Taste and Smell Dysfunction in Patients More Than Two Years After Start of Immune Checkpoint Inhibitor Therapy

In this cross-sectional study, patients with melanoma, NSCLC or urogenital cancer ≥ 2 years following ICI therapy and their caregivers will be included. The investigators will include patients who have previously participated in the study "Quality of life, cognitive function, and physical fitness of patients surviving more than 2 years after immune checkpoint inhibitor therapy" and additional patients who are under control at the departments of Medical Oncology and Pulmonary Disease and did not participate in this previous study. A patient cohort of patients and caregivers has already been built and patients who have given permission to be approached for future research again will be invited for our study. Patients can be approached in two ways: 1) Patients will be asked during an outpatient clinic appointment by their clinical doctor if they can be approached afterwards by the investigator. When permission is given, the investigator will explain the study design and give the patient and the caregiver both a letter. These letters explains the study design and includes an informed consent form, 2) Patients who do not have an outpatient clinic appointment in the near future will be sent the letter with the study design and the informed consent form. In this letter, each participant will be asked to invite their caregiver to participate in this study. For this, a separate letter directed at the caregiver will be sent to the participant. Patients and caregivers are asked to contact the investigator team if they are willing to participate. If the patient consents, a single appointment will be made during a regular follow-up visit to the outpatient clinic. If the caregiver consents too, an appointment will be made with both participants at the same time, if possible. Patients can participate alone if the caregiver is not willing to participate, and vice versa. During this visit, if patients and caregivers have no questions regarding the study or the study information that was sent, they are first asked to sign the informed consent. Next, saliva will be collected, and taste, smell and dry mouth will be subjectively and objectively be measured. Afterwards, characteristics will be taken from the patients' electronic file, including age, gender, medical history and medication use. As the caregivers do not have a medical file, they are asked for these characteristics.