Increased risk of chronic lymphocytic leukaemia among cancer survivors in the Netherlands: increased detection, causal factors or both?

Common genetic polymorphisms contribute to the association between chronic lymphocytic leukaemia and non-melanoma skin cancer

BACKGROUND

Epidemiological studies have demonstrated a positive association between chronic lymphocytic leukaemia (CLL) and non-melanoma skin cancer (NMSC). We hypothesized that shared genetic risk factors between CLL and NMSC could contribute to the association observed between these diseases.

METHODS

We examined the association between (i) established NMSC susceptibility loci and CLL risk in a meta-analysis including 3100 CLL cases and 7667 controls and (ii) established CLL loci and NMSC risk in a study of 4242 basal cell carcinoma (BCC) cases, 825 squamous cell carcinoma (SCC) cases and 12802 controls. Polygenic risk scores (PRS) for CLL, BCC and SCC were constructed using established loci. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Higher CLL-PRS was associated with increased BCC risk (OR4th-quartile-vs-1st-quartile = 1.13, 95% CI: 1.02-1.24, Ptrend = 0.009), even after removing the shared 6p25.3 locus. No association was observed with BCC-PRS and CLL risk (Ptrend = 0.68). These findings support a contributory role for CLL in BCC risk, but not for BCC in CLL risk. Increased CLL risk was observed with higher SCC-PRS (OR4th-quartile-vs-1st-quartile = 1.22, 95% CI: 1.08-1.38, Ptrend = 1.36 × 10-5), which was driven by shared genetic susceptibility at the 6p25.3 locus.

CONCLUSION

These findings highlight the role of pleiotropy regarding the pathogenesis of CLL and NMSC and shows that a single pleiotropic locus, 6p25.3, drives the observed association between genetic susceptibility to SCC and increased CLL risk. The study also provides evidence that genetic susceptibility for CLL increases BCC risk.

Monoclonal B-cell lymphocytosis and prostate cancer: incidence and effects of radiotherapy

Monoclonal B-cells lymphocytosis (MBL) is a benign condition that may precede chronic lymphocytic leukemia (CLL), not rarely present in peripheral blood of healthy elderly people, among which there is also a male prevalence. Though CLL has been associated with various types of solid tumors, including prostate cancer (PC), no data exist about the relationship between PC and MBL. We studied the frequency of CLL-like MBL clones in a group of 48 patients affected by PC and followed them during and after whole-pelvis radiotherapy (WPRT) treatment. We found four MBL clones (8.3%), two of which (4.2%) had a B-cell clonal count >1000 cells/µL (‘clinical MBL’). A single case (1.8%) of ‘low-count’ MBL occurred in a control group of 54 healthy males. Notably, normal B-lymphocytes were consistently affected by WPRT, while MBL clones were less radiosensitive. Our results suggest a possible association between ‘clinical’ MBL and PC and show a different impact of the radiation on monoclonal respect to normal B-cells, which could also imply a greater risk of clonal transformation.

Is there an epidemic of chronic lymphocytic leukaemia (CLL) in China?

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is 10- to 20-fold less common in Asians (including Han Chinese) compared with persons of predominately European descent. Why is unknown but seems predominately genetic. We observed an increasing frequency of new cases of CLL at our Haematology Centre beginning 2011 and wondered why.

OBJECTIVE

Determine the cause(s) for this increased frequency.

METHOD

We interrogated the context of CLL diagnosis in 483 consecutive subjects seen at the Institute of Haematology of a large referral hospital in Beijing. 3 cohorts were considered based on why a CBC was done to establish the CLL diagnosis: (1) a CBC-testing situation unrelated to a health condition such as a routine annual health exam or application for employment or medical insurance (termed routine CBC); (2) an unrelated medical condition such as a cold, influenza, heart disease etc. (termed CBC for other disorders); and (3) signs and/or symptoms consistent with CLL such as lymph-adenopathy, hepato- or splenomegaly, fatigue, B-symptoms etc. (termed CBC for possible CLL).

RESULTS

Data regarding context of CLL diagnosis were available for 389 subjects (81%). Proportions of subjects in the 3 cohorts were 44% (95% confidence interval [CI]; 39, 49%), 24% (20, 28%) and 32% (28, 37%). The proportion of subjects whose evaluation of CLL was prompted by an abnormal CBC not for possible CLL (cohorts 1 and 2) increased over the surveillance interval (r = 0.164; P = 0.001) as did median age at diagnosis (r = 0.207; P < 0.001). Age at diagnosis was correlated with probability of CLL being suspected because of an abnormal routine CBC (r = 0.249; P < 0.001); 42% (32, 53%) amongst subjects ≤50 years versus 86% (75, 92%; P < 0.001) among those >70 years. Consistent with this, older subjects were diagnosed at Rai stage-0 with asymptomatic disease compared with younger subjects (P < 0.001).

CONCLUSION

Our data suggest much of the increased frequency of CLL at our centre and likely elsewhere in China predominately reflects ascertainment bias. Other variables may also operate.

Association of various risk factors with chronic lymphocytic leukemia and its cytogenetic characteristics

This study aimed to investigate whether occupational and environmental exposures, lifestyle, family, and medical history are associated with chronic lymphocytic leukemia (CLL) risk and its chromosomal abnormalities. The study included 138 CLL cases and 141 age- and sex-matched controls. Information data were collected through in-person interviews from cases and controls. Cytogenetic analysis was performed on CLL bone marrow cells. Positive associations were found between CLL and cancer family history, smoking, pneumonia, and exposure to petroleum, metals, pesticides/chemical fertilizers, detergents, and medical radiation. Chromosome deletions of 11q and 13q were more frequent in patients exposed to pesticides and rubber, respectively. This study investigated for the first time specific risk factors in relation to CLL aberrations and presented positive correlations. Moreover, it indicates the possible involvement of specific occupational and lifestyle risk factors in the onset of CLL.

[fMRI and DTI in delayed development of number processing]

The neuronal correlate of the current cultural performance arose from developmental processes that can be observed by functional and anatomical magnetic resonance imaging. The velocity of these maturation processes occurs differently between adolescents, causing implications for both school career and academic performance. Regarding spatial-numerical cognition the myelinization of the superior longitudinal bundle appears to be crucial because this fiber connection intermediates between the linguistic nature of number words and conception of their spatial-numerical magnitude. The neuroscientific observation of anatomical brain maturation and its influence on school-relevant number processing may be helpful for educational purposes as well as for school psychology.