Prediction of Chemosensitivity in Multiple Primary Cancer Patients Using Machine Learning.

BACKGROUND/AIM: Many cancer patients face multiple primary cancers. It is challenging to find an anticancer therapy that covers both cancer types in such patients. In personalized medicine, drug response is predicted using genomic information, which makes it possible to choose the most effective therapy for these cancer patients. The aim of this study was to identify chemosensitive gene sets and compare the predictive accuracy of response of cancer cell lines to drug treatment, based on both the genomic features of cell lines and cancer types. MATERIALS AND METHODS: In this study, we identified a gene set that is sensitive to a specific therapeutic drug, and compared the performance of several predictive models using the identified genes and cancer types through machine learning (ML). To this end, publicly available gene expression datasets and drug sensitivity datasets of gastric and pancreatic cancers were used. Five ML algorithms, including linear discriminant analysis, classification and regression tree, k-nearest neighbors, support vector machine and random forest, were implemented. RESULTS: The predictive accuracy of the cancer type models were 0.729 to 0.763 on the training dataset and 0.731 to 0.765 on the testing dataset. The predictive accuracy of the genomic prediction models was 0.818 to 1.0 on the training dataset and 0.759 to 0.896 on the testing dataset. CONCLUSION: Performance of the specific gene models was much better than those of the cancer type models using the ML methods. Therofore, the most effective therapeutic drug can be chosen based on the expression of specific genes in patients with multiple primary cancers, regardless of cancer types.

Clinicopathological Characteristics of Metaplastic Papillary Tumor of the Fallopian Tube.

Metaplastic papillary tumor (MPT) of the fallopian tube is a very uncommon lesion, displaying papillary growth of bland-appearing cells with abundant, eosinophilic cytoplasm and mucinous metaplasia. It is difficult for pathologists to determine whether to categorize this lesion as a metaplastic proliferative lesion or a true neoplasm. We recently experienced a case of tubal MPT and initiated a comprehensive review of previously published cases with thorough analysis of clinicopathological characteristics. MPT is typically related to pregnancy, but we describe the first case of pregnancy-unrelated, incidentally detected tubal MPT in a 51-year-old woman who underwent surgery for endometrial cancer. The MPT consisted of small papillary formations with epithelium consisting of nonciliated, columnar cells with abundant eosinophilic cytoplasm arranged as either a single layer or pseudostratified layer. The stroma had a myxoid appearance. Intraluminal and extracellular mucin and floating papillary tufts were observed. Nuclei of the epithelial lining cells were centrally located, rounded or oval, and displayed intranuclear pseudoinclusions or grooves. The MPT cells were positive for paired box 8, epithelial membrane antigen, and cytokeratin. Interestingly, Wilms tumor 1 (WT1) protein was localized within the cytoplasm of MPT cells. Furthermore, the MPT cells did not express phosphatase and tensin homolog deleted on chromosome 10 (PTEN). In summary, MPT of the fallopian tube is a very unusual, distinctive entity displaying unique histopathological features and immunophenotype. Our observation of cytoplasmic WT1 expression and loss of PTEN expression in tubal MPT suggests its neoplastic nature and raises the possibility of WT1 or PTEN involvement in the development of MPT.

Age-hardening reactions in a type III dental gold alloy.

The age-hardening reactions in a commercial type III dental gold alloy were studied by means of hardness test, X-ray diffraction study and scanning and transmission electron microscopic observations. The hardening was attributed to the formation of the metastable AuCu 1' type ordered phase in the grain interior by the isothermal ageing at 225 and 450 degrees C at which two hardness peaks were observed by the isochronal ageing. By ageing at 450 degrees C, the hardening did not begin immediately because the incubation period was required. The age hardening at 225 degrees C was characterized by a slow growth rate of the metastable AuCu 1' type ordered phase. The overageing with softening which occurred following prolonged ageing at 450 degrees C was due to the formation of the lamellar structure composed of the Ag-rich alpha1 and AuCu 1 type ordered phases at grain boundaries.

Age-hardening associated with grain boundary precipitation in a commercial dental gold alloy.

The aim of this study was to make clear the age-hardening mechanism in a dental high carat gold alloy. For this purpose, age-hardening behaviour of a commercial dental high carat gold alloy, 65.5 wt% Au-14.0 wt% Ag-10.0 wt% Cu-8.9 wt% Pt, was investigated by means of hardness testing, X-ray diffraction study and scanning electron microscopy. Age-hardening was generated by the coherency strain resulting from the transformation of the alpha single phase to the Ag-rich alpha 1 phase and the AuCu I type ordered phase. The coherency strain seemed to be associated with the nucleation of the AuCu ordered structure initially, and then was brought about with the simultaneous formation of the Ag-rich alpha 1 phase and the AuCu I type ordered phase. Hardening was attributed mainly to the very fine coherent precipitates of a lamellar structure composed of the Ag-rich alpha 1 phase and the AuCu I type ordered phase at grain boundaries, and softening, which occurred following prolonged ageing, was due to the coarsening of the fine lamellar structure by releasing the strain at the interfaces of the adjacent lamellae.

Age-hardening associated with precipitation reaction and spinodal decomposition in a commercial dental low-carat Au-Ag-Cu-Pd alloy.

Two distinguishable hardening mechanisms, depending on the temperature, were found by isothermal ageing in a commercial dental low-carat Au-Ag-Cu-Pd alloy. Age-hardening was attributed to the precipitation of the metastable AuCu I' and equilibrium AuCu I ordered phases and spinodal decomposition depending on the ageing temperature. It was clearly visible, by using the direct-ageing method, that the XRD peaks of the parent phases showed a shift during transformation.