Malignancy and rheumatoid arthritis

Spondyloarthritis and Risk of Malignancy: A Narrative Review on a Still Controversial Issue

Current literature regarding cancer risk in rheumatic and musculoskeletal diseases (RMDs) is particularly poor and controversial, even though the incidence of malignancy in some patients with RMDs is considered to be increased compared with the general population. Malignancy may be a major comorbidity in subjects with spondyloarthritis (SpA) as the result of multifactorial mechanisms, from disease pathogenesis to the iatrogenic effect of immunomodulating drugs. Several recommendations for screening and management of cancer risk have been developed in recent years with the aim of improving the different outcomes in these patients. The goal of this narrative review is to provide an overview of the currently available evidence on the risk of malignancy connected with RMDs and examine the association of SpA with cancer and the potential impact of its treatment with biologic and targeted synthetic disease-modifying anti-rheumatic drugs on development of malignancy.

How to Use Janus Kinase Inhibitors in the Treatment of Rheumatoid Arthritis? A Clinical Assessment of Risks and Benefits

PURPOSE OF REVIEW

To provide an updated understanding of risks and benefits of Janus kinase inhibitors (JAKi) versus biologic disease-modifying antirheumatic drugs (bDMARDs) in the management of rheumatoid arthritis (RA).

RECENT FINDINGS

Shared decision-making is needed in choosing between JAKi and bDMARDs. Cardiovascular disease, malignancy, and thromboembolic events guide this choice. In patients with active RA despite methotrexate use, tumor necrosis factor inhibitor is conditionally favored over JAKi for low-cardiovascular-risk patients and strongly favored in those with pre-existing cardiovascular disease or multiple cardiovascular risk factors. Suboptimal treatment of treatment-refractory RA patients may pose a greater absolute cardiovascular risk than with JAKi use. Use of aspirin and statin may be considered to reduce cardiovascular risk. New safety data on JAKi has redefined the treatment approach in RA. JAKi remains an important oral medication option in active RA despite treatment with bDMARDs, especially in those with low cardiovascular risk.

Efficacy and safety of abatacept in patients with rheumatoid arthritis with previous malignancy

Background

Abatacept (ABT) is known to lower infection risk than other biologics and is effective and safe in elderly patients with rheumatoid arthritis (RA). However, there were inconsistent reports on the impact of ABT on malignancies which are more common in the elderly and strongly related to prognosis.

Objectives

This study aimed to evaluate the efficacy and safety of ABT in patients with RA with previous malignancy in clinical practice.

Design

A multicenter, retrospective study.

Methods

Patients who received ABT for RA in two hospitals in Yokohama until May 2022 were included in this study. The patients were divided into two groups according to the presence or absence of a history of malignancy (no previous malignancy: NP group, previous malignancy: PM group). The collected parameters were compared between the groups using propensity score matching.

Results

In this study, 312 patients were included, of whom 73 had previous malignancies when starting ABT. The age at ABT initiation was significantly higher in the PM group, the rate of methotrexate use was significantly lower in the PM group, and the Steinbrocker stage was significantly higher in the PM group. After matching these 3 factors, 68 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation. In addition to these factors, when matched for smoking history, interstitial lung disease, disease duration, sex, and inflammatory status, which are known risk factors for malignancy in RA, 40 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation.

Conclusion

In our clinical practice, ABT was as effective and safe in patients with a history of malignancy as in those without.

The Complex Role of C-Reactive Protein in Systemic Lupus Erythematosus

C-reactive protein (CRP) is well-known as a sensitive albeit unspecific biomarker of inflammation. In most rheumatic conditions, the level of this evolutionarily highly conserved pattern recognition molecule conveys reliable information regarding the degree of ongoing inflammation, driven mainly by interleukin-6. However, the underlying causes of increased CRP levels are numerous, including both infections and malignancies. In addition, low to moderate increases in CRP predict subsequent cardiovascular events, often occurring years later, in patients with angina and in healthy individuals. However, autoimmune diseases characterized by the Type I interferon gene signature (e.g., systemic lupus erythematosus, primary Sjögren’s syndrome and inflammatory myopathies) represent exceptions to the general rule that the concentrations of CRP correlate with the extent and severity of inflammation. In fact, adequate levels of CRP can be beneficial in autoimmune conditions, in that they contribute to efficient clearance of cell remnants and immune complexes through complement activation/modulation, opsonization and phagocytosis. Furthermore, emerging data indicate that CRP constitutes an autoantigen in systemic lupus erythematosus. At the same time, the increased risks of cardiovascular and cerebrovascular diseases in patients diagnosed with systemic lupus erythematosus and rheumatoid arthritis are well-established, with significant impacts on quality of life, accrual of organ damage, and premature mortality. This review describes CRP-mediated biological effects and the regulation of CRP release in relation to aspects of cardiovascular disease and mechanisms of autoimmunity, with particular focus on systemic lupus erythematosus.

Autoimmunity and cancer

In many autoimmune rheumatic diseases, there is an increased risk of cancer compared to the general population. The link between autoimmunity and cancer is dynamic and bidirectional. Recent advances in terms of knowledge of biology, epidemiology, and long-term outcomes for the autoimmune rheumatic diseases have revealed several new connections between these two entities. Data suggest that chronic inflammation from the rheumatic diseases or their therapies may contribute to the onset and promotion of cancer. Conversely, antitumor immune responses may become cross-reactive with self-tissues resulting in the development of autoimmunity. In this review, we discuss about the potential mechanisms that link autoimmune rheumatic diseases and cancer and the association of malignancies with common autoimmune disorders. The increased incidence of malignancy in autoimmune rheumatic diseases has been largely described, although the biology underpinning this relationship should be further investigated. The development of evidence-based cancer screening recommendations in patients with autoimmune rheumatic diseases is complex due to the heterogeneity of clinical rheumatic phenotypes, cancer sites at risk and exposure to anti-neoplastic and anti-rheumatic treatment. In order to lay the foundation of risk stratification and targeted cancer screening, larger longitudinal cohort studies that provide a more detailed framework of the links between cancer and autoimmunity are urgently needed.

Identification of the Main Active Components and Mechanism of Wang Bi Tablet in Treating Rheumatoid Arthritis Based on Integrative Pharmacology

Wang Bi tablet (WBT) is used to treat rheumatoid arthritis (RA) in China. We employed integrative pharmacology, including rapid analysis of chemical composition, pharmacological experiment, and network pharmacology analysis, to elucidate the active components and mechanism underlying the effect of WBT against RA. The chemical fingerprint of WBT was revealed by UPLC-QTOF-MS/MS, and the chemical composition was identified. The anti-inflammatory effect of WBT was evaluated in TNF-α-stimulated RAW264.7 cells by ELISA and transcriptome sequencing. Network pharmacology analysis, functional enrichment analysis, and network visualization were performed. A total of 293 chemical constituents were preliminarily identified or tentatively characterized in WBT extract, and they effectively inhibited inflammatory response in TNF-α-stimulated RAW264.7 cells. Forty-eight key active constituents were identified based on high-frequency binding to hub targets and their corresponding targets number. Next, 135 corresponding hub genes, which may be the putative targets of WBT in treating RA, were selected. Functionally, the putative targets were significantly associated with the inflammatory immune response regulation module, energy metabolism regulation module, and cell function regulation module, corresponding to the traditional efficacy of WBT. In summary, this study revealed, for the first time using integrative pharmacology, that WBT may attenuate RA through the inflammation-immune regulation system.

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common systemic inflammatory autoimmune disease characterized by painful, swollen joints that can severely impair physical function and quality of life. The presenting symptoms of musculoskeletal pain, swelling, and stiffness are common in clinical practice, so familiarity with diagnosing and managing RA is crucial. Patients with RA are at greater risk for serious infection, respiratory disease, osteoporosis, cardiovascular disease, cancer, and mortality than the general population. In recent years, early diagnosis, aggressive treatment, and expanded therapeutic options of disease-modifying antirheumatic drugs have markedly improved both the management and long-term prognosis of RA.

Malignancy and the Risks of Biologic Therapies: Current Status

Cancer is a common event in patients with rheumatic diseases. In some cases, the disease, its risk factors, or its treatment could play a role in favoring cancer. This article analyzes the current knowledge on the risk of malignancy associated with biologics in rheumatic diseases and discusses some methodological issues to be considered when evaluating the association between disease, treatments, and the risk of cancer. This article focuses on the risk of overall malignancy but also of skin cancer, lymphoma, and recurrent cancer associated with all biologics marketed for the treatment of rheumatic diseases.

Risk of lymphoma and solid cancer among patients with rheumatoid arthritis in a primary care setting

BACKGROUND

Several studies have demonstrated an association between rheumatoid arthritis (RA) and lymphoproliferative malignancies, but pathogenic mechanisms remain unclear. We investigated 1) the risk of lymphoproliferative malignancies and solid tumors in adults with RA identified in primary care and 2) the possible mediating role of blood eosinophilia in the clonal evolution of cancer in these patients.

METHODS

From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356,196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count between 2000-2007. From these, one DIFF was randomly chosen (the index DIFF). By linking to the Danish National Patient Register, we categorized the selected individuals according to known longstanding (≥3 years) or recent onset (<3 years) RA prior to the index DIFF. In addition, the cohort was stratified according to management in primary or secondary care. From the Danish Cancer Registry we ascertained malignancies within four years following the index DIFF. Using multivariable logistic regression, odds ratios (OR) were calculated and adjusted for sex, age, year, month, eosinophilia, comorbid conditions and C-reactive protein (CRP).

RESULTS

921 patients had recent onset RA and 2,578 had longer disease duration. Seventy three percent of RA patients were managed in primary care. After adjustment for sex, age, year, and month, neither recent onset nor long-standing RA was associated with incident lymphoproliferative malignancies or solid cancers. These risk estimates did not change when eosinophilia, CRP, and comorbidities were included in the models.

CONCLUSIONS

In this large cohort of patients with RA of short or long duration recruited from a primary care resource, RA was not associated with an increased risk of lymphoproliferative or solid cancers during 4 years of follow-up, when the models were adjusted for confounders. Blood eosinophilia could not be identified as a mediator of cancer development in the present setting.

[Gastrointestinal tumors. Clinical manifestations of paraneoplastic rheumatic symptoms]

Paraneoplastic syndromes, as syndromes associated with malignancy, can present unrelated to tumor invasion or metastases. They can occur with varying clinical appearance and are often indistinguishable from idiopathic rheumatic symptoms. Some musculoskeletal disorders are more associated with malignancies. The therapy of rheumatic syndromes can itself have an effect on the tumorigenic process. The clinical severity of paraneoplastic rheumatic symptoms can in many cases aid in the assessment of tumor activity and the response to therapy. While generally an extensive search for occult malignancies in every older rheumatoid patient in cases with no indications of malignancy is not advisable, knowledge of rheumatic symptoms associated with malignancies aids in the important early detection of tumors, while avoiding unnecessary examinations.

Pulmonary manifestations of rheumatoid arthritis

Pulmonary disease is a major source of morbidity and mortality in rheumatoid arthritis, manifesting most commonly as interstitial lung disease, airways disease, rheumatoid nodules, and pleural effusions. The diagnostic assessment of respiratory abnormalities is complicated by underlying risk for infection, the use of drugs with known pulmonary toxicity, and the frequency of lung disease related to rheumatoid arthritis itself. Evaluation and management of rheumatoid arthritis-associated pulmonary disease frequently necessitates a multidisciplinary approach.

Cancer in patients with rheumatic diseases exposed to TNF antagonists

OBJECTIVE

To describe the risk of cancer in patients exposed to tumor necrosis factor (TNF) antagonists.

METHODS

The following 2 clinical cohorts were studied: (1) BIOBADASER 2.0: a registry of patients suffering from rheumatic diseases exposed to TNF antagonists (2531 rheumatoid arthritis (RA), 1488 spondyloarthropathies, and 675 other rheumatic conditions); and (2) EMECAR: a cohort of 789 RA patients not exposed to TNF antagonists. Cancer incidence rates (IR) per 1000 patient-years and incidence rate ratios (IRR) were calculated for BIOBADASER 2.0 and EMECAR patients. The IR over time in BIOBADASER 2.0 patients was analyzed by joinpoint regression. The IRR was estimated to compare cancer rates in exposed versus nonexposed RA patients. Standardized incidence and mortality ratios (SIR, SMR) were also estimated. Risk factors for cancer in patients exposed to TNF antagonists were investigated by generalized linear models.

RESULTS

The SMR for cancer in BIODASER 2.0 was 0.67 (95% CI: 0.51-0.86), and the SIR was 0.1 (95% CI 0.03-0.23). The IR in RA patients exposed to TNF antagonists was 5.8 (95% CI: 4.4-7.6), and the adjusted IRR was 0.48 (95% CI: 0.09-2.45). The IR in patients with previous cancer was 26.4 (95% CI: 4.1-171.5). Age, chronic obstructive pulmonary disease, and steroids were associated with a higher risk of developing cancer. The IR decreased after the first 4 months of exposure, without statistical significance.

CONCLUSION

Overall cancer and mortality rates in patients with rheumatic diseases exposed to TNF antagonists are no higher than in the background Spanish population. However special attention should be paid to elderly patients, those with previous cancers, and patients treated with steroids.

Familial association of inflammatory bowel diseases with other autoimmune and related diseases

OBJECTIVES

Familial risk estimates are useful for genetic counseling, etiological understanding, and design of gene identification studies. We wanted to estimate the associations of ulcerative colitis (UC) and Crohn's disease (CD) with 32 autoimmune and related diseases among parents and offspring, singleton siblings, twins, and spouses.

METHODS

The Multigeneration Register in Sweden provides reliable access to information on families among 11.5 million individuals throughout the last century. The diseases in individual family members were obtained through linkage to the Hospital Discharge Register. Standardized incidence ratios (SIRs) and 95% confidence intervals were calculated as relative risks for UC/CD in family members of patients diagnosed with any of the 34 diseases compared with those lacking affected family members through years 1964-2004.

RESULTS

Among a total of 441,642 patients diagnosed with autoimmune and related conditions, 25,846 were diagnosed with UC and 18,885 with CD. Familial cases amounted to 5.4% of all UC patients and 6.5% of CD patients. SIR for UC was 3.9 (95% confidence interval 3.5-4.3) in offspring of affected parents, 4.6 (3.0-7.4) in siblings, 10.4 (6.5-15.8) in families of affected parents and siblings, and 6.3 (1.9-17.7) for monozygotic twins. The respective SIRs for CD were 6.0 (5.4-6.7), 6.3 (4.1-9.8), 34.0 (24.9-45.3), and 23.4 (10.1-51.1). All discordant associations, i.e., those between CD and other diseases, were also found for UC, including ankylosing spondylitis, asthma, polymyalgia rheumatica, psoriasis, and sarcoidosis. For UC, six additional associations were observed. No correlations between specific diseases were found among spouses, but between UC or CD and any disease it was 1.1 (1.0-1.1).

CONCLUSIONS

The concordant familial risks for UC and CD were lower than those commonly cited. Both diseases are associated with several autoimmune and related diseases, suggesting genetic sharing.

The safety of anti-tumour necrosis factor treatments in rheumatoid arthritis: meta and exposure-adjusted pooled analyses of serious adverse events

OBJECTIVE

To evaluate the safety of biological treatments for rheumatoid arthritis (RA) using results from randomised controlled trials (RCT).

METHODS

The literature was searched to December 2007 for RCT evaluating inhibitors of tumour necrosis factor alpha (anti-TNF) for RA. Safety data were abstracted and risk estimates were calculated using three approaches, meta-analysis with and without adjustment for exposure and simple exposure-adjusted pooling.

RESULTS

Eighteen randomised trials involving 8808 RA subjects were included. Treatment with recommended doses of anti-TNF found no increase in the odds of death (odds ratio (OR) 1.39; 95% CI 0.74 to 2.62), serious adverse events (OR 1.11; 95% CI 0.94 to 1.32), serious infection (OR 1.21; 95% CI 0.89 to 1.63), lymphoma (OR 1.26; 95% CI 0.52 to 3.06), non-melanoma skin cancers (OR 1.27; 95% CI 0.67 to 2.42) or the composite endpoint of non-cutaneous cancers plus melanomas (OR 1.31; 95% CI 0.69 to 2.48) when evaluated using the unadjusted meta-analytic method. Risk estimates were similar with the other methods. For subjects who received two to three times the recommended doses of anti-TNF the risk of serious infection was increased with the unadjusted meta-analytic and pooled analysis, (OR 2.07; 95% CI 1.31 to 3.26) and (risk ratio (RR) 1.83; 95% CI 1.18 to 2.85), respectively, but not increased in the exposure-adjusted meta-analysis (RR 1.99; 95% CI 0.90 to 4.37). Meta-regression identified that the risk of serious infection with anti-TNF therapy decreases with increasing trial duration (p = 0.035).

CONCLUSION

Meta-analytic and exposure-adjusted pooled analyses on over 8800 RA subjects in RCT treated over an average of 0.8 years did not identify an increased risk of serious adverse events with recommended doses. High-dose anti-TNF therapy was associated with a twofold increase in the risk of serious infections.

Etanercept therapy in rheumatoid arthritis and the risk of malignancies: a systematic review and individual patient data meta-analysis of randomised controlled trials

PURPOSE

Tumour necrosis factor (TNF) plays an important role in inflammation and may affect tumour growth control. To assess the risk of malignancy with etanercept, a fusion protein that inhibits TNF action, a meta-analysis was performed using individual patient data from randomised controlled trials (RCT) in patients with rheumatoid arthritis (RA).

METHODS

A search was conducted of bibliographic databases, abstracts from annual meetings and any unpublished studies on file with manufacturers of etanercept to December 2006. Only RCT of etanercept used for 12 weeks or more in patients with RA were included. Nine trials met the inclusion criteria. To adjudicate endpoints, the case narratives of potential cases were reviewed. Patient-level data were extracted from the clinical trials databases.

RESULTS

The nine trials included 3316 patients, 2244 who received etanercept (contributing 2484 person-years of follow-up) and 1072 who received control therapy (1051 person-years). Malignancies were diagnosed in 26 patients in the etanercept group (incidence rate (IR) 10.47/1000 person-years) and seven patients in the control group (IR 6.66/1000 person-years). A Cox's proportional hazards, fixed-effect model stratified by trial yielded a hazard ratio of 1.84 (95% CI 0.79 to 4.28) for the etanercept group compared with the control group.

CONCLUSIONS

In this analysis, the point estimate of malignancy risk was higher in etanercept-treated patients, although the results were not statistically significant. The approach of obtaining individual patient data of RCT in cooperation with trial sponsors allowed important insights into the methodological advantages and challenges of sparse adverse event data meta-analysis.

Familial associations of rheumatoid arthritis with autoimmune diseases and related conditions

OBJECTIVE

In the era of genome-wide association studies, familial risks are used to estimate disease heritability and the likelihood of candidate-gene identification. This study was undertaken to estimate associations of rheumatoid arthritis (RA) with any of 33 autoimmune diseases and related conditions among parents and offspring, singleton siblings, twins, and spouses.

METHODS

The Multigeneration Register in Sweden was used as a reliable source of information on Swedish families throughout the last century. Data on autoimmune diseases in individual family members were obtained through linkage to the Hospital Discharge Register. The standardized incidence ratio (SIR) was calculated as a measure of the relative risk of RA in family members of patients with RA or any of 33 other autoimmune diseases or related conditions, as compared with the relative risk of RA in those lacking an affected family member.

RESULTS

Among a total of 447,704 patients, 47,361 were diagnosed as having RA. The SIRs for RA were 3.02 in offspring of affected parents, 4.64 in siblings, 9.31 in multiplex families, 6.48 in twins, and 1.17 in spouses. Significant associations with the familial risk of RA in offspring according to parental proband were observed for ankylosing spondylitis (SIR 2.96), localized scleroderma (SIR 2.40), Sjögren's syndrome (SIR 2.25), systemic lupus erythematosus (SIR 2.13), systemic sclerosis (SIR 1.65), Hashimoto thyroiditis/hypothyroidism (SIR 1.54), pernicious anemia (SIR 1.53), sarcoidosis (SIR 1.40), psoriasis (SIR 1.36), Wegener's granulomatosis (SIR 1.34), and asthma or polymyalgia rheumatica (SIR 1.32).

CONCLUSION

This is the first study to compare the familial risks of RA in relation to a large number of autoimmune diseases and related conditions using data from a single population. The high discordant familial risks in this population suggest that there is extensive genetic sharing between RA and the associated diseases.

Cancer risks in Crohn disease patients

BACKGROUND

Patients diagnosed with Crohn disease (CD) are known to be at an increased risk of bowel cancers and lymphoma. CD is an autoimmune disease and we hypothesize that the patients are predisposed to a wider spectrum of cancers.

PATIENTS AND METHODS

A CD research database was constructed by identifying hospitalized CD patients from the Hospital Discharge Register and cancer patients from the Swedish Cancer Registry. Follow-up of 21 788 CD patients first hospitalized during the years 1964-2004 identified 1424 cancer cases. Standardized incidence ratios (SIRs) were calculated by comparing cancers in CD patients with subjects without CD.

RESULTS

In addition to the known sites, many additional sites were in excess in CD patients. These included liver, pancreatic, lung, prostate, testicular, kidney and skin (squamous cell) cancers; nonthyroid endocrine tumors and leukemia. The previously established sites showed the highest SIRs; however, SIRs >2.0 were noted for the novel sites of the liver, testis and kidney. For testicular cancer, the SIR of seminoma was 2.74. Cancer risks were influences by age at first hospitalization for CD but whether the age effects were increasing or decreasing depending on the cancer type.

CONCLUSIONS

This large study identified many novel subsequent cancers in CD patients.

Cancer risks in ulcerative colitis patients

Patients diagnosed with ulcerative colitis (UC) are known to be at an increased risk of colorectal and liver cancers and leukemia. UC is an autoimmune disease, which may present a wider spectrum of cancers. We wanted to examine the risk of cancer in a large population of UC patients in order to reach high statistical power. A UC research database was constructed by identifying UC patients from the Swedish Hospital Discharge Register and cancer patients from the Cancer Registry. Follow-up of 27,606 UC patients hospitalized for the first time during the years 1964-2004 identified 2,058 patients with cancer. Standardized incidence ratios were calculated for cancer in UC patients by comparing to subjects without hospitalization for UC. The novel tumor sites in UC patients included small intestinal (carcinoid), pancreatic, breast and prostate cancers, nonthyroid endocrine gland tumors, non-Hodgkin lymphoma and multiple myeloma. A total of 11 sites showed an increased risk, which remained at 6 sites when tumors diagnosed in the year of UC hospitalization were excluded; even chronic myeloid leukemia was in excess. Cancer risks depended on the age at first hospitalization for UC. The SIRs for colon, rectal, liver and pancreatic cancers declined by age at hospitalization for UC, while for endocrine tumors the older patients were at higher risk. Our large study identified novel subsequent cancers in UC patients. However, some of these, including small intestinal carcinoids, prostate cancers and nonthyroid endocrine tumors, may be in excess because of intensified medical surveillance of the patients.

Malignancy and biologic therapy in rheumatoid arthritis

PURPOSE OF REVIEW

Owing to the complex functions of the inflammatory response systems--potentially or clearly of importance in human carcinogenesis--that biological therapies interfere with uncertainty regarding their safety profile for malignancy is more or less expected. This uncertainty has been further sparked by the apparent discordance between trial data and observational studies of anti-TNF agents, and the methodological challenges inherent in addressing the safety profile of new drugs for delayed and multifactorial events like cancer.

RECENT FINDINGS

This review provides a summary of the pattern of cancer seen in patients with rheumatoid arthritis not treated with biologics, and the currently published data on cancer risk following treatment with biologics in patients with rheumatoid arthritis, primarily anti-TNF therapy.

SUMMARY

Published data currently do not exclude clinically important increased risks, nor do they refute beneficial effects. As per definition, much of the currently available safety data from trials or clinical practice do not capture the impact of either any effect that biological therapy might have on early events in carcinogenesis, or of sustained exposure to biologics. Beyond the risk of de-novo cancer development, several other clinically important aspects of cancer safety remain to be addressed, including issues of prognosis, progression, and relapse.

A meta-analysis of the incidence of malignancy in adult patients with rheumatoid arthritis

Introduction

The risk of malignancies in patients with rheumatoid arthritis (RA) has raised some concern, particularly with immunosuppressive approaches to disease management.

Methods

We conducted a systematic review of the literature and meta-analysis characterizing the associated risk of overall malignancy and four site-specific malignancies (lymphoma, lung, colorectal, and breast cancer) in patients with RA. A Medline search from 1990 to 2007 was conducted using specified search terms and predefined inclusion criteria for identification of relevant observational studies that provide estimates of relative risk of malignancy associated with RA. Study-specific estimates of the relative risk, as measured by standardized incidence ratios (SIRs) and estimated in comparison with the general population, were combined using a random effects model.

Results

A total of 21 publications were identified, of which 13 reported the SIR for overall malignancy, 14 for lymphoma, 10 for colorectal, 12 for lung, and 9 for breast cancer. Compared with the general population, the overall SIR estimates suggest that RA patients have approximately a two-fold increase in lymphoma risk (SIR 2.08, 95% confidence interval [CI] 1.80 to 2.39) and greater risk of Hodgkin than non-Hodgkin lymphoma. The risk of lung cancer was also increased with an SIR of 1.63 (95% CI 1.43 to 1.87). In contrast, a decrease in risk was observed for colorectal (SIR 0.77, 95% CI 0.65 to 0.90) and breast (SIR 0.84, 95% CI 0.79 to 0.90) cancer. The SIR for overall malignancy was 1.05 (95% CI 1.01 to 1.09).

Conclusion

Patients with RA appear to be at higher risk of lymphoma and lung cancer and potentially decreased risk for colorectal and breast cancer compared with the general population.

Breast cancer and systemic sclerosis: a clinical description of 21 patients in a population-based cohort study

Previous studies have demonstrated an increased risk of breast cancer among patients with systemic sclerosis (scleroderma). To describe the clinical characteristics of 21 patients with both systemic sclerosis and breast cancer, and compare their risk factors to female scleroderma patients without breast cancer, in a population-based cohort study of South Australia. Subjects with scleroderma and breast cancer were identified from the South Australian Scleroderma Register with cross-linking to the South Australian Cancer Registry, last updated to the end of December 2005. Clinical information was obtained from standardised self-administered questionnaires and case note reviews. Odds ratios for the risk factors for breast cancer in scleroderma were determined, and clinical variables were analysed using chi square, Fisher's exact, Mann-Whitney and t tests. At the end of December 2005 there were a total of 389 female patients with scleroderma. Of these, 21 (5.4%) had been diagnosed with breast cancer. The mean age of onset of scleroderma was 43.5 years, and the mean age of breast cancer was 60.5 years in those with scleroderma and breast cancer. The majority (71.4%) had limited scleroderma, with anti-centromere antibody being the most prevalent serological abnormality. In 16 (76%) patients the diagnosis of breast cancer occurred on an average of 22.3 years after the onset of their first scleroderma symptom. When compared to 48 controls, scleroderma patients with breast cancer were found to have a higher incidence of a positive family history of breast cancer (Fisher's exact test, p = 0.04) and a lower incidence of hormone-replacement therapy use (Fisher's exact test, p = 0.0026). This population-based cohort study provides evidence that the majority of patients with scleroderma and breast cancer have limited scleroderma and anti-centromere antibody. Given the increased incidence of solid tumours in systemic sclerosis, we suggest regular screening of female patients for breast cancer, especially in those with a family history.