As for today, transcatheter aortic valve implantation (TAVI) is indicated only in symptomatic patients with severe aortic stenosis (AS) at high surgical risk. As cancer therapy improves, some AS patients suffering active malignancy (including advanced metastatic diseases) may be more endangered by their untreated valvular disease than their oncological disease. Among these patients, TAVI may be indicated before cancer related surgery or cardiotoxic anti-cancer therapy in order to achieve better anti-cancer therapy outcomes. Individualized life expectancy assumptions should be evaluated by the heart team in the clinical decision-making process as an essential factor in weighing the risk-benefit ratio for oncologic patients undergoing TAVI. A multicenter, international TAVI in Oncology Patients with AS (TOP-AS) registry was designed to collect data on patients with an active malignancy and severe AS undergoing TAVI. The aim of the study is to evaluate the outcomes, benefits and risks of oncology patients undergoing TAVI, mainly the patients' survival and cause of death and also the interactions between the valvular and the oncologic conditions.