5-Hydroxymethylcytosine is an independent predictor of survival in malignant melanoma.

Outcomes for melanoma patients vary within cancer stage. Prognostic biomarkers are potential adjuncts to provide more precise prognostic information. Simple, low-cost biomarker assays, such as those based on immunohistochemistry, have strong translational potential. 5-hydroxymethylcytosine (5 hmC) shows prognostic potential in melanoma but prior studies were small. We, therefore, analysed 5 hmC in a retrospective cohort to provide external validation of its prognostic value. Two hundred primary melanomas were evaluated for 5 hmC expression using immunohistochemistry. The primary objective was to assess the effect on overall survival while controlling for important confounders. Univariable and multivariable analyses were performed. REMARK guidelines were followed. The 5 hmC immunohistochemistry scoring showed very strong inter-observer agreement (ICC 0.88) and expression was significantly related to age, site, Breslow thickness, ulceration, mitotic rate, and stage. Kaplan-Meier analysis showed 5 hmC was associated with metastasis-free, melanoma-specific, and overall survival, P<0.0001 for each. In univariable Cox proportional hazards models, 5 hmC hazard ratios were significant and remained so in a multivariable model. A two-step cox model was created using stage and 5 hmC, as stage is the gold standard for clinical practice. The addition of 5 hmC produced significant improvement in the model and 5 hmC and stage were independent significant predictors. This is the largest study of the prognostic value of 5 hmC immunohistochemistry in melanoma. The 5 hmC scoring was easily and reproducibly performed and it was an independent predictor of metastasis-free survival, melanoma-specific survival, and overall survival. This work supports further development of 5 hmC as a prognostic biomarker and suggests that it could add more precision to American Joint Committee on Cancer staging.

Characterisation of DNA probes for the analysis of metallothionein gene expression in the bank vole (Clethrionomys glareolus).

DNA probes have been developed for subsequent use in monitoring the exposure of animals to heavy metal pollution in terrestrial environments using metallothionein (MT) gene expression in the bank vole (Clethrionomys glareolus). Three different bank vole sequences were characterised corresponding to the cDNA and the genomic DNA for MT-I and the genomic DNA for MT-II. Nucleotide sequence analysis indicates that the coding sequences of the bank vole MT-I and MT-II genes exhibit a very high degree of similarity (greater than 92%) to the corresponding genes of the Chinese hamster, the mouse and the rat. In common with other mammalian MT genes, both the MT-I and MT-II genes in the bank vole are interrupted by two introns, which are at identical positions as those in other rodent MT genes; furthermore, the sizes of these introns are similar to those in other rodents with the first intron being larger than the second and those in the MT-I gene being larger than those in the MT-II gene. The predicted amino acid sequence for the proteins shows that both proteins contain 20 cysteine residues at positions identical to those in other known mammalian MTs. The availability of these DNA sequences now provides a good opportunity to investigate MT gene expression and possible gene amplification in bank voles exposed to metal pollution.

Delayed metastasis to the mandible of esophageal adenocarcinoma.

Around 1 % of oral cancers are metastases from distant sites. Tumor metastases to the jaw bones are uncommon and are most likely to arise from primary lung, breast, prostate or kidney tumors. Jaw bone metastases from a primary esophageal adenocarcinoma are especially rare, with only 7 reports published in the literature. Here, we describe a case of a 69 year-old male patient where 7 years elapsed between the diagnosis and successful treatment of a poorly differentiated, stage pT2N0 primary esophageal adenocarcinoma and re-presentation with jaw pain due to a metastatic mandibular deposit. The morphological appearance of the metastasis and immunohistochemical positivity with CK20, CK7 and CDX2 strongly supported an adenocarcinoma of upper gastrointestinal tract origin. This case is of particular interest as there is an unusually long time between the detection of the primary esophageal adenocarcinoma and diagnosis of metastatic disease. The longest period of time we have found for this in the literature is 9 months, although it is also reported that some oral metastases may appear more than 10 years following the primary tumor diagnosis.