Human Telomerase Reverse Transcriptase (Htert) Expression in Carcinogenesis of Serous Cystic Neoplasm of the Pancreas
Akira Nakashima*1, Yoshiaki Murakami1, Kenichiro Uemura1, Yasuo Hayashidani1, Takeshi Sudo1, Yasushi Hashimoto1, Hiroki Ohge1, Taijiro Sueda1, Eiso Hiyama2
1Department of Surgery, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan; 2Department of Biomedicine, Graduate School of Biomedical Sciences and Natural Science Center of Basic Research and Development, Hiroshima University, Hiroshima, Japan
Backgrounds: Serous cystic neoplasms of the pancreas (SCNs) have a low malignancy rate. The histopathological features in the primary tumor of serous cystadenocarcinoma (SCAC) are remarkably similar to those of serous cystic adenoma (SCA), it is therefore difficult to separate SCAC from SCA when the SCAC doesn’t have distant metastases or distinct direct invasion. Expression of human telomerase reverse transcriptase (hTERT), a catalytic subunit of telomerase, is a useful marker for cancer diagnosis, because expression of hTERT is upregulated in almost all human malignant tumors but not in benign or normal tissues with the exception of germline cells, proliferative stem cells, activated lymphocytes, and certain benign tumors.Objectives: To evaluate hTERT expression in SCNs, which have potential to be a biomarker of the SCAC.
Methods: hTERT expression was examined by immunohistochemistry in eight patients who underwent pancreatic resection for SCNs which included serous microcystic adenoma (SMA; n=3), serous oligocystic adenoma (SOA; n=3), and SCAC (n=2).
Results: The histopathological findings of the two SCACs were similar to those of the other SCNs, and difficult to give a diagnosis without findings of invasions or metastasis. hTERT expression was detectable in two of two SCACs. One case had four lesions of liver metastases and direct invasion to transverse colon. The other case had invasions to lymph nodes and adipose around the pancreas. Cancer cells of the primary tumors, and all of the metastatic lesions were immunoreactive for hTERT, and the intensity of staining were stronger in presenting parts than the central portions of the tumors. The expression of hTERT was not detected in the three of three SMAs and three of three SOAs. The cells in the papillary structures, which were found on the cyst walls of two of SMAs, were not also stained.
Conclusions: Our results suggested that hTERT expression indicates malignant transformation in SCNs. hTERT may be a useful biomarker for diagnosis of serous cystadenocarcinoma of the pancreas.
Back ground of the patients
| Subtype | Serous microcystic adenoma | Serous oligocystic adenoma | Serous cystadenocarcinoma |
| number of the subtype | 3 | 3 | 2 |
| average age | 65(58-69) | 46(45-58) | 73.5(71-76) |
| sex(Male/Female) | 0/3 | 0/3 | 1/1 |
| average of the tumor | 60mm(40-92) | 24.7mm(19-30) | 93.5mm(40-147) |
| part of the tumor | head:3 | body to tail:3 | body to tail:2 |
| have sympton | 3/3 | 0/3 | 1/2 |
| hTERT expression | 0/3 | 0/3 | 2/2 |
