Knowledge, attitudes and practices of cancer genetics in family medicine in Japan: a mixed methods study

Primary care physicians face multiple challenges in integrating clinical cancer genetics into routine care. Most studies of genomic medicine come from countries with well-developed primary healthcare systems, while research on the integration of clinical genetics in primary care remains limited in Japan and Asia. In Japan, where family medicine is still emerging as a specialty, no prior studies have examined Japanese family physicians' engagement with clinical cancer genetics, including genetic counseling and referral. This study investigates Japanese family physicians' knowledge, attitudes and practices regarding hereditary cancer syndromes.

This is mixed methods research employing an explanatory sequential design with survey data collection followed by qualitative interviews. First, a quantitative survey assessed Japanese family physicians' knowledge, attitudes, and practices regarding genetic counseling and referrals for hereditary cancer syndromes. We then explored their practices and perspectives in relation to the quantitative findings through semi-structured individual interviews with a subset of the family physicians. Finally, we integrated both findings in a joint display table and generated conclusions or metainferences.

A total of 149 family physicians completed a survey (response rate: 26.7%), with 11 who did not have experience in genetic counseling or referrals participating in follow-up qualitative interviews. Survey responses found that only 6% of respondents provided genetic counseling, and 5% referred patients to genetic professionals. Most family physicians (64-73%) demonstrated limited knowledge of hereditary cancer syndrome, leading to difficulty interpreting family history and assessing cancer risk in clinical practice. While many family physicians (71-94%) conceptually acknowledged the benefits of clinical genetics in the survey, interviews highlighted concerns about the potential harm of genetic testing. Interviews helped explain the reasons for low engagement rates. Family physicians were uncertain about the clinical utility of genetic interventions and about the psychological impact discussing cancer genetics might have on patients. Further, the term "heredity" carries negative connotations, which made family physicians hesitant to initiate such conversations.

Japanese family physicians encounter challenges in applying clinical cancer genetics. Further research is needed to explore effective approaches that support family physicians in addressing these challenges while enhancing their role in clinical cancer genetics.