Record linkage to conduct an epidemiologic study on the association of rheumatoid arthritis and lymphoma in the Province of Saskatchewan, Canada

Risk of cancer among rheumatoid arthritis patients in California

OBJECTIVE

The objective of this retrospective cohort study was to evaluate cancer risk among rheumatoid arthritis (RA) patients in California.

METHODS

The study cohort derived from statewide patient discharge records was followed via linkage with cancer registry data over the period 1991-2002. Age and sex adjusted standardized incidence ratios (SIRs) and 95% confidence intervals were calculated to compare observed to expected numbers of cancers based on age, race, and sex specific incidence rates in the California population.

RESULTS

Among the 84,475 RA patients, who were observed for 405,540 person-years, 5,533 incident cancers were diagnosed during the observation interval. The risk of developing lymphohematopoietic cancer was significantly higher in the cohort for both sexes. Males had significantly higher risks of lung, liver, and esophageal cancer, but a lower risk of prostate cancer. Females were at significantly decreased risk for several cancers including breast, ovary, uterus, cervix, and melanoma, with the risk reduction ranging from 15 to 57% lower than the general population. Hispanics had increased risks of leukemia, vagina/vulva, lung, and liver cancers.

CONCLUSION

Studies investigating the mechanisms that underlie the reported associations between RA and specific cancer types are needed.

Risk of cancer among rheumatoid arthritis patients in California

OBJECTIVE

The objective of this retrospective cohort study was to evaluate cancer risk among rheumatoid arthritis (RA) patients in California.

METHODS

The study cohort derived from statewide patient discharge records was followed via linkage with cancer registry data over the period 1991-2002. Age and sex adjusted standardized incidence ratios (SIRs) and 95% confidence intervals were calculated to compare observed to expected numbers of cancers based on age, race, and sex specific incidence rates in the California population.

RESULTS

Among the 84,475 RA patients, who were observed for 405,540 person-years, 5,533 incident cancers were diagnosed during the observation interval. The risk of developing lymphohematopoietic cancer was significantly higher in the cohort for both sexes. Males had significantly higher risks of lung, liver, and esophageal cancer, but a lower risk of prostate cancer. Females were at significantly decreased risk for several cancers including breast, ovary, uterus, cervix, and melanoma, with the risk reduction ranging from 15 to 57% lower than the general population. Hispanics had increased risks of leukemia, vagina/vulva, lung, and liver cancers.

CONCLUSION

Studies investigating the mechanisms that underlie the reported associations between RA and specific cancer types are needed.

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.

Update on the Japanese guidelines for the use of infliximab and etanercept in rheumatoid arthritis

Application of biological agents targeting tumor necrosis factor-alpha (TNF-alpha) caused a paradigm shift in the treatment of rheumatoid arthritis (RA). The introduction of infliximab in 2003 and etanercept in 2005 in Japan had a significant impact on both Japanese rheumatologists and RA patients, although serious adverse effects such as bacterial pneumonia, tuberculosis and Pneumocystis jiroveci pneumonia are significant concerns. Based on the data from post-marketing surveillance in Japan and accumulating evidence worldwide, the Internal Medicine Rheumatology Study Group of the Ministry of Health, Labor and Welfare (MHLW), Japan, has updated the guidelines for the use of anti-TNF-alpha agents for RA, which were subsequently approved by the Board of Japan College of Rheumatology (JCR). In the present revised guidelines, we combined the guidelines for use of each of infliximab and etanercept together with some modifications and precautions, paying special attention to serious adverse reactions. Although it is still controversial whether the use of TNF-alpha blocking agents per se increases the risk of infection or not, bacterial pneumonia, regardless of the pathogens, is the most frequent complications in RA. The risk factors associated with pneumonia identified in the post-marketing surveillance of infliximab in Japan are presented in this guideline. The diagnostic algorithm is also designed for early diagnosis and treatment of pulmonary lesions seen during the treatment of biological agents. Preventive measures and precautions against tuberculosis, another frequent and significant complication in Japan, are also described. Furthermore, risk factors for developing Pneumocystis pneumonia, which uniquely occurs at 30- to 50-fold frequency under TNF-alpha blockade therapy in Japan, are described here and its preventive measures are discussed. It is stressed that secondary-care rheumatologists should be better familiarized with the proper use of TNF-alpha blocking agents and be alert to any adverse events for a better management of RA patients.

Diabetes mellitus associated with the occurrence and prognosis of non-Hodgkin's lymphoma

The aim of this case-control study was to assess the effect of preexisting diabetes mellitus on the risk of developing non-Hodgkin's lymphoma, and also to investigate whether preexisting diabetes mellitus could further affect survival after diagnosis of non-Hodgkin's lymphoma. The retrospective cohort consisted of 242 study participants with pathologically confirmed non-Hodgkin's lymphoma who were referred to the Department of Radiation Oncology in Chang-Gung Memorial Hospital between January 2000 and March 2004. The controls were derived from a population-based multiple screening program. A logistic regression model was employed to calculate the odds ratios of the risk factors we examined and then to evaluate the association between preexisting diabetes mellitus and the occurrence of non-Hodgkin's lymphoma. The results showed that preexisting diabetes mellitus was an independent risk factor for the occurrence of non-Hodgkin's lymphoma (odds ratio, 1.88; 95% confidence interval, 1.22-2.89; P=0.0045). When subgroup analyses regarding certain tumor or disease characteristics were performed, the impact of preexisting diabetes mellitus was found to be particularly evident in some subgroups such as the tumors of T-cell origin (P=0.0266), those with extranodal involvement (P=0.0346), and those that were not localized or low grade (P=0.0096). The effect of preexisting diabetes mellitus on the risk of death from non-Hodgkin's lymphoma varied with follow-up time. Such an effect modification was statistically significant (P=0.05). In the current study, preexisting diabetes mellitus was an independent risk factor for the occurrence of non-Hodgkin's lymphoma, and it was also an accelerated factor for the risk of death from causes related to non-Hodgkin's lymphoma.

Malignancy and rheumatoid arthritis

The occurrence of cancer is not an infrequent event in patients with rheumatoid arthritis (RA). Indeed, following diagnosis of RA at a typical age (55 years), one in five patients will be diagnosed with cancer. In the vast majority of such cases, the cancer has nothing to do with RA or its treatment; rather, it represents the "background" risk applicable to all humans. In some cases, the cancer occurs as a result of factors also associated with the risk of developing RA (eg, smoking), even though no direct link exists between the cancer and the RA. In a fraction of cases, however, the cancer is causally associated with the RA disease or its treatments. This review summarizes our current understanding of the occurrence of cancer in RA, possible links to RA disease and to traditional and newer RA treatments.

Cyclooxygenase-2 (cox-2) and the inflammogenesis of cancer

Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that aberrant induction of COX-2 and up-regulation of the prostaglandin cascade play a significant role in carcinogenesis, and reciprocally, blockade of the process has strong potential for cancer prevention and therapy. Supporting evidence includes the following: [1] expression of constitutive COX-2-catalyzed prostaglandin biosynthesis is induced by most cancer-causing agents including tobacco smoke and its components (polycylic aromatic amines, heterocyclic amines, nitrosamines), essential polyunsaturated fatty acids (unconjugated linoleic acid), mitogens, growth factors, proinflammatory cytokines, microbial agents, tumor promoters, and other epigenetic factors, [2] COX-2 expression is a characteristic feature of all premalignant neoplasms, [3] COX-2 expression is a characteristic feature of all malignant neoplasms, and expression intensifies with stage at detection and cancer progression and metastasis, [4] all essential features of carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis, and immunosuppression) are linked to COX-2-driven prostaglandin (PGE-2) biosynthesis, [5] animal studies show that COX-2 up-regulation (in the absence of genetic mutations) is sufficient to stimulate the transformation of normal cells to invasive cancer and metastatic disease, [6] non-selective COX-2 inhibitors, such as aspirin and ibuprofen, reduce the risk of human cancer and precancerous lesions, and [7] selective COX-2 inhibitors, such as celecoxib, reduce the risk of human cancer and precancerous lesions at all anatomic sites thus far investigated. Results confirming that COX-2 blockade is effective for both cancer prevention and therapy have been tempered by observations that some COX2 inhibitors pose a risk to the cardiovascular system, and more studies are needed in order to determine if certain of these drugs can be taken at dosages that prevent cancer without increasing cardiovascular risk. It is emphasized that the "inflammogenesis model of cancer" is not mutually exclusive and may in fact be synergistic with the accumulation of somatic mutations in tumor suppressor genes and oncogenes or epigenetic factors in the development of cancer.

Persistent Chronic Inflammation Contributes to the Development of Cancer in Patients with Rheumatoid Arthritis from a Defined Population of Northwestern Spain

OBJECTIVE

We assessed the contribution of clinical features, routine laboratory markers of inflammation, HLA-DRB1 alleles, and methotrexate therapy to cancer incidence and mortality in a cohort of rheumatoid arthritis (RA) patients prospectively followed at the single referral center for an area of Northwestern Spain.

METHODS

Patients fulfilling the 1987 American College of Rheumatology classification criteria for RA seen at the rheumatology outpatient clinic of Hospital Xeral Calde, Lugo between March and September 1996 were included. HLA-DRB1 phenotype, epidemiological and clinical data from the time of RA diagnosis were assessed at that time. Afterward, patients were prospectively followed and clinical records were examined until the patient's death or September 1, 2005. Presence of histologically confirmed diagnosis of cancer was assessed over the extended follow-up in all cases.

RESULTS

One hundred eighty-two consecutive patients were assessed. Compared with the general Spanish population, the age- and gender-standardized mortality ratio for cancer was 1.01 (95% confidence interval: 0.49 to 1.75). Cancer mortality adjusted by age and sex was associated with chronic inflammation determined by C-reactive protein (CRP) (hazard ratio, HR, = 1.15; P < 0.001), and erythrocyte sedimentation rate (ESR) (HR = 1.05; P = 0.006). Increased risk of cancer was also associated with CRP (HR = 1.13; P = 0.001), ESR (HR = 1.04; P = 0.02), and the HLA-DRB1*0404 allele (HR = 3.24; P = 0.05).

CONCLUSION

This study does not support an increased mortality due to cancer in RA patients from Northwestern Spain. However, the present data indicate that high-grade inflammation contributes to both the risk and the mortality of cancer in RA.

Estimating Osteoarthritis Incidence From Population-Based Administrative Health Care Databases

PURPOSE

The aim of the study is to develop a method to estimate osteoarthritis (OA) incidence by using administrative health care databases.

METHODS

Using actual counts of OA diagnoses in different periods, we generated an equation that estimated the number of new OA diagnoses based on the length of time used for excluding prevalent OA cases. Physicians billing files from 1983 to 2002 maintained at Alberta Health and Wellness were used to verify the proposed method. Age- and sex-specific and crude OA incidences in 2002 were calculated by using this method.

RESULTS

Women aged 50 to 59 years had the greatest incidence. For men, the greatest incidence was in the 60- to 69-year age category. Crude incidences for women and men were 1103 and 934 per 100,000 person-years, respectively. The overall crude rate was 1040 per 100,000 person-years.

CONCLUSIONS

Modified power function accurately summarizes the relationship between number of first OA diagnoses and length of the clearance period and thus provides an effective model to estimate OA incidence. Not restricted to OA, this model also can be implemented to estimate incidences of other chronic conditions.

Are monoclonal gammopathies in rheumatoid arthritis predictive for lymphoproliferative disorders?

There is limited evidence for the association of specific malignancies with rheumatoid arthritis (RA). Monoclonal gammopathies can occur in RA. Their predictive value for the development of a lymphoproliferative disorder remains unclear and disputed. We reviewed charts of 214 RA patients all of whom had at least one serum protein electrophoresis. We performed a retrospective study of 12 patients with RA and an M spike. We further characterized the M spike by serum immunofixation and bone marrow studies. The median age at which the M spike was identified was 69 years. IgG was the predominant gammopathy in 50% of patients, with no difference in the amount of kappa (kappa) and lambda (lambda) chains. One patient was diagnosed with multiple myeloma, one with an undefined primary lymphoproliferative disorder, one with T-cell leukemia, five with myelodysplastic syndrome, and four with monoclonal gammopathy of undetermined significance at most recent evaluation. Of our patients, 42% had a myelodysplastic syndrome, which has not been previously reported, and, in contrast to previous reports, no lymphomas were identified. The follow-up evaluation of patients with myelodysplastic syndrome and monoclonal gammopathy of undetermined significance is important because they may progress to an overt neoplasia.

Prospective Study of Survival Outcomes in Non-Hodgkin's Lymphoma Patients With Rheumatoid Arthritis

Purpose

Although preliminary studies suggest that non-Hodgkin's lymphoma (NHL) complicating rheumatoid arthritis (RA) may be a clinically distinct entity compared with that occurring in the general population, studies examining the impact of antecedent RA on survival are limited. In this prospective study, we examined the association of RA with survival in patients with NHL.

Patients and Methods

Using two large lymphoma registries, we identified patients with evidence of RA preceding NHL. Survival in RA patients was compared with that of controls using proportional hazards regression, adjusting for the effects of age, sex, lymphoma diagnosis-to-treatment lag time, calendar year, International Prognostic Index score, and NHL grade.

Results

The frequency of NHL subtypes was similar in RA patients (n = 65) and controls (n = 1,530). Compared with controls, RA patients with NHL had similar overall survival (hazard ratio [HR] = 0.95; 95% CI, 0.70 to 1.30) but were at lower risk of lymphoma progression or relapse (HR = 0.41; 95% CI, 0.25 to 0.68) or death related to lymphoma or its treatment (HR = 0.60; 95% CI, 0.37 to 0.98), but were more than twice as likely to die from causes unrelated to lymphoma (HR = 2.16; 95% CI, 1.33 to 3.50).

Conclusion

RA is associated with improved NHL-related outcomes, including a 40% reduced risk of death occurring as a result of lymphoma or its treatment and approximately a 60% lower risk of lymphoma relapse or progression compared with non-RA controls. However, the survival advantage gained in RA from the acquisition of lymphomas with favorable prognoses is negated through an increased mortality from other comorbid conditions.

Safety of extended treatment with anakinra in patients with rheumatoid arthritis

OBJECTIVE

To determine the safety profile of anakinra after extended exposure in a diverse clinical trial population of patients with rheumatoid arthritis.

METHODS

A six month, randomised, double blind phase comparing anakinra (100 mg/day) with placebo was followed by open label anakinra treatment for up to three years in patients with rheumatoid arthritis. Concomitant non-steroidal anti-inflammatory drugs, corticosteroids, and other disease modifying antirheumatic drugs were permitted.

RESULTS

In all 1346 patients with rheumatoid arthritis received anakinra for up to three years. Patients had varying levels of disease severity, concomitant drug use, and comorbid conditions. Cumulative, exposure adjusted event (EAE) rates for all adverse events (AEs), serious AEs, and deaths were similar during each year of anakinra treatment; the overall rate (0 to 3 years) was similar to that observed for controls during the blinded phase. The most frequent AEs were injection site reactions (122.26 events/100 patient-years), rheumatoid arthritis progression (67.80 events/100 patient-years), and upper respiratory infections (26.09 events/100 patient-years). The EAE rate of serious infections was higher for patients treated with anakinra for 0 to 3 years (5.37 events/100 patient-years) than for controls during the blinded phase (1.65 events/100 patient-years). However, if the patient was not receiving corticosteroid treatment at baseline, the serious infection rate was substantially lower (2.87 event/100 patient-years). The overall incidence of malignancies was consistent with expected rates reported by SEER. Neutralising antibodies developed in 25 patients, but appeared to be transient in 12; neutralising antibody status did not appear related to occurrence of malignancies or serious infections. There were no clinically significant trends in laboratory data related to anakinra.

CONCLUSION

Anakinra is safe and well tolerated for up to three years of continuous use in a diverse population of patients with rheumatoid arthritis.

Tumour necrosis factor blockers do not increase overall tumour risk in patients with rheumatoid arthritis, but may be associated with an increased risk of lymphomas

OBJECTIVE

To determine whether TNF blockers increase tumour risk in patients with RA.

MATERIALS AND METHODS

The South Swedish Arthritis Treatment Group register (SSATG) comprises over 90% of anti-TNF treated patients with RA in the area. 757 patients treated with etanercept or infliximab included between 1 February 1999 and 31 December 2002 were identified. 800 patients with conventional antirheumatic treatment in a community based cohort served as a comparison cohort. Tumours and deaths were identified in the cancer registry and population census registers. Patients were followed up from initiation of anti-TNF treatment or 1 July 1997 for the comparison group, until death or 31 December 2002.

RESULTS

In the anti-TNF group, 16 tumours (5 lymphomas) were identified in 1603 person-years at risk, and in the comparison group 69 tumours (2 lymphomas) in 3948 person-years. Standardised incidence ratios (SIRs) for total tumour relative risk for the anti-TNF group and the comparison group were 1.1 (95% confidence interval (CI) 0.6 to 1.8) and 1.4 (95% CI 1.1 to 1.8), respectively. The lymphoma relative risk (RR) was 11.5 (95% CI 3.7 to 26.9) and 1.3 (95% CI 0.2 to 4.5), respectively The total tumour RR excluding lymphoma was 0.79 (95% CI 0.4 to 1.42) and 1.39 (95% CI 1.08 to 1.76), respectively. Proportional hazard analysis for lymphomas yielded RR 4.9 (95% CI 0.9 to 26.2) in anti-TNF treated versus untreated patients.

CONCLUSION

Community based patients with RA treated conventionally had an increased overall tumour risk compared with the background population. A possible additional increased risk for lymphoma associated with TNF blockers was based on few cases and needs confirmation.

Effects of use of specialty services on disease-modifying antirheumatic drug use in the treatment of rheumatoid arthritis in an insured elderly population

BACKGROUND

In community settings, disease-modifying antirheumatic drug (DMARD) use for rheumatoid arthritis (RA) falls short of treatment recommendations. This population-based study investigates the relationship between the use of DMARDs and specialty care in an insured population.

METHOD

A cohort of individuals aged 65 or older with RA was identified from a population-based physician billing database in Ontario, Canada, together with information on visit rates to general and specialist physicians and visit-specific diagnoses. DMARD prescription data were obtained from the Ontario Drug Benefits Plan database. The proportions of individuals with RA using DMARDs and specialist care were calculated for the 43 counties in Ontario, and the relationship between the 2 was determined using logistic multilevel modeling, controlling for possible confounders.

RESULTS

A total of 13,698 RA individuals aged 65 or older were identified, representing 1% of the 65-or-older population. Within this cohort, 58% received DMARDs and 68% made 1 or more RA-related visits to a specialist in 3 years. There was considerable variation by county in both the proportion of those with RA making visits to specialists (39-82 per 100 RA population) and receiving DMARDs (36-81%). The use of DMARDs was significantly associated with the use of specialist services by individuals with RA (odds ratio 1.9 [95% confidence interval 1.87, 1.88] for counties with highest versus lowest proportional use of specialists) independent of effects of age, sex, income, and comorbidities.

CONCLUSION

Even in a universally funded setting, suboptimal treatment of RA is associated with lack of access to specialist services. These findings are likely applicable to many jurisdictions worldwide.

Lymphoma in rheumatoid arthritis: the effect of methotrexate and anti-tumor necrosis factor therapy in 18,572 patients

OBJECTIVE

The risk of lymphoma is increased in patients with rheumatoid arthritis (RA), and spontaneous reporting suggests that methotrexate (MTX) and anti-tumor necrosis factor (anti-TNF) therapy might be associated independently with an increased risk of lymphoma. However, data from clinical trials and clinical practice do not provide sufficient evidence concerning these issues because of small sample sizes and selected study populations. The objective of this study was to determine the rate of and standardized incidence ratio (SIR) for lymphoma in patients with RA and in RA patient subsets by treatment group. Additionally, we sought to determine predictors of lymphoma in RA.

METHODS

We prospectively studied 18,572 patients with RA who were enrolled in the National Data Bank for Rheumatic Diseases (NDB). Patients were surveyed biannually, and potential lymphoma cases received detailed followup. The SEER (Survey, Epidemiology, and End Results) cancer data resource was used to derive the expected number of cases of lymphoma in a cohort that was comparable in age and sex with the RA cohort.

RESULTS

The overall SIR for lymphoma was 1.9 (95% confidence interval [95% CI] 1.3-2.7). The SIR for biologic use was 2.9 (95% CI 1.7-4.9) and for the use of infliximab (with or without etanercept) was 2.6 (95% CI 1.4-4.5). For etanercept, with or without infliximab, the SIR was 3.8 (95% CI 1.9-7.5). The SIR for MTX was 1.7 (95% CI 0.9-3.2), and was 1.0 (95% CI 0.4-2.5) for those not receiving MTX or biologics. Lymphoma was associated with increasing age, male sex, and education.

CONCLUSION

Lymphomas are increased in RA. Although the SIR is greatest for anti-TNF therapies, differences between therapies are slight, and confidence intervals for treatment groups overlap. The increased lymphoma rates observed with anti-TNF therapy may reflect channeling bias, whereby patients with the highest risk of lymphoma preferentially receive anti-TNF therapy. Current data are insufficient to establish a causal relationship between RA treatments and the development of lymphoma.

Associations between rheumatoid arthritis and malignancy

There are many complex associations between rheumatoid arthritis(RA) and malignancy. Patients with rheumatic diseases on the whole appear to be at increased risk for the development of certain malignancies. The data from several studies are persuasive that the presence of RA conveys an increased risk for the development of lymphoproliferative disorders and may convey a decreased risk for the development of malignancies of the digestive tract. Understanding the complex interrelationships between RA and malignancy will lead to more accurate diagnosis of underlying pathology, more effective treatment of symptoms and underlying disease, and appropriate surveillance for the development of later complications.

Rheumatoid arthritis and malignant lymphomas

PURPOSE OF REVIEW

The reason for the increased lymphoma risk in patients with rheumatoid arthritis (RA) has remained unclear. Reports of lymphomas in patients treated with TNF-blockers have brought renewed interest in this issue. This review summarizes data on possible associations between RA and lymphomas, including different treatments and RA disease related risk factors.

RECENT FINDINGS

Some recent studies reported increased lymphoma risks linked to RA disease activity. The hypothesis that disease-modifying drugs, and in particular methotrexate, would increase the lymphoma risk receives little support. Observation times for the TNF-blocking therapies are still short, but so far no clear increased risk for lymphoma has been observed. Presence of Epstein-Barr virus, as analyzed with EBER in situ hybridization, appears to be uncommon in RA related lymphomas. Hypothetically, an increased proliferative drive caused by self or non-self antigens may play a role in lymphoma development in RA patients, but this has to be further studied.

SUMMARY

Rheumatologists need to be aware of the increased lymphoma risk in their RA patients. The reason for the increased lymphoma risk in RA patients is still unclear, but available studies rather support the hypothesis of a link between RA disease severity and the risk of lymphoma than increased risks associated with specific treatment regimens. To facilitate the future evaluation of lymphoma risks in connection with treatment, we suggest that patients treated with new drugs should be subject to structured surveillance. Collected information should include data about RA disease activity and severity.

Association of aspirin and other non-steroidal anti-inflammatory drug use with incidence of non-Hodgkin lymphoma

Non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, seem to have chemopreventive properties against several types of cancer, particularly colon cancer. Persons with rheumatoid arthritis, an autoimmune disease for which NSAIDs are used commonly, have been reported to be at lower risk of colon cancer but at elevated risk of non-Hodgkin lymphoma (NHL), raising the possibility that NSAIDs may be a risk factor for NHL. We evaluated the association of use of NSAIDs, arthritis history, and risk of NHL in a prospective cohort of 27,290 postmenopausal women from the state of Iowa. The frequency of use of aspirin and of other NSAIDs excluding aspirin (e.g., ibuprofen), as well as a physician diagnosis of rheumatoid arthritis (RA) or osteoarthritis (OA), were self-reported on a questionnaire mailed in 1992. The incidence of NHL was ascertained through annual linkages to the Iowa SEER Cancer Registry. Relative risks (RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression. Through 7 years of follow-up, 131 cases of NHL were identified. Compared to women who did not use either aspirin or other non-aspirin NSAIDs, women using aspirin exclusively (RR = 1.71; 95% CI = 0.94-3.13), non-aspirin NSAIDs exclusively (RR = 2.39; 95% CI = 1.18-4.83), or both types of drugs (RR = 1.97; 95% CI = 1.06-3.68) were at increased risk of NHL. A diagnosis of RA (RR = 1.75; 95% CI = 1.09-2.79), but not OA (RR = 1.06; 95% CI = 0.67-1.68), was associated with risk of NHL, but the positive association of use of aspirin and other NSAIDs with NHL was independent of RA history. Multivariate adjustment for other NHL risk factors only attenuated slightly these associations, whereas exclusion of cases occurring during the first 2 years of follow-up strengthened the associations. These data suggest that use of NSAIDs, either aspirin or other non-aspirin NSAIDs, are associated positively with risk of NHL, and that this association is independent of RA history.

Rheumatic diseases and malignancy--is there an association?

An association between rheumatic diseases and malignancy has been claimed in a variety of settings. This editorial reviews published data addressing the overall risk of malignancy, and of particular types of cancer, in the context of various autoimmune rheumatic diseases. For patients with Sjögren's syndrome, systemic sclerosis with pulmonary fibrosis, or with dermatomyositis/polymyositis there is a documented association with an increased risk of malignant disease. Patients with rheumatoid arthritis may also have an increased risk of cancer. It is still controversial whether systemic lupus erythematosus is associated with an increased risk of developing malignancy. More epidemiologic studies are needed to try and clarify many of these associations, in particular the potential risks associated with cytotoxic therapy.

Concordance on the recording of cancer in the Saskatchewan Cancer Agency Registry, hospital charts and death registrations

Accurate and complete registries are an important source of knowledge about cancer. The concordance of the recording of neoplasms in the Saskatchewan cancer registry with that in hospital charts and death registrations was evaluated for 368 patients. The agreement between registry and hospital charts or death registrations was excellent (kappa: 0.93; 95% confidence interval: 0.89, 0.97), with 91.3% of those with cancer having the same neoplasm recorded in their chart or death registration as in the registry. There was only one patient whose hospital chart indicated cancer who was not in the registry and one apparent major discrepancy relating to the cancer site, which was due to the recording of the primary site in the registry and a secondary in the hospital chart. Although based on a relatively small number of patients, these results suggest a high degree of consistency between cancer registry, hospital charts and death registrations in Saskatchewan.

The incidence of cancer associated with the treatment of rheumatoid arthritis

OBJECTIVES

The treatment of rheumatoid arthritis (RA) targets inflammation either by inhibiting the activation of immune cells or their clonal expansion. We evaluated the available evidence concerning the risk of cancer associated with RA treatment.

METHOD

Articles published between 1966 and 1998 reporting the incidence of cancer in RA patients were reviewed.

RESULTS

Large follow-up studies suggest the relative risk (RR) of lymphomas associated with RA is about twofold higher than in the general population. A role for azathioprine in the development of lymphomas and a role for cyclophosphamide in cancers, particularly bladder cancer, has been suggested. However, no studies have shown that methotrexate increases the risk of cancer in RA patients. Studies that showed an increased risk of cancer associated with gold or cyclosporine therapy in RA patients are inconclusive as they have used cancer incidence in the general population as the reference. One study measured the RR of cancer in a group of cyclosporine-treated RA patients (1.6 year on average) using RA patients as a control and found no enhanced risk.

CONCLUSIONS

Although evidence suggests an increased risk of specific cancers associated with the use of some treatments, this may be outweighed by the potential benefit of therapy, especially in patients with severe disease.

Rheumatic syndromes: clues to occult neoplasia

OBJECTIVES

Rheumatic disorders associated with cancer include a variety of conditions, most of which have no features distinguishing them from idiopathic rheumatic disorders. It is generally held that an extensive search for occult malignancy in most rheumatic syndromes is not recommended unless accompanied by specific findings suggestive of malignancy. The objective of this review are to identify rheumatic syndromes associated with cancer, to call attention to features that may suggest the presence of a hidden cancer, and to examine the role to additional clinical and laboratory data as clues to the possible neoplastic cause of those syndromes.

METHODS

A MEDLINE search of the literature dealing with cancer-associated rheumatic syndromes was conducted.

RESULTS

Review of the literature identified significant progress in this area. First, the association of malignancy with certain rheumatic syndromes was convincingly established, such as asymmetric polyarthritis presenting in the elderly with an explosive onset, rheumatoid arthritis with monoclonal gammopathy, Sjögren's syndrome with monoclonality, hypertrophic osteoarthropathy, dermatomyositis, polymyalgia rheumatica with atypical features, Lambert-Eaton myasthenic syndrome, palmar fasciitis and arthritis, eosinophilic fasciitis poorly responsive to corticosteroid therapy, erythema nodosum lasting more than 6 months, and onset of Raynaud's phenomenon or cutaneous leukocytoclastic vasculitis after age 50 years. Second, the list of cancer-associated rheumatic syndromes was extended by including additional entities such as benign edematous polysynovitis, sacroiliitis, adult-onset Still's disease, dermatomyositis sine myositis, systemic sclerosis, Sweet's syndrome, osteomalacia, skeletal hyperostosis, antiphospholipid syndrome, and essential mixed cryoglobulinemia. Third, evidence was provided substantiating that certain long-standing rheumatic syndromes, in particular rheumatoid arthritis, Felty's syndrome, Sjögren's syndrome, dermatomyositis, systemic sclerosis, systemic lupus erythematosus, and temporal arteritis behave like "premalignant conditions." Fourth, it was shown that the recognized tumor markers alpha-fetoprotein, prostate-specific antigen, CA-125, CA 19-9, and CA-3 have low sensitivity and specificity in screening for occult cancer in a population of rheumatic patients, whereas the presence of a monoclonal gammopathy in rheumatoid arthritis and the monoclonal antibody 17-109 in Sjögren's syndrome are reliable signs of malignant transformation.

CONCLUSIONS

The presence of specific rheumatic syndromes and certain clinical and laboratory findings may justify a workup for hidden cancer. Studies of the epidemiology of the cancer-associated rheumatic syndromes and evaluation of the validity of aforementioned clues in prospective studies are goals for future investigations.

Does methotrexate increase the risk of infection or malignancy?

Most patients do not exhibit overt signs of immunosuppression. Studies cited in this article support a modest increase in the rate of bacterial respiratory and skin infections. Opportunistic infections occur rarely, however, and may be life threatening. The case for MTX carcinogenicity is less clear. The risk for malignancy other than lymphoproliferative disorders does not seem to be elevated, although multiple sporadic malignancies have been reported in treated patients. MTX is a superb agent for the therapy of a large group of immune-mediated diseases. Although an increased risk for infection and possible malignancy exists, the risk is small compared with the potential clinical benefit.

Reliability of the recording of schizophrenia and depressive disorder in the Saskatchewan health care datafiles

Administrative data have long been used in psychiatric epidemiology and outcomes evaluation. This article examines the reliability of the recording of schizophrenia and depressive disorder in three Saskatchewan administrative health care utilization datafiles. Due to their comprehensive nature, these datafiles have been used in a wide range of epidemiologic studies. Close agreement was found between hospital computer data and patients' charts for personal and demographic factors (> or = 94.7%). Diagnostic concordance between computerized hospital data and medical charts was very good for schizophrenia (94%) but poor for depressive disorder (58%). Appropriate physician services were identified for 60% and 72% of hospital discharges for schizophrenia and depressive disorder, respectively, and exact diagnostic agreement between hospital and physician datafiles was 62% for schizophrenia and 66% for depressive disorder. Appropriate provincial mental health branch services were found for 83% and 38% of hospital discharges for schizophrenia and depressive disorder, respectively; exact diagnostic concordance between these datafiles was 75% for schizophrenia and 0% for depressive disorder. A significant number of patients with major or neurotic depression appeared to be wrongly coded as having depressive disorder in the hospital file. The differences in diagnostic agreement may also be partly a function of how the two conditions are differentially treated in the health system. These findings suggest that more specific and severe psychiatric diagnoses are likely to be recorded accurately and consistently in the Saskatchewan datafiles. However, disorders with multiple manifestations or those for which there are several possible codes should be examined with caution and ways sought to validate them. Attention should also be paid to which service sectors are involved in the treatment of specific disorders.

Can we predict aggressive disease?

This chapter will describe the reasons why prognostic factors that predict aggressive disease are helpful and what the problems are in interpreting studies in this field. A summary of cohort studies on prognosis of patients with early rheumatoid arthritis are presented. This is done separately for studies predicting radiographic damage, functional outcome and mortality. The overall conclusions of these studies and the value they have for the clinician are demonstrated.

Serum levels of soluble CD44 variant isoforms are elevated in rheumatoid arthritis

Serum levels of soluble CD44 variant proteins including sequences encoded by exon v5 and exon v6 (sCD44v5, sCD44v6) were determined in patients with inflammatory rheumatic diseases: 56 with rheumatoid arthritis (RA+) and 31 with miscellaneous inflammatory rheumatic diseases (MIRD). There were very significantly higher serum levels of sCD44v5 and sCD44v6 in patients with RA+ than in those with MIRD (RA+ to MIRD: sCD44v5: 81 +/- 54 ng/ml to 33 +/- 13 ng/ml; sCD44v6: 237 +/- 124 ng/ml to 166 +/- 53 ng/ml; both P << 0.001). In RA+ elevated serum levels of sCD44v5 were correlated with the inflammatory activity of disease. In 17 patients with RA+ three or four follow-up measurements of sCD44v5 were performed within 6 months. The development of sCD44v5 serum levels reflected the clinical course of disease in the patients investigated.

Chromosomal changes in rheumatoid arthritis patients treated with CPH82

Chromosomal changes were assessed in 19 patients with rheumatoid arthritis (RA) treated with CPH82, a benzylidated podophyllotoxin glycoside, for up to one year. The frequency of chromosomal aberrations (CA) and sister chromatid exchanges (SCE) in peripheral lymphocytes increased significantly after 12 weeks of treatment and remained elevated after 48 weeks treatment in peripheral lymphocytes. The number of CA and SCE were significantly increased in CPH82 treated patients compared with the RA patients treated with other disease modifying anti-rheumatic drug (sulphasalazine, gold, D-penicillamine, azathioprine, methotrexate, cyclophosphamide). Only two patients treated with cyclophosphamide and azathioprine had changes of comparable levels. The results of this study suggest a mutagenic potential of CPH82 similar to that described for other immunosuppressive drugs and the newer podophyllotoxin derivatives, etoposide and teniposide.

Reliability of the recording of hysterectomy in the Saskatchewan health care system

OBJECTIVE

To determine the validity of data pertaining to hysterectomy in the Saskatchewan health care utilisation datafiles.

DESIGN

Retrospective analysis of routinely collected data covering hospital discharge records and practitioner claims for reimbursement of services, together with a review of clinical charts.

SETTING

Province of Saskatchewan, Canada.

SAMPLE

All 1905 cases of hysterectomy in one calendar year for analysis of datafiles and a random sample of 227 clinical charts for review.

METHOD

Information in the hospitalisation datafile was validated through an external comparison with data extracted from a review of clinical charts, as well as an internal comparison with independent data from the practitioner claims file. Corresponding context data on drug use and performance of related procedures were also analysed.

RESULTS

Concordance between hospital data and clinical charts was greater than 95% for those items of an administrative nature as well as type of hysterectomy and was around 85% for the diagnoses. When hospitalisation and practitioner claims data were compared, the concordance was 98% for type of hysterectomy but only 56% for diagnoses.

CONCLUSIONS

The agreement between hospital data and clinical charts was excellent. The concordance between hospitalisation and practitioner claims data was almost exact for type of hysterectomy, while discrepancies in diagnoses between these files were mostly explainable on the basis of accepted clinical practice. Saskatchewan health care utilisation datafiles provide a source of valid data for research and evaluation studies.

Cancer risk after metal on metal and polyethylene on metal total hip arthroplasty

The incidence of cancer after metal on metal total hip arthroplasty (McKee-Farrar) and polyethylene on metal total hip arthroplasty (Brunswik, Lubinus) was compared with that of the general population in Finland. The mean followup time for the patients who had metal on metal total hip arthroplasty was 15.7 (9092 person years) and for the patients who had polyethylene on metal total hip arthroplasty it was 12.5 years (19,846 person years). One hundred thirteen malignant cancers were observed in patients who had metal on metal total hip arthroplasty and 212 were observed in patients who had polyethylene on metal total hip arthroplasty. The standardized incidence ratio for all cancers of the metal on metal arthroplasty group was 0.95 (95% confidence limits 0.79-1.13) and that of the polyethylene on metal arthroplasty group was 0.76 (95% confidence limits 0.68-0.86). The risk of total cancer in the patients who had metal on metal total hip arthroplasty was 1.23-fold compared with that of the patients who had polyethylene on metal total hip arthroplasty. Both groups had significantly less lung cancer than the general population: the leukemia incidence in the patients who had metal on metal total hip arthroplasty was slightly increased (observed to experienced 7/3.03, standardized incidence ratio 0.61; 95% confidence limits 0.17-1.56). The leukemia rate of the patients who had metal on metal total hip arthroplasty was 3.77-fold compared with that of the patients who had polyethylene on metal total hip arthroplasty, but this difference was not statistically significant. No sarcomas were observed at the site of the prosthesis. The incidence of the other forms of cancers did not differ significantly from those in the general population. The observed variation in the incidence of different cancers among patients who had total hip arthroplasty compared with the general population suggests that factors other than total hip arthroplasty play a major role in the origin of cancer.

Validity of the recording of ischaemic heart disease and chronic obstructive pulmonary disease in the Saskatchewan health care datafiles

The internal validity of the recording of information about ischaemic heart disease (IHD) and chronic obstructive pulmonary disease (COPD) in the administrative health care datafiles of the Canadian province of Saskatchewan is investigated. Comparisons between hospital data and medical charts for acute myocardial infarction and chronic airways obstruction patients showed excellent diagnostic agreement: 97 per cent and 94 per cent, respectively. Appropriate physician service claims were identified for 89 per cent of hospitalizations for IHD and COPD and exact concordance between diagnoses in the two datafiles varied between 15 per cent for acute/sub-acute IHD and 80 per cent for asthma; including any physician diagnosis within the same broad category (IHD or COPD) increased concordance to 79-94 per cent for IHD and 64-88 per cent for COPD. Contextual information related to the hospitalizations was clinically and epidemiologically realistic.

Cancer morbidity in rheumatoid arthritis patients treated with Proresid or parenteral gold

The cancer risk was studied by comparison of 305 rheumatoid arthritis (RA) patients exposed to Proresid during a mean time of 22 months and 305 RA patients exposed to sodium aurothiomalate during a mean time of 19 months with the regional cancer register. The mean observation time was 6.9 years (2,117 person-years) for the Proresid-treated and 7.5 years (2,293 person-years) for the gold-treated patients. No increased risk of total malignancies was observed for either group. However, looking at separate tumours, an increased risk of lymphoma and leukemia was found although only significant in the gold-treated group. It was not correlated to dosage or duration of either therapy. The increased risk is consistent with earlier reports of an increased risk of hematopoietic malignancies in RA patients. Marginal over and underreporting, particularly of hematopoietic malignancies, were observed, mainly due to clinicians' failure to report and to recall false reports.