Probability, rate and timing of reconstructive surgery following colectomy for inflammatory bowel disease in Sweden: a population-based cohort study

AIM

Many patients with inflammatory bowel disease (IBD) need colectomy, but the rate of reconstructive surgery with restoration of intestinal continuity is unknown. The aim of this study was to investigate the probability, rate and timing of reconstructive surgery after colectomy in patients with IBD in a population-based setting.

METHOD

The study cohort included all patients with IBD in Sweden who underwent colectomy from 2000 to 2009. Each patient was followed from admission for colectomy to admission for reconstructive surgery, date of death, migration or 31 December 2010. Kaplan-Meier survival curves and multivariable Poisson regression models were used to describe the probability, rate and timing of reconstructive surgery.

RESULTS

Out of 2818 IBD patients treated with colectomy, 61.0% were male and 78.9% had ulcerative colitis. No reconstructive surgery had been performed in 1595 (56.6%) patients by the end of follow-up. Of the remaining 1223 patients, 526 underwent primary reconstructive surgery and 697 had a secondary reconstruction following a median interval of 357 days from primary surgery in the form of colectomy. The probability of reconstructive surgery was dependent on age (55.6% and 18.1% at ages 15-29 and ≥ 59 years, respectively), and the chance of reconstructive surgery was higher in hospitals that performed more than 13 colectomies for IBD per year [incidence rate ratio and 95% confidence interval 1.27 (1.09-1.49)].

CONCLUSION

Fewer than half of the patients having a colectomy for IBD underwent subsequent reconstructive surgery. Older age and low hospital volume were risk factors for no reconstructive surgery.

Risk of disability pension in patients following rectal cancer treatment and surgery

BACKGROUND

Aspects of survivorship, such as long-term ability to work, are increasingly relevant owing to the improved survival of patients with rectal cancer. The aim of this study was to assess risk and determinants of disability pension (DP) in this patient group.

METHODS

Using Swedish national clinical and population-based registers, patients with stage I-III rectal cancer aged 18-61 years in 1995-2009 were identified at diagnosis and matched with population comparators. Prospectively registered records of DP during follow-up were retrieved up to 2013. Non-proportional and proportional hazards models were used to estimate the incidence rate ratio (IRR) for DP annually and overall. Potential variations in risk by demographic and clinical factors were calculated, with relapse as a time-varying exposure.

RESULTS

A total of 2815 patients were identified and compared with 13 465 population comparators. During a median follow-up of 6·0 (range 0-10) years, 23·3 per cent of the relapse-free patients and 10·3 per cent of the population comparators received DP (IRR 2·40, 95 per cent c.i. 2·17 to 2·65). An increased annual risk of DP was evident almost every year until the tenth year of follow-up. Abdominoperineal resection was associated with an increased DP risk compared with anterior resection (IRR 1·44, 1·19 to 1·75). Surgical complications (IRR 1·33, 1·10 to 1·62) and reoperation (IRR 1·42, 1·09 to 1·84), but not radiotherapy or chemotherapy, were associated with risk of DP.

CONCLUSION

Relapse-free patients with rectal cancer of working age are at risk of disability pension.

Non-Hodgkin Lymphoma, Body Mass Index, and Cytokine Polymorphisms: A Pooled Analysis from the InterLymph Consortium

BACKGROUND

Excess adiposity has been associated with lymphomagenesis, possibly mediated by increased cytokine production causing a chronic inflammatory state. The relationship between obesity, cytokine polymorphisms, and selected mature B-cell neoplasms is reported.

METHOD

Data on 4,979 cases and 4,752 controls from nine American/European studies from the InterLymph consortium (1988-2008) were pooled. For diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), joint associations of body mass index (from self-reported height and weight) and 12 polymorphisms in cytokines IL1A (rs1800587), IL1B (rs16944, rs1143627), IL1RN (rs454078), IL2 (rs2069762), IL6 (rs1800795, rs1800797), IL10 (rs1800890, rs1800896), TNF (rs1800629), LTA (rs909253), and CARD15 (rs2066847) were investigated using unconditional logistic regression. BMI-polymorphism interaction effects were estimated using the relative excess risk due to interaction (RERI).

RESULTS

Obesity (BMI ≥ 30 kg/m(2)) was associated with DLBCL risk [OR = 1.33; 95% confidence interval (CI), 1.02-1.73], as was TNF-308GA+AA (OR = 1.24; 95% CI, 1.07-1.44). Together, being obese and TNF-308GA+AA increased DLBCL risk almost 2-fold relative to those of normal weight and TNF-308GG (OR = 1.93; 95% CI, 1.27-2.94), with a RERI of 0.41 (95% CI, -0.05-0.84; Pinteraction = 0.13). For FL and CLL/SLL, no associations with obesity or TNF-308GA+AA, either singly or jointly, were observed. No evidence of interactions between obesity and the other polymorphisms were detected.

CONCLUSIONS

Our results suggest that cytokine polymorphisms do not generally interact with BMI to increase lymphoma risk but obesity and TNF-308GA+AA may interact to increase DLBCL risk.

IMPACT

Studies using better measures of adiposity are needed to further investigate the interactions between obesity and TNF-308G>A in the pathogenesis of lymphoma.

Mortality after total colectomy in 3084 patients with inflammatory bowel disease: a population-based cohort study

BACKGROUND

A high post-operative mortality has been reported following colectomy in patients with inflammatory bowel disease (IBD), especially in some patient groups.

AIMS

To investigate the 40-day mortality following colectomy in patients with IBD. The secondary aim was to assess whether colectomised IBD patients have an increased mortality compared to the general population.

METHODS

This is a population-based register study of all patients with IBD in Sweden who underwent total colectomy in 2000-2010. The cohort was identified using international classification codes for ulcerative colitis (UC) and Crohn's disease (CD). Patients registered with both UC and CD before colectomy (UCCD) were analysed separately. Each patient was followed-up to the date of death, migration or 31st of December 2010, whichever came first. Kaplan-Meier survival curves, Cox proportional hazards models and relative mortality rates were used to describe mortality.

RESULTS

In the cohort of 3084 patients, 2424 were diagnosed with UC, 326 with CD and 334 with UCCD. The 40-day, 1-year and 3-year mortality was 1.3%, 3.1% and 6.0%, respectively. The highest 40-day mortality was seen in patients ≥59 years of age (4.4%). Colectomy at the primary hospitalisation for IBD did not significantly increase the risk of post-operative mortality, nor did hospital volume. The relative survival after 3 years was 0.99, 0.98, 0.97 and 0.90 in those <30, 30-43, 44-58 and ≥59 years old, respectively.

CONCLUSION

The 40-day mortality following total colectomy in IBD patients in Sweden is low, except in patients ≥59 years old.

Recurrent mutations refine prognosis in chronic lymphocytic leukemia

Through the European Research Initiative on chronic lymphocytic leukemia (CLL) (ERIC), we screened 3490 patients with CLL for mutations within the NOTCH1 (n=3334), SF3B1 (n=2322), TP53 (n=2309), MYD88 (n=1080) and BIRC3 (n=919) genes, mainly at diagnosis (75%) and before treatment (>90%). BIRC3 mutations (2.5%) were associated with unmutated IGHV genes (U-CLL), del(11q) and trisomy 12, whereas MYD88 mutations (2.2%) were exclusively found among M-CLL. NOTCH1, SF3B1 and TP53 exhibited variable frequencies and were mostly enriched within clinically aggressive cases. Interestingly, as the timespan between diagnosis and mutational screening increased, so too did the incidence of SF3B1 mutations; no such increase was observed for NOTCH1 mutations. Regarding the clinical impact, NOTCH1 mutations, SF3B1 mutations and TP53 aberrations (deletion/mutation, TP53ab) correlated with shorter time-to-first-treatment (P<0.0001) in 889 treatment-naive Binet stage A cases. In multivariate analysis (n=774), SF3B1 mutations and TP53ab along with del(11q) and U-CLL, but not NOTCH1 mutations, retained independent significance. Importantly, TP53ab and SF3B1 mutations had an adverse impact even in U-CLL. In conclusion, we support the clinical relevance of novel recurrent mutations in CLL, highlighting the adverse impact of SF3B1 and TP53 mutations, even independent of IGHV mutational status, thus underscoring the need for urgent standardization/harmonization of the detection methods.

A meta-analysis of Hodgkin lymphoma reveals 19p13.3 TCF3 as a novel susceptibility locus

Recent genome-wide association studies (GWAS) of Hodgkin lymphoma (HL) have identified associations with genetic variation at both HLA and non-HLA loci; however, much of heritable HL susceptibility remains unexplained. Here we perform a meta-analysis of three HL GWAS totaling 1,816 cases and 7,877 controls followed by replication in an independent set of 1,281 cases and 3,218 controls to find novel risk loci. We identify a novel variant at 19p13.3 associated with HL (rs1860661; odds ratio (OR)=0.81, 95% confidence interval (95% CI) = 0.76-0.86, P(combined) = 3.5 × 10(-10)), located in intron 2 of TCF3 (also known as E2A), a regulator of B- and T-cell lineage commitment known to be involved in HL pathogenesis. This meta-analysis also notes associations between previously published loci at 2p16, 5q31, 6p31, 8q24 and 10p14 and HL subtypes. We conclude that our data suggest a link between the 19p13.3 locus, including TCF3, and HL risk.

Aspirin intake and breast cancer survival - a nation-wide study using prospectively recorded data in Sweden

Background

Aspirin (ASA) use has been associated with improved breast cancer survival in several prospective studies.

Methods

We conducted a nested case–control study of ASA use after a breast cancer diagnosis among women using Swedish National Registries. We assessed prospectively recorded ASA exposure during several different time windows following cancer diagnosis using conditional logistic regression with breast cancer death as the main outcome. Within each six-month period of follow-up, we categorized dispensed ASA doses into three groups: 0, less than 1, and 1 or more daily doses.

Results

We included 27,426 women diagnosed with breast cancer between 2005 and 2009; 1,661 died of breast cancer when followed until Dec 31, 2010. There was no association between ASA use and breast cancer death when exposure was assessed either shortly after diagnosis, or 3–12 months before the end of follow-up. Only during the period 0–6 months before the end of follow-up was ASA use at least daily compared with non-use associated with a decreased risk of breast cancer death: HR (95% CI) = 0.69 (0.56-0.86). However, in the same time-frame, those using ASA less than daily had an increased risk of breast cancer death: HR (95% CI) = 1.43 (1.09-1.87).

Conclusions

Contrary to other studies, we did not find that ASA use was associated with a lower risk of death from breast cancer, except when assessed short term with no delay to death/end of follow-up, which may reflect discontinuation of ASA during terminal illness.

Short telomere length is associated with NOTCH1/SF3B1/TP53 aberrations and poor outcome in newly diagnosed chronic lymphocytic leukemia patients

Most previous studies on telomere length (TL) in chronic lymphocytic leukemia (CLL) are based on referral cohorts including a high proportion of aggressive cases. Here, the impact of TL was analyzed in a population-based cohort of newly diagnosed CLL (n = 265) and in relation to other prognostic markers. Short telomeres were particularly associated with high-risk genetic markers, such as NOTCH1, SF3B1, or TP53 aberrations, and predicted a short time to treatment (TTT) and overall survival (OS) (both P < 0.0001). TL was an independent prognostic factor and subdivided patients with otherwise good-prognostic features (e.g., mutated IGHV genes, favorable cytogenetics) into subgroups with different outcome. Furthermore, in follow-up samples (n = 119) taken 5-8 years after diagnosis, TL correlated well with TL at diagnosis and remained unaffected by treatment. Altogether, these novel data indicate that short TL already at diagnosis is associated with poor outcome in CLL and that TL can be measured at later stages of the disease.

Cigarette smoking and risk of Hodgkin lymphoma and its subtypes: a pooled analysis from the International Lymphoma Epidemiology Consortium (InterLymph)

BACKGROUND

The etiology of Hodgkin lymphoma (HL) remains incompletely characterized. Studies of the association between smoking and HL have yielded ambiguous results, possibly due to differences between HL subtypes.

PATIENTS AND METHODS

Through the InterLymph Consortium, 12 case-control studies regarding cigarette smoking and HL were identified. Pooled analyses on the association between smoking and HL stratified by tumor histology and Epstein-Barr virus (EBV) status were conducted using random effects models adjusted for confounders. Analyses included 3335 HL cases and 14 278 controls.

RESULTS

Overall, 54.5% of cases and 57.4% of controls were ever cigarette smokers. Compared with never smokers, ever smokers had an odds ratio (OR) of HL of 1.10 [95% confidence interval (CI) 1.01-1.21]. This increased risk reflected associations with mixed cellularity cHL (OR = 1.60, 95% CI 1.29-1.99) and EBV-positive cHL (OR = 1.81, 95% CI 1.27-2.56) among current smokers, whereas risk of nodular sclerosis (OR = 1.09, 95% CI 0.90-1.32) and EBV-negative HL (OR = 1.02, 95% CI 0.72-1.44) was not increased.

CONCLUSION

These results support the notion of etiologic heterogeneity between HL subtypes, highlighting the need for HL stratification in future studies. Even if not relevant to all subtypes, our study emphasizes that cigarette smoking should be added to the few modifiable HL risk factors identified.

No association between infections, HLA type and other transplant-related factors and risk of cutaneous squamous cell carcinoma in solid organ transplant recipients

Recipients of solid organ transplants are at a markedly increased risk of cutaneous squamous cell carcinoma (SCC). We investigated potential associations between post-transplant infections, HLA type, and other transplant-related factors and risk of SCC, taking immuno-suppressive treatment into account. A population-based case-control study was conducted. All patients who developed SCC during follow-up (1970-1997) were eligible as cases (n = 207). Controls (n = 189) were individually matched to the cases on age and calendar period of transplantation. Detailed exposure information was collected through an extensive, blinded review of medical records. Odds ratios were computed with conditional logistic regression. There were no significant associations with any infectious agents, or with number and timing of infections, specific HLA-type, donor characteristics, or other transplant characteristics and risk of post-transplant SCC. These results suggest that risk of post-transplant SCC is neither closely related to specific post-transplant infectious disorders, nor to the infectious load or specific HLA types.

Self-reported history of infections and the risk of non-Hodgkin lymphoma: an InterLymph pooled analysis

We performed a pooled analysis of data on self-reported history of infections in relation to the risk of non-Hodgkin lymphoma (NHL) from 17 case-control studies that included 12,585 cases and 15,416 controls aged 16-96 years at recruitment. Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were estimated in two-stage random-effect or joint fixed-effect models, adjusting for age, sex and study centre. Data from the 2 years before diagnosis (or date of interview for controls) were excluded. A self-reported history of infectious mononucleosis was associated with an excess risk of NHL (OR = 1.26, 95% CI = 1.01-1.57 based on data from 16 studies); study-specific results indicate significant (I(2) = 51%, p = 0.01) heterogeneity. A self-reported history of measles or whooping cough was associated with an approximate 15% reduction in risk. History of other infection was not associated with NHL. We find little clear evidence of an association between NHL risk and infection although the limitations of data based on self-reported medical history (particularly of childhood illness reported by older people) are well recognized.

Genome-wide association study of classical Hodgkin lymphoma and Epstein-Barr virus status-defined subgroups

BACKGROUND

Accumulating evidence suggests that risk factors for classical Hodgkin lymphoma (cHL) differ by tumor Epstein-Barr virus (EBV) status. This potential etiological heterogeneity is not recognized in current disease classification.

METHODS

We conducted a genome-wide association study of 1200 cHL patients and 6417 control subjects, with validation in an independent replication series, to identify common genetic variants associated with total cHL and subtypes defined by tumor EBV status. Multiple logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) assuming a log-additive genetic model for the variants. All statistical tests were two-sided.

RESULTS

Two novel loci associated with total cHL irrespective of EBV status were identified in the major histocompatibility complex region; one resides adjacent to MICB (rs2248462: OR = 0.61, 95% CI = 0.53 to 0.69, P = 1.3 × 10(-13)) and the other at HLA-DRA (rs2395185: OR = 0.56, 95% CI = 0.50 to 0.62, P = 8.3 × 10(-25)) with both results confirmed in an independent replication series. Consistent with previous reports, associations were found between EBV-positive cHL and genetic variants within the class I region (rs2734986, HLA-A: OR = 2.45, 95% CI = 2.00 to 3.00, P = 1.2 × 10(-15); rs6904029, HCG9: OR = 0.46, 95% CI = 0.36 to 0.59, P = 5.5 × 10(-10)) and between EBV-negative cHL and rs6903608 within the class II region (rs6903608, HLA-DRA: OR = 2.08, 95% CI = 1.84 to 2.35, P = 6.1 × 10(-31)). The association between rs6903608 and EBV-negative cHL was confined to the nodular sclerosis histological subtype. Evidence for an association between EBV-negative cHL and rs20541 (5q31, IL13: OR = 1.53, 95% CI = 1.32 to 1.76, P = 5.4 x 10(-9)), a variant previously linked to psoriasis and asthma, was observed; however, the evidence for replication was less clear. Notably, one additional psoriasis-associated variant, rs27524 (5q15, ERAP1), showed evidence of an association with cHL in the genome-wide association study (OR = 1.21, 95% CI = 1.10 to 1.33, P = 1.5 × 10(-4)) and replication series (P = .03).

CONCLUSION

Overall, these results provide strong evidence that EBV status is an etiologically important classification of cHL and also suggest that some components of the pathological process are common to both EBV-positive and EBV-negative patients.

Time trends in risk and risk determinants of non-Hodgkin lymphoma in solid organ transplant recipients

Organ transplantation increases risk of non-Hodgkin lymphoma (NHL), but long-term risk and time trends have seldom been evaluated. Immunosuppressive drug load is an important risk determinant, but the details are unclear. We studied NHL risk in a nationwide Swedish cohort of 11 081 graft recipients transplanted 1970-2008. Relative risks (RRs) were estimated within the cohort and versus the general population by age, sex, follow-up time and calendar period. NHL risk was also assessed by cumulative and average doses of immunosuppressive treatments in a nested case-control design throughout 1997 using conditional logistic regression. We observed 153 NHL cases during 97 853 years of follow-up. Compared with the general population, NHL risk was eightfold increased (RR 7.9; 95% confidence interval [CI] 6.6-9.4), and increased risks persisted after ≥15 years of follow-up among kidney (6.1; 95% CI 3.5-10) and nonkidney recipients (44; 14-103). Among nonkidney recipients, NHL risk was lower in the 2000s compared with the 1990s (0.5; 95% CI 0.3-1.0; p = 0.04). A high average dose of antithymocyte immunoglobulin (ATG) conferred an eightfold increased risk of NHL (OR 8.5; 95% CI 1.9-38). To conclude, posttransplant NHL risk decreased during the last decade among nonkidney recipients, possibly because of a more careful use of ATG, the introduction of new drugs, or both.

LPL is the strongest prognostic factor in a comparative analysis of RNA-based markers in early chronic lymphocytic leukemia

BACKGROUND

The expression levels of LPL, ZAP70, TCL1A, CLLU1 and MCL1 have recently been proposed as prognostic factors in chronic lymphocytic leukemia. However, few studies have systematically compared these different RNA-based markers.

DESIGN AND METHODS

Using real-time quantitative PCR, we measured the mRNA expression levels of these genes in unsorted samples from 252 newly diagnosed chronic lymphocytic leukemia patients and correlated our data with established prognostic markers (for example Binet stage, CD38, IGHV gene mutational status and genomic aberrations) and clinical outcome.

RESULTS

High expression levels of all RNA-based markers, except MCL1, predicted shorter overall survival and time to treatment, with LPL being the most significant. In multivariate analysis including the RNA-based markers, LPL expression was the only independent prognostic marker for overall survival and time to treatment. When studying LPL expression and the established markers, LPL expression retained its independent prognostic strength for overall survival. All of the RNA-based markers, albeit with varying ability, added prognostic information to established markers, with LPL expression giving the most significant results. Notably, high LPL expression predicted a worse outcome in good-prognosis subgroups, such as patients with mutated IGHV genes, Binet stage A, CD38 negativity or favorable cytogenetics. In particular, the combination of LPL expression and CD38 could further stratify Binet stage A patients.

CONCLUSIONS

LPL expression is the strongest RNA-based prognostic marker in chronic lymphocytic leukemia that could potentially be applied to predict outcome in the clinical setting, particularly in the large group of patients with favorable prognosis.

Array-based genomic screening at diagnosis and during follow-up in chronic lymphocytic leukemia

BACKGROUND

High-resolution genomic microarrays enable simultaneous detection of copy-number aberrations such as the known recurrent aberrations in chronic lymphocytic leukemia [del(11q), del(13q), del(17p) and trisomy 12], and copy-number neutral loss of heterozygosity. Moreover, comparison of genomic profiles from sequential patients' samples allows detection of clonal evolution.

DESIGN AND METHODS

We screened samples from 369 patients with newly diagnosed chronic lymphocytic leukemia from a population-based cohort using 250K single nucleotide polymorphism-arrays. Clonal evolution was evaluated in 59 follow-up samples obtained after 5-9 years.

RESULTS

At diagnosis, copy-number aberrations were identified in 90% of patients; 70% carried known recurrent alterations, including del(13q) (55%), trisomy 12 (10.5%), del(11q) (10%), and del(17p) (4%). Additional recurrent aberrations were detected on chromosomes 2 (1.9%), 4 (1.4%), 8 (1.6%) and 14 (1.6%). Thirteen patients (3.5%) displayed recurrent copy-number neutral loss of heterozygosity on 13q, of whom 11 had concurrent homozygous del(13q). Genomic complexity and large 13q deletions correlated with inferior outcome, while the former was linked to poor-prognostic aberrations. In the follow-up study, clonal evolution developed in 8/24 (33%) patients with unmutated IGHV, and in 4/25 (16%) IGHV-mutated and treated patients. In contrast, untreated patients with mutated IGHV (n=10) did not acquire additional aberrations. The most common secondary event, del(13q), was detected in 6/12 (50%) of all patients with acquired alterations. Interestingly, aberrations on, for example, chromosome 6q, 8p, 9p and 10q developed exclusively in patients with unmutated IGHV.

CONCLUSIONS

Whole-genome screening revealed a high frequency of genomic aberrations in newly diagnosed chronic lymphocytic leukemia. Clonal evolution was associated with other markers of aggressive disease and commonly included the known recurrent aberrations.

Risk of lymphoproliferative malignancy in relation to small intestinal histopathology among patients with celiac disease

BACKGROUND

Celiac disease is associated with an increased risk of malignant lymphomas. The risk of lymphoproliferative malignancies in patients with small intestinal inflammation without villous atrophy and in patients with latent celiac disease is unknown.

METHODS

We performed a cohort study using duodenal and jejunal biopsy data that were collected from all 28 Swedish pathology departments (July 1969 to February 2008). We identified two population-based cohorts composed of 28,989 individuals with biopsy-verified celiac disease (villous atrophy, Marsh stage 3) and 13,140 individuals with small intestinal inflammation without villous atrophy (Marsh 1 + 2) and a regional cohort of 3711 individuals with latent celiac disease (positive celiac disease serology and normal mucosa). Cancer data were obtained by linkage to the National Cancer Registry. We used Cox regression to estimate hazard ratios (HRs) for lymphoproliferative malignancy and any solid cancer among the three cohorts compared with a total of 227,911 age- and sex-matched reference individuals.

RESULTS

Although biopsy-verified celiac disease and intestinal inflammation were associated with lymphoproliferative malignancy (for celiac disease, HR = 2.82; 95% confidence interval [CI] = 2.36 to 3.37, n = 193; for inflammation, HR = 1.81; 95% CI = 1.42 to 2.31, n = 89), latent celiac disease was not associated with lymphoproliferative malignancy (HR = 0.97; 95% CI = 0.44 to 2.14, n = 7). The absolute rates of lymphoproliferative malignancies among persons with celiac disease, small intestinal inflammation, and latent celiac disease were 70.3 per 100,000 person-years, 83.4 per 100,000 person-years, and 28.0 per 100,000 person-years, respectively. Compared with individuals with celiac disease, individuals with small intestinal inflammation or latent celiac disease were at a statistically significantly lower risk of lymphoproliferative malignancy. Risk of any solid cancer was not increased beyond the first year of follow-up in any cohort. Celiac disease was associated with Hodgkin lymphoma and both T-cell and B-cell non-Hodgkin lymphomas.

CONCLUSION

The risk of lymphoproliferative malignancy in celiac disease is dependent on small intestinal histopathology, with no increased risk in latent celiac disease.

Pediatric organ transplantation and risk of premalignant and malignant tumors in Sweden

Increased cancer risks are well documented in adult organ transplant recipients. However, the spectrum of malignancies and risk in the pediatric organ transplant population are less well described. We identified all solid organ transplanted patients aged <18 in Sweden between 1970-2007 (n = 536) in the National Patient Register and linked to the Cancer Register. Nationwide rates were used to calculate standardized incidence rate ratios and 95% CI estimating the association between transplant and cancer during maximum 36 years of follow-up. Nearly 7% of pediatric solid organ transplant recipients developed a premalignant or malignant tumor during follow-up. Transplantation was associated with an increased risk of any cancer (n = 24, SIR = 12.5, 95% CI: 8.0-18.6): non-Hodgkin lymphoma (NHL) (n = 13, SIR = 127, 95% CI: 68-217), renal cell (n = 3, SIR = 105, 95% CI: 22-307), vulva/vagina (n = 3, SIR = 665, 95% CI: 137-1934) and nonmelanoma skin cancers (n = 2, SIR = 64.7, 95% CI: 7.8-233.8). NHL typically appeared during childhood, while other tumors were diagnosed during adulthood. Apart from short-term attention toward the potential occurrence of NHL, our results suggest cancer surveillance into adulthood with special attention to skin, kidneys and the female genitalia.

Vitamin D receptor genotypes, ultraviolet radiation exposure, and risk of non-Hodgkin lymphoma

Ultraviolet radiation (UVR) exposure may influence risk of non-Hodgkin lymphoma (NHL) through vitamin D, with antineoplastic effects mediated through the vitamin D receptor (VDR). To explore the role of vitamin D in NHL risk and the potential interaction with UVR, the authors genotyped 10 VDR polymorphisms in 2,448 NHL patients and 1,981 controls from Denmark and Sweden who were recruited in 1999-2002. Odds ratios and 95% confidence intervals were computed with logistic regression. P values were 2-sided. Most VDR variants (e.g., rs731236/TaqI, rs15444410/BsmI) were not associated with overall risk of NHL, but there was some evidence of a positive association between rs4760655 and follicular lymphoma risk (nominal P(trend) = 0.004, corrected P(trend) = 0.24). There was no support for an effect of interaction between VDR variants and UVR exposure on risk of overall NHL or B-cell lymphoma subtypes. However, there was some evidence that rs731236 altered associations between UVR and T-cell NHL risk; while increasing UVR frequency lowered T-cell NHL risk among rs731236 TT carriers, an elevated risk was observed among rs731236 CC carriers (nominal P(interaction) ≤ 0.008, corrected P(interaction) ≥ 0.12). VDR does not appear to harbor major determinants of NHL risk, except perhaps for follicular lymphoma. Possible heterogeneity in effects of UVR exposure on T-cell lymphoma risk by VDR rs731236 genotype merits further investigation.

Distinct gene expression profiles in subsets of chronic lymphocytic leukemia expressing stereotyped IGHV4-34 B-cell receptors

BACKGROUND

Numerous subsets of patients with chronic lymphocytic leukemia display similar immunoglobulin gene usage with almost identical complementarity determining region 3 sequences. Among IGHV4-34 cases, two such subsets with "stereotyped" B-cell receptors were recently identified, i.e. subset #4 (IGHV4-34/IGKV2-30) and subset #16 (IGHV4-34/IGKV3-20). Subset #4 patients appear to share biological and clinical features, e.g. young age at diagnosis and indolent disease, whereas little is known about subset #16 at a clinical level.

DESIGN AND METHODS

We investigated the global gene expression pattern in sorted chronic lymphocytic leukemia cells from 25 subset/non-subset IGHV4-34 patients using Affymetrix gene expression arrays.

RESULTS

Although generally few differences were found when comparing subset to non-subset 4/16 IGHV4-34 cases, distinct gene expression profiles were revealed for subset #4 versus subset #16. The differentially expressed genes, predominantly with lower expression in subset #4 patients, are involved in important cell regulatory pathways including cell-cycle control, proliferation and immune response, which may partly explain the low-proliferative disease observed in subset #4 patients.

CONCLUSIONS

Our novel data demonstrate distinct gene expression profiles among patients with stereotyped IGHV4-34 B-cell receptors, providing further evidence for biological differences in the pathogenesis of these subsets and underscoring the functional relevance of subset assignment based on B-cell receptor sequence features.