Incidence and impact of other malignancies after immunochemotherapy by fludarabine, cyclophosphamide, and rituximab as frontline treatment for chronic lymphocytic leukemia: A single-center retrospective study

Individuals with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) have a high risk of developing other malignancies (OMs). The development of OMs may be associated with the advanced age of CLL/SLL patients, presence of a tumor-promoting microenvironment, immune alterations inherent to CLL/SLL, or chemotherapy. Importantly, the occurrence of OMs following frontline fludarabine, cyclophosphamide and rituximab (FCR) treatment is associated with a reduction in the overall survival (OS). This retrospective study included 108 CLL/SLL patients treated with FCR immunochemotherapy, as a first line treatment. With a median follow-up of 94.9 (6-222) months, 31% developed an OM or more, within a median of 61.8 months post-FCR initiation. The most common OMs were non-melanoma skin cancers (7%), Richter's syndrome (RS) (7%), myelodysplastic syndromes (6%), prostate cancer (4%), and acute myeloid leukemia (3%). Patients with OMs had shorter survival compared to those without (104.0 versus 149.0 months, P=0.02), with RS having the worst OS at 4.8 months (P<0.0001), followed by therapy-related myeloid neoplasia (t-MN) at 14.5 months. Although the onset of OMs in patients with CLL/SLL was observed after considerable delays, its impact on survival is significant in the immunochemotherapy era, necessitating a better understanding of these patterns to improve CLL/SLL management and guide future treatment strategies.