Real Life Dates of Chronic Lymphocytic Leukemia (CLL) in Germany. Interim Analysis of 234 Consecutively New Diagnosed Patients in a German Epidemiological-Clinical Register

Background:

Therapy studies yield important insights into clinical features and therapeutic options of CLL. However studies in Germany represent less then 20% of all CLL patients (pts); pts >75 years (yrs) are included in 3% only. Furthermore initial phases are not reflected in multicenter studies and data representing real life situation are scarce.

Methods:

Out of 1.443 patients consulting our center because of leucocytosis (>10 Gpt/l) between 2003/07/01 and 2018/06/30 we diagnosed CLL consecutively in 234 pts (16,2%): 143 male (m), 91 female (f). Median age at diagnosis is 71,4 yrs. Median leucocyte count is 18,0 Gpt/l. BINET - Stages are: A in 82%, B in 11% and C in 7% of pts. Diagnoses are strictly based on WHO definition: Pts with small lymphocytic lymphomas (sLL, n=11) are included but those with monoclonal lymphocytosis of unknown significance (MLUS) or monoclonal B - lymphocytoses with uncertainly flow cytometry (FC) results are excluded. Histopathology, FC and genetics have been performed by external hematological reference laboratories. All investigations followed the rules of best clinical and laboratory practice. Dates of death are given by the record sections of the involved communities (deadline 2018/06/30).

To address different questions we defined 3 groups of pts: A: "collective group", (n=234), i.e. all pts.diagnosed from 2003/07/01 to 2018/06/30. B: "epidemiological group" (n=129), i.e. pts from 3 communities (113.000 inhabitants - inc - in 2009/12/31) in close proximity referred to our center. C: "genetic features group" (n=99), i.e. pts diagnosed continuously between 2012/07/01 and 2018/06/30 with systematically performed genetics, (i.e. at least 80% of pts in this group. Genetics are: Cytogenetic (banding) n=88; FISH (del 6q21/6q, del 11q22.3, +12/+12q, del 13q14/ 13q34, del 17p13.1, 14q32) n=85. PCR (IgVH status - mutated vs. unmutated; TP53, NOTCH1, SF3B1 mutation) n=82.

Results:

"Collective group" (A): 7,5 years OS is 72% and 15 years OS is 33% respectively (KAPLAN-MEIER). Age of pts acts as a predominant factor for long term OS: 77% in pts < 60 yrs vs. 40% in pts ≥60 to <75 yrs vs. 16% in pts ≥75 yrs. 15 yrs OS of treated pts is 32% (n=78, median age at diagnosis: 73,3 yrs, m : f = 1,50); 15 yrs OS of untreated patients is 33% (n=146, median age at diagnosis: 71,0 yrs, m : f = 1,56). Mean time to 1st treatment was 16,0 month (0,1 to 132,6 months).

"Epidemiological group" (B): Raw incidence is 7,56/10⁵ inh. (m: 9,13, f: 6,06), age adjusted incidence is 10,3/10⁵ inh (m: 12,5, f: 8,3), with highest rate of age between 75 to < 80 yrs. Standard incidence is calculated as 6,27/10⁵ (BRD 1987), 4,78/10⁵ (Europe) and 5,06/10⁵ (USA 2000). Prevalence could be measured directly (2017-12-31): 79,1/10⁵ inh.

"Genetic features group" (C): IgVH mutation status is hypermutated in 48 pts. vs. unmutated in 39 pts. Results of FISH analyses (n = 85) are: del 6: 5,5%, del 11: 17,6%, +12: 3%, del 13q: 70,3%, del 17p: 8,8%; normal status: 13,2%. PCR revealed mutations of NOTCH1 in 7%, of SF3B1 in 10,5% and of TP53 in 8,6% of 82 pts, respectively. Combined del17p by FISH and molecular TP53 mutations at diagnosis are found in 3 of 81 pts (3,7%).

Cytogenetic findings different to results of FISH and/or PCR were found in 36 of 82 pts (43,9%).

Calculated 5 yrs freedom of therapy is 75% in IgVH hypermutated pts vs. 45% in unmutated pts (p = 0,0005; log rank test); calculated 5 yrs OS is 92% vs. 59% (p=0,023).

Special situations in CLL: 13 of 234 pts (5,5%) have one parent or sibling with low grade NHL, mostly CLL. In contrast there is non spouse suffering of CLL / low grade NHL. Deficiency in Immunoglobuline G (Ig G < 4,0 g/l) was found in 17 of 199 pts at diagnose (8,5%), 29 pts (12,4%) were substituted with Ig G's in the Course of CLL. In 14 (6,0%) pts. we diagnosed a 2nd hematologic malignancy (3x cMPN, 1x CML, 3x MDS, 3x AML, 1x FL, 1x MCL, 1x MZL, 1x DLCBL-independent of CLL; monoclonal gammopathies are not considered). RICHTER syndrome was found in 1 case, but progression to plasmocytic/plasmoblastic disease was seen in 3 cases. Li FRAUMENI Syndrome was revealed in 1 male patient, he has been in stable disease for 13 yrs.

Conclusion:

CLL seems to be more frequent than yet considered. IgVH mutation status seems to be very important as a single prognostic factor concerning time of 1st therapy as well as OS. Clinical features of CLL are very different and impressing.