The Impact of Pre-analytical Quality Initiatives on Cholangiocarcinoma Diagnostics in Thailand

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. CCA is the second most common primary liver tumour and the incidence is increasing worldwide. CCA has high mortality owing to its aggressiveness, late diagnosis and refractory nature. In May 2015, the "European Network for the Study of Cholangiocarcinoma" (ENS-CCA: www.enscca.org or www.cholangiocarcinoma.eu) was created to promote and boost international research collaboration on the study of CCA at basic, translational and clinical level. In this Consensus Statement, we aim to provide valuable information on classifications, pathological features, risk factors, cells of origin, genetic and epigenetic modifications and current therapies available for this cancer. Moreover, future directions on basic and clinical investigations and plans for the ENS-CCA are highlighted.

Attempts at histochemical localization of estrogen receptor with anti-steroid antibody or some fluoresceinated estrogens have given unacceptable sensitivities and specificities when compared with biochemical methods or clinical response. In the present study a monoclonal antibody against estrogen receptor (H222 Sp gamma) was used on cryostat sections of freshly frozen breast tumors with a peroxidase-antiperoxidase immunoperoxidase technique. Biochemical receptor analyses were by dextran-coated charcoal analyses. Tumors from three separate cohorts of patients were studied as follows: population A, 62 primary breast cancers from 1983; population B, 72 primary lesions stored from 1976 to 1983; and population C, 23 patients with metastases, treated with hormonal therapy. Distinct staining was seen in the cell nucleus. A semiquantitative relationship was seen between histochemical score assessment of staining and biochemical assay in each cohort. The sensitivity and specificity using a threshold of 75 for the histochemical score and more than 20 femtomoles/mg of protein for dextran-coated charcoal analyses were as follows: population A, specificity, 89%, and sensitivity, 95%; population B, specificity, 94%, and sensitivity 88%; and for population C, the comparison was with objective clinical response yielding specificity, 89%, and sensitivity, 93%.

Immunohistochemistry (IHC) is a newer technique for assessing the estrogen receptor (ER) status of breast cancers, with the potential to overcome many of the shortcomings associated with the traditional ligand-binding assay (LBA). The purpose of this study was to evaluate the ability of ER status determination by IHC, compared with LBA, to predict clinical outcome-especially response to adjuvant endocrine therapy-in a large number of patients with long-term clinical follow-up. ER status was evaluated in 1,982 primary breast cancers by IHC on formalin-fixed paraffin-embedded tissue sections, using antibody 6F11 and standard methodology. Slides were scored on a scale representing the estimated proportion and intensity of positive-staining tumor cells (range, 0 to 8). Results were compared with ER values obtained by the LBA in the same tumors and to clinical outcome. An IHC score of greater than 2 (corresponding to as few as 1% to 10% weakly positive cells) was used to define ER positivity on the basis of a univariate cut-point analysis of all possible scores and disease-free survival (DFS) in patients receiving any adjuvant endocrine therapy. Using this definition, 71% of all tumors were determined to be ER-positive by IHC, and the level of agreement with the LBA was 86%. In multivariate analyses of patients receiving adjuvant endocrine therapy alone, ER status determined by IHC was better than that determined by the LBA at predicting improved DFS (hazard ratios/P = 0.474/.0008 and 0.707/.3214, respectively) and equivalent at predicting overall survival (0.379/.0001 and 0.381/.0003, respectively). IHC is superior to the LBA for assessing ER status in primary breast cancer because it is easier, safer, and less expensive, and has an equivalent or better ability to predict response to adjuvant endocrine therapy.