Improved Survival in Recent Years of Chronic Myeloid Leukemia (CML) Observed in the Real World in a Cohort of Patients Cared in a Haematological Regional Network HEMATOLIM.

In recent area, management of CML has benefited from important changes with the development of targeted therapies and monitoring therapeutic response. Respect of good practices in rural countries, geographically isolated as the Limousin, requires patient's (pts) care in an health network like HEMATOLIM that includes 13 private or public health care facilities. The outcome of all new pts suffering CML, treated or not according a clinical trial and included in a regional database was analysed for estimate the impact of these new practices in real world.

we conducted a retrospective observational, descriptive and analytical study of epidemiological data of consecutive pts with CML and in care into the regional network HEMATOLIM. Included criteria were cytogenetic or molecular proved CML, in regional pluridisciplinary staff and cytogenetic results and molecular response. Clinical data, biological data, therapeutic response, survival were collected in the database and statistically analysed by StatView.

176 pts diagnosed between 1978 and 2009, resident in Limousin for 75% (n=132), in limit departments 25% (n=44), sex ratio 1.2 and median age 59 years [22-84]. Between 2001 and 2007, regional incidence is 1.084/100000 pop per year versus 1 in France. At diagnosis, pts were in chronic phase 92% (n=162), accelerated phase 5.7% (n=10), blast crisis 0.6% (n=1), missing (ND) 1.7% for n=3 pts. Sokal was <0.8 for 61% (n=108), 0.8-1.2 24% (n=42), >1.2 11% (n=19), ND 4% (n=7). Cytogenetic t(9,22) or BCR-ABL expressing in initial molecular biology was 100% with another cytogenetic abnormality in 8%. Treatment was done by inclusion in a clinical trial (n=36) for 20% of pts. Treatment was Imatinib (IMB) for 72% (127/176) of pts with CML: 54% (n=68) in 1st line, 20% (n=26) 2nd line and 26% (n=33) 3rd line or more. RCC at 6, 12 and 24 months were respectively 57% (75 pts evaluable), 66% (71), 83% (58). RMC at 6, 12 and 24 months were respectively 14% (59), 23% (66), 37% (73). During treatment, 12% pts had resistance to IMB (n=15): 2 of them had a mutation of resistance to the IMB (2/15). Toxicity to IMB was observed in 12% (n=15). Pts have developed another malignancy during or after tyrosine kinase inhibitor (TKI) treatment for 9.5% (n=12) localized to prostate 3, colon 2, breast 1, pancreas 1, lung 1, parotid 1, melanoma 1, kidney 1 and bladder 1. Median survival of pts receiving TKI in 1^st line is not reached, receiving TKI in 2^nd line or more: 18 years and for pts never receiving TKI (1978-) 4 years (p<0.0001).

In real life, impact of TKI and monitoring of molecular response on the survival of pts with CML is strongly illustrated by this retrospective cohort network study. The better survival since the XXI century included elderly patients CML, having already received several lines of treatment and often excluded of clinical research due to comorbidity. A long term follow-up of these cohorts of pts will be interesting in term of incidence of ITK resistance, emergence of second malignancies and medico-economic impacts.

No relevant conflicts of interest to declare.