Heterogeneous FDG-guided dose-escalation for locally advanced NSCLC (the NARLAL2 trial): Design and early dosimetric results of a randomized, multi-centre phase-III study.

BACKGROUND AND PURPOSE: Local recurrence is frequent in locally advanced NSCLC and is primarily located in FDG-avid parts of tumour and lymph nodes. Aiming at improving local control without increasing toxicity, we designed a multi-centre phase-III trial delivering inhomogeneous dose-escalation driven by FDG-avid volumes, while respecting normal tissue constraints and requiring no increase in mean lung dose. Dose-escalation driven by FDG-avid volumes, delivering mean doses of 95Gy (tumour) and 74Gy (lymph nodes), was pursued and compared to standard 66Gy/33F plans. MATERIAL AND METHODS: Dose plans for the first thirty patients enroled were analysed. Standard and escalated plans were created for all patients, blinded to randomization, and compared for each patient in terms of the ability to escalate while protecting normal tissue. RESULTS: The median dose-escalation in FDG-avid areas was 93.9Gy (tumour) and 73.0Gy (lymph nodes). Escalation drove the GTV and CTV to mean doses for the tumour of 87.5Gy (GTV-T) and 81.3Gy (CTV-T) in median. No significant differences in mean dose to lung and heart between standard and escalated were found, but small volumes of e.g. the bronchi received doses between 66 and 74Gy due to escalation. CONCLUSIONS: FDG-driven inhomogeneous dose-escalation achieves large increment in tumour and lymph node dose, while delivering similar doses to normal tissue as homogenous standard plans.

The prognostic value of simultaneous tumor and serum RAS/RAF mutations in localized colon cancer.

The impact of RAS/RAF mutations in localized colon cancer needs clarification. Based on analysis of tumor-specific DNA, this study aimed at elucidating the prognostic influence of mutational status in tumor and serum using an extended panel of mutations. The study retrospectively included 294 patients with curatively resected stage I-III adenocarcinoma of the colon. Mutations in tumor and serum were determined at time of surgery. Analyses were performed with droplet digital PCR technology. Hazard ratio (HR) for the association between mutational status and survival was estimated in multivariate analysis taking known prognostic factors into account. Mutational status in tumor did not on its own have significant prognostic impact (P = 0.22). Patients with a RAS mutation simultaneously in tumor and serum had a significantly worse prognosis, overall survival (OS) (HR = 2.30, 95% CI = 1.27-4.15, P = 0.0057), and disease-free survival (DFS) (HR = 2.18, 95%CI = 1.26-3.77, P = 0.0053). BRAF mutation in the serum and proficient mismatch repair (pMMR) protein in tumor also indicated significantly worse prognosis, OS (HR = 3.45, 95% CI = 1.52-7.85, P = 0.0032) and DFS (HR = 3.61, 95% CI = 1.70-7.67, P = 0.0008). In conclusion, RAS mutations in serum, and BRAF mutation in serum combined with pMMR in tumor were strong independent prognostic factors in patients with RAS/RAF mutated tumors.

Ultrasonic mirror image from ruthenium plaque facilitates calculation of uveal melanoma treatment dose.

BACKGROUND/AIMS: To present a new method to determine dose depth and the distance from the concave side of the plaque to the tumour base in patients with uveal melanoma treated with ruthenium-106 based on ultrasonic mirror image. METHODS: We used the mirror image associated with ultrasound during plaque brachytherapy to determine intraobserver reproducibility and interobserver agreement between two surgeons. 230 eyes with primary uveal melanoma were included in a retrospective analysis to determine the distance from the plaque to the tumour base using ultrasound. A phantom study was used to illustrate the effects on radiation dose to apex of the tumour when the dose depth was incorrectly determined. Doses to apex of the tumour were determined using Plaque Simulator. RESULTS: The intraobserver variation in dose depth measurement with plaque was significantly lower than for measures without plaque (p<0.001). Agreement between the surgeons was better with a plaque in place. Distances from the plaque to the tumour base were distributed with mean=0.99 (median: 1, range: 0.1-2.9 mm). From the phantom study, it was clear that the tumour did not receive the prescribed 100 Gy if the dose depth was incorrectly determined. CONCLUSIONS: The dose depth in patients with uveal melanoma must be measured accurately for correct calculation of the radiation dose to the apex of the tumour. Repeated in vivo and in vitro ultrasound measurements of dose depth showed higher variance than measurements using the mirror image produced from a ruthenium plaque. Using the mirror image thus help to improve the dose calculation.

Intratumoral Heterogeneity of MicroRNA Expression in Rectal Cancer.

INTRODUCTION: An increasing number of studies have investigated microRNAs (miRNAs) as potential markers of diagnosis, treatment and prognosis. So far, agreement between studies has been minimal, which may in part be explained by intratumoral heterogeneity of miRNA expression. The aim of the present study was to assess the heterogeneity of a panel of selected miRNAs in rectal cancer, using two different technical approaches. MATERIALS AND METHODS: The expression of the investigated miRNAs was analysed by real-time quantitative polymerase chain reaction (RT-qPCR) and in situ hybridization (ISH) in tumour specimens from 27 patients with T3-4 rectal cancer. From each tumour, tissue from three different luminal localisations was examined. Inter- and intra-patient variability was assessed by calculating intraclass correlation coefficients (ICCs). Correlations between RT-qPCR and ISH were evaluated using Spearman's correlation. RESULTS: ICCsingle (one sample from each patient) was higher than 50% for miRNA-21 and miRNA-31. For miRNA-125b, miRNA-145, and miRNA-630, ICCsingle was lower than 50%. The ICCmean (mean of three samples from each patient) was higher than 50% for miRNA-21(RT-qPCR and ISH), miRNA-125b (RT-qPCR and ISH), miRNA-145 (ISH), miRNA-630 (RT-qPCR), and miRNA-31 (RT-qPCR). For miRNA-145 (RT-qPCR) and miRNA-630 (ISH), ICCmean was lower than 50%. Spearman correlation coefficients, comparing results obtained by RT-qPCR and ISH, respectively, ranged from 0.084 to 0.325 for the mean value from each patient, and from -0.085 to 0.515 in the section including the deepest part of the tumour. CONCLUSION: Intratumoral heterogeneity may influence the measurement of miRNA expression and consequently the number of samples needed for representative estimates. Our findings with two different methods suggest that one sample is sufficient for adequate assessment of miRNA-21 and miRNA-31, whereas more samples would improve the assessment of miRNA-125b, miRNA-145, and miRNA-630. Interestingly, we found a poor correlation between the expression estimates obtained by RT-qPCR and ISH, respectively.

Late Relapses in Stage I Testicular Cancer Patients on Surveillance.

BACKGROUND: Comprehensive data on late relapse (LR) and very LR (VLR) in patients with clinical stage I (CS-1) testicular cancer followed on surveillance are missing. These data are essential for planning optimal follow-up. OBJECTIVE: Assess incidence and outcome of LR (>2 yr) and VLR (>5 yr) in a large cohort of CS-1 surveillance patients, and examine differences in the clinical characteristics of patients with early relapse (ER), LR, and VLR. DESIGN, SETTING, AND PARTICIPANTS: CS-1 surveillance patients diagnosed between 1984 and 2007 were identified from the retrospective Danish Testicular Cancer (DaTeCa) database. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We estimated survival and relapse probabilities and compared the results using log-rank tests and Cox regression analyses. We compared differences in patient characteristics by using χ(2), Fisher exact, and Mann-Whitney tests. RESULTS AND LIMITATIONS: Our study included 3366 (2000 seminoma and 1366 nonseminoma) patients. Median follow-up was 15 yr. Five-year conditional risk of LR was 5.0% and 2.1% for seminoma and nonseminoma patients, respectively. There were no significant differences in disease-specific or overall survival when comparing the LR(VLR) and ER patients by log-rank, but Cox regression adjusted for age showed a significant effect of time to relapse on survival for seminoma patients. Apart from significantly more ER nonseminoma patients with elevated human chorionic gonadotropin at relapse, there were no significant differences in patient characteristics at orchiectomy or relapse. Limitations include retrospective design and exclusion of patients who had been offered adjuvant therapy. CONCLUSIONS: The risk of VLR is minimal, and the patients carry a good prognosis. Patient characteristics of CS-1 surveillance patients with LR(VLR) do not differ significantly from patients with ER. PATIENT SUMMARY: We compared stage I testicular cancer surveillance patients with early relapse (ER) versus late relapse (LR; >2 yr). LR patients as a group did no worse than ER patients, although increased time to relapse was negatively associated with survival for seminoma patients.

Clinical utility of KRAS status in circulating plasma DNA compared to archival tumour tissue from patients with metastatic colorectal cancer treated with anti-epidermal growth factor receptor therapy.

BACKGROUND: Circulating cell-free DNA (cfDNA) in plasma is a mixture of DNA from malignant and normal cells, and can be used as a liquid biopsy to detect and quantify tumour specific mutations e.g. KRAS. We investigated the clinical value of KRAS mutations when detected in plasma compared to tumour in patients from metastatic colorectal cancer (mCRC) prior to anti-epidermal growth factor receptor (anti-EGFR) therapy. Secondly, we investigated the concentration of total cfDNA in relation to clinical outcome. PATIENTS AND METHODS: Patients were resistant to 5-FU, oxaliplatin and irinotecan and treated with 3rd line irinotecan (180 mg/m(2)) and cetuximab (500 mg/m(2)) q2w in a prospective phase II trial. The study was conducted prior to implementation of KRAS as selection criteria. Plasma was obtained from a pre-treatment EDTA blood-sample, and the total cfDNA, and KRAS mutations were quantified by an in-house qPCR method. Results are presented according to REMARK. RESULTS: One-hundred-and-forty patients were included. Thirty-four percent had detectable KRAS mutations in the tumour, compared to 23% in plasma. KRAS detection in archival tumour tissue showed no correlation to survival, whereas plasma KRAS status remained a strong predictive and prognostic factor in multivariate analysis (Hazard Ratio (HR)=2.98 (95% CI 1.53-5.80, p=0.001) and 2.84 (1.46-5.53, p=0.002), for OS and PFS, respectively). Combining the information of total cell free DNA levels and plasma KRAS mutation status, produced an additional prognostic effect. CONCLUSION: The value of clinically relevant mutations could be improved by performing the analysis on circulation plasma DNA rather than archival tumour tissue.