Prediction of disease-free survival using relative change in FDG-uptake early during neoadjuvant chemoradiotherapy for potentially curable esophageal cancer: A prospective cohort study.

18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) has been investigated as a tool for monitoring response to neoadjuvant chemo- and chemoradiotherapy (CT and CRT, respectively) and as a predictor for survival in patients with esophageal cancer. In contrast to patients who undergo neoadjuvant CT, it is not known whether patients who are clinically identified as responders after neoadjuvant CRT show better disease-free survival (DFS) than patients identified as nonresponders. The aim of the study was to determine the predictive value of FDG-uptake measured prior to and early during neoadjuvant CRT. Patients treated with neoadjuvant CRT between 2004 and 2009 within a randomized trial were included. FDG-uptake was measured at baseline and after 14 days of CRT. According to the PERCIST-criteria, patients were allocated to have metabolic response, stable disease, or progression. Patients were followed until recurrence of disease or death. The predictive value of FDG-PET was determined with univariable and multivariable analysis in patients who underwent potentially curative surgery. One-hundred and six patients were included in the analysis. Minimal follow-up for surviving patients was 60 months. No significant differences in DFS were found between patients with metabolic response, stable disease, or progression, with 5-year DFS rates of 66%, 53%, and 67%, respectively (P = 0.39). Relative change in FDG uptake after 14 days of CRT is not associated with DFS in patients with esophageal cancer undergoing neoadjuvant chemoradiotherapy followed by surgery. These measurements should not be used for prognostication in this specific group of patients.

Automated assessment of numerical chromosomal aberrations in paraffin embedded prostate tumor cells stained by in situ hybridization.

We investigated the feasibility of automated counting of in situ hybridization signals (ISH) in interphase cells isolated from paraffin embedded prostate tissue. In total, 34 specimens from 7 patients with prostate cancer were stained with probes specific for the centromeric regions of chromosomes Y, 1, 7, 8, 10, and 15, using an immunoperoxidase based technique suitable for bright-field microscopy. Enumeration of the number of ISH spots of 500 nuclei per specimen was performed (1) using an automatic system developed without any human intervention and (2) using the same system, but including verification of the counts based on visual inspection of the stored images. As reference from each specimen, 200 cell nuclei were evaluated manually, using conventional microscopy. A typical analysis procedure (including user verification) took 35 min. The difference (root mean error) between the automated counting and the counting after visual interaction was relatively small (15%). The percentage of cells with incorrect counts by automated analysis was 20.2%, a number that could easily be improved by user interaction. Detection of cells with aneusomy proved to be more sensitive compared to the routine manual counting, in cases where aberrant frequencies were low. Automated counting of samples with low frequencies (< 10%) resulted in a higher frequency of aberrant cells in 9 of 11 cases, probably due to the fact that an unbiased cell selection is guaranteed. Automated assessment of ISH signals is considered useful for the evaluation of chromosomal aberrations in prostate tumor cells, provided that the counts are visually confirmed.