Immunohistochemical examination of ER-beta1 in addition to ER-alpha and PR is clinically important in patients with breast cancer treated with tamoxifen monotherapy. Further studies are needed to confirm our findings.
Pancreatic cancer is one of the most lethal malignancies, with virtually all patients eventually succumbing to their disease. Mutations in p53 have been documented in >50% of pancreatic cancers. Owing to the high incidence of p53 mutations in PanIN 3 lesions and pancreatic tumors, we interrogated the comparative ability of adult pancreatic acinar and ductal cells to respond to oncogenic Kras and mutant Tp53(R172H) using Hnf1b:CreER(T2) and Mist1:CreER(T2) mice. These studies involved co-activation of a membrane-tethered GFP lineage label, allowing for direct visualization and isolation of cells undergoing Kras and mutant p53 activation. Kras activation in Mist1(+) adult acinar cells resulted in brisk PanIN formation, whereas no evidence of pancreatic neoplasia was observed for up to 6 months following Kras activation in Hnf1beta(+) adult ductal cells. In contrast to the lack of response to oncogenic Kras alone, simultaneous activation of Kras and mutant p53 in adult ductal epithelium generated invasive PDAC in 75% of mice as early as 2.5 months after tamoxifen administration. These data demonstrate that pancreatic ductal cells, whereas exhibiting relative resistance to oncogenic Kras alone, can serve as an effective cell of origin for pancreatic ductal adenocarcinoma in the setting of gain-of-function mutations in p53.
Background and Aims
It has been reported that the incidence of intrahepatic cholangiocarcinoma (ICC) has increased in the USA, while extrahepatic cholangiocarcinoma (ECC) has decreased or remained stable. However, neither the recent trends nor the effects of the misclassification of Klatskin tumors are known.
Methods
Using the Surveillance, Epidemiology, and End Results program databases, we calculated the average annual age-adjusted incidence rates (AA-IRs) of ICC and ECC in 4-year time periods (1992–1995, 1996–1999, 2000–2003, 2004–2007). These AA-IRs were calculated with misclassified as well as correctly classified Klatskin tumors. AA-IRs were also calculated based on age, sex, and race. Multivariable Poisson regression models were used to evaluate the secular trends of ICC and ECC.
Results
The AA-IR of ICC was 0.92 in 1992–1995 and 0.93 in 2004–2007, while the AA-IR of ECC increased from 0.70 in 1992–1995 to 0.95 in 2004–2007. There was no significant trend in AA-IR of ICC (p = 0.07), while there was a significant increase in ECC across the 4-year time periods (p < 0.001). Klatskin tumors comprised 6.7 % of CCs with approximately 90 and 45 % misclassified as ICC during 1992–2000 and 2001–2007, respectively. Adjusted Poisson models showed no significant differences in the temporal trend of ICC or ECC due to misclassification of Klatskin tumors.
Conclusions
The incidence of ICC has remained stable between 1992 and 2007 with only slight fluctuations, while the incidence of ECC has been increasing. Misclassification of Klatskin tumors does not appear to play a significant role in the trends of CCs.
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