ABSTRACT
With the recent advances in medical technologies, gastric cancer can often be removed with minimally invasive surgical techniques when identified early. Surgery must remove all gastric cancer, since residual cancerous tissue may lead to recurrence. Resected cancerous tissues are pathologically evaluated to determine whether all cancerous areas have been removed, but such assessments are rarely straightforward, and cancer markers could inform such pathological evaluations of cancer. An ideal marker would be identifiable in formalin-fixed paraffin-embedded (FFPE) tumor tissue. The first objective of the present study was to compare levels of angiopoietin-like protein 2 (ANGPTL2) in cancerous and noncancerous areas of FFPE tissues to determine whether ANGPTL2 is a marker relevant to the pathological diagnosis of cancer. The second objective was to evaluate whether ANGPTL2 mRNA is useful as a marker of the extent of vascular invasion of gastric cancer. Out of the 15 patients studied, 12 had a higher ANGPTL2 mRNA levels in cancerous areas compared with noncancerous areas. This finding indicated that ANGPTL2 mRNA is useful as a biomarker for identifying cancerous areas in FFPE tissues, at least for male patients. Spearman's rank correlation analysis showed a significant correlation between the ANGPTL2 mRNA level and the degree of vascular invasion of cancer (r=0.66; P=0.01). In receiver operating characteristic curve analysis of the association between the ANGPTL2 mRNA level and the degree of vascular invasion, the area under the curve was 0.92 (95% confidence interval, 0.78-1.00; P=0.01), indicating a significant association. The present study demonstrates that ANGPTL2 mRNA in FFPE tissues is a potential biomarker that informs the pathological diagnosis of gastric cancer and that ANGPTL2 mRNA may be predictive of vascular invasion, which is an indicator of metastasis in gastric cancer.
ABSTRACT
Pancreatic cancer is one of the tumors with the worst prognosis, with the 5-year survival rate reported to be 6%. The number of patients suffering from pancreatic cancer in recent years has continued to increase dramatically. Carbohydrate antigen 19-9 is an established biomarker of pancreatic cancer, but it does not have sufficient ability to detect pancreatic cancer at an early stage. We focused on angiopoietin-like protein 2 (ANGPTL2), which has been reported to be related to chronic inflammation and Type 2 diabetes mellitus. In this study, whether ANGPTL2 can detect early pancreatic cancer was evaluated. It was found that the concentration of serum ANGPTL2 was significantly higher in pancreatic cancer patients and tumor stage 0-I patients than in healthy individuals (5.84 ± 1.82 ng/mL vs 3.61 ± 0.64 ng/mL; P < 0.001) (5.68 ± 0.79 ng/mL vs 3.61 ± 0.64 ng/mL; P = 0.010). In addition, the diagnostic capability of serum ANGPTL2 levels for pancreatic cancer was evaluated using receiver operating characteristic (ROC) curve analysis. The area under the ROC curve (AUC) for ANGPTL2 was 0.906 (95% confidence interval (CI): 0.815-0.997; P < 0.001). To identify the risk factors for pancreatic cancer, multivariate regression models were used. Ten factors were included, and increasing age (odds ratio (OR), 1.318, 95% CI, 1.058-1.642; P = 0.014) and high ANGPTL2 levels (OR, 22.219, 95% CI, 1.962-251.659, P = 0.012) were found to be independent risk factors for pancreatic cancer, with ANGPTL2 having the strongest relationship. In addition, serum ANGPTL2 levels were strongly correlated with inflammatory markers, with blood sugar levels showing the strongest correlation with serum ANGPTL2 levels. In conclusion, this study suggested that an elevated serum ANGPTL2 level has the potential to be a biomarker capable of early detection of pancreatic cancer, and it was correlated with inflammation of the pancreas and the risk of developing diabetes mellitus.
ABSTRACT
Colorectal cancer (CRC) is the third most common malignancy worldwide. Disease progression leads to its spread to other organs, such as the liver, and is associated with higher mortality rates. Early CRC detection is therefore crucial for maximizing the chances of complete cure. The measurement of serum-based tumor biomarkers has shown great potential for the detection of CRC. In this study, we investigated the feasibility of using angiopoietin-like protein 2 (ANGPTL2) as a candidate biomarker for CRC. We first investigated ANGPTL2 expression in 7 CRC cell lines, among which Colo320, NCC-CoCK-115P, Caco-2 and Colo205 exhibited comparatively high ANGPTL2 expression. The serum levels of ANGPTL2 in CRC patients (3.45±1.30 ng/ml) were higher compared with those in healthy controls (2.74±0.64 ng/ml) (P<0.05). A receiver operating characteristic analysis demonstrated that the diagnostic performance of ANGPTL2 was marginally lower compared with that of the established biomarker C-reactive protein, but higher compared with that of carbohydrate antigen 19-9. These results suggested that the simultaneous measurement of ANGPTL2, along with previously established serum biomarkers, may increase the likelihood of early detection of CRC.
