Australians with chronic lymphocytic leukaemia continue to have high rates of second primary malignancies in the modern era.

Population‐based studies have demonstrated a high risk of second cancers, especially of the skin, among patients with chronic lymphocytic leukaemia (CLL). We describe age‐standardised incidence ratios (SIRs) of second primary malignancies (SPM) in Australian patients with relapsed/refractory CLL treated with at least two lines of therapy, including ibrutinib. From December 2014 to November 2017, 156 patients were identified from 13 sites enrolled in the Australasian Lymphoma and Related Diseases Registry, and 111 had follow‐up data on rates of SPM. At 38.4 months from ibrutinib therapy commencement, 25% experienced any SPM. SIR for melanoma and all cancers (excluding nonmelanomatous skin cancers) were 15.8 (95% confidence interval (CI): 7.0–35.3) and 4.6 (95% CI: 3.1–6.9) respectively. These data highlight the importance of primary preventive interventions and surveillance, particularly as survival from CLL continues to improve. [ABSTRACT FROM AUTHOR]