The Five "Ws" of Frailty Assessment and Chronic Lymphocytic Leukemia: Who, What, Where, Why, and When

Simple Summary Recent advances in treating elderly patients with chronic lymphocytic leukemia (CLL) have emphasized the importance of geriatric assessment (GA) to evaluate patient fitness and predict treatment outcomes. Targeted therapies (BTK inhibitors and venetoclax) have demonstrated significant clinical benefits and are now a reality in CLL treatment. They have a different toxicity profile that may affect frailty. Therefore, incorporating GA before treatment initiation, considering physical and cognitive function, emotional health, comorbidity, polypharmacy, nutrition, and social support, is essential.Abstract Chronic lymphocytic leukemia (CLL) is a disease of the elderly, but chronological age does not accurately discriminate frailty status at the inter-individual level. Frailty describes a person's overall resilience. Since CLL is a stressful situation, it is relevant to assess the patient & PRIME;s degree of frailty, especially before starting antineoplastic treatment. We are in the era of targeted therapies, which have helped to control the disease more effectively and avoid the toxicity of chemo (immuno) therapy. However, these drugs are not free of side effects and other aspects arise that should not be neglected, such as interactions, previous comorbidities, or adherence to treatment, since most of these medications are taken continuously. The challenge we face is to balance the risk of toxicity and efficacy in a personalized way and without forgetting that the most frequent cause of death in CLL is related to the disease. For this purpose, comprehensive geriatric assessment (GA) provides us with the opportunity to evaluate multiple domains that may affect tolerance to treatment and that could be improved with appropriate interventions. In this review, we will analyze the state of the art of GA in CLL through the five Ws.