Comparative Assessment of Two Strategies for Interpreting Tumor Markers in Ascitic Effusions.

BACKGROUND/AIM: There are two strategies for the interpretation of tumor markers (TM) in fluid effusions: i) high cut-off and ii) fluid/serum ratio (F/S) and low cut-off. The objective of this study is to compare these two strategies and to determine whether diagnostic accuracy improves by the identification of possible false positives using Adenosine deaminase (ADA), C reactive protein (CRP) and % of polymorphonuclear cells (%PN). PATIENTS AND METHODS: We studied 157 ascitic fluids, 74 of which were malignant. ADA, CRP and %PN were determined in ascitic fluid, and Carcinoembryonic antigen (CEA), Cancer antigen 72-4 (CA72-4), Cancer antigen CA19-9 and Cancer antigen 15-3 (CA15-3) in both fluid and serum. RESULTS: The strategy of high cut-off showed 59.5% sensitivity at 100% specificity. The F/S strategy showed 75.7% sensitivity at 95.2% specificity. Subclassifying cases with ADA, CRP and %PN negative showed 67.5% sensitivity at 100% specificity for high cut-off and for the F/S strategy was 81.7% sensitivity at 98.7% specificity. CONCLUSION: The strategy of F/S with negative ADA, CRP and %PN allow the best interpretation for TM in the ascitic fluid.

Status of External Quality Assessment on Tumor Markers in China.

BACKGROUND: The nationwide external quality assessment (EQA) of tumor markers in China has been launched for years. The quality of the performance of Chinese clinical laboratories on tumor markers is partly reflected through analysis of EQA results. This report presents an 8-year EQA result of the six most common tumor markers from 2006 to 2013. METHODS: Ten freeze-dried EQA samples were distributed to participants every year. Satisfactory performance was defined as scores of more than 80% of acceptable responses with the evaluation criterion of ± 25%. The robust coefficient of variability (CV) between laboratories and percentage difference against the target value of each sample were also calculated by year. RESULTS: A total number of 1154 laboratories submitted results in 2013, which was more than threefold of 2006. The proportion of laboratories with satisfactory performance showed an overall rising trend over the years and was up to 95% for the second survey in 2013. The overall decrease of robust CV was observed for all analytes including alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), total prostate specific antigen (t-PSA), cancer antigen 125 (CA 125), cancer antigen 15-3 (CA 15-3), and cancer antigen 19-9 (CA 19-9) except for CEA, which exhibited a rise followed by a flat trend. The percentage difference narrowed gradually and was less than 2% in 2013. CONCLUSIONS: The 8-year EQA results showed a significant enhancement of degree of harmonization of tumor markers in China. However, standardization among various testing systems and improvement of harmonization has yet to be achieved.

Tumor marker evolution: comparison with imaging for assessment of response to chemotherapy in patients with colorectal liver metastases.

BACKGROUND: As the real clinical significance of carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA19.9) evolution during preoperative chemotherapy for colorectal liver metastases (CLM) is still unknown, we explored the correlation between biological and radiological response to chemotherapy, and their comparative impact on outcome after hepatectomy. METHODS: All patients resected for CLM at our hospital between 1990 and 2004 with the following eligibility criteria were included in the study: (1) preoperative chemotherapy, (2) complete resection of CLM, (3) no extrahepatic disease, and (4) elevated baseline tumor marker values. A 20% change of tumor marker levels while on chemotherapy was used to define biological response (decrease) or progression (increase). Correlation between biological and radiological response at computed tomography (CT) scan, and their impact on overall survival (OS) and progression-free survival (PFS) after hepatectomy were determined. RESULTS: Among 119 of 695 consecutive patients resected for CLM who fulfilled the inclusion criteria, serial CEA and CA19.9 were available in 113 and 68 patients, respectively. Of patients with radiological response or stabilization, 94% had similar biological evolution for CEA and 91% for CA19.9. In patients with radiological progression, similar biological evolution was observed in 95% of cases for CEA and in 64% for CA19.9. On multivariate analysis, radiological response (but not biological evolution) independently predicted OS. However, progression of CA19.9, but not radiological response, was an independent predictor of PFS. CONCLUSIONS: In patients with CLM and elevated tumor markers, biological response is as accurate as CT imaging to assess "clinical" response to chemotherapy. With regards to PFS, CA19.9 evolution has even better prognostic value than does radiological response. Assessment of tumor markers could be sufficient to evaluate chemotherapy response in a nonsurgical setting, limiting the need of repeat imaging.

Carbohydrate antigen 19.9 accurately selects patients for laparoscopic assessment to determine resectability of pancreatic malignancy.

BACKGROUND: Laparoscopy with laparoscopic ultrasonography (L-LUS) may be useful in the selection of patients for surgery to resect peripancreatic malignancy in addition to contrast-enhanced computed tomography (CE-CT). The present prospective study assessed the strategy of using carbohydrate antigen 19.9 (CA19.9) levels to select patients for L-LUS. METHODS: Patients with suspected peripancreatic malignancy that appeared resectable on CE-CT were selected for immediate surgery if CA19.9 was low (up to 150 kU/l, or up to 300 kU/l if serum bilirubin was above 35 micromol/l), or to L-LUS if CA19.9 was high (over 150 kU/l, or over 300 kU/l if serum bilirubin was above 35 micromol/l). Data were assessed to determine the clinical utility of this strategy. RESULTS: A total of 94 patients went straight to surgery, of whom 65 proved resectable: 63 of 80 with a low CA19.9 level but only two of 14 with a high CA19.9 level and gastric outlet obstruction. From 55 patients with high CA19.9 levels, L-LUS correctly identified 26 of 31 resectable tumours and eight of 24 unresectable tumours. CONCLUSION: Using CA19.9 levels to help select patients with pancreatic malignancy for immediate surgery or L-LUS for further assessment of resectability effectively increased resection rates and reduced unnecessary laparotomies.