The Effect of a Combined Lifestyle Intervention for Patients With Cancer on Quality of Life

Inclusion Criteria:

* Be diagnosed with an invasive or hematological cancer type and either within five years post-primary treatment with curative intent OR having advanced cancer (stage IV) with a prolonged life expectancy (chronic cancer patients) . Primary treatment in this context, includes among others surgery (\> 3 months ago), radiotherapy, and/or chemotherapy or a stem cell transplant in case of hematological cancers.
* Report a reduced HRQoL, i.e., a low score on at least 2 of the functioning scales and/or the symptom scale fatigue of the EORTC-QLQ-30 based on the thresholds of clinical importance of Giesinger et al. (2020)
* Be 40 years of age or older. The investigators have chosen this cut-off because they believe that younger cancer patients (AYA's) face different challenges and should not be mixed with the average older patient. This approach ensures greater homogeneity within the study population.
* Be able to speak and understand Dutch

Exclusion Criteria:

* Following, or planned to follow a combined lifestyle intervention (i.e., one of the existing interventions for overweight) during the intervention period
* Patients in the terminal phase (life expectancy \< 3 months)
* Mental or behavioural problems that hinder participating in group lifestyle coaching indicated by the health care professional who is referring to GLINK or by the study team
* Any circumstances that would impede ability to give informed consent or adherence to study requirements as determined by the study team or treating physician