How Many Attended the Oncogenetic Consultation, When, and Who?: A Population-Based Study Among Relatives of French Patients With Cancer

Background: In France, individuals newly diagnosed with genetic cancer (probands) inform their relatives (related cases) about the risk of cancer transmission. Participation rates, delays in attending oncogenetic consultations and characteristics of the related cases remain undocumented. Objective: This study aimed to (1) assess the proportion of related cases who attend oncogenetic consultation, (2) estimate the delay until related cases attend oncogenetic consultation, and (3) identify factors associated with the use of oncogenetic consultation among related cases. Methods: Data from 98 probands with hereditary cancer and their 263 related cases were collected from oncogenetic consultations at the University Cancer Institute of Toulouse between 2017 and 2020. Related cases were followed until February 2022. Attendance rates were analyzed using descriptive statistics, while logistic regression and mixed-effects models identified influencing factors. Results: A total of 59% of related cases attended oncogenetic consultation. Among those expected to attend, 50% did so within 374 days, with early attenders presenting within 78 days. After accounting for the family effect, a higher attendance rate was observed among women (odds ratio [OR] men = 0.49 [0.24–0.99]), those with a frequent relationship with their proband (OR <once year = 0.21 [0.07–0.61]; OR none = 0.11 [0.02–0.58]) and among those whose proband was younger (OR [40–50 years] = 0.15 [0.02–1.12]; OR [50–65 years] = 0.08 [0.01–0.53]; OR >65 years = 0.06 [0.01–0.43]). Conclusions: Improving access to oncogenetic consultation and the dissemination of genetic risk information remains a critical challenge. Implications for Practice: In-depth qualitative research is essential to support the development of research aimed at improving health literacy and collaboration between patients and healthcare providers in the context of hereditary cancers.