Pediatric patients with cancer predisposition in Japan: Results of a questionnaire survey

To the Editor: Approximately 10% of children with cancer have germline pathogenic variants in cancer predisposition genes.1–3 Recent reports have demonstrated that patients with cancer predisposition benefit from a particular treatment and that surveillance according to the risk of developing certain cancers contributes to better survival.4–6 Accordingly, there is an urgent requirement for establishing clinical infrastructure in Japan. To address these issues, the Japanese Pediatric Hereditary Tumor Study Group was formed in 2017. The group investigated the current medical condition of pediatric patients with cancer predisposition because presently no data are available on the number of pediatric patients with cancer predisposition and on the associated diagnosis and management by pediatric oncologists in Japan. A questionnaire was mailed to 107 hospitals accredited by the Japanese Society of Pediatric Hematology/Oncology. The questionnaire comprised close-ended questions regarding (1) the number and age of the patients they followed up in a 1-year period, (2) the diagnosis of the patients, (3) the use of genetic testing, and (4) whether they provide any particular care in addition to routine care for the survivors. Responses were received from 82 (76.6%) hospitals. In total, 937 patients with cancer predisposition underwent follow-up within a 1-year period in 2017. Of them, 451were being treated for or had a history of malignancy and 486 did not; diagnosis was confirmed through genetic testing in 153 (33.9%) of the former and 193 (39.7%) of the latter patients. The remaining patients were diagnosed clinically without genetic testing (Figures 1A and B). Twenty-eight percent of all patients were aged ≥15 years (Figure 1C); of all hospitals, 64% experienced <10 cases per year (Figure 1D). For performing genetic analysis, 63 hospitals used institutional laboratories and 10 outsourced the testing to commercial laboratories. The cost of testing was covered by research funding in 59 hospitals; however, in nine hospitals, the patients paid themselves. During follow-up of cancer survivors, 42 (51%) hospitals offered specific/additional care according to cancer risk. Open-ended questions related to the problems and needs revealed several issues, including “limited availability of genetic testing,” “lack of insurance coverage for surveillance and genetic testing,” “difficulty in transition to adult care,” and “lack of clinicians and genetic counselors with knowledge of this field. ” This survey has several limitations. First, diagnostic criteria are not standardized across physicians and the availability of genetic testing is limited. Therefore, it is possible that we underestimated the number of patients. Second, respondents were pediatric oncologists, and patients followed up by other specialists may not have been included. Importantly, however, our survey showed that in Japan, nearly 1000 children, adolescents, and young adults with cancer predisposition undergo follow-up. Most genetic testing was conducted in research settingswith support from research funds. Surveillance strategies vary across institutions maybe because of the lack of insurance coverage for testing and the lack of a standard protocol of cancer surveillance in Japan. Furthermore, our results suggest that most patients and families are followed up by physicians with limited experience. Therefore, in addition to appropriate clinical care, promotion and standardization of genetic testing areneeded toprovidepatients andpractitionerswith adequate information that comprises the pros and cons of this testing.