Stable use of radiotherapy in lymphoma patients over time - A comprehensive national overview of radiotherapy use in Sweden with focus on older patients

Background and purpose

The role of radiotherapy (RT) in lymphoma is constantly refined with the advent of novel treatments. However, RT is still an effective treatment and tolerability is high. Therefore, we aimed to describe the use of RT in primary treatment of lymphoma over calendar time, with a specific focus on older patients (age ≥ 70 years) with non-Hodgkin lymphoma (NHL) subtypes.

Materials & Methods

All adult patients diagnosed with lymphoma from 2007 to 2018 in Sweden were included and followed for survival until end of 2020. Patient characteristics and relative survival (RS) were described for patients with NHL by subtype and RT use.

Results

In the cohort of lymphoma patients aged ≥ 70 years (n = 12,698) 11 % received RT as part of primary treatment. No decline in use of RT over calendar period was seen. Use of RT as monotherapy was associated with stage I-II disease and older age among patients with stage III-IV disease. Patients with indolent lymphomas aged ≥ 70 years who were selected for treatment with RT as monotherapy with a dose of ≥ 20 Gy had 2-year RS rate of 100 % which remained similar at five years. For patients with DLBCL, RT as monotherapy with a dose of ≥ 20 Gy was mostly administered to patients aged ≥ 85 years with a 2-year RS rate of 68 %.

Conclusion

The use of RT in first-line lymphoma treatment was stable over calendar time. RT monotherapy is associated with encouraging outcomes among patients with NHL aged ≥ 70 years who were selected to receive this.

Erratum: Adaptation of the Charlson Comorbidity Index for Register-Based Research in Sweden [Corrigendum]

[This corrects the article DOI: 10.2147/CLEP.S282475.].

Data-driven support to decision-making in molecular tumour boards for lymphoma: A design science approach

Background

The increasing amount of molecular data and knowledge about genomic alterations from next-generation sequencing processes together allow for a greater understanding of individual patients, thereby advancing precision medicine. Molecular tumour boards feature multidisciplinary teams of clinical experts who meet to discuss complex individual cancer cases. Preparing the meetings is a manual and time-consuming process.

Purpose

To design a clinical decision support system to improve the multimodal data interpretation in molecular tumour board meetings for lymphoma patients at Karolinska University Hospital, Stockholm, Sweden. We investigated user needs and system requirements, explored the employment of artificial intelligence, and evaluated the proposed design with primary stakeholders.

Methods

Design science methodology was used to form and evaluate the proposed artefact. Requirements elicitation was done through a scoping review followed by five semi-structured interviews. We used UML Use Case diagrams to model user interaction and UML Activity diagrams to inform the proposed flow of control in the system. Additionally, we modelled the current and future workflow for MTB meetings and its proposed machine learning pipeline. Interactive sessions with end-users validated the initial requirements based on a fictive patient scenario which helped further refine the system.

Results

The analysis showed that an interactive secure Web-based information system supporting the preparation of the meeting, multidisciplinary discussions, and clinical decision-making could address the identified requirements. Integrating artificial intelligence via continual learning and multimodal data fusion were identified as crucial elements that could provide accurate diagnosis and treatment recommendations.

Impact

Our work is of methodological importance in that using artificial intelligence for molecular tumour boards is novel. We provide a consolidated proof-of-concept system that could support the end-to-end clinical decision-making process and positively and immediately impact patients.

Conclusion

Augmenting a digital decision support system for molecular tumour boards with retrospective patient material is promising. This generates realistic and constructive material for human learning, and also digital data for continual learning by data-driven artificial intelligence approaches. The latter makes the future system adaptable to human bias, improving adequacy and decision quality over time and over tasks, while building and maintaining a digital log.

Low-dose aspirin use and colorectal cancer survival in 32,195 patients-A national cohort study

BACKGROUND

Results from previous studies indicate that use of aspirin may improve colorectal cancer (CRC) survival. The aim of this study was to assess whether use of aspirin influences overall survival or CRC-specific survival in an unselected cohort of patients diagnosed with CRC.

METHODS

The study was performed using the Colorectal Cancer Data Base Sweden (CRCBaSe), a mega-linkage originating from the Swedish Colorectal Cancer Register, with additional linkages to other national health care registers. All patients diagnosed with primary CRC stage I-III treated with curative surgery, aged 18-85 years at diagnosis, from 2007 through 2016 were identified. Information on low-dose aspirin use was extracted from the Swedish Prescribed Drug Register. Exposure was defined as dispensed prescription for at least 6 months. Aspirin exposure was analyzed at the time of surgery (yes/no) and as a time-varying exposure during follow-up. Follow-up was restricted to a maximum 6 years, to model 5-year survival. Cox regression models were fitted to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). Adjustments were performed for sex, age, year of diagnosis, Charlson comorbidity index, hypertension, and ASA score as potential confounders.

RESULTS

A total of 32,195 patients diagnosed with CRC were included. 6764 (21%) were exposed to aspirin at the time of CRC surgery. The median time of follow-up was 4.2 years. Aspirin use at the time of surgery was not associated with all-cause (adjusted HR = 1.03, 95% CI: 0.97-1.08) nor CRC-specific mortality (adjusted HR = 0.99, 95% CI: 0.91-1.07). Aspirin use during follow-up was associated with increased all-cause (adjusted HR = 1.09, 95% CI: 1.04-1.15) but not CRC-specific mortality (adjusted HR = 0.98, 95% CI: 0.91-1.06). A CRC-specific effect associated with aspirin was noted from approximately 3 years following surgery.

CONCLUSIONS

In this large nation-wide cohort study there was no convincing association between aspirin use after CRC and OS or CRC-specific survival.

Myocardial infarction in diffuse large B-cell lymphoma patients - a population-based matched cohort study

BACKGROUND

The outcome for diffuse large B-cell lymphoma (DLBCL) patients has improved with the immunochemotherapy combination R-CHOP. An increased rate of heart failure is well documented following this treatment, whereas incidence and outcome of other cardiac complications, for example myocardial infarction, are less well known.

METHOD

We identified 3548 curatively treated DLBCL patients in Sweden diagnosed between 2007 and 2014, and 35474 matched lymphoma-free general population comparators. The incidence, characteristics and outcome of acute myocardial infarctions (AMIs) were assessed using population-based registers up to 11 years after diagnosis. The rate of AMI was estimated using flexible parametric models.

RESULTS

Overall, a 33% excess rate of AMI was observed among DLBCL patients compared with the general population (HR: 1.33, 95% CI: 1.14-1.55). The excess rate was highest during the first year after diagnosis and diminished after 2 years. High age, male sex and comorbidity were the strongest risk factors for AMI. Older patients (>70 years) with mild comorbidities (i.e. hypertension or diabetes) had a 61% higher AMI rate than comparators (HR: 1.61, 95% CI: 1.10-2.35), whereas the corresponding excess rate was 28% for patients with severe comorbidities (HR: 1.28, 95% CI: 1.01-1.64). Among younger patients (≤70), a short-term excess rate of AMI was limited to those with severe comorbidities. There was no difference in AMI characteristics, pharmacological treatment or 30-day survival among patients and comparators.

CONCLUSION

DLBCL patients have an increased risk of AMI, especially during the first 2 years, which calls for improved cardiac monitoring guided by age and comorbidities. Importantly, DLBCL was not associated with differential AMI management or survival.

Adaptation of the Charlson Comorbidity Index for Register-Based Research in Sweden

Purpose

Comorbidity indices are often used to measure comorbidities in register-based research. We aimed to adapt the Charlson comorbidity index (CCI) to a Swedish setting.

Methods

Four versions of the CCI were compared and evaluated by disease-specific experts.

Results

We created a cohesive coding system for CCI to 1) harmonize the content between different international classification of disease codes (ICD-7,8,9,10), 2) delete incorrect codes, 3) enhance the distinction between mild, moderate or severe disease (and between diabetes with and without end-organ damage), 4) minimize duplication of codes, and 5) briefly explain the meaning of individual codes in writing.

Conclusion

This work may provide an integrated and efficient coding algorithm for CCI to be used in medical register-based research in Sweden.

Cancer survival statistics for patients and healthcare professionals - a tutorial of real-world data analysis

Monitoring survival of cancer patients using data collected by population-based cancer registries is an important component of cancer control. In this setting, patient survival is often summarized using net survival, that is survival from cancer if there were no other possible causes of death. Although net survival is the gold standard for comparing survival between groups or over time, it is less relevant for understanding the anticipated real-world prognosis of patients. In this review, we explain statistical concepts targeted towards patients, clinicians and healthcare professionals that summarize cancer patient survival under the assumption that other causes of death exist. Specifically, we explain the appropriate use, interpretation and assumptions behind statistical methods for competing risks, loss in life expectancy due to cancer and conditional survival. These concepts are relevant when producing statistics for risk communication between physicians and patients, planning for use of healthcare resources, or other applications when consideration of both cancer outcomes and the competing risks of death is required. To reinforce the concepts, we use Swedish population-based data of patients diagnosed with cancer of the breast, prostate, colon and chronic myeloid leukaemia. We conclude that when choosing between summary measures of survival it is critical to characterize the purpose of the study and to determine the nature of the hypothesis under investigation. The choice of terminology and style of reporting should be carefully adapted to the target audience and may range from summaries for specialist readers of scientific publications to interactive online tools aimed towards lay persons.

Impact of modern systemic therapies and clinical markers on treatment outcome for metastatic melanoma in a real-world setting

BACKGROUND

The survival in metastatic melanoma has dramatically improved after the introduction of immune checkpoint- (ICIs) and MAPKinase inhibitors (MAPKis).

OBJECTIVE

Our aim was to describe therapy response and survival in a real-world population as well as to assess the associations between clinical variables and therapy outcome for patients with metastatic melanoma receiving first-line ICIs or MAPKis.

METHODS

A total of 252 patients with metastatic (stage IV) melanoma were prospectively followed between 1 January 2010 and 3 December 2017 with follow-up until 31 March 2019, at the Karolinska University Hospital, Sweden. Hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were analysed with Cox regression, and logistic regression was used to estimate odds ratios (ORs) for therapy response.

RESULTS

Patients receiving ICIs (n = 138) experienced longer PFS compared to patients that received MAPKis (n = 114; median PFS for ICIs was 6.8 months, and median PFS for MAPKis was 5.3 months). In the multivariable analyses of clinical markers, increasing M-stage (OR 0.65; 95% CI 0.45-0.94; P = 0.022) and male sex (OR 0.41; 95% CI 0.19-0.90; P = 0.027) were significantly associated with lower response to ICIs. Lower baseline albumin levels (OR 0.90; 95% CI 0.83-0.98; P = 0.019) and male sex (OR 0.33; 95% CI 0.12-0.93; P = 0.036) were related with lower response to MAPKis. For ICIs, increasing M-stage (HR 1.34; 95% CI 1.07-1.68; P = 0.010), increasing LDH (HR 1.73; 95% CI 1.19-2.50; P = 0.004) and decreasing albumin (HR 1.06; 95% CI 1.01-1.10; P = 0.011) were significantly associated lower PFS in the adjusted model. The corresponding markers for MAPKis were increasing LDH (HR 1.44; 95% CI 1.08-1.92; P = 0.013) and decreasing albumin (HR 1.05; 95% CI 1.02-1.09; P = 0.005) for PFS.

CONCLUSION

ICIs and MAPKis were effective in this real-world population, and we could confirm the importance of previously reported clinical prognostic markers. Albumin values may be associated with therapy outcome but need further validation.

Increasing incidence of colorectal cancer among the younger population in Sweden

Background

The incidence of colorectal cancer in patients aged less than 50 years is increasing in Western countries. This population‐based study investigated the age‐ and sex‐specific incidence of colorectal cancer over time in Sweden, and characterized trends in tumour localization and stage at diagnosis.

Methods

Patients diagnosed with colorectal cancer between 1970 and 2016 were identified from the Swedish Cancer Registry, and categorized by sex, age and tumour location. The incidence and average annual percentage change (AAPC) were estimated and compared between age groups.

Results

There was an overall increase in the incidence of colorectal cancer between 1970 and 2006, but a decrease in 2006–2016 (AAPC −0·55 (95 per cent c.i. −1·02 to −0·07) per cent). The largest increase in colonic cancer was in 1995–2005 in women aged less than 50 years (AAPC 2·30 (0·09 to 4·56) per cent versus 0·04 (−1·35 to 1·44) and − 0·67 (−1·62 to 0·28) per cent in women aged 50–74 and 75 years or more respectively). Since 1990, rectal cancer increased in patients of both sexes aged below 50 years, with higher AAPC values in women (2006–2016: 2·01 (−1·46 to 5·61) per cent versus 0·20 (−2·25 to 2·71) per cent in men). Younger patients were more likely than those aged 50–74 and 75 years or more to present with stage III–IV colonic (66·2, 57·6 and 49·6 per cent respectively) and rectal (61·2, 54·3 and 51·3 per cent) cancer. From the mid 1990s, rates of proximal and distal colorectal cancer, and rectal cancer were increased in patients aged less than 50 years.

Conclusion

The overall incidence of colorectal cancer in Sweden decreased in the past decade. However, in patients under 50 years of age the incidence of colorectal cancer – proximal, distal and rectal – continued to increase over time.

Population-based study of patients with primary Sjögren's syndrome and lymphoma: lymphoma subtypes, clinical characteristics, and gender differences

Objective: To examine lymphoma subtypes, clinical characteristics, and gender differences in patients with primary Sjögren's syndrome (pSS) and lymphoma in a population-based setting.Method: Patients with Sjögren's syndrome and lymphoma diagnoses were identified by linkage of the Swedish Patient Register 1964-2007 with the Cancer Register 1990-2007. Clinical data were collected from medical records and lymphoma tissues were re-examined. The lymphoma subtype distribution was compared with the Swedish Lymphoma Register.Results: We identified 105 pSS patients with lymphoma. Diffuse large B-cell lymphoma (DLBCL) (32%) and marginal zone lymphoma [MZL including mucosa-associated lymphoid tissue (MALT) lymphoma] (31%) were the most common lymphoma subtypes. The proportion of DLBCL was not increased compared to the general population reference (32%, p = 1), in contrast to MZL (general population 5%, p < 0.0001). Compared to DLBCL, MALT lymphoma was diagnosed at a younger age (55 vs 67 years, p = 0.0001), and earlier after patient-reported sicca onset (7 vs 18 years, p = 0.0001) and pSS diagnosis (2 vs 9 years, p = 0.0005). Sixteen of the pSS-lymphoma cases were men (15%), twice the proportion in general pSS populations. Compared to women, men had a shorter median time from pSS diagnosis to lymphoma diagnosis (1 vs 8 years, p = 0.0003) and more often had lymphoma in the salivary glands (56% vs 29%, p = 0.04).Conclusion: DLBCL and MZL are common in pSS patients, but only MZL/MALT lymphoma occurs at an increased relative frequency in pSS compared to the general population. The study supports increased awareness of signs of lymphoma in men in the first years after pSS diagnosis.

Impact of comorbidity on disease characteristics, treatment intent and outcome in diffuse large B-cell lymphoma: a Swedish lymphoma register study

BACKGROUND

Comorbidity impacts overall survival amongst patients with diffuse large B-cell lymphoma (DLBCL). However, associations of comorbidity with lymphoma characteristics, treatment selection and lymphoma-specific mortality are less well known.

OBJECTIVE

To examine the impact of comorbidity on DLBCL characteristics, treatment intent and cause of death.

METHODS

We identified 3905 adult patients diagnosed with DLBCL 2007-2013 through the Swedish Lymphoma Register. We assessed comorbid disease history according to the Charlson comorbidity index (CCI). Comorbidity data and causes of death were collected through register linkage. Associations were estimated using multinomial regression and flexible parametric survival models.

RESULTS

Overall, 45% of the patients (n = 1737) had a history of at least one comorbidity at DLBCL diagnosis (cardiovascular disease, diabetes and solid cancer were most frequent), and 997 (26%) had a CCI score of ≥2. The relative probability of presenting with poor performance status (PS > 2) was higher amongst comorbid patients [Relative Risk Ratio (RRR)_PS>2 : 2.02, 95% CI: 1.63-2.51]. Comorbid patients had a substantially lower relative probability of receiving curative treatment (RRR: 0.48, 95% CI: 0.38-0.61). Amongst all patients, CCI ≥ 1 was associated with a significantly increased risk of all-cause and lymphoma-specific death after adjustments. Amongst patients selected for curative treatment, comorbidity was associated with an increased risk of all-cause death (HR_CCI>1 : 1.54, 95% CI: 1.32-1.80), but not with lymphoma-specific death (HR_CCI>1 : 1.05, 95% CI: 0.86-1.28).

CONCLUSION

Comorbidity is associated with inferior DLBCL outcome, mainly due to a lower likelihood of receiving treatment with curative intent. Possibly, more comorbid DLBCL patients could be treated with curative intent if comorbid conditions were optimized in parallel.

Chemotherapy-Free Initial Treatment of Advanced Indolent Lymphoma Has Durable Effect With Low Toxicity: Results From Two Nordic Lymphoma Group Trials With More Than 10 Years of Follow-Up

PURPOSE

For indolent lymphoma, the optimal timing, sequence, and choice of therapeutic regimens remain a matter of debate. In two Nordic Lymphoma Group randomized trials, symptomatic or clearly progressing patients were treated first line with a rituximab-containing regimen without chemotherapy. The purpose of this study was to assess long-term survival, risk of transformation, and need of new therapies.

METHODS

Data were collected at cross-sectional follow-up for 321 patients with indolent lymphoma (84% with follicular lymphomas [FL]) included in one of two Nordic Lymphoma Group trials (accrual 1998 to 1999 and 2002 to 2008). All patients received first-line therapy with one or two cycles of four weekly infusions of rituximab 375 mg/m2, and 148 were randomly allocated to the addition of interferon alfa-2a. Follow-up data were retrieved from initial trial databases and medical records on repeated clinical evaluations.

RESULTS

At the end of follow-up, 73% of patients were alive, with a median follow-up after random assignment of 10.6 years. Among all, 36% (38% with FL) had never needed chemotherapy. For patients with FL who required new therapy within 24 months because of early disease progression, the 10-year survival rate was 59% versus 81% for those with longer remission. Interferon was not shown to improve long-term outcome. Transformation was diagnosed in 20% of all patients (2.4% per person-year) and in 18% with FL. An additional malignancy was found in 12%.

CONCLUSION

Approximately one third of patients with symptomatic indolent lymphoma (30% with FL, 23% without FL) did not need new therapy in the long term after first-line rituximab without chemotherapy. In the entire cohort, 10-year survival was excellent with no major safety issues, which suggests that chemotherapy can be delayed safely in the majority of patients.

Anti-cyclic citrullinated peptide antibodies, other common autoantibodies, and smoking as risk factors for lymphoma in patients with rheumatoid arthritis

OBJECTIVES

Patients with rheumatoid arthritis (RA) are at increased risk of lymphoma. There is no biomarker to indicate future lymphoma risk in RA and it is not known whether factors associated with an increased risk of RA also confer an increased risk of lymphoma. We investigated whether anti-cyclic citrullinated peptide (CCP) antibodies, other autoantibodies, and smoking, are associated with lymphoma development in RA.

METHOD

From two population-based case-control studies, the Scandinavian Lymphoma Etiology (SCALE) study and the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) I study, we identified lymphoma cases with a validated RA diagnosis (n = 50), to whom we matched study participants with RA but no lymphoma (n = 261), lymphoma but no RA (n = 257), and neither RA nor lymphoma (n = 233). Lymphomas were classified according to the WHO classification. Blood samples were analysed for immunoglobulin G (IgG), IgM, and IgA isotypes and IgG_1-4 subclasses of anti-CCP antibodies and for 15 antinuclear antibody (ANA)-associated specific autoantibodies. Relative risks were estimated as crude and adjusted odds ratios (adjOR) with 95% confidence intervals (CIs) using logistic regression.

RESULTS

We found no association between anti-CCP IgG ≥ 25 units/mL (adjOR 1.4, 95% CI 0.7-2.7), anti-CCP IgG ≥ 500 units/mL (adjOR 1.4, 95% CI 0.7-3.0), anti-CCP Ig of other isotypes, other autoantibodies (adjOR any vs none 0.6, 95% CI 0.3-1.2), or cigarette smoking (adjOR ever vs never 1.1, 95% CI 0.5-2.2) and lymphoma risk among patients with RA.

CONCLUSION

In this study, neither anti-CCP antibodies (IgG, IgG_1-4, IgM, or IgA), nor other common autoantibodies, nor smoking predicted lymphoma risk in RA.

The aetiology of B-cell lymphoid malignancies with a focus on chronic inflammation and infections

B-cell malignancies are a heterogeneous group of lymphoproliferative disorders with different molecular characteristics and clinical course. It is increasingly recognized that the group displays considerable heterogeneity also regarding aetiologic factors. Here, we summarize the latest developments in the aetiology of B-cell lymphoid malignancy subtypes focusing on immune perturbation. Severe immune suppression constitutes a strong and well-established risk factor for aggressive subtypes (e.g. diffuse large B-cell and Burkitt lymphoma), but appears unrelated to risk of common low-grade subtypes (e.g. follicular and mantle cell lymphoma). Inflammation and infections are known co-factors amongst the immunosuppressed; however, immune stimulation is now recognized as a crucial determinant of lymphomagenesis also amongst immunocompetent individuals. This is best exemplified in marginal zone lymphomas where local chronic inflammation and infection in the stomach, ocular adnexa and salivary glands have been directly linked with the development of oligoclonal and monoclonal malignant B-cell populations. Aggressive subtypes (e.g. diffuse large B-cell lymphoma) are increasingly linked with features of systemic immune stimulation including autoimmune/inflammatory disease and subclinical cytokine elevations. Lifestyle factors (e.g. high body mass index, cigarette smoking) are associated with risk of diffuse large B-cell and follicular lymphoma, respectively, possibly mediated through inflammation. Recent genome-wide association studies further underline the importance of immune function by linking several subtypes to variations in the human leucocyte antigen (HLA) class genes. In the future, improved knowledge of mechanistic pathways of inflammation/infections in lymphoma development may translate to active measures of prevention or treatment, as is already the case for some low-grade lymphoma subtypes.

Childhood onset inflammatory bowel disease and risk of cancer: a Swedish nationwide cohort study 1964-2014

Objective To assess risk of cancer in patients with childhood onset inflammatory bowel disease in childhood and adulthood.Design Cohort study with matched general population reference individuals using multivariable Cox regression to estimate hazard ratios.Setting Swedish national patient register (both inpatient and non-primary outpatient care) 1964-2014.Participants Incident cases of childhood onset (<18 years) inflammatory bowel disease (n=9405: ulcerative colitis, n=4648; Crohn's disease, n=3768; unclassified, n=989) compared with 92 870 comparators from the general population matched for sex, age, birth year, and county.Main outcome measures Any cancer and cancer types according to the Swedish Cancer Register.Results During follow-up through adulthood (median age at end of follow-up 27 years), 497 (3.3 per 1000 person years) people with childhood onset inflammatory bowel disease had first cancers, compared with 2256 (1.5 per 1000 person years) in the general population comparators (hazard ratio 2.2, 95% confidence interval 2.0 to 2.5). Hazard ratios for any cancer were 2.6 in ulcerative colitis (2.3 to 3.0) and 1.7 in Crohn's disease (1.5 to 2.1). Patients also had an increased risk of cancer before their 18th birthday (2.7, 1.6 to 4.4; 20 cancers in 9405 patients, 0.6 per1000 person years). Gastrointestinal cancers had the highest relative risks, with a hazard ratio of 18.0 (14.4 to 22.7) corresponding to 202 cancers in patients with inflammatory bowel disease. The increased risk of cancer (before 25th birthday) was similar over time (1964-1989: 1.6, 1.0 to 2.4; 1990-2001: 2.3, 1.5 to 3.3); 2002-06: 2.9, 1.9 to 4.2; 2007-14: 2.2, 1.1 to 4.2).Conclusion Childhood onset inflammatory bowel disease is associated with an increased risk of any cancer, especially gastrointestinal cancers, both in childhood and later in life. The higher risk of cancer has not fallen over time.

Prevalence of paediatric inflammatory bowel disease in Sweden: a nationwide population-based register study

BACKGROUND

We evaluated the impact of different case definition algorithms on the prevalence of paediatric inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC) and to compare the occurrence of certain diseases compared to matched controls.

METHODS

Paediatric patients (<18 years) were identified via ICD codes for UC and CD in Swedish registers between 1993 and 2010 (n = 1432). Prevalence was defined as ≥2 IBD-related visits. Prevalence of treated children in 2010 was defined as ≥2 IBD-related visits with one visit and ≥1 dispensed IBD-related drug prescription in 2010. To test the robustness of the estimates, prevalence was also calculated according to alternative case definitions. The presence of rheumatic, hepatobiliary, pancreatic, and dermatologic diseases were compared with age-/sex-/county-of-residence-matched general population controls.

RESULTS

The IBD prevalence was 75/100,000 (CD: 29/100,000; UC: 30/100,000; patients with IBD-U: 16/100,000). Prevalence of treated disease in 2010 was 62/100,000 (CD: 23/100,000; UC: 25/100,000; patients with IBD-U: 13/100,000). When age restrictions were employed, the prevalence estimate decreased (<17y: 61/100,000, <16y: 49/100,000 and <15y: 38/100,000). Compared to general population controls (n = 8583), children with IBD had a higher prevalence of dermatologic (4.7% vs. 0.6%), hepatobiliary (including primary sclerosing cholangitis) (5.5% vs. 0.1%), pancreatic (1.7% vs. 0%) and rheumatic diseases (7.2% vs. 1.2%; all P < 0.01).

CONCLUSIONS

The overall prevalence of paediatric IBD in Sweden was similar to that in earlier regional cohorts. IBD patients had a higher prevalence of comorbid conditions than matched general population controls.

EGR2 mutations define a new clinically aggressive subgroup of chronic lymphocytic leukemia

Recurrent mutations within EGR2 were recently reported in advanced-stage chronic lymphocytic leukemia (CLL) patients and associated with a worse outcome. To study their prognostic impact, 2403 CLL patients were examined for mutations in the EGR2 hotspot region including a screening (n=1283) and two validation cohorts (UK CLL4 trial patients, n=366; CLL Research Consortium (CRC) patients, n=490). Targeted deep-sequencing of 27 known/postulated CLL driver genes was also performed in 38 EGR2-mutated patients to assess concurrent mutations. EGR2 mutations were detected in 91/2403 (3.8%) investigated cases, and associated with younger age at diagnosis, advanced clinical stage, high CD38 expression and unmutated IGHV genes. EGR2-mutated patients frequently carried ATM lesions (42%), TP53 aberrations (18%) and NOTCH1/FBXW7 mutations (16%). EGR2 mutations independently predicted shorter time-to-first-treatment (TTFT) and overall survival (OS) in the screening cohort; they were confirmed associated with reduced TTFT and OS in the CRC cohort and independently predicted short OS from randomization in the UK CLL4 cohort. A particularly dismal outcome was observed among EGR2-mutated patients who also carried TP53 aberrations. In summary, EGR2 mutations were independently associated with an unfavorable prognosis, comparable to CLL patients carrying TP53 aberrations, suggesting that EGR2-mutated patients represent a new patient subgroup with very poor outcome.

Risk of second primary cancer in patients treated with radiotherapy for rectal cancer

BACKGROUND

Many patients with rectal cancer receive radiotherapy (RT) to reduce the risk of local recurrence. Radiation may give rise to adverse effects, including second primary cancers. In view of the divergent results of previous studies, the present study evaluated the risk of second primary cancer following RT in all randomized RT rectal cancer trials conducted in Sweden and in the Swedish ColoRectal Cancer Registry (SCRCR).

METHODS

Patients included in five randomized trials and the SCRCR were linked to the Swedish Cancer Registry. Cox regression models estimated the hazard ratio (HR) of second primary cancer among patients who received RT compared with those who did not.

RESULTS

A total of 13 457 patients were included in this study; 7024 (52·2 per cent) received RT and 6433 (47·8 per cent) had surgery alone. Overall, no increased risk of second primary cancer was observed with RT (HR 1·03; 95 per cent c.i. 0·92 to 1·15), independently of follow-up time and location within or outside of the irradiated volume. In the randomized trials, with longer follow-up (maximum 31 years), a slight increase was observed outside of (HR 1·33, 1·01 to 1·74) but not within (HR 1·11, 0·73 to 1·67) the irradiated volume. Irradiated men had a lower risk of prostate cancer than those treated with surgery alone (HR 0·68, 0·51 to 0·91).

CONCLUSION

Overall, there was no increased risk of second primary cancer following RT for rectal cancer within or outside of the irradiated volume up to 20 years of follow-up. Men with rectal cancer who received RT had a reduced risk of prostate cancer.

Risk of basal cell carcinoma in Swedish organ transplant recipients: a population-based study

BACKGROUND

Risk of basal cell carcinoma (BCC) has been reported to be several-fold increased among organ transplant recipients (OTRs). However, due to lack of reliable BCC registration, population-based risk estimates are scarce.

OBJECTIVES

To characterize risk of BCC among OTRs compared with the general population, and contrast with risk of cutaneous squamous cell carcinoma (SCC).

SUBJECTS AND METHODS

OTRs transplanted during 2004-2011 were identified through national healthcare registers and linked with the nationwide Swedish BCC Register initialized in 2004. Relative risk of BCC was expressed as standardized incidence ratios (SIR) with 95% confidence intervals (CI).

RESULTS

Altogether, 4023 transplanted patients developed 341 BCCs during follow-up. Compared with the general population, the relative risk of BCC was increased sixfold (SIR 6·1, 95% CI 5·4-6·9). The risk was higher in kidney and heart/lung than in liver recipients (SIRkidney 7·2, 6·3-8·3; SIRheart/lung 5·8, 4·0-8·2; SIRliver 2·6, 1·7-4·0), and risk increased with time since transplantation (Ptrend < 0·01). The SCC to BCC ratio was 1 : 1·7 and BCC developed earlier after transplantation than SCC. Distribution of anatomical sites and histological types did not differ substantially between OTR- and population-BCCs.

CONCLUSIONS

Risk of BCC was strikingly elevated in OTRs compared with the general population. Risk was higher in kidney recipients and increased with follow-up time. These findings support a tumour-promoting effect of immunosuppressive drugs in BCC development. The low SCC to BCC ratio was possibly attributed to short follow-up time.

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.