Abstract.In previous studies we demonstrated telomerase activity in frozen tissue from head and neck squamous cell carcinoma (HNSCC) and their tumor-free tumor margins. In the present study frozen sections from the same tissues were examined for in situ presence of hTERT. In preliminary investigations we established that the most suitable method of tissue preparation was fixation in acetone and methanol followed by steaming and visualization by APAAP. Most of the assays involved eleven anti-hTERT antibodies and were supplemented with the inclusion of antibodies Ki-67, antinucleolin and CD45. hTERT expression was investigated in the tissues of 61 patients with HNSCC and 37 patients without tumor. Semi-quantitative immunoreactive scores were correlated with telomerase activity. We examined the prognostic significance of hTERT expression with Kaplan-Meier curves and tested the immunological specificity of the antibodies by immunoabsorption with two hTERT peptides and a nucleolin peptide. Nuclear staining of satisfactory distribution and intensity was achieved in seven anti-hTERT antibodies both in the carcinomas and in the squamous epithelia of the tumor resection margins and in the control tissues. Proof of hTERT did not differ from telomerase activity. The telomerase activity demonstrated in tumor-free resection margins and in control tissues did, however, correlate with lymphocytic-monocytic infiltration (CD45 expression). This telomerase activity might be related to nuclear hTERT expression in the squamous epithelium, given that the hTERT score values in the connective tissue tended to be negative. The prognostic significance of hTERT expression demonstrated on paraffin sections from different tumor localizations was not confirmed for the frozen sections of patients with HNSCC. The hTERT specificity of the monoclonal NCL-L-hTERT, whose use as an antibody against hTERT has been questioned, was reexamined with immunohistochemical methods, but the intensity of its immunoabsorption with the nucleolin peptide did not exceed that observed in the other anti-hTERT antibodies.

TEM is feasible for the treatment of large benign rectal tumors. It may be an alternative method for proctectomy in selected patients with large rectal lesions.

Abstract.In previous studies we demonstrated telomerase activity in frozen tissues from BCC and their tumor-free margins by the PCR ELISA. In this study we examined in the same frozen sections immunohistochemical presence of hTERT in the nucleus. After fixation in acetone and methanol followed by steaming we used for visualization the antigenantibody reactions by APAAP. This was the best method of preparation of the frozen sections in our preliminary hTERT-study with squamous cell carcinomas. This study was supplemented with antibodies against Ki-67, nucleolin, common leucocyte antigen CD45 and mutated p53. The immunoreactive scores were determined and included the comparison with telomerase activity. The investigation of hTERT expression was performed in the tissues of 41 patients with BCC and control tissues of 14 patients without tumor. Eleven commercial antibodies were used for a nuclear staining of hTERT expression. With the anti-hTERT antibodies we looked for both satisfactory distribution and intensity of immunohistochemical labeling in the carcinomas and in the squamous epithelia of the tumor centers, of the tumor-free margins and of the control tissues. The hTERT expression in the BCC was distributed heterogeneously. The score values established by the anti-hTERT antibodies used were variably or significantly increased. In the stroma they tended to be negative, so we disregarded stroma hTERT. Proof of hTERT did not differ uniformly from telomerase activity. We compared the high with the lower median hTERT values in the Kaplan-Meier curve. Patients with lower hTERT scores in the center or tumor margin as shown by some of the antibodies suffered relapse earlier. Finally, we compared the hTERT expression in BCC tissues with the hTERT scores in HNSCC tissues from our previous study. Only one anti-hTERT antibody (our Ab 7) yielded significantly higher scores in BCC than in HNSCC.

Background Identification of pancreatic cancer (PC) local invasion is crucial to optimize patients’ selection for surgery. Aims To determine the diagnostic accuracy of contrast-enhanced computed tomography (CECT) and endoscopic ultrasound (EUS) in local staging of PC. Methods We performed a multicenter study including all patients with PC who underwent surgery. Results One hundred twelve patients were included. Surgical findings of peri-pancreatic lymph nodes (LN), vascular and adjacent organ involvement were seen in 67 (59.8%), 33 (29.5%) and 19 patients (17%), respectively. The diagnostic performance of EUS was better than CECT in peri-pancreatic LN. The sensitivity, specificity, positive predictive value (PPV) and negative predictive (NPV) of CECT vs. EUS were 28.4%, 80%, 67.9% and 42.9% vs. 70.2%, 75.6%, 81% and 63%, respectively. For vascular and adjacent organ involvement, the sensitivity, specificity, PPV and NPV were 45.5%, 93.7%, 75%, 80.4% and 31.6%, 89.2%, 37.5% and 86.5% for CECT, respectively, vs. 63.6%, 93.7%, 80.8%, 86.1% and 36.8%, 94.6%, 58.3% and 88% for EUS, respectively. Combining both CECT and EUS, the sensitivity for peri-pancreatic LN, vascular and adjacent organ involvement improved (76.1%, 78.8% and 42%), respectively. Conclusion EUS was superior to CECT in local staging. Combined EUS and CECT had a higher sensitivity than either alone.