A statistically significant dose response was observed for all nervous system tumors combined and for schwannoma considered separately, indicating that exposure to even moderate doses (i.e., <1 Sv) of radiation is associated with an elevated incidence of nervous system tumors.

Thyroid cancer risk following exposure to ionizing radiation in childhood and adolescence is a topic of public concern. To characterize the long-term temporal trend and age-at-exposure variation in the radiation-induced risk of thyroid cancer, we analyzed thyroid cancer incidence data for the period from 1958 through 2005 among 105,401 members of the Life Span Study cohort of Japanese atomic-bomb survivors. During the follow-up period, 371 thyroid cancer cases (excluding those with microcarcinoma with a diameter <10 mm) were identified as a first primary among the eligible subjects. Using a linear dose–response model, the excess relative risk of thyroid cancer at 1 Gy of radiation exposure was estimated as 1.28 (95% confidence interval: 0.59–2.70) at age 60 after acute exposure at age 10. The risk decreased sharply with increasing age-at-exposure and there was little evidence of increased thyroid cancer rates for those exposed after age 20. About 36% of the thyroid cancer cases among those exposed before age 20 were estimated to be attributable to radiation exposure. While the magnitude of the excess risk has decreased with increasing attained age or time since exposure, the excess thyroid cancer risk associated with childhood exposure has persisted for >50 years after exposure

Cytodiagnosis of pancreatic juice using ENPD multiple times proved to be useful in the diagnosis of pancreatic carcinoma in situ.

High-grade pancreatic intraepithelial neoplasia (HG-PanIN) is the major precursor of pancreatic ductal adenocarcinoma (PDAC) and is an ideal target for early detection. To characterize pure HG-PanIN, we analysed 23 isolated HG-PanIN lesions occurring in the absence of PDAC. Whole-exome sequencing of five of these HG-PanIN lesions revealed a median of 33 somatic mutations per lesion, with a total of 318 mutated genes. Targeted next-generation sequencing of 17 HG-PanIN lesions identified KRAS mutations in 94% of the lesions. CDKN2A alterations occurred in six HG-PanIN lesions, and RNF43 alterations in five. Mutations in TP53, GNAS, ARID1A, PIK3CA, and TGFBR2 were limited to one or two HG-PanINs. No non-synonymous mutations in SMAD4 were detected. Immunohistochemistry for p53 and SMAD4 proteins in 18 HG-PanINs confirmed the paucity of alterations in these genes, with aberrant p53 labelling noted only in three lesions, two of which were found to be wild type in sequencing analyses. Sixteen adjacent LG-PanIN lesions from ten patients were also sequenced using targeted sequencing. LG-PanIN harboured KRAS mutations in 94% of the lesions; mutations in CDKN2A, TP53, and SMAD4 were not identified. These results suggest that inactivation of TP53 and SMAD4 are late genetic alterations, predominantly occurring in invasive PDAC.

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