Incidence and pattern of second primary cancer in patients diagnosed with primary cancer.

The long survival of patients with primary cancer increases the chance of such patients developing second primary cancer (SPC). The development of SPC in cancer survivors exerts a large psychological, social and economic burden on patients and their families. The aim of the present study was to assess the risk of cancer survivors developing SPC. The study included patients who had been diagnosed with a first primary cancer in five organs (stomach, colorectum, lung, breast and thyroid), which are the five most common sites of cancer in patients from Korea, at the regional cancer center in Jeonbuk National University Hospital between January 2007 and December 2009. The standardized incidence ratio (SIR) of SPC according to sex and site was calculated from 5,209 patients who were followed up to September 2017. General incidence was acquired from the National Cancer Registry of Republic of Korea. SPC occurred in 6.2% (323/5,209) of patients, and the incidence of SPC among the five major types of cancer was in the order of breast (8.8%, 46/524), colorectum (8.6%, 86/1,003), gastric (6.6%, 89/1,358), thyroid (4.7%, 67/1,437) and lung cancer (3.9%, 35/887). When all SPC sites were included, the SIRs of SPC in patients with colorectal cancer and breast cancer were >1.0 (1.21 and 1.66, respectively). Breast cancer and thyroid cancer exhibited a high site relationship (P<0.05), and colorectal cancer had a high site relationship with gastric cancer (P<0.05). The present study analyzed the incidence and pattern of SPC in patients with cancer who were diagnosed with primary carcinoma in five organs. The results of the study may be useful for effective follow-up and early detection of SPC in patients with cancer.

Immunohistochemical Expression and Clinical Significance of Suggested Stem Cell Markers in Hepatocellular Carcinoma.

BACKGROUND: Increasing evidence has shown that tumor initiation and growth are nourished by a small subpopulation of cancer stem cells (CSCs) within the tumor mass. CSCs are posited to be responsible for tumor maintenance, growth, distant metastasis, and relapse after curative operation. We examined the expression of CSC markers in paraffin-embedded tissue sections of hepatocellular carcinoma (HCC) and correlated the results with clinicopathologic characteristics. METHODS: Immunohistochemical staining for the markers believed to be expressed in the CSCs, including epithelial cell adhesion molecule (EpCAM), keratin 19 (K19), CD133, and CD56, was performed in 82 HCC specimens. RESULTS: EpCAM expression was observed in 56% of the HCCs (46/82) and K19 in 6% (5/82). EpCAM expression in HCC significantly correlated with elevated α-fetoprotein level, microvessel invasion of tumor cells, and high histologic grade. In addition, EpCAM expression significantly correlated with K19 expression. The overall survival and relapsefree survival rates in patients with EpCAM-expressing HCC were relatively lower than those in patients with EpCAM-negative HCC. All but two of the 82 HCCs were negative for CD133 and CD56, respectively. CONCLUSIONS: Our results suggest that HCCs expressing EpCAM are associated with unfavorable prognostic factors and have a more aggressive clinical course than those not expressing EpCAM. Further, the expression of either CD133 or CD56 in paraffin-embedded HCC tissues appears to be rare.

The role of nuclear EpICD in extrahepatic cholangiocarcinoma: association with ß-catenin.

After intramembranous proteolysis-mediated loss of the extracellular domain of the epithelial cell adhesion molecule (EpEx) and release of an intracellular domain (EpICD) into the cytoplasm, EpICD sequentially associates with FHL2 to form a nuclear complex with ß-catenin and Lef-1. This association induces gene transcription involved in the activation of the oncogenic potential of epithelial cell adhesion molecule (EpCAM). We examined the localization and expression of EpEx, EpICD and ß-catenin in surgical specimens of extrahepatic cholangiocarcinoma (ECC) from 79 patients and focused on the relationship between nuclear expression of EpICD and ß-catenin. We also examined the role of EpICD by transfecting the EpICD cDNA in cholangiocarcinoma (CC) cell lines. There was a significant correlation between the nuclear expression of EpICD and ß-catenin in ECC tissues. Frequent nuclear co-localization of EpICD and ß-catenin was observed in cancer cells forming the invasive front. Nuclear expression of EpICD also significantly correlated with histologic grade of tumor. Overexpression of EpICD in the CC cells significantly increased the cell growth and proliferation. The overexpression of EpICD in the CC cells also increased the expression levels of the active form of ß-catenin and EpCAM target genes, such as c-myc and cyclin D1. Furthermore, the overexpression of EpICD significantly enhanced the migration and invasiveness of CC cells. Conversely, the inhibition of EpCAM in EpCAM-overexpressing cells by siRNA significantly decreased cell proliferation, migration and invasion. These results indicate that the spatial localization of EpICD and its mutual interaction with ß-catenin may be important in ECC progression and invasion.