BACKGROUND: Precision medicine based on genomic analysis of germline or tumor tissue is attracting attention. However, there is no consensus on how to apply the results of genomic analysis to treatment.
METHODS: A 59-year-old man diagnosed with metastatic prostate cancer was diagnosed with castration-resistant prostate cancer. Although he was sequentially treated with enzalutamide and abiraterone, bone metastasis progression was identified by skeletal scintigraphy. Therefore, we sequentially performed docetaxel therapy followed by cabazitaxel. After the third cycle of cabazitaxel, his prostate-specific antigen level was stable at < 10 ng/mL, and no radiological progression was detected. The patient\'s formalin-fixed paraffin-embedded tumor biopsy specimen underwent multiple-gene testing by next-generation sequencing, which identified a FANCA homodeletion. No significant germline mutation was observed.
CONCLUSIONS: We describe a case of aggressive, castration-resistant prostate cancer with FANCA homodeletion. Genomic analysis of prostate cancer tissue can be useful to determine optimal treatment of such cancers.

Tobacco smoke and alcohol use play important roles in the etiology of squamous cell carcinoma of the head and neck (SCCHN). Smoking causes DNA damage, including double-strand DNA breaks (DSBs), that leads to carcinogenesis. To test the hypothesis that suboptimal DSB repair capacity is associated with risk of SCCHN, we applied a flow cytometry-based method to detect the DSB repair phenotype first in four EBV-immortalized human lymphoblastoid cell lines and then in human peripheral blood T-lymphocytes (PBTLs). With this blood-based laboratory assay, we conducted a pilot case-control study of 100 patients with newly diagnosed, previously untreated SCCHN and 124 cancer-free controls of non-Hispanic whites. We found that the mean DSB repair capacity level was significantly lower in cases (42.1%) than that in controls (54.4%) (P<0.001). When we used the median DSB repair capacity level in the controls as the cutoff value for calculating the odds ratios (ORs) with adjustment for age, sex, smoking and drinking status, the cases were more likely than the controls to have a reduced DSB repair capacity (adjusted OR=1.93; 95% confidence interval, CI=1.04-3.56, P=0.037), especially for those subjects who were ever drinkers (adjusted OR=2.73; 95% CI=1.17-6.35, P=0.020) and had oropharyngeal tumors (adjusted OR=2.17; 95% CI=1.06-4.45, P=0.035). In conclusion, these findings suggest that individuals with a reduced DSB repair capacity may be at an increased risk of developing SCCHN. Larger studies are warranted to confirm these preliminary findings.

Mobile elements using a \"cut and paste\" mechanism of transposition (Class II) are frequently prone to internal deletions and the question of the origin of these copies remains elusive. In this study, we looked for copies belonging to the Lemi Family (Tc1-mariner-IS630 SuperFamily) in the plant genomes, and copies within internal deletions were analyzed in detail. Lemi elements are found exclusively in Eudicots, and more than half of the copies have been deleted. All deletions occur between microhomologies (direct repeats from 2 to 13 bp). Copies less than 500 bp long, similar to MITEs, are frequent. These copies seem to result from large deletions occurring between microhomologies present within a region of 300 bp at both extremities of the element. These regions are particularly A/T rich, compared to the internal part of the element, which increases the probability of observing short direct repeats. Most of the molecular mechanisms responsible for double strand break repair are able to induce deletions between microhomologies during the repair process. This could be a quick way to reduce the population of active copies within a genome and, more generally, to reduce the overall activity of the element after it has entered a naive genome.