Holistic Evaluation of Approaches to Long-term Health & Survivorship

This study aims at investigating behaviors of cancer patient regarding complementary and alternative medicine (CAM) with mixed methodology. The investigators want to realize a pilot study evaluating patient's use and attitude with particular focus on natural products (phyto- and aromatherapy). They aim at giving an overview of their actual consumption (and not to promote natural products) in order to (1) prioritize needs regarding integrative care to promote quality of life and survivorship; (2) identify potential short- or medium-term safety issues for patients; and (3) propose adequate pharmaceutical council. Studied period (years): 2026, approximately 9 months * Date of first enrolment: to be determined * Date of last completed: to be determined Objectives: The study has three complementary objectives: Primary objective (quantitative): To descriptively quantify the use of complementary and alternative medicine (CAM) among cancer patients treated at Institut Jules Bordet and to identify patient-reported needs and information sources. Secondary objective (interventional mixed-methods) : To explore patient behaviors, perceptions and expectations regarding CAM use through questionnaires and semi-structured focus groups, including perceptions related to treatment adherence and survivorship experience. In addition, a structured medication review will be conducted for all participants in the focus group phase in order to identify and describe drug-related problems, including potential interactions between conventional treatments and herbal products. Operational objective : To support the prioritization and development of integrative oncology and survivorship programs within the ONCO.CARE and CAIROS projects. Hypotheses: No formal hypothesis testing is planned. This is an exploratory, descriptive study. Study Design (Treatment Schema): Prospective, single-center, two-phase study: * Phase 1: anonymous quantitative study based on a self-administered questionnaire collecting, among other variables, health-related patient-reported data, including information on cancer type, treatments and symptoms * Phase 2: Interventional, non-medicinal mixed-methods phase including descriptive questionnaires (pre- and post-session) and semi-structured focus group discussions. Number of patients (planned and analysed): Phase 1 (quantitative survey) : * Planned: minimum 500 patients; * Analysed: all completed questionnaires. Phase 2 (interventional mixed-methods) : * Planned: 30-60 participants (6-8 focus groups, 5-10 participants per group) ; * Analysed: all participants who attend a focus group session. Endpoints : Primary : * Descriptive quantification of CAM use among cancer patients ; * Identification of unmet needs regarding CAM information and guidance. Secondary : * Descriptive documentation of patient-reported perceptions and experiences related to CAM use and survivorship ; * Descriptive assessment of the perceived usefulness and acceptability of the focus group sessions. * Descriptive analysis of the number and type of drug-related problems identified through medication review (PCNE classification, version 9.1) Exploratory : Identification of areas of interest for future research and institutional initiatives related to CAM and integrative oncology. Diagnosis : All cancer types. Main criteria for inclusion (inclusion/exclusion criteria) Inclusion criteria : * Phase 1 : French-speaking cancer patients entering the Bordet Institute ; * Phase 2 : French-speaking adult cancer survivor patients who have completed active cancer treatment (in remission or undergoing long-term oral therapy). Exclusion criteria : * Phase 1 : Individuals without a cancer diagnosis; participants who have already completed the survey ; * Phase 2 : Patients currently undergoing active cancer treatment. Duration of treatment : Not applicable (no treatment administered) Statistical Considerations: * Quantitative data will be analyzed using descriptive statistics to summarize socio-demographic characteristics, CAM usage patterns and unmet needs. * Pre- and post-focus group questionnaires will be analyzed descriptively and separately, without paired or comparative analyses. * Drug-related problems will be analyzed descriptively according to number and type (PCNE classification, version 9.1). * Qualitative data from focus groups will be analyzed using rapid qualitative analysis methods to identify key themes, facilitators and barriers related to CAM use and integrative care.