deficient (dMMR) locally advanced rectal cancer

Only few data on microsatellite instability in rectal cancer are available in literature, and dMMR role in pre-operative chemoradiotherapy response is under debate. The aim of our study was to evaluate the frequency and therapeutic implications of dMMR status in patients (pts) with locally advanced rectal cancer belonging to our Center.

ADC correlation with Sirtuin1 to assess early chemoradiotherapy response of locally advanced esophageal carcinoma patients

AimsTo determine the biological correlation between apparent diffusion coefficient (ADC) values and Sirtuin1 (SIRT1) levels of tumour tissues in patients with esophageal carcinoma (EC), and to ascertain the treatment biomarker of ADC in predicting the early response of patients undergoing definitive chemoradiotherapy (CRT).MethodsA total of 66 patients were enrolled, and the specimens of tumour tissues were collected before treatment to perform immunohistochemical (IHC) examinations and quantify the levels of SIRT1. Then all patients were given two esophageal magnetic resonance imaging (MRI) examinations with diffused weighed imaging (DWI) including pretreatment and intra-treatment (1~2 weeks after the start of radiotherapy). The regions of interest (ROIs) were contoured according to the stipulated rules in advance using off-line software, and the values of the ADC in the ROIs were generated automatically. Then, the values of the ADC at baseline and intra-treatment were labeled as pre-ADC and intra-ADC respectively, and ΔADC, ADCratio were calculated. Pearson’s correlation coefficients were acquired to estimate the correlation between each of ADC values and SIRT1 levels. Spearman’s rank correlation coefficients were acquired to estimate the correlation between early response and the values of each ADC. Receptor operation characteristics (ROC) curves were constructed to estimate the accuracy of the ADC in predicting the early response of CRT.ResultsThe findings of this study showed different correlations between ADC values and the levels of SIRT1 (ΔADC: r = − 0.943, P = 0.002; ADCratio: r = − 0.911, P = 0.000; intra-ADC: r = − 0.748, P = 0.002; pre-ADC: r = 0.109, P = 0.558). There was a positive correlation between ΔADC and early response to treatment (ρ = 0.615, P = 0.023), and multivariable logistic regression revealed that ΔADC was significantly associated with short-term response of CRT in esophageal carcinoma patients.ConclusionsIn summary, early increases in ADC may facilitate the predication of early CRT response in patients with esophageal squamous cell carcinoma (ESCC), which may be attributed to the different correlation between ADC changes and SIRT1 expression.

Histogram analysis of DCE-MRI for chemoradiotherapy response evaluation in locally advanced esophageal squamous cell carcinoma.

The aim of the study was to predict and assess treatment response by histogram analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to patients with locally advanced esophageal squamous cell carcinoma receiving chemoradiotherapy (CRT). Seventy-two patients with locally advanced esophageal squamous cell carcinoma who underwent DCE-MRI before and after chemoradiotherapy were enrolled and divided into the complete response (CR) group and the non-CR group based on RECIST. The histogram parameters (10th percentile, 90th percentile, median, mean, standard deviation, skewness, and kurtosis) of pre-CRT and post-CRT were compared using a paired Student's t test in the CR and non-CR groups, respectively. The histogram parameter differences between the CR and the non-CR groups were compared using an unpaired Student's t test. A receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance. The histogram parameters of Ktrans values were observed to have significantly decreased after chemoradiotherapy in the CR group. The CR responders showed significantly higher median, mean, and 10th and 90th percentile of pre-Ktrans values than those of the non-CR group. The histogram analysis indicated the decreased heterogeneity in the CR group after CRT. Esophageal cancer with higher pre-Ktrans and lower post-Ktrans values indicated a good treatment response to CRT. Pre-Ktrans-10th showed the best diagnostic performance in predicting the chemoradiotherapy response. The histogram parameters of Ktrans are useful in the assessment and prediction of the chemoradiotherapy response in patients with advanced esophageal squamous cell carcinoma. DCE-MRI could serve as an adjunctive imaging technique for treatment planning.

Oesophageal squamous cell carcinoma: histogram-derived ADC parameters are not predictive of tumour response to chemoradiotherapy

ObjectivesTo evaluate correlations between tumour response to definitive chemoradiotherapy (CRT) in oesophageal squamous cell carcinoma (SCC) and histogram-derived apparent diffusion coefficient (ADC) parameters on diffusion-weighted MR images.MethodsForty patients with clinical T3–4 oesophageal SCC underwent concurrent CRT. MR examination at 3 T was performed 1–3 days prior to CRT. Readout-segmented echo-planar diffusion imaging was used to acquire ADC maps. Pre- and post-treatment CT examinations were performed. Histogram parameters (mean, 10th, 25th, 50th, 75th, 90th percentiles, skewness and kurtosis) of the ADC values were compared with post-treatment disease status based on RECIST and the tumour regression ratio.ResultsNone of the ADC parameters showed significant correlation with post-treatment status (range of Spearman’s ρ values − 0.19 to 0.14, range of p values 0.22–0.47) or tumour regression ratio (range of Spearman’s ρ values − 0.045 to 0.18, range of p values 0.26–0.96). Neither progression-free survival (PFS) (p = 0.17) nor overall survival (OS) (p = 0.15) was significantly different between the two groups corresponding to the lower (< median) and upper arms (≥ median) of the mean ADC values.ConclusionsHistogram-derived pretreatment ADC parameters were not predictive imaging biomarkers for tumour response to CRT in patients with oesophageal SCC.Key Points• Apparent diffusion coefficient (ADC) values are derived from diffusion-weighted MR imaging.• High-resolution diffusion-weighted images are generated by readout-segmented echo-planar diffusion imaging.• Readout-segmented echo-planar diffusion-weighted imaging enabled evaluation of ADC parameters.• Pretreatment ADC parameters do not predict chemoradiotherapy response in patients with oesophageal carcinoma.

Value of introvoxel incoherent motion imaging on evaluating concurrent chemoradiotherapy response in patients with advanced uterine cervix cancer

Objective To investigate the value of introvoxel incoherent motion (IVIM) using 3.0 T MRI to evaluate response to concurrent chemoradiotherapy (CCRT) in patients with advanced uterine cervix cancer. Methods From July 2015 to December 2016, 63 patients with advanced (≥ⅡB) cervical cancer diagnosed by clinical and imaging study, who had completed CCRT plan in Henan Cancer Hospital, were prospectively enrolled. Pelvic MRI protocol including T1WI, T2WI, IVIM and dynamic contrasted enhanced scans were performed in each patient before CCRT and 3 weeks after starting therapy (total dose of 30 Gy), and at the end of therapy (total dose of 90 Gy, 8 weeks after therapy). The mean values of ADC, true molecular diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f) in each tumor at pre-therapy, in the middle of therapy and post-therapy were measured and recorded as ADC-pre, D-pre, D*-pre, f-pre;ADC-mid, D-mid, D*-mid, f-mid and ADC-post, D-post, D*-post, f-post, respectively;the change rates of these parameters during and after therapy (recorded as ΔADC-mid, ΔD-mid, ΔD*-mid, Δf-mid; ΔADC-post, ΔD-post, ΔD*-post, Δf-post) were also calculated. Patients were classified into response group and non-response group, according to response evaluation criteria in solid tumors after CCRT. MRI imaging study was performed in each patient within 1 month after CCRT to follow up, and tumor regression rate was calculated. The Mann-Whitney U test was used to compare differences of parameters and their change rates between response group and non-response group. Spearman correlation analysis was performed to assess relationships between parameters, parameter change rates and tumor regression rate. Logistic regression model was applied to find potential ADC values for predicting therapeutic response. ROC was used to analyze efficacy of ADC values for evaluating therapeutic response in advanced uterine cervix cancer after CCRT. Results The mean value of tumor maximum diameter before and after therapy was (47.5 ± 12.9) and (12.8 ± 10.0) mm, tumor regression rate was (66.7 ± 33.6)%. Forty-eight patients were in the response group and 15 in the non-response group. The mean value of ADC-pre, D-pre, D*-pre and f-pre was 0.74(0.43, 1.14)×10-3, 0.58(0.33, 0.91)×10-3, 12.12(2.30, 21.4)×10-3mm2/s, 9.65%(4.45%, 13.89%), respectively. Tumor regression rate had positive correlation with ADC-pre and D-pre (r=0.773, 0.840;P<0.05). Responders had increased ADC-pre, D-pre values than non-responders, which had statistically significant difference (P<0.05). Responders had increased ADC-mid, D-mid and f-mid values than non-responders, which had statistically significant difference (P<0.05), tumor regression rate had positive correlation with ADC-mid, D-mid and f-mid (r=0.808, 0.834, 0.563;P<0.05). Responders had increased ADC-post, D-post and f-post values than non-responders, which had statistically significant difference (P<0.05), tumor regression rate had positive correlation with ADC-post and D-post (r=0.799, 0.829;P<0.05).Tumor regression rate had positive correlation with ΔADC-mid, ΔD-mid, Δf-mid(r=0.526, 0.573, 0.454;P<0.05) and with ΔADC-post, ΔD-post, Δf-post (r=0.541, 0.555, 0.388;P<0.05). Responders had increased ΔADC-mid, ΔD-mid, Δf-mid and ΔADC-post, ΔD-post, Δf-post, which had statistically significant difference (P<0.05). Logistic regression analysis revealed only ADC-pre and D-post could be independent factors to predict therapeutic response in advanced uterine cervix cancer after CCRT, values of B, Wald, odds ratio and P was 22.488, 8.431, 1.429, 0.004 and 16.542, 8.517, 1.779, 0.004. ROC analysis showed the area under the curve (AUC) of ADC-pre, D-pre, ΔADC-mid, ΔD-mid, Δf-mid, ΔADC-post, ΔD-post and Δf-post for predicting therapeutic response in advanced uterine cervix cancer after CCRT were 0.890, 0.926, 0.942, 0.851, 0.803, 0.929, 0.951 and 0.906, respectively. Conclusion The IVIM parameters before and during CCRT process and their changes are valuable for predicting and evaluating therapeutic response in advanced uterine cervix cancer after CCRT, with high clinical practice value. Key words: Uterine cervical neoplasms; Magnetic resonance imaging; Introvoxel incoherent motion; Efficacy evaluation; Concurrent chemoradiotherapy

Relationship Between Expression of Proteins ERCC1, ERCC2, and XRCC1 and Clinical Outcomes in Patients with Rectal Cancer Treated with FOLFOX-Based Preoperative Chemoradiotherapy.

Platinum resistance enhances DNA damage repair through nucleotide excision repair mechanisms involving the excision repair cross-complementing group 1 (ERCC1), X-ray cross-complementing group 1 (XRCC1), and excision repair cross-complementing group 2 (ERCC2). We evaluated the correlation between the expression of these three DNA repair genes and clinical outcomes in patients with rectal cancer receiving FOLFOX-based preoperative chemoradiotherapy (CRT). Using immunohistochemistry, we examined the expression of ERCC1, ERCC2, and XRCC1 in pre-CRT cancer tissues from 86 patients with rectal cancer who had undergone curative resection and preoperative CRT with FOLFOX-4 to identify potential predictors of clinical outcomes. Following CRT, 57 and 29 patients were classified as responders (pathological tumor regression grade TRG 0 and TRG 1) and poor responders (TRG 2 and TRG 3), respectively. The multivariate analysis revealed that ERCC1 overexpression was correlated with a poor CRT response [p<0.0001; odds ratio (OR), 9.397; 95% confidence interval (CI) 2.721-32.457]. Furthermore, a poor response to CRT (pathological TRG of 2-3) (p=0.18; OR 5.685; 95% CI 1.349-23.954) and abnormal pre-CRT serum carcinoembryonic antigen levels (>5ng/mL) (p=0.03; OR 6.288; 95% CI 1.198-33.006) were independent predictors of postoperative relapse. By contrast, ERCC2 and XRCC1 expression did not play predictive roles in the analyzed patients. ERCC1 overexpression is associated with a poor preoperative CRT response in patients with rectal cancer receiving FOLFOX-based preoperative CRT. ERCC1 is a potential biomarker for identifying patients who can benefit from customized treatment programs.

Seven low-mass ions in pretreatment serum as potential predictive markers of the chemoradiotherapy response of rectal cancer.

Preoperative chemoradiotherapy (CRT) is generally performed for locally advanced rectal cancer (LARC, cStage 2 or 3) to improve local disease control and patient survival. The pathological tumor response to CRT is a surrogate marker that is associated with oncological outcome. Thus, markers that predict the response to CRT would be valuable for individualizing treatment for LARC patients. The current study used metabolomics-based approaches to identify molecular markers that predict the response to CRT. Seventy-six patients with LARC who received pelvic radiotherapy and concurrent chemotherapy using tegafur-uracil and leucovorin were enrolled. Radical surgery was performed 6-8 weeks after the completion of CRT. The postsurgical pathological CRT response was evaluated using the ypStage or tumor regression grade. Profiling patterns of low-mass ions (LMIs) in the pretreatment sera were obtained from all patients using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Our previously developed two-step algorithms, which showed a powerful diagnostic capability during colorectal cancer screening, were then used to screen for meaningful LMIs with discriminatory power. One combination consisting of seven LMIs was identified, whose discriminatory score separated a good CRT response (ypStage 0-1) from a poor CRT response (ypStage 3-4) successfully. However, each individual LMI alone showed insignificant discriminatory power. This finding suggests that analysis of the LMIs in pretreatment serum could serve as a predictive marker of the CRT response in patients with LARC.

Serum ferritin predicted prognosis in patients with locally advanced pancreatic cancer.

The present study evaluated the value of serum ferritin (SF) level for the prognosis of patients with locally advanced pancreatic cancer (LAPC). A total of 79 patients with LAPC treated by chemoradiotherapy were reviewed retrospectively. Pretreatment and post-treatment levels of SF were obtained. Median progression-free survival (PFS) was 11.8 months; median overall survival was 18.3 months. A total of 36 patients with elevated SF level showed significantly worse overall survival and PFS than patients with low SF level (p = 0.002 and p = 0.004, respectively). In total, 17 patients showed normal SF level after chemoradiotherapy, and their median PFS was 3.2 months longer than that of patients whose SF levels were not restored after chemoradiotherapy. SF may serve as a valuable tool to assess prognosis and monitor chemoradiotherapy response in patients with LAPC.

PTU-194 Hpv genotyping as a potential predictive biomarker of chemo-radiotherapy response in patients with rectal cancer (homer project)

Introduction Human Papilloma Viruses (HPV) infection may occur in 40% of rectal adenocarcinomas (RCa). HPV positivity (mainly HPV16) at other tumour sites is a predictor for treatment response to chemo-radiotherapy (CRT). Here, we performed a ‘proof of concept’ study in patients with RCa testing the hypothesis that HPV16 tumour positivity is a treatment predictive biomarker for complete response (CR) to CRT. Method The study was a case-control design in 118 patients undergoing CRT for RCa (CR, 30: non-CR, 88) from two UK cancer centres (2008 to 2013). DNA was extracted from pre-treatment paraffin-embedded blocks with histologically verified carcinoma. High-sensitivity multiplex PCR for HPVs was performed using two sets of primers for each HPV to identify genotypes: HPV6, 16, 18, 33. The probability of a CR was expressed as odd ratios (ORs) using logistic regression models. Results Any HPV positivity was noted in 25% of tumours. Individual genotype frequencies were: HPV16, 16%; HPV18, 6%; HPV33, 3%; HPV6, 3%. In multivariate models that included age, gender, pre-treatment T-size and N status, there was no association between either any HPV positivity (OR = 1.095, 95% CIs: 0.394, 3.044) or HPV16 positivity (OR = 1.072, 95% CIs: 0.332, 3.465), and complete response to CRT. Conclusion In this stage 2 biomarker discovery study using high-sensitivity HPV multi-valent assays, we found tumour HPV positivity rates lower than those reported elsewhere in the literature. We found no clear ‘signal’ to take forward HPV genotyping for validation as a predictive biomarker for chemo-radiotherapy response in patients with rectal cancer. This study was generously supported by the BDRF. Disclosure of interest None Declared. References Baricevic-Jones, et al . High-sensitivity HPV genotyping reveals near universal positivity in anal squamous cell carcinoma: different implications for vaccine prevention and prognosis. Eur J Cancer [in press]

Time course of serum C-reactive protein levels during induction chemoradiotherapy and its correlation with treatment response and survival in patients with advanced esophageal squamous cell carcinoma

Preoperative serum C-reactive protein (CRP) levels have been shown to be of prognostic significance in patients with advanced esophageal carcinoma. However, the clinical significance of serum CRP levels in patients with unresectable or marginally resectable tumors in the absence of induction therapy has not been fully elucidated in relation to treatment response and prognosis. Thirty-four patients with clinical T3-T4 esophageal squamous cell carcinoma who underwent induction chemoradiotherapy (CRT) followed by esophagectomy were enrolled in this retrospective study. Serum CRP levels were measured during the course of CRT, i.e., prior to, during (1, 2, 3 and 4 weeks following initiation) and after CRT (prior to surgery). The association between CRP levels, CRT response and survival was analyzed. Elevated serum CRP levels exhibited a favorable decrease 2-3 weeks following CRT initiation in pathological responders and CRP ≤0.3 mg/dl at 2 and 3 weeks following CRT initiation, as well as prior to surgery, was significantly correlated with responders. In patients with pretreatment CRP >0.3 mg/dl (67.6% of patients in this study), CRP ≤0.3 mg/dl at 2 and 3 weeks following CRT initiation predicted responders with accuracies of 87.0 and 73.9%, respectively. In the univariate survival analysis, CRP levels 3 weeks following CRT initiation, as well as CRP levels prior to surgery and pathological stage, were significant prognostic factors, although CRP levels prior to surgery was the only independent prognostic factor in the multivariate analysis. Serum CRP levels during the course of CRT may be of prognostic and predictive significance for the CRT response in patients with unresectable or marginally resectable esophageal squamous cell carcinoma who undergo induction CRT.

Abstract 1145: Molecular markers of neoadjuvant chemotherapy and combined chemoradiotherapy response in patients with oropharynx squamous cell carcinoma

Abstract The treatment currently considered standard for advanced oropharyngeal tumors involves concomitant chemo- and radiotherapy or surgery followed by adjuvant chemo- and radiotherapy. However, only 30 to 50% of patients with locally advanced disease survive more than three years, even with the advances in surgical techniques and the recognized benefits of therapy combined with radio- and chemotherapy. Treatment with induction TPF (docetaxel plus cisplatin and fluorouracil) chemotherapy followed by chemoradiotherapy was associated with a trend toward improved survival (Posner et al., 2007. N Engl J Med. 357:1705). The aim of this study was to investigate biological markers as potential predictors of response to chemotherapy and/or radiotherapy according to HPV infection in oropharyngeal carcinomas (OC). Thirty-two OC were evaluated by array CGH (4x180k, Agilent). A total of 35% of cases were HPV positives; HPV16 subtype was the most frequently detected (8/37), followed by subtype 18 (2/37). In general, HPV- cases showed a large number of copy number alterations (117 CNAs) in comparison with HPV+ samples. Losses on 7q22.1 and 14q12 were found exclusively in HPV+ tumors (p=0.044). Comparative analysis of genomic alterations among the patients which received combined chemoradiotherapy (22 cases) was done aiming to identify molecular markers that could predict the complete response (CR), partial response (PR) to treatment or progressive disease (PD). Tumors with CR showed a lower number of genomic alterations (90 CNAs versus 110 per cases in PR and PD). Losses at 1p21.3-p21.1 and gains on 10p13-p12.33 and 10p12.31-p12.1(p≤0.017) were exclusively found in patients with PD and PR. Overall survival (OS) analysis between HPV- and HPV+ cases demonstrated no significant differences (p&amp;gt;0.05). HPV- tumors showed more complexity and genomic instability than HPV+ tumors. Genomic losses or gains at different loci have been reported in HPV- compared to few or no alterations in HPV+ cases. In this study, it was detected specific chromosomal imbalances associated with therapy response and consequently, putative candidates to be validated in a large series of cases. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1145. doi:1538-7445.AM2012-1145