title: Can serial monitoring of serum Vascular Endothelial Growth Factor (VEGF), Nitric Oxide (NO), and Angiotensin II (ANGII) levels have predictive role during Bevacizumab treatment?
abstract: BACKGROUND
  Standard treatment of colorectal cancer includes both cytostatic chemotherapy and targeted therapies. Bevacizumab, targeting the VEGF receptor, is one of the primary targeted therapies that achieve better response rate and survival rate as compared to combination chemotherapy. To the best of our knowledge, there is no established single marker that can be used as a predictive marker in bevacizumab therapy.
  
  
  METHODS
  We enrolled 24 patients with the diagnosis of metastatic colorectal cancer in our study. During the study, 2 blood samples were drawn from patients before the first cycle and after the sixth cycle of bevacizumab therapy. Serum levels of VEGF, ANG II, and NO were recorded.
  
  
  RESULTS
  While the change across VEGF levels was found to be a statistically significant decreasing trend (p=0.009), this decrease was not found to be correlated with treatment response and hypertension development. Additionally, no statistically significant difference was found in terms of NO and ANG II levels.
  
  
  CONCLUSIONS
  This study showed a significant decrease in serum VEGF, but failed to show a significant change in NO and ANG II levels during bevacizumab treatment. Although no significant correlation was found between the presence of hypertension and markers, most patients (83%) had an increase in their blood pressure. Our results suggest that dynamic monitoring of NO and ANG II, along with VEGF, may not be useful as predictive markers for bevacizumab treatment in colorectal cancer.
authors.affiliation: Depertment of Medical Oncology, Mustafa Kemal University Medical Faculty, Hatay, Turkey.
authors.forename: Ahmet Taner
authors.initials: AT
authors.lastname: Sümbül
authors.affiliation: Depertment of Medical Oncology, Hatay Defne Hospital, Hatay, Turkey.
authors.forename: Umut
authors.initials: U
authors.lastname: Dişel
authors.affiliation: Depertment of Biochemistry, Başkent University Medical Faculty, Adana, Turkey.
authors.forename: Nurzen
authors.initials: N
authors.lastname: Sezgin
authors.affiliation: Depertment of Medical Oncology, Başkent University Medical Faculty, Adana, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Sezer
authors.affiliation: Medical Oncology, Başkent University Medical Faculty, Adana, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Köse
authors.affiliation: Depertment of Medical Oncology, Başkent University Medical Faculty, Adana, Turkey.
authors.forename: Ali Ayberk
authors.initials: AA
authors.lastname: Beşen
authors.affiliation: Depertment of Cardiology, Hatay Antakya State Hospital, Hatay, Turkey.
authors.forename: Zehra
authors.initials: Z
authors.lastname: Sümbül
authors.affiliation: Depertment of Medical Oncology, Başkent University Medical Faculty, Adana, Turkey.
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Abalı
authors.affiliation: Depertment of Medical Oncology, Başkent University Medical Faculty, Adana, Turkey.
authors.forename: Özgür
authors.initials: Ö
authors.lastname: Özyılkan
mesh_terms: D000328:Adult; D000368:Aged; D000804:Angiotensin II / Q000097:blood*; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000627:therapeutic use*; D000068258:Bevacizumab; D015179:Colorectal Neoplasms / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000473:pathology; D003710:Demography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000209:etiology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009569:Nitric Oxide / Q000097:blood*; D011379:Prognosis; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
chemical_list: D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000804:Angiotensin II; D000068258:Bevacizumab; D009569:Nitric Oxide