Non-chronic Lymphocytic Leukemia Research Articles

Targeted next‐generation sequencing reveals molecular heterogeneity in non‐chronic lymphocytic leukemia clonal B‐cell lymphocytosis

Non-chronic lymphocytic leukemia (non-CLL) clonal B-cell lymphocytosis (CBL) encompasses a heterogeneous group of hematologic disorders that are still poorly understood. To shed light on their biological aspects, we retrospectively analyzed a highly selected series of 28 patients, who had a clonal B-cell population in the peripheral blood and in the bone marrow, without evidence of lymphoma. Extended targeted next-generation sequencing revealed wide molecular heterogeneity with MYD88 (14%), PDE4DIP (14%), BIRC3 (11%), CCND3 (11%), NOTCH1 (11%), and TNFAIP3 (11%) as the most mutated genes. Mutations of MYD88 were "nonclassic" in most cases. Although some genetic lesions were overlapping with indolent lymphomas, mainly splenic B-cell lymphomas of marginal zone origin and splenic diffuse red pulp small B-cell lymphoma, the genetic profile of our non-CLL CBL series seemed to suggest that various pathways could be involved in the pathogenesis of these disorders, not mirroring any specific lymphoma entity. These data better enlighten the molecular characteristics of non-CLL CBL; however, more efforts are needed in order to improve the diagnostic process, prognostication, and clinical management.

Targeted Next Generation Sequencing Reveals Molecular Heterogeneity in Non-CLL Clonal B-Cell Lymphocytosis

Background. Non-chronic lymphocytic leukemia (non-CLL) clonal B-cell lymphocytosis (CBL) encompasses a heterogeneous group of hematologic disorders that are still poorly understood. The main purpose of this study was to explore the genomic landscape of non-CLL CBL, correlating the results with clinical, histological and immunogenetic features. Methods. We retrospectively analysed the disease characteristics in a highly selected series of 28 patients, who had a clonal lymphocytosis in peripheral blood (PB) and clonal lymphoid populations in the bone marrow (BM), without evidence of lymphadenopathy, splenomegaly, peripheral cytopenia or constitutional symptoms.In all patients the BM evaluation, comprising flow cytometry, histology and immunohistochemistry, was not able to classify the lymphoproliferative disorder in any of the WHO-defined entities. A diagnosis of CLL or a leukemic phase of mantle cell or follicular lymphoma was ruled out in each subject. Targeted next generation sequencing (NGS) was performed on DNA extracted from CD19+ BM or PB cells using a core panel of 138 genes frequently reported in mature B cell neoplasms.On the basis of the information retrieved from the KEGG and REACTOME databases, each mutated gene was assigned to a specific lymphoma-enriched pathway. Results: Clinical, flow cytometric and histological data are presented in Table 1.The median BM infiltration was 30% (range: 5-80%); the pattern of infiltration was interstitial or mixed (nodular and interstitial) in the majority of the cases; sinusoidal localization was noticed in 54% of cases. There was a borderline correlation between the extent of BM infiltration and the absolute number of PB clonal B cells count (Spearman's Rho: 0.38, p=0.05), that ranged from 851/mmc to 14508/mmc (median: 3604/mmc). With a median follow-up of 35.2 months (range: 6-125), only 1 patient developed disease progression to a B-cell lymphoma not otherwise specified (5-yrs CI of progression: 11.9%; 95%CI: 0.6%-40.7%). The sequence analysis of 138 genes revealed a total number of 74 somatic mutations in 51 genes. All the 28 cases displayed at least 1 mutation, with the number of mutations ranging from 1 to 7 (median 2). The most frequently mutated genes were MYD88 (14%), PDE4DIP (14%), BIRC3 (11%), CCND3 (11%), NOTCH1 (11%) and TNFAIP3 (11%) (fig.1).Notably, 3 out of 4 MYD88 variants were different from the classical p.L265P (p.M232T, p.V217F and p.L204F not previously described). Data on IGHV were available for 22 patients (79%) (Fig.2): VH gene repertoire was similar to that reported in non-CLL malignancies and no distinct stereotyped subset was found. Truly unmutated IGHV genes with 100% of germline identity were present in 3 cases (11%). The analysis of disease features according to mutated genes showed that MCwas more frequent in patients harbouring mutations in MYD88 (p=0.08) or TNFAIP3 (p=0.02); these patients had also a higher number of mast cells on BM histology than the wild type ones (p=0.02 and p=0.05, respectively). NOTCH1 mutated patients showed an absolute number of B-cell peripheral clonal lymphocytes higher than wild type cases (p=0.037). The most frequently involved pathways were NF-kB signalling (32%) and cell communication pathways (32%), followed by cell cycle (29%), chromatin organization (25%), transcriptional misregulation (21%), Toll-like receptor (TLR) signalling (18%) and NOTCH signalling pathways (14%) (Fig. 3).Patients with mutated chromatin organization pathway more often showed normal LDH levels compared with wild type cases (100% vs 40% p=0.01). Conclusions. We characterised non-CLL CBL, integrating BM histological features and IGHV data with an extended NGS panel. The mutational landscape was extremely heterogeneous, pointing out a wide spectrum of somatic mutations. Most of them have been already described in Waldenström's Macroglobulinemia and splenic B-cell lymphomas; of note, we found a new variant of MYD88 associated with an IgM MC and recurrent mutations of PDE4DIP, which have not been previously reported in indolent B-cell malignancies. Disclosures Varettoni: Janssen: Consultancy; Roche: Consultancy; ABBVIE: Other: travel expenses; Gilead: Other: travel expenses. Arcaini:Bayer, Celgene, Gilead Sciences, Roche, Sandoz, Janssen-Cilag, VERASTEM: Consultancy; Celgene: Speakers Bureau; Celgene, Roche, Janssen-Cilag, Gilead: Other: Travel expenses; Gilead Sciences: Research Funding.

Abstract 3256: The prevalence of non-chronic lymphocytic leukemia (CLL) phenotype monoclonal B-cell lymphocytosis (MBL) in a population-based cohort of U.S. adults

Abstract Introduction: CLL phenotype (CD5+CD23+CD20dim) MBL is present in 5-10% of the general population. The prevalence and outcomes of adults with non-CLL like MBL (including CD5+CD23-, CD5+CD20bright, and CD5-) are not known. We screened for MBL using highly sensitive flow-cytometry in a clinic-based cohort of adults from the Mayo Clinic Biobank. Methods: The Mayo Clinic Biobank is a large scale bio-repository of 50,000 adults seen in primary care-based clinics. Herein, we focused on those adults ≥40 years who had stored peripheral blood mononuclear cells available (10% of the overall cohort). We screened for MBL using an 8 color (CD38, CD45, Kappa, Lambda, CD19, CD23, CD5 and CD20) flow cytometry assay validated to detect clonal B-cell events to the 0.005% level (1/20,000 events). Chi-square tests were used to assess associations with demographic characteristics. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for death. Results: A total of 2594 adults were screened; their median age was 63 years (range, 40-96) and 1111 (43%) were male. 2445/2594 (94%) individuals had interpretable flow cytometry results. A total of 336 (14%) individuals had MBL identified, of whom 276 (82%) had CLL-like MBL and 60 (18%) had non-CLL like MBL (including 39 adults with CD5- and 21 with CD5+CD23- or CD5+CD20 bright phenotype). A strong association between age and the prevalence of non-CLL like MBL was observed, with 0/278 (0%) in 40-49 years, 6/613 (1%) in 50-59 years, 20/674 (3%) in 60-69 years, 21/490 (4%) in 70-79 years, and 13/114 (11%) ≥80 years demonstrating non-CLL like MBL (p<0.001). Non-CLL like MBL was more common in men compared to women (5% vs. 1%; p<0.001). Compared to adults with no MBL, a higher proportion of non-CLL like MBL had a first-degree relative with a lymphoproliferative disorder (8% vs. 17%; p=0.03), and prior non-hematologic cancer (22% vs. 38%, p=0.006). The remainder of the present analysis is focused on adults with non-CLL like MBL (n=60). After a median follow-up of 5 years (range 0-8 years), 3/60 (5%) adults with non-CLL like MBL developed a hematologic malignancy (one myelodysplastic syndrome, two mantle cell lymphoma) compared to 5/2109 (0.2%) adults with no MBL (two large cell lymphoma, one multiple myeloma, one acute myeloid leukemia, one myelofibrosis). Among adults with non-CLL like MBL, the estimated 7-year overall survival (OS) was 79% compared to 94% in those with no MBL (p<0.001, HR for death 3.8, 95% CI 1.98-7.3). After adjusting for age, sex, and self-reported prior non-hematologic cancer, the HR for death was 1.50 (95% CI 0.74-3.05, p=0.26). Conclusion: In this large study, ~1 of 40 adults seen in a primary care setting had non-CLL like MBL. The prevalence of the non-CLL phenotype MBL increased with age. With current follow-up, the risk of progression to an overt lymphoproliferative neoplasm appears to be low. Citation Format: Sameer A. Parikh, Sara J. Achenbach, Kari G. Chaffee, Neil E. Kay, Connie E. Lesnick, James R. Cerhan, Curtis A. Hanson, Tait D. Shanafelt, Susan L. Slager. The prevalence of non-chronic lymphocytic leukemia (CLL) phenotype monoclonal B-cell lymphocytosis (MBL) in a population-based cohort of U.S. adults [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3256.

Mortality among a cohort of U.S. commercial airline cockpit crew.

We evaluated mortality among 5,964 former U.S. commercial cockpit crew (pilots and flight engineers). The outcomes of a priori interest were non-chronic lymphocytic leukemia, central nervous system (CNS) cancer (including brain), and malignant melanoma. Vital status was ascertained through 2008. Life table and Cox regression analyses were conducted. Cumulative exposure to cosmic radiation was estimated from work history data. Compared to the U.S. general population, mortality from all causes, all cancer, and cardiovascular diseases was decreased, but mortality from aircraft accidents was highly elevated. Mortality was elevated for malignant melanoma but not for non-chronic lymphocytic leukemia. CNS cancer mortality increased with an increase in cumulative radiation dose. Cockpit crew had a low all-cause, all-cancer, and cardiovascular disease mortality but elevated aircraft accident mortality. Further studies are needed to clarify the risk of CNS and other radiation-associated cancers in relation to cosmic radiation and other workplace exposures.

Cancer Mortality Following Radiotherapy for Benign Gynecologic Disorders

The purpose of this study is to quantify cancer mortality in relationship to organ-specific radiation dose among women irradiated for benign gynecologic disorders. Included in this study are 12,955 women treated for benign gynecologic disorders at hospitals in the Northeastern U.S. between 1925 and 1965; 9,770 women treated by radiation and 3,186 women treated by other methods. The average age at treatment was 45.9 years (range, 13-88 years), and the average follow-up period was 30.1 years (maximum, 69.9 years). Radiation doses to organs and active bone marrow were reconstructed by medical physicists using original radiotherapy records. The highest doses were received by the uterine cervix (median, 120 Gy) and uterine corpus (median, 34 Gy), followed by the bladder, rectum and colon (median, 1.7-7.2 Gy), with other abdominal organs receiving median doses ≤1 Gy and organs in the chest and head receiving doses <0.1 Gy. Standardized mortality rate ratios relative to the general U.S. population were calculated. Radiation-related risks were estimated in internal analyses using Poisson regression models. Mortality was significantly elevated among irradiated women for cancers of the uterine corpus, ovary, bladder, rectum, colon and brain, as well as for leukemia (exclusive of chronic lymphocytic leukemia) but not for cancer of the cervix, Hodgkin or non-Hodgkin lymphoma, multiple myeloma, or chronic lymphocytic leukemia. Evidence of a dose-response was seen for cancers of the ovary [excess relative risk (ERR) = 0.31/Gy, P < 0.001], bladder (ERR = 0.21/Gy, P = 0.02) and rectum (ERR = 0.23/Gy, P = 0.05) and suggested for colon (ERR = 0.09/Gy, P = 0.10), but not for cancers of the uterine corpus or brain nor for non-chronic lymphocytic leukemia. Relative risks of mortality due to cancers of the stomach, pancreas, liver and kidney were close to 1.0, with no evidence of dose-response over the range of 0-1.5 Gy. Breast cancer was not significantly associated with dose to the breast or ovary. Mortality due to cancers of heavily irradiated organs remained elevated up to 40 years after irradiation. Significantly elevated radiation-related risk was seen for cancers of organs proximal to the radiation source or fields (bladder, rectum and ovary), as well as for non-chronic lymphocytic leukemia. Our results corroborate those from previous studies that suggest that cells of the uterine cervix and lymphopoietic system are relatively resistant to the carcinogenic effects of radiation. Studies of women irradiated for benign gynecologic disorders, together with studies of women treated with higher doses of radiation for uterine cancers, provide quantitative information on cancer risks associated with a broad range of pelvic radiation exposures.

The Ukrainian-American Study of Leukemia and Related Disorders among Chornobyl Cleanup Workers from Ukraine: III. Radiation Risks

Leukemia is one of the cancers most susceptible to induction by ionizing radiation, but the effects of lower doses delivered over time have not been quantified adequately. After the Chornobyl (Chernobyl) accident in Ukraine in April 1986, several hundred thousand workers who were involved in cleaning up the site and its surroundings received fractionated exposure, primarily from external gamma radiation. To increase our understanding of the role of protracted low-dose radiation exposure in the etiology of leukemia, we conducted a nested case-control study of leukemia in a cohort of cleanup workers identified from the Chornobyl State Registry of Ukraine. The analysis is based on 71 cases of histologically confirmed leukemia diagnosed in 1986-2000 and 501 age- and residence-matched controls selected from the same cohort. Study subjects or their proxies were interviewed about their cleanup activities and other relevant factors. Individual bone marrow radiation doses were estimated by the RADRUE dose reconstruction method (mean dose = 76.4 mGy, SD = 213.4). We used conditional logistic regression to estimate leukemia risks. The excess relative risk (ERR) of total leukemia was 3.44 per Gy [95% confidence interval (CI) 0.47-9.78, P < 0.01]. The dose response was linear and did not differ significantly by calendar period of first work in the 30-km Chornobyl zone, duration or type of work. We found a similar dose-response relationship for chronic and non-chronic lymphocytic leukemia [ERR = 4.09 per Gy (95% CI < 0-14.41) and 2.73 per Gy (95% CI < 0-13.50), respectively]. To further clarify these issues, we are extending the case-control study to ascertain cases for another 6 years (2001-2006).

Results of the US-Ukrainian Study of Leukemia and Related Disorders Among Chernobyl Cleanup Workers

Leukemia is one of the early cancers induced by ionizing radiation. Following the Chornobyl accident in Ukraine in April 1986, several hundred thousand workers received fractionated exposure, primarily from external gamma radiation. A nested case-control study of leukemia was performed in a cohort of 110,645 cleanup workers identified from the Chornobyl State Registry of Ukraine during the period 1986 to 2000. A provisional computerized registry of leukemia and 99 related hematological disorders was created through an intensive search of the files of the oncology, hematology and pathology departments within the study area encountering 37,605 possible cases. After linkage and case ascertainment by the international hematology review 111 cases were confirmed as leukemia (87), multiple myeloma (8) and MDS (7). 66.6% of cases and 7.1% of selected controls were deceased. Individual bone marrow doses were estimated using RADRUE method enabling dose reconstruction from the interviews carried out with proxy respondents. Two types of proxies were selected for each deceased subject: a spouse or next-of-kin proxy to provide data on demographic factors and medical history, and to propose co-workers who could serve as proxy respondents regarding the deceased subject’s work history. Detailed interviews were conducted and in 71 case and 501 age- and residence-matched controls selected from the same cohort (mean dose=76.4 (SD=213.4) mGy). In order to reduce uncertainties in the dose estimates, a series of validation studies was undertaken. Conditional logistic regression to estimate leukemia risks. The excess relative risk of total leukemia was 3.44 per Gy (95% confidence interval 0.47– 9.78, p<0.01). The dose-response was linear and did not significantly differ by calendar period of first work in the 30-km Chornobyl zone, duration or type of work. A similar dose-response relationship was found for chronic and non-chronic lymphocytic leukemia.

Cytogenetic Aberrations and ImmunoglobulinVHGene Mutations in Clinically Benign CD5– Monoclonal B-Cell Lymphocytosis

The finding of monoclonal B-cell lymphocytosis (MBL) raises questions on the nature of clonal cell expansion and its risk of progression. We identified and characterized 7 cases of clinically benign clonal B-cell lymphocytosis. The clonal lymphocytes were clearly of CD5- and non-chronic lymphocytic leukemia (CLL) phenotype. All cases had mild to moderate absolute lymphocytosis. The clonal population accounted for 95% to 99% of B cells. For a follow-up period of 4 to 16 years, clonal lymphocytosis was persistent but virtually not progressing. Patients' conditions remained clinically stable and asymptomatic. The clonal populations had somatic hypermutations of the VH gene in 6 cases, indicating a germinal center or post-germinal center B-lymphocyte origin. Clonal cytogenetic aberrations were found in 5 of 6 cases, with 2 clones bearing isochromosome 17q that resulted in loss of p53 and 2 other clones with 7q abnormalities. By the presence of absolute lymphocytosis, this series differs from MBL cases identified by sensitive flow cytometry in normal populations. The phenotypic profiles are distinct from that of benign CLL. We suggest these CD5-B-cell lymphocytosis cases may represent an intermediate condition between covert clonal expansions and overt malignancy.

Adult leukemia and proximity-based surrogates for exposure to Pilgrim plant's nuclear emissions.

Possible associations between adult leukemia incidence and proximity-based surrogate measures of potential for exposure to radioactive emissions from the Pilgrim nuclear power plant in Plymouth, Massachusetts, were investigated. Included in this study were 105 nonchronic lymphocytic leukemia cases, diagnosed between 1978 and 1986 at age 13 y or older, that occurred in 22 towns near Pilgrim; population controls numbered 208. Residence within 4 mi (6.4 km) of Pilgrim during "high-emissions" years was related to case-control status (adjusted odds ratio [OR] = 3.88, 95% confidence interval [95% CI] = 0.81-10.64). A high "exposure" score (i.e., a value that accounted for downwind time) was also related to case-control status (OR = 3.46, 95% CI = 1.50-7.96). Some statistically significant dose-response trends were found. Cautious interpretation of associations is warranted in light of the low levels of reported emissions.

Second primary cancer after treatment for cervical cancer. An international cancer registries study

The pattern of second cancers after treatment for cervical cancer provides important information on the risk of radiation-induced malignancies. Large numbers of women survive many years and can be studied for late effects. Incident second cancers in 86,193 patients with cervical cancer reported to 13 population-based cancer registries in 5 countries were evaluated to estimate the risk of second cancer among very long term survivors. Overall, 7543 second cancers were observed versus 6015 cancers expected based on population rates (observed/expected = 1.2). Lung cancer accounted for nearly half of the excess cancers. Among the 49,828 women treated with radiation, 3750 survived 30 or more years and a two-fold risk of cancers of heavily irradiated organs was seen. Most of the excess cancers were of the rectum, vagina, vulva, ovary, and bladder. Patterns of risk over time since treatment were consistent with a radiation etiology. Significant increases of nonchronic lymphocytic leukemia and cancers of the bone and kidney were also linked to radiotherapy. Women treated surgically were also at significant risk of second cancers, in all likelihood related to cigarette smoking and risk factors similar to those of cervical cancer. Curative therapy for cervical cancer results in large numbers of long term survivors who develop second cancers very late in life. Radiation is an important cause of this increase and there is no evidence that risk returns to normal levels.

Leukemia Mortality after X-Ray Treatment for Ankylosing Spondylitis

Leukemia mortality has been studied in 14,767 adult ankylosing spondylitis patients diagnosed between 1935 and 1957 in the United Kingdom, of whom 13,914 patients received X-ray treatment. By 1 January 1992, there were 60 leukemia deaths among the irradiated patients, almost treble that expected from national rates. Leukemia mortality was not increased among unirradiated patients. Among those irradiated, the ratio of observed to expected deaths for leukemia other than chronic lymphocytic leukemia was greatest in the period 1-5 years after the first treatment (ratio = 11.01, 95% confidence interval 5.26-20.98) and decreased to 1.87 (95% confidence interval 0.94-3.36) in the 25+ year period. There was no significant variation in this ratio with sex or age at first treatment. The ratio for chronic lymphocytic leukemia was slightly but not significantly raised (ratio = 1.44, 95% confidence interval 0.62-2.79). Most irradiated patients received all their exposure within a year. Based on a 1 in 15 random sample, the mean total marrow dose was 4.38 Gy. Doses were nonuniform, with heaviest doses to the lower spine. The risk for nonchronic lymphocytic leukemia was adequately described by a linear-exponential model that allowed for cell sterilization in heavily exposed parts of the marrow and time since exposure. Ten years after first exposure, the linear component of excess relative risk was 12.37 per Gy (95% confidence interval 2.25-52.07), and it was estimated that cell sterilization reduced the excess relative risk by 47% at 1 Gy (95% confidence interval 17%-79%). The average predicted relative risk in the period 1-25 years after exposure to a uniform dose of 1 Gy was 7.00.