Chronic myeloid leukemia incidence, survival and accessibility of tyrosine kinase inhibitors: a report from population-based Lithuanian haematological disease registry 2000-2013.

BACKGROUND: Currently available chronic myeloid leukaemia (CML) survival reports have originated from more affluent countries. Herein we report the entire country data on incidence and survival of CML, as well as penetrance of tyrosine kinase inhibitors (TKIs) in Lithuania. METHODS: We analyzed all patients (N = 601) from the national haematological disease monitoring system who were diagnosed with CML between 2000 and 2013. Crude (CR) and age-standardized (weighted) (ASW(R)) incidence and mortality rates, as well as 1-, 5-, and 10-year relative survival rates (RSR) were calculated. Information on TKI penetration is also reported. RESULTS: Throughout the entire 2000-2013 period the median age at diagnosis of CML patients was 62 years. The respective incidence and mortality CRs were 1.28 and 0.78, both characterized by decreasing trends over the observation period. A 5-year RSR increased from 0.33 [95 % CI, 0.27-0.40] in 2000-2004 to 0.55 [95 % CI, 0.47-0.63] in 2005-2009. However, the respective 5-year RSRs for patients aged 65-74 and ≥75 were only 0.33 [95 % CI, 0.24-0.42] and 0.18 [95 % CI 0.07-0.23] during the entire study period. TKI penetrance for CML patients grew from 1.5 % in 2000-2004 to 30.6 % in 2005-2009 and 69.1 % in 2010-2013. TKI penetrance was low in the older age groups (60 % for the 65-74 and 19 % for the ≥75 patient group, in 2010-2013). CONCLUSION: Relative CML survival in Lithuania steadily improved and paralleled the increase in TKI treatment availability. Patients above 64 years rarely received TKIs and their relative survival remained low throughout the observation period. The latency of TKI availability may have influenced the survival trends.

Unique composite hematolymphoid tumor consisting of a pro-T lymphoblastic lymphoma and an indeterminate dendritic cell tumor: evidence for divergent common progenitor cell differentiation.

Until recently, hematopoietic neoplasms were considered monoclonal proliferations belonging to one cell lineage. In the last years, evidence for transdifferentiation from one cell lineage to another or divergent common progenitor cell differentiation has accumulated, mainly based on composite hematolymphoid tumors, sharing common genetic abnormalities. We report the case of a 59-year-old woman with a composite pro-T lymphoblastic lymphoma (LBL) and indeterminate dendritic cell tumor infiltrating the lymph nodes, bone marrow and stomach. Genetic analyses revealed that both cell populations bore +21, while a G13D mutation of the NRAS gene and monosomy 18 were detected only in the pro-T LBL. The synchronous appearance of two distinct uncommon hematolymphoid tumors in the same patient, recurrent at three different anatomic locations, with an identifiable common genetic denominator, namely +21, but also with unique genetic anomalies in the pro-T LBL raises the hypothesis of a divergent common progenitor cell differentiation.