Positron emission tomography/computed tomography for early treatment response evaluation in metastatic colon cancer

• Published in: Journal of clinical oncology Vol. 32; no. 3_suppl; p. 614
• Main Authors: Engelmann, Bodil E., Loft, Annika, Kjær, Andreas, Nielsen, Hans J., von Benzon, Eric, Brünner, Nils, Christensen, Ib Jarle, Gerds, Thomas A., Hansson, Susanne H., Hollander, Niels Henrik, Kristensen, Michael Holmsgaard, Löfgren, Johan, Markova, Elena, Sloth, Carsten, Højgaard, Liselotte
• Format: Journal Article
• Language: English
• Published: 20.01.2014
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2014.32.3_suppl.614

Abstract only 614 Background: Treatment options for metastatic colon cancer (mCC) are widening. We prospectively evaluated serial 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography/ computed tomography (PET/CT) and measurements of tissue inhibitor of metalloproteinases type 1 (TIMP-1), carcinoembryonic antigen (CEA) and urokinase plasminogen activator receptor domain I [uPAR(I)] for early assessment of treatment response in mCC patients. Methods: Thirty-three mCC patients scheduled for first line chemotherapy with capecitabine, oxaliplatin (CAPOX) and bevacizumab participated; 27 were evaluated by PET/CT before treatment, after one and four treatment series. Morphological and metabolic response was independently assessed according to Response Evaluation Criteria In Solid Tumours (RECIST1.1) and EORTC PET criteria. Plasma TIMP-1, plasma uPAR(I) and serum CEA were determined. Results: Metabolic response after one treatment course predicted the ability of CAPOX and bevacizumab to induce morphological response after four treatment series with a sensitivity of 80 %, specificity of 69 % and an Odds Ratio of 13.9 [CI 1.9; 182]. Early metabolically stable or progressive disease was associated with shorter progression-free survival (PFS) (hazard ratio (HR) = 3.2 [CI 1.3; 7.8]). Biomarker levels at early evaluation were associated to shorter PFS (TIMP-1 per unit increase on a log-2 transformed ng/mL scale: HR = 2.23 [CI 1.20; 4.14]; uPAR(I) per 25 fmol/mL increase: HR = 1.36 [CI 1.03; 1.79]). Conclusions: This monocentric study demonstrated predictive value of early metabolic PET response and prognostic value of TIMP-1 and uPAR(I) levels in mCC treated with CAPOX and bevacizumab. Results support investigation of PET/CT, TIMP-1 and uPAR(I) guided early treatment adaptation in mCC.