When and how to enlighten citizens on genetics and hereditary cancer: a web survey of online video viewers.

With the rapid expansion of genomic medicine, more citizens are compelled to think about genetics in their daily lives. This study aims to explore appropriate types of educational media and methods to enlighten activities for genetics and hereditary cancer. We presented an 18-min YouTube video on genetics and hereditary cancer to participants at a scientific event, Science Agora 2020, and administered a web questionnaire to investigate their opinions about when and how citizens should start learning about genetics and hereditary cancer. We recruited 133 participants who watched the video, and 26.3% (35/133) responded to the questionnaire. Most of them were evaluated to understand and appreciate the contents of the video. They identified websites, or videos as suitable learning media, irrespective of their sex, age, or profession. They highlighted upper elementary school or junior high school as appropriate educational stages to start learning about genetics and hereditary cancer to facilitate collecting their own genetic information by themselves. Our findings show that educational institutions should provide opportunities to learn about genetics and hereditary cancers, especially for upper elementary school and junior high school students, using learning media, such as videos, depending on their level or demand.

The association of ectopic craniopharyngioma in the fourth ventricle with familial adenomatous polyposis: illustrative case.

BACKGROUND: Craniopharyngioma (CP) often arises in the sellar and suprasellar areas; ectopic CP in the posterior fossa is rare. Familial adenomatous polyposis (FAP) is a genetic disorder involving the formation of numerous adenomatous polyps in the gastrointestinal tract, and it is associated with other extraintestinal manifestations. OBSERVATIONS: The authors reported the case of a 63-year-old woman with FAP who presented with headache and harbored a growing mass in the fourth ventricle. Magnetic resonance imaging (MRI) findings revealed a well-circumscribed mass with high intensity on T1-weighted images and low intensity on T2-weighted images and exhibited no contrast enhancement. Gross total resection was performed and histopathology revealed an adamantinomatous CP (aCP). The authors also reviewed the previous reports of ectopic CP in the posterior fossa and found a high percentage of FAP cases among the ectopic CP group, thus suggesting a possible association between the two diseases. LESSONS: An ectopic CP may be reasonably included in the differential diagnosis in patients with FAP who present with well-circumscribed tumors in the posterior fossa.

Mortality and morbidity of infants with trisomy 21, weighing 1500 grams or less, in Japan.

Although very low birth weight (VLBW) is well studied in neonatology and the perinatal prognosis of VLBW infants has improved over time, little is known about the prognosis of VLBW infants with trisomy 21 (T21). We aimed to investigate the mortality and morbidity of VLBW infants with T21 during NICU admission in Japan, in comparison to those of infants without birth defects (BD-). Maternal and neonatal data of infants weighing 1500 grams or less admitted to the centers of the Neonatal Research Network of Japan from 2003 to 2016 were collected prospectively. Of 60,136 infants, 328 (0.55%) had T21. Although maternal age in the case of T21 infants was higher, maternal complications tended to be less frequent than in those with BD-. Multivariable analysis revealed that morbidities were higher in infants with T21 than in those with BD- but respiratory distress syndrome and retinopathy of prematurity were less frequent in those with T21 (p < 0.001, and p = 0.014, respectively), and no significant difference was observed between the two groups in the proportion of late-onset circulatory collapse of prematurity as well as cystic periventricular leukomalacia (p = 0.739 and p = 0.733, respectively). The survival rate at discharge from the NICU was 77% and 94% for T21 and BD-, respectively. This was the first nationwide survey of VLBW infants with T21 in Japan. Although there were no data regarding the timing of diagnosis, these data will aid prenatal genetic counseling and perinatal management of T21 infants.

Prevalence of pathogenic germline variants in the circulating tumor DNA testing.

BACKGROUND: Somatic and germline variants are not distinguishable by circulating tumor DNA (ctDNA) testing without analyzing non-tumor samples. Although confirmatory germline testing is clinically relevant, the criteria for selecting presumed germline variants have not been established in ctDNA testing. In the present study, we aimed to evaluate the prevalence of pathogenic germline variants in clinical ctDNA testing through their variant allele fractions (VAFs). METHODS: A total of consecutive 106 patients with advanced solid tumors who underwent ctDNA testing (Guardant360®) between January 2018 and March 2020 were eligible for this study. To verify the origin of pathogenic variants reported in ctDNA testing, germline sequencing was performed using peripheral blood DNA samples archived in the Clinical Bioresource Center in Kyoto University Hospital (Kyoto, Japan) under clinical research settings. RESULTS: Among 223 pathogenic variants reported in ctDNA testing, the median VAF was 0.9% (0.02-81.8%), and 88 variants with ≥ 1% VAFs were analyzed in germline sequencing. Among 25 variants with ≥ 30% VAFs, seven were found in peripheral blood DNA (BRCA2: n = 6, JAK2: n = 1). In contrast, among the 63 variants with VAFs ranging from 1 to < 30%, only one variant was found in peripheral blood DNA (TP53: n = 1). Eventually, this variant with 15.6% VAF was defined to be an acquired variant, because its allelic distribution did not completely link to those of neighboring germline polymorphisms. CONCLUSION: Our current study demonstrated that VAFs values are helpful for selecting presumed germline variants in clinical ctDNA testing.

Germline sequencing for presumed germline pathogenic variants via tumor-only comprehensive genomic profiling.

BACKGROUND: The European Society for Medical Oncology Precision Medicine Working Group (ESMO-PMWG) published recommendations regarding confirmatory germline testing for presumed germline pathogenic variants (PGPVs) in tumor-only comprehensive genomic profiling (CGP). However, the clinical validity of these recommendations has not been investigated in a real-world practice. METHODS: Medical records of 180 consecutive patients who obtained the results of a tumor-only CGP (FoundationOne® CDx, Foundation Medicine, Inc, Cambridge, MA, USA) between October 2018 and March 2020, were retrospectively reviewed. After excluding patients with no reported variants in 45 actionable genes (n = 6), or no archived germline DNA samples (n = 31), 143 patients were investigated. The PGPVs were selected from the CGP report and germline sequencing were performed using DNA samples archived in Clinical Bioresource Center in Kyoto University Hospital (Kyoto, Japan). RESULTS: A total of 195 variants were classified as PGPV based on the conventional criteria. Germline sequencing disclosed that 12 variants (6.2%) were of germline origin. In contrast, after filtering these 195 variants through the ESMO-PMWG recommendation criteria for confirmatory germline testing, following seven PGPVs, BRCA2 (n = 2), BRIP1 (n = 1), BAP1 (n = 1), PMS2 (n = 1), MSH2 (n = 1), and SDHB (n = 1) remained and six variants (85.7%) were confirmed to be of germline origin. CONCLUSION: Our current data suggested that the application of ESMO-PMWG criteria is helpful in selecting PGPVs with a high likelihood of germline origin in a tumor-only CGP in daily clinical practice.

Current status and issues related to secondary findings in the first public insurance covered tumor genomic profiling in Japan: multi-site questionnaire survey.

In June 2019, the Japanese National Health Insurance (NHI) system introduced coverage for two types of tumor genomic profiling (TGP): FoundationOneⓇ CDx (F1) and OncoGuide™ NCC OncoPanel System (NCCOP). TGP sometimes reveals germline variants that are potentially pathogenic as secondary findings (SFs). We conducted a questionnaire-based survey to find out the operational statuses of F1 and NCCOP at institutions where TGP was performed to elucidate issues related to SFs. Responses were received from 97 of 112 institutions (86.6%). As of May 31, 2020, 88 (90.7%) and 78 (80.4%) institutions started performing F1 and NCCOP, respectively. Since F1 only examines tumor samples, germline confirmatory testing is necessary to determine whether they are actually germline pathogenic variants (GPVs). When physicians are obtaining informed consent all but 2.3% of the patients requested SF disclosure. Conversely, when presumed germline pathogenic variants (PGPVs) were detected, 46.2% were not willing to receive confirmatory tests as they wanted to prioritize cancer treatment over SFs investigation, while only 23.3% underwent confirmatory tests. Problems in cancer genomic medicine reported by clinical genetics departments included short-staffing (n = 10), insufficient interdepartmental cooperation (n = 9), inconsistent understanding of genetics among healthcare professionals (n = 8), and low utilization rate of SFs due to lack of insurance coverage for confirmatory tests and post-test health checkups (n = 8). Solutions include; determining the appropriate timing to confirm patient intent on SF disclosure, covering confirmatory tests for PGPVs by the NHI, and establishing cooperation between the oncology and clinical genetics departments.

[Hereditary Tumor Medical Care in the Age of Cancer Genomic Medicine].

How to efficiently suspect a germline gene variant(presumed germline pathogenic variant: PGPV)in comprehensive tumor-profiling tests using only cancer tissue(cells)as a sample is an important issue. This is because a few percent are derived from germline variants, which leads to the diagnosis of hereditary tumor syndromes and is useful information for the health management of patients and relatives. Clues include allele frequency, gene type, germline founder mutation, age of onset, present illness and past history, cancer type, family history, and tumor cell proportion. More than 97% of patients want to know such secondary findings before the test, but only about 23% of patients undergo confirmation tests even if PGPV is detected, and it is necessary to improve this in the future.

Gender Differences in Smoking Initiation and Cessation Associated with the Intergenerational Transfer of Smoking across Three Generations: The Nagahama Study.

Global tobacco policies lowered overall and male smoking rates, but female smoking rates have remained unchanged. Parent-child studies revealed the effects of parental smoking, but gender differences had mixed results. We investigated the effects of long-term smoking behavior in families over three generations in order to clarify gender differences. A cross-sectional study in a community-based genome cohort was conducted using a self-reported questionnaire. A total of 8652 respondents were stratified by gender regarding smoking initiation. A logistic regression analysis was performed to analyze the family smoking history. A total of 2987 current smokers and ever-smokers were compared regarding smoking cessation. With respect to smoking initiation, women were affected by their smoking mothers (odds ratio (OR), 2.4; 95% confidence interval (CI), 1.8-3.2) and grandmothers (OR, 1.7; CI, 1.1-2.4). Women who continued smoking were affected only by their smoking mothers (OR, 1.6; CI, 1.05-2.49). In conclusion, gender differences in smoking initiation and cessation are possibly associated with family smoking history. Mothers and grandmothers were shown to have a strong influence on women with respect to both smoking initiation and cessation. Future research should focus on providing evidence for effective gender-specific intervention programs to curb long-term smoking in women.

Physicians' perceptions of the factors influencing disclosure of secondary findings in tumour genomic profiling in Japan: a qualitative study.

Tumour genomic profiling (TGP), conducted in search of therapeutics, sometimes reveals potentially pathogenic germline variants as secondary findings (SFs). Physicians involved in TGP are often specialised in oncology and not in clinical genetics. To better utilise SFs, we explored issues physicians have during disclosure and the potential for collaborations with clinical genetics professionals. Semi-structured interviews were conducted with 14 physicians who had experience in handling outpatient TGP at designated core hospitals for cancer genomic medicine in Japan. The data were analysed thematically. The difficulties physicians experienced during informed consent (IC) included educating patients about SFs, providing detailed information on SFs, and explaining the impact of SFs on patients' family members. When SFs were detected, physicians had reservations regarding the relevance of the disclosure criteria. Confirmatory germline tests were performed using peripheral blood when tumour-only tests detected suspected SFs. Some physicians had reservations about the necessity of confirmatory tests when they did not affect the patients' treatment options. To encourage patients to receive confirmatory tests, improvements are necessary in the healthcare system, such as insurance reimbursements, education for physicians so that they can provide a better explanation to their patients, and genetic literacy of physicians and patients. The physicians offered insights into the challenges they experienced related to IC, disclosure of SFs, and expectations for active collaborations with clinical genetics professionals. Wider healthcare insurance coverage and better genetic literacy of the population may lead to more patients taking confirmatory tests when SFs are suspected.

Japanese women's reasons for accompaniment status to hereditary breast and ovarian cancer-focused genetic counseling.

Genetic counselors routinely assess and understand clients' needs at the beginning of a session. Attending a genetic counseling session with or without companions is an objective sign that genetic counselors can easily notice. This study focused on clients' reasons for their accompaniment status for genetic counseling, which we categorize into attending with or without a companion(s). A questionnaire survey and interviews were conducted using snowball sampling, starting with the chief executive officer (CEO) of the Japanese hereditary breast and ovarian cancer (HBOC) support group. Of 32 participants, 19 continued with an in-depth interview after answering the questionnaire. Five themes were identified from the interview: (1) personal confidence, (2) decision-making style, (3) family members' habits and time availability, (4) considerations and conflicts with family members, and (5) healthcare provider's suggestion. Our data suggested that the clients expected their companion(s) to play certain roles. This indicates that the reasons of accompaniment status will be helpful for genetic counselors to understand both clients' and their families' motivations, personalities, habits, and psychosocial backgrounds. In a high-context culture such as that of Japan, accompaniment status may be a helpful sign to understand clients' true worries. In addition, some companions may be future clients in genetic counseling, due to the genetic nature of the disease. In conclusion, our study indicated that it is important for genetic counselors to record accompaniment status before the initial genetic counseling and to pay attention to its reasons at the beginning of the session, which may lead them to understand the client's psychosocial background to facilitate better client-centered genetic counseling.

The association between the Moyamoya disease susceptible gene RNF213 variant and incident cardiovascular disease in a general population: the Nagahama study.

OBJECTIVE: An association between the Moyamoya disease susceptible gene ring finger protein 213 (RNF213) variant and ischemic stroke and coronary artery disease has been suggested in case-control studies. We aimed to investigate the possible association between the RNF213 variant and the incidence of cardiovascular disease in a general population. METHODS: The study participants consisted of 9153 Japanese community residents without history of cardiovascular disease. The clinical parameters employed in this analysis were observed at baseline between 2008 and 2010. The RNF213 p.R4859K variant was determined by TaqMan probe assay and then confirmed by Sanger sequencing. RESULTS: During 8.52 years follow-up period, we observed 214 incident cases of cardiovascular diseases (99 total stroke cases, 119 major adverse cardiac event cases, including 4 cases of both). The incidence rate was higher for the variant allele carriers (120 cases; incidence rate, 71.0 per 10 000 person-years) than for the homozygotes of the wild-type allele (26.9), and the group differences achieved statistical significance (P = 0.009). Although the RNF213 variant was also associated with systolic blood pressure (dominant model: coefficient of 8.19 mmHg; P < 0.001), the Cox regression analysis adjusted for major covariates including systolic blood pressure identified the RNF213 variant as an independent determinant for cardiovascular disease (hazard ratio of 3.41, P = 0.002) and major adverse cardiac event (hazard ratio of 3.80, P = 0.010) but not with total stroke (P = 0.102). CONCLUSION: The Moyamoya disease susceptible RNF213 variant was associated with blood pressure and the incidence of cardiovascular disease in a Japanese general population.

Real-world outcome of universal screening for Lynch syndrome in Japanese patients with colorectal cancer highlights the importance of targeting patients with young-onset disease.

Despite the recommendations of the latest guidelines, the practical efficacy of universal screening for identifying Lynch syndrome (LS) among patients with colorectal cancer (CRC) may be limited in the real world due to infrequent referrals and the difficulties of genetic testing. Thus, the present study aimed to retrospectively analyze the results of universal screening of patients with CRC at a referral hospital in Japan. Immunohistochemistry was performed for mismatch repair proteins [including DNA mismatch repair protein MSH6 (MSH6), mismatch repair endonuclease PMS2 (PMS2), DNA mismatch repair protein Msh2 (MSH2) and DNA mismatch repair protein Mlh1 (MLH1)] and BRAF V600E mutation. Tumors that showed the following were considered to indicate LS and patients with such tumors were designated as genetic testing candidates (GTCs): i) Loss of MSH6/MSH2; ii) loss of MSH6 alone; iii) loss of PMS2 alone; and iv) loss of PMS2/MLH1 with negative BRAF V600E. MLH1 methylation and BRAF V600E mutation were analyzed in deficient mismatch repair (dMMR) tumors retrospectively. The frequency of dMMR and GTCs in an independent cohort of patients with young-onset CRC were also investigated. Universal screening revealed dMMR tumors, GTCs and LS probands in 7.3, 3.9 and 0.4%, respectively, of 463 patients with CRC. Although dMMR tumors were observed in both younger (<50 years) and older (≥60 years) patients, the GTCs were enriched in younger individuals. Evaluation of mismatch repair status in an independent cohort confirmed the high rate of GTCs in patients with young-onset CRC. The low detection rate of LS demonstrated in this study questions the implementation of routine universal screening in regions with low prevalence of LS. Considering the enrichment of GTCs in young-onset CRCs, age-restricted strategies may be simple and efficient practical alternatives to universal screening in the real world.

Prevalence of Germline Variants in a Large Cohort of Japanese Patients with Pheochromocytoma and/or Paraganglioma.

The high incidence of germline variants in pheochromocytoma and paraganglioma (PPGL) has been reported mainly in Europe, but not among Japanese populations in Asia. We aimed to study the prevalence of germline variants in Japanese PPGL patients and the genotype-phenotype correlation. We examined 370 PPGL probands, including 43 patients with family history and/or syndromic presentation and 327 patients with apparently sporadic (AS) presentation. Clinical data and blood samples were collected, and the seven major susceptibility genes (MAX, SDHB, SDHC, SDHD, TMEM127, VHL, and RET) were tested using Sanger sequencing. Overall, 120/370 (32.4%) patients had pathogenic or likely pathogenic variants, with 81/327 (24.8%) in AS presentation. SDHB was the most frequently mutated gene (57, 15.4%), followed by SDHD (27, 7.3%), and VHL (18, 4.9%). The incidence of metastatic PPGL was high in SDHB carriers (21/57, 36.8%). A few unique recurrent variants (SDHB c.137G>A and SDHB c.470delT) were detected in this Japanese cohort, highlighting ethnic differences. In summary, almost a quarter of patients with apparently sporadic PPGL in Japan harboured germline variants of the targeted genes. This study reinforces the recommendation in Western guidelines to perform genetic testing for PPGL and genotype-based clinical decision-making in the Japanese population.

Optimization of prediction methods for risk assessment of pathogenic germline variants in the Japanese population.

Predicting pathogenic germline variants (PGVs) in breast cancer patients is important for selecting optimal therapeutics and implementing risk reduction strategies. However, PGV risk factors and the performance of prediction methods in the Japanese population remain unclear. We investigated clinicopathological risk factors using the Tyrer-Cuzick (TC) breast cancer risk evaluation tool to predict BRCA PGVs in unselected Japanese breast cancer patients (n = 1,995). Eleven breast cancer susceptibility genes were analyzed using target-capture sequencing in a previous study; the PGV prevalence in BRCA1, BRCA2, and PALB2 was 0.75%, 3.1%, and 0.45%, respectively. Significant associations were found between the presence of BRCA PGVs and early disease onset, number of familial cancer cases (up to third-degree relatives), triple-negative breast cancer patients under the age of 60, and ovarian cancer history (all P < .0001). In total, 816 patients (40.9%) satisfied the National Comprehensive Cancer Network (NCCN) guidelines for recommending multigene testing. The sensitivity and specificity of the NCCN criteria for discriminating PGV carriers from noncarriers were 71.3% and 60.7%, respectively. The TC model showed good discrimination for predicting BRCA PGVs (area under the curve, 0.75; 95% confidence interval, 0.69-0.81). Furthermore, use of the TC model with an optimized cutoff of TC score ≥0.16% in addition to the NCCN guidelines improved the predictive efficiency for high-risk groups (sensitivity, 77.2%; specificity, 54.8%; about 11 genes). Given the influence of ethnic differences on prediction, we consider that further studies are warranted to elucidate the role of environmental and genetic factors for realizing precise prediction.

[Factors Influencing the Decision‒Making Process in Secondary Findings Disclosure in Next‒Generation Sequencing-A Literature Review].

With the increased availability of comprehensive genetic testing, the number of cases where secondary findings(SF)are identified has also increased. Since not only patients, but also healthcare professionals influence the decision‒making process in SF disclosure, understanding their attitude toward disclosure is vital. Therefore, a literature review using PubMed and Japan Medical Abstracts Society was conducted. We searched for original qualitative studies focusing on clinical genome analysis. Consequently, 12 articles that focus on 3 main stakeholders were identified: patients and/or their families, genetics professionals, and the general public. Relevant findings were synthesized and chronologically categorized into 27 subcategories, 11 categories, and 3 main themes, namely(1)"at the time of consent,"(2)"when results are returned,"and(3) "after the return of results."All categories in theme(3)were found in patients. Most subcategories found in the general public were also present in patients. The general public is unique because they considered receiving SF for the first time after participating in the study. The result suggests that people are aware of what might happen after receiving SF at the time of providing consent. This awareness will improve patient attitude toward receiving SF. Therefore, it is important to inform patients about the continuous support at the time of providing consent.

Complex hereditary spastic paraplegia associated with episodic visual loss caused by ACO2 variants.

Most patients with homozygous or compound heterozygous pathogenic ACO2 variants present with muscular hypotonia features, namely, infantile cerebellar-retinal degeneration. Recently, two studies reported rare familial cases of ACO2 variants presenting as complex hereditary spastic paraplegia (HSP) with broad clinical spectra. Here, we report the case of a 20-year-old Japanese woman with complex HSP caused by compound heterozygous ACO2 variants, revealing a new phenotype of episodic visual loss during febrile illness.

[Management of Secondary Findings].

Paradigm shift on the era of next generation sequencing(NGS): NGS completely changed the volume and acquiring speed of the genetic information. Secondary findings obtained by cancer profiling genomic testing should be handled by cooperation of genetic medicine and cancer medicine. Recommendations of the Communication Process on Genomic Medicine was announced for clinical sequencing using Next Generation Sequencer by Japan Agency for Medical Research and Development( AMED)Research Team. Secondary findings to be disclosed are listed up by American College of Medical Genetics and Genomics. Actionability of these 59 genes to be re-accessed on the conditions in Japan.

Attitudes toward and current status of disclosure of secondary findings from next-generation sequencing: a nation-wide survey of clinical genetics professionals in Japan.

The management of secondary findings (SFs), which are beyond the intended purpose of the analysis, from clinical comprehensive genomic analysis using next generation sequencing (NGS) presents challenges. Policy statements regarding their clinical management have been announced in Japan and other countries. In Japan, however, the current status of and attitudes of clinical genetics professionals toward reporting them are unclear. We conducted a questionnaire survey of clinical genetics professionals at two time points (2013 and 2019) to determine the enforcement of the SF management policy in cases of comprehensive genetic analysis of intractable diseases and clinical cancer genome profiling testing. According to the survey findings, 40% and 70% of the respondents stated in the 2013 and 2019 surveys, respectively, that they had an SF policy in the field of intractable diseases, indicating that SF policy awareness in Japan has changed significantly in recent years. Furthermore, a total of 80% of respondents stated that their facility had established a policy for clinical cancer genome profiling testing in the 2019 survey. In both surveys, the policies included the selection criteria for genes to be disclosed and the procedure to return SFs, followed by recommendations and proposals regarding SFs in Japan and other countries. To create a better list of the genes to be disclosed, further examination is needed considering the characteristics of each analysis.

Negative recollections regarding doctor-patient interactions among men receiving a prostate cancer diagnosis: a qualitative study of patient experiences in Japan.

OBJECTIVES: To explore the negative recollections of prostate cancer patients regarding the attitudes and language used by the doctors in delivering their diagnoses in Japan, in order to improve patient-centred communication. DESIGN AND SETTING: This is a qualitative secondary analysis of the prostate cancer narrative data from the Database of Individual Patients' Experiences-Japan archives. A thematic analysis was conducted regarding negative recollections of doctors' words/attitudes when delivering a cancer diagnosis. Recruitment was based on maximum variation sampling. Participants were recruited from medical institutions, patient associations and through media advertisements. PARTICIPANTS: Men with a diagnosis of prostate cancer (n=51). FINDINGS: Of the 51 participants, 17 had negative recollections of the doctors' words/attitudes during the delivery of the cancer diagnosis. After thematic analysis, 11 categories emerged: 'Surprised by the abrupt disclosure of the diagnosis', 'Displeased by the direct disclosure of the diagnosis to the patient in the absence of family members', 'Unable to accept the doctor's negative words in the explanations', 'Unable to understand the doctor's technical jargon', 'Distrust due to failure in diagnosis based on previous examinations', 'Aggrieved at the doctor's unwillingness to allow questions', 'Dissatisfied with explanations involving facts only', 'Indignant over the unexpected disclosure of life expectancy', 'Unable to accept the doctor's blame for the delay in the initial hospital visit', 'Uncomfortable with the usage of inappropriate metaphors' and 'Pessimistic thoughts despite optimistic explanations'. CONCLUSIONS: It is clear that patients have recollections of a variety of negative experiences regarding the words/attitudes of their doctors at the time they received their prostate cancer diagnosis. Thus, the use of narrative data would facilitate the appropriate application of commonly used guidelines for the delivery of cancer diagnoses tailored to individual patients in clinical practice.

Clinical significance of TP53 variants as possible secondary findings in tumor-only next-generation sequencing.

In tumor-only next-generation sequencing (NGS), identified variants have the potential to be secondary findings (SFs), but they require verification through additional germline testing. In the present study, 194 patients with advanced cancer who underwent tumor-only NGS between April 2015 and March 2018 were enrolled, and the incidences of possible and true SFs were evaluated. Among them, 120 patients (61.9%) harbored at least one possible SF. TP53 was the most frequent gene in which 97 variants were found in 91 patients (49.5%). Nine patients provided informed consent to undergo additional germline testing, and a total of 14 variants (BRCA1, n = 1; BRCA2, n = 2; PTEN, n = 2; RB1, n = 1; SMAD4, n = 1; STK11, n = 1; TP53, n = 6) were analyzed. Three variants (BRCA1, n = 1; BRCA2, n = 2) were confirmed to be SFs, whereas TP53 variants were confirmed to be somatic variants. To confirm the low prevalence of SFs in TP53, we analyzed 24 patients with TP53 variants who underwent a paired tumor-normal NGS assay. As expected, all TP53 variants were confirmed to be somatic variants. A total of 30 patients were tested for germline variants in TP53, but none of them resulted in true SFs, suggesting the low prevalence of SFs in this gene. Therefore, the significance of additional germline testing for TP53 variants appears to be relatively low in daily clinical practice using a tumor-only NGS assay, unless patients have any relevant medical or family history.