Red blood cell utilization and transfusion triggers in patients diagnosed with chronic lymphocytic leukaemia in Iceland 2003-2016.

BACKGROUND AND OBJECTIVES: Revised Icelandic guidelines proposed a restrictive haemoglobin (Hb) threshold of 70 g/l for red blood cell (RBC) transfusions in general, but 100 g/l for malignancies/bone marrow suppression. Chronic lymphocytic leukaemia (CLL) is frequently complicated by anaemia. The objective was to investigate RBC transfusion practices in CLL. MATERIALS AND METHODS: This retrospective nation-wide study utilized an Icelandic registry of CLL patients diagnosed between 2003 and 2016. Medical records were reviewed and haemoglobin transfusion triggers compared for two periods: Earlier (2003-2012) and latter (2013-2017). RESULTS: Two hundred and thirteen patients were diagnosed with CLL over the period whereof 77 (36·2%) received RBC transfusion(s). Median time from diagnosis to first transfusion was 2·2 years. Higher age, Rai stage 3/4 at diagnosis (P < 0·05) and chemotherapy (P < 0·001) were associated with increased odds of transfusions. Shorter time to first transfusion correlated with higher age (P < 0·001) and Rai stage (P = 0·02) at diagnosis. The mean Hb trigger was 90·4 and 81·2 in the earlier and latter period respectively (P = 0·01). This difference in Hb triggers was most pronounced in patients without documented bone marrow involvement, or 80·5 g/l compared to 93·5 g/l (P = 0·004). The median time from diagnosis to transfusion was longer in the latter period (2·9 years vs. 1·6 years, P = 0·01). After RBC transfusions the survival decreased significantly (P < 0·001). CONCLUSION: One-third of CLL patients received RBC transfusions but few were heavily transfused. Older age, Rai stage, and chemotherapy predicted RBC use. The Hb transfusion trigger decreased over time while time to first RBC transfusion increased. RBC transfusions predict poor survival.

[Chronic lymphocytic leukemia in Iceland from 2003 to 2013: Incidence, presentation and diagnosis].

INTRODUCTION: Chronic lymphocytic leukemia (CLL) is characterized by the proliferation of monoclonal B-lymphocytes. MBL (monoclonal B-cell lymphocytosis) is considered a precursor state of the disease. Although CLL is incurable it is an indolent disorder and often detected incidentally on routine blood counts. Until now little information has been available on CLL in Iceland, including the incidence, diagnosis, symptoms or MBL precursor state. MATERIAL AND METHODS: This is a retrospective, descriptive study including CLL patients diagnosed in Iceland over the years 2003-2013. Registries of patients with a CLL diagnosis were obtained from the Icelandic Cancer Registry, Landspitali National University Hospital and the Medical Center in Mjódd. Medical records were reviewed for information on symptoms, diagnosis and treatment. Survival data and causes of death were obtained from national registries. RESULTS: The number of patients diagnosed with CLL over the study period was 161 (109 males, 52 females). The calculated incidence was 4.55/100,000, and the age-standardized incidence was 3.00/100,000. Mean age at diagnosis was 70.9 years (range 35-96 years). The Icelandic Cancer Registry lacked information on 28 patients (17.4%). The initial diagnosis of CLL was obtained exclusively with flow cytometry in 47.2% of cases. Symptoms were present at diagnosis in 67 of 151 patients (44.4%). One third of the group received chemotherapy and the average time to treatment was 1.3 years. Five-year survival was 70% and median survival was 9.4 years. Elevated lymphocyte counts (≥4,0x109/L) in peripheral blood prior (0.1 to 13.4 years) to diagnosis of CLL was identified in 85 of 99 CLL patients (85.9%). CONCLUSION: The incidence of CLL in Iceland is similar to other Western countries. The registration of CLL cases in the Icelandic Cancer Registry must be improved, especially in cases where diagnosis is based solely on flow cytometry. Elevated lymphocyte counts were present in a large proportion of cases prior to the diagnosis of CLL. KEY WORDS: Chronic lymphocytic leukemia, CLL, monoclonal B-cell lymphocytosis, MBL, incidence, diagnosis. Correspondence: Anna Margret Halldorsdottir, annamha@landspitali.is.