Karen-Lise Garm Spindler

The predictive value of single nucleotide polymorphisms in the VEGF system to the efficacy of first-line treatment with bevacizumab plus chemotherapy in patients with metastatic colorectal cancer: results from the Nordic ACT trial.

PurposeBevacizumab and chemotherapy is a common choice for first-line treatment of metastatic colorectal cancer (mCRC). So far, no predictive markers have been identified. The aim was to investigate the possible predictive value of single nucleotide polymorphisms (SNPs) in the vascular endothelial growth factor (VEGF) system in this setting.MethodsPre-treatment blood samples and response evaluations were available from 218 of the 249 included patients. All patients received bevacizumab and chemotherapy comprising fluorouracil and leucovorin or capecitabine combined with either oxaliplatin (FOLFOX or XELOX, nu2009=u2009183) or irinotecan (FOLFIRI or XELIRI, nu2009=u200966). Germline DNA was isolated from whole blood, and five SNPs in the VEGF-A gene, one SNP in the VEGF receptor 1 (VEGFR-1) gene and three SNPs in the VEGFR-2 gene were analysed by polymerase chain reaction. Response was evaluated according to RECIST version 1.0, and the association to genotypes was analysed using Fisher’s exact test.ResultsThe VEGFR-1 319xa0C/A SNP was significantly associated with response. Objective response was observed in 36% of the patients with CC genotype, 40% with CA and 56% with AA, pu2009=u20090.048. The response rates also differed significantly between patients with C-allele containing genotypes (CCu2009+u2009CA) (39%) and patients homozygous for the A-allele (AA) (56%), pu2009=u20090.015. There was no correlation between response rates and the remaining SNPs.ConclusionsThe VEGFR-1 319xa0C/A SNP is a potential predictive marker for bevacizumab plus chemotherapy in patients with mCRC. Patients with the A allele appeared to have increased response rates. The results call for validation.

Immunohistological expression of HIF‐1α, GLUT‐1, Bcl‐2 and Ki‐67 in consecutive biopsies during chemoradiotherapy in patients with rectal cancer

The aim of this study was to describe the dynamics of HIF‐1α, GLUT‐1, Bcl‐2 and Ki‐67 during chemoradiotherapy (CRT) of rectal cancer, and to investigate the fluctuation of these biomarkers in relation to pathological response to CRT. The study included 86 patients with rectal adenocarcinoma receiving preoperative CRT (>50.4 Gy and Uracil/Tegafur). Immunohistological expressions of HIF‐1α, GLUT‐1, Bcl‐2 and Ki‐67 were investigated in biopsies taken before treatment, after 2, 4 and 6 weeks of CRT and in specimens from the operation. Decreasing expressions of HIF‐1α, Bcl‐2 and Ki‐67 were observed during CRT, whereas GLUT‐1 overall was unchanged. No significant changes of the markers were observed in the interval between CRT and surgery. A significant association was observed between the presence of residual carcinoma after 6 weeks of treatment and pathological response to CRT, but no association was seen between the fluctuations of any of the markers and response to CRT.

Limitations of tissue micro array in Duke's B colon cancer

Tissue micro array (TMA) is widely used in cancer research in search of new predictive and prognostic markers. Colon cancer is known to be heterogeneous and the present study addresses some methodological aspects using cores of different size and analysing markers with different cellular distribution. We selected 61 paraffin‐embedded tissue blocks representing patients diagnosed with Dukes B colon cancer. Two 1 mm and two 2 mm cores were taken from both the centre and the invasive front of the tumour respectively. The immunostaining included MLH1, MSH2, PMS2, p53, COX‐2, TIMP and Betacatenin. Twenty‐five percent of the cores taken from paraffin blocks less than 0.5 cm was lost and the total loss was 8%. The homogeneous stains (MLH1, MSH2 and PMS2) all showed high agreement between TMA and whole tissue stains (kappa = 0.96,1 and 1 respectively). The COX‐2, p53 and Betacatenin illustrated moderate to high agreement (kappa = 0.54–0.9) whereas TIMP‐1 had the lowest score (kappa 0.19–0.25). The application of TMA in Dukes B colon cancer has several pitfalls and depends substantially on the immunohistochemical marker in question. Therefore a validation study seems justified before applying large scale TMA in this setting.