Preface

No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77506/1/1700_ftp.pd

Clinical Utility of Germline Genetic Testing in Japanese Men Undergoing Prostate Biopsy

Background: Multiple common variants and also rare variants in monogenic risk genes such as BRCA2 and HOXB13 have been reported to be associated with risk of prostate cancer (PCa); however, the clinical setting in which germline genetic testing could be used for PCa diagnosis remains obscure. Herein, we tested the clinical utility of a 16 common variant-based polygenic risk score (PRS) that has been developed previously for Japanese men and also evaluated the frequency of PCa-associated rare variants in a prospective cohort of Japanese men undergoing prostate biopsy. Methods: A total of 1336 patients undergoing first prostate biopsy were included. PRS was calculated based on the genotype of 16 common variants, and sequencing of 8 prostate cancer-associated genes was performed by multiplex polymerase chain reaction based target sequencing. PRS was combined with clinical factors in logistic regression models to assess whether addition of PRS improves the prediction of biopsy positivity. Results: The top PRS decile was associated with an odds ratio of 4.10 (95% confidence interval = 2.46 to 6.86) with reference to the patients at average risk, and the estimated lifetime absolute risk approached 20%. Among the patients with prostate specific antigen 2-10 ng/mL who had prebiopsy magnetic resonance imaging, high PRS had an equivalent impact on biopsy positivity as a positive magnetic resonance imaging finding. Rare variants were detected in 19 (2.37%) and 7 (1.31%) patients with positive and negative biopsies, respectively, with BRCA2 variants being the most prevalent. There was no association between PRS and high-risk rare variants. Conclusions: Germline genetic testing could be clinically useful in both pre- and post-PSA screening settings

Association of variations in HLA class II and other loci with susceptibility to EGFR-mutated lung adenocarcinoma

Lung adenocarcinoma driven by somatic EGFR mutations is more prevalent in East Asians (30-50%) than in European/Americans (10-20%). Here we investigate genetic factors underlying the risk of this disease by conducting a genome-wide association study, followed by two validation studies, in 3,173 Japanese patients with EGFR mutation-positive lung adenocarcinoma and 15,158 controls. Four loci, 5p15.33 (TERT), 6p21.3 (BTNL2), 3q28 (TP63) and 17q24.2 (BPTF), previously shown to be strongly associated with overall lung adenocarcinoma risk in East Asians, were re-discovered as loci associated with a higher susceptibility to EGFR mutation-positive lung adenocarcinoma. In addition, two additional loci, HLA class II at 6p21.32 (rs2179920; P =5.1 × 10(-17), per-allele OR=1.36) and 6p21.1 (FOXP4) (rs2495239; P=3.9 × 10(-9), per-allele OR=1.19) were newly identified as loci associated with EGFR mutation-positive lung adenocarcinoma. This study indicates that multiple genetic factors underlie the risk of lung adenocarcinomas with EGFR mutations

Genome-Wide Association Study of Lung Adenocarcinoma in East Asia and Comparison With a European Population

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (P interaction  = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population.

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

Significance of prediction of the dorsal landmark using three-dimensional computed tomography during laparoscopic lymph node dissection along the proximal splenic artery in gastric cancer

Objectives: Dissection of the No. 11p lymph nodes is technically challenging because of variations in anatomical landmarks. This study aimed to determine the accuracy and efficacy of predicting the dorsal landmark of No. 11p lymph node using three-dimensional computed tomography simulation. Methods: Laparoscopic gastrectomy with No. 11p lymph node dissection with preoperative simulation using three-dimensional computed tomography was performed in 24 patients at our institution from October 2016 to May 2018. Initially, preoperative three-dimensional computed tomography findings with operative videos in these 24 patients were compared. The dorsal landmark was defined as an anatomical structure behind the splenic artery on preoperative three-dimensional computed tomography and operative videos. The dorsal landmark of No. 11p lymph node was divided into four types: (1) splenic vein type, (2) splenic vein and pancreas type, (3) pancreas type, and (4) unclear type. Then, to investigate the efficacy of three-dimensional computed tomography, we compared the clinical and pathological features and surgical outcomes of nine patients who underwent preoperative three-dimensional computed tomography simulation (three-dimensional computed tomography group) and 23 patients who did not undergo three-dimensional computed tomography simulation from August 2014 to September 2016 (non-three-dimensional computed tomography group). All procedures were performed by one surgeon certified by the Endoscopic Surgical Skill Qualification System in Japan. Results: The concordance rate between three-dimensional computed tomography and operative videos of the dorsal landmark using three-dimensional computed tomography was 79% (19/24). The operative time of No. 11p lymph node dissection was significantly shorter in the three-dimensional computed tomography group than in the non-three-dimensional computed tomography group (7.7 versus 15.8 min, P = 0.044). Conclusion: The accuracy of predicting the dorsal landmark of No. 11p lymph node using three-dimensional computed tomography was extremely high. Preoperative simulation with three-dimensional computed tomography was useful in shortening the operative time of No. 11p lymph node dissection