The prevalence of malignant tumors in patients with psoriasis

Cancer risks in patients with psoriasis administered biologics therapy: a nationwide population-based study

PURPOSE

To assess cancer risks in patients with psoriasis and the effect of TNF-α inhibitor and interleukin (IL)-12/23 inhibitor therapy on those cancer risks.

METHODS

Using the Korean Health Insurance Review and Assessment Service database, patients with newly diagnosed psoriasis between 2008 to 2019 were included. Standardized incidence ratios (SIRs) of overall and specific cancers were calculated in patients with psoriasis. The effect of TNF-α inhibitor and IL-12/23 inhibitor exposure on the risk of cancers was assessed by multivariable Cox regression models.

RESULTS

In total, 191,678 patients with psoriasis were included in this study. The overall risk of cancer was significantly higher in patients with psoriasis than in the general population (SIR, 1.12; 95% confidence interval (CI), 1.09-1.14). TNF-α inhibitor users had a significantly higher risk for overall cancer (adjusted hazard ratio (aHR), 1.41; 95% CI 1.01-1.97). In contrast, IL-12/23 inhibitor exposure had a significantly lower risk for overall cancer (aHR, 0.57; 95% CI 0.37-0.87). Among specific cancers, the risks of non-Hodgkin lymphoma (aHR, 2.98; 95% CI 1.02-8.69) were increased by TNF-α inhibitor therapy, while the risk of other cancers, including nonmelanoma skin cancer (aHR, 2.31; 95% CI 0.51-10.46), was not significantly altered by TNF-α inhibitor therapy.

CONCLUSION

TNF-α inhibitor therapy in psoriasis is associated with a significantly increased risk of overall cancer and lymphoma, while the risk of solid organ cancer was not affected by this therapy. The IL-12/23 inhibitor is not associated with an increased risk of any cancer.

Investigation of the causal relationship between breast cancer and autoimmune diseases: A bidirectional mendelian randomization study

A clear bidirectional relationship exists between malignant cancers including breast cancer and different autoimmune diseases. However, none of the studies have assessed whether this association is causal and none have used Mendelian randomization for determining this relationship. This study therefore investigated the causal relationship between autoimmune diseases and breast cancer using the Mendelian randomization approach. Summary statistical data were obtained from genome-wide association studies to investigate the causal relationship between different autoimmune diseases including Graves' disease, Sjögren's syndrome, Crohn disease, systemic sclerosis, and psoriasis and breast cancer risk. The results revealed no strong evidence to support the causal relationship between Graves disease (odds ratio [OR] = 0.9958; 95% confidence interval [CI]: 0.9982-1.0035), Sjögren's syndrome (OR = 1.0018; 95% CI: 0.9950-1.0087), Crohn disease (OR = 2.1195, 95% CI: 0.1872-23.9978), systemic sclerosis (OR = 1.0024; 95% CI: 0.997-1.0079), and psoriasis (OR = 1.0016; 95% CI: 0.9913-1.0121) to breast cancer risk. A similar result was obtained in the reverse Mendelian randomization analysis. Our study provides evidence that autoimmune diseases might not have a causal relationship with breast cancer risk in the European population and concludes that shared genetic effects or environmental confounders.

Association of Psoriasis With the Risk of Developing or Dying of Cancer: A Systematic Review and Meta-analysis

Importance

The risk of cancer developing in people with psoriasis has raised some concern, with little clarity regarding differentiation in risk according to psoriasis severity.

Objective

To conduct a systematic review and meta-analysis of observational studies on the risk of cancer incidence and mortality in people with psoriasis.

Data Sources

Six electronic databases (MEDLINE, Embase, MEDLINE in Process, Cochrane Central Register, Web of Science, and LILACS [Literatura Latino-Americana e do Caribe em Ciências da Saúde]) were searched from inception to November 15, 2017, for eligible studies.

Study Selection

Cohort and case-control studies that provided estimates of the risk of cancer incidence or cancer mortality associated with psoriasis were included.

Data Extraction and Synthesis

Data were extracted relating to study design, study population, and risk estimates. Study-specific estimates of the relative risk (RR) were combined using a random-effects model. Heterogeneity was quantified using the I2 statistic. Data were analyzed from April 9, 2018, through February 22, 2019.

Main Outcomes and Measures

Pooled RR estimates for cancer incidence and cancer mortality for psoriasis cohorts compared with people without psoriasis.

Results

A total of 58 unique studies were included, with quality varying for the incidence and the mortality studies. Severe psoriasis (RR, 1.22; 95% CI, 1.08-1.39 [9 studies]) and all severities of psoriasis (RR, 1.18; 95% CI, 1.06-1.31 [7 studies]) were associated with an increased risk of cancer (overall), and associations were found for a range of site-specific cancers, including colon (RR, 1.18 [95% CI, 1.03-1.35]), colorectal (RR, 1.34 [95% CI, 1.06-1.70]), kidney (RR, 1.58 [95% CI, 1.11-2.24]), laryngeal (RR, 1.79 [95% CI, 1.06-3.01]), liver (RR, 1.83 [95% CI, 1.28-2.61]), lymphoma (RR, 1.40 [95% CI, 1.24-1.57]), non-Hodgkin lymphoma (RR, 1.28 [95% CI, 1.15-1.43]), keratinocyte cancers (RR, 1.71 [95% CI, 1.08-2.71]), esophageal (RR, 2.05 [95% CI, 1.04-4.07]), oral cavity (RR, 2.80 [95% CI, 1.99-3.93]), and pancreatic (RR, 1.41 [95% CI, 1.16-1.73]). Overall cancer mortality risk was higher in patients with severe psoriasis (RR, 1.22; 95% CI, 1.08-1.38 [4 studies]). Specifically, liver (RR, 1.43 [95% CI, 1.09-1.88]), esophageal (RR, 2.53 [95% CI, 1.87-3.41]), and pancreatic (RR, 1.31 [95% CI, 1.02-1.69]) cancer mortality were found to be elevated in those with severe psoriasis. The heterogeneity of estimates was often very high despite stratification. Marked attenuation of risk was found in those studies that adjusted estimates for smoking, alcohol consumption, and obesity.

Conclusions and Relevance

In this study, people with psoriasis appeared to have an increased risk of cancer incidence and cancer-related mortality involving a range of site-specific cancers. Future research examining specific lifestyle factors, treatments, and the inflammatory processes that contribute to psoriasis may help provide additional information on the underlying mechanisms for the apparent increased cancer risk.

Prevalence, Incidence, and Risk of Cancer in Patients With Psoriasis and Psoriatic Arthritis: A Systematic Review and Meta-analysis

Importance

The association between psoriasis and risk of cancer remains debatable.

Objective

To evaluate the association and risk of cancer in patients with psoriasis or psoriatic arthritis, including risk of specific cancer subtypes.

Data Sources

Two databases (PubMed and Embase) were screened from inception to January 1, 2019, using the search string psoriasis or psoriatic and neoplasms or malignancy or cancer. The search was filtered to only include human participants and publications in English.

Study Selection

Observational cohort studies with a population of patients with psoriasis or psoriatic arthritis were included. Studies had to be original and report the incidence or prevalence of cancer within this population. Studies evaluating pediatric populations and cancer types not included in the protocol were excluded.

Data Extraction and Synthesis

This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search string, objectives, and study protocol methods were defined before the study was initiated. A total of 365 studies were included for full-text assessment. Owing to the heterogeneity of the included studies, a random-effects model was used.

Main Outcomes and Measures

Main outcome was cancer (overall and specific subtypes) and measures were prevalence, incidence, and risk estimate for cancer in patients with psoriasis or psoriatic arthritis.

Results

Of the 365 studies assessed, 112 were included in the analysis (N = 2 053 932 patients). The overall prevalence of cancer in patients with psoriasis was 4.78% (95% CI, 4.02%-5.59%), with an incidence rate of 11.75 per 1000 person-years (95% CI, 8.66-15.31) and a risk ratio (RR) of 1.21 (95% CI, 1.11-1.33). There was an increased risk of several cancers, including keratinocyte cancer (RR, 2.28; 95% CI, 1.73-3.01), lymphomas (RR, 1.56; 95% CI, 1.37-1.78), lung cancer (RR, 1.26; 95% CI, 1.13-1.40), and bladder cancer (RR, 1.12; 95% CI, 1.04-1.19). No increased risk of cancer for patients with psoriasis treated with biologic agents was found (RR, 0.97; 95% CI, 0.85-1.10). Psoriatic arthritis was not associated with increased risk of cancer overall (RR, 1.02; 95% CI, 0.97-1.08).

Conclusions and Relevance

Patients with psoriasis appear to have a slightly increased risk of cancer, particularly keratinocyte cancer and lymphomas. Data on treatment with biologic agents did not show an increased risk of cancer. Data on cancer in patients with psoriatic arthritis remain scarce, and further research is warranted in this area.

Cancer risk in 892 089 patients with psoriasis in Korea: A nationwide population-based cohort study

The relationship between psoriasis and cancer has not yet been established. The aim of this study was to evaluate the association of psoriasis with certain cancers using national statistics. All patients with psoriasis (n = 892 089; 51.7% male) and age- and sex-matched control subjects (n = 4 460 445) at a 5:1 ratio were enrolled using data from the National Health Insurance Service between 2007 and 2014 in Korea. In psoriatic subjects, overall cancer risk was higher than for subjects without psoriasis after adjusting for income level, diabetes, hypertension, dyslipidemia and place of residence (hazard ratio, 1.065; 95% CI, 1.049-1.081). The risk of cancer increased in the following order: prostate, thyroid, liver, ovarian, lung, leukemia, skin, multiple myeloma, lymphoma and testicular. The severity and sex of psoriatic patients also had different cancer risks. In psoriatic patients, a slightly increased risk for specific malignant neoplasms was shown. Therefore, periodic screening for cancer risk is recommended in patients with psoriasis.

The risk of malignancy among biologic-naïve pediatric psoriasis patients: A retrospective cohort study in a US claims database

BACKGROUND

Little published literature exists regarding malignancy risk in pediatric psoriasis patients.

OBJECTIVE

To compare malignancy risk in biologic-naïve pediatric psoriasis patients with a matched pediatric population without psoriasis.

METHODS

This retrospective cohort study used IMS LifeLink Health Plan Claims data covering 1998-2008. Cancer incidence was compared with the US Surveillance, Epidemiology, and End Results (SEER) data using standardized incidence ratios (SIR), and between cohorts using Cox models.

RESULTS

Among 9045 pediatric psoriasis patients and 77,206 comparators, 18 probable or highly probable cancers were identified. Pediatric psoriasis patients had a nonsignificantly lower incidence than comparators (hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.05-3.54). The HR increased to 1.67 (95% CI 0.54-5.18) when cancer diagnosed during the first 90 days of follow-up was included. The pediatric psoriasis cohort had a significantly increased lymphoma rate compared with SEER (SIR 5.42, 95% CI 1.62-12.94), but no significant increase relative to the comparator cohort.

LIMITATIONS

Misclassification of disease and outcome might have occurred with patients in the claims database.

CONCLUSION

Patients with pediatric psoriasis showed no significant increase in overall cancer risk compared with those without psoriasis. A potential increased risk for lymphoma was observed when compared with the general population.

Psoriasis: female skin changes in various hormonal stages throughout life--puberty, pregnancy, and menopause

Psoriasis is one of the most prevalent immune mediated skin diseases worldwide. Despite the large prevalence in both men and women, the pathogenesis of this disease has not yet been fully clarified. Nowadays, it is believed that psoriasis is most likely a T helper Th1/Th17 induced inflammatory disease. Stressful life situations are known to cause flare-ups and psoriasis activity may be linked to stress from major life events. We know that stress greatly affects both the hormone and immune systems and that there are many different hormonal phases throughout a woman's lifetime. The severity of psoriasis may fluctuate or be influenced by each phase and this relationship can be seen as disease frequency seems to peak during puberty, postpartum, and menopause when hormone levels fall, while symptoms improve during pregnancy, a state when hormone levels are increased.

Risk of cancer in psoriasis: a systematic review and meta-analysis of epidemiological studies

The relationship between psoriasis and increased cancer risk is debated. The aim of this study was to evaluate if there is an increase in the background risk of cancer in psoriasis patients compared with the general population. A systematic literature search was performed on PubMed, Embase and Cochrane databases, using the keywords 'Psoriasis [Majr] AND Neoplasms', from 1980 to January 2012. Meta-analysis was performed based on observational studies showing consistency in cancer risk assessment methods. Of the 1080 articles retrieved, 37 references were selected. There may be an increased risk of some solid cancers in psoriasis: respiratory tract cancer [standardized incidence ratio (SIR) = 1.52, 95% confidence interval (CI) 1.35-1.71], upper aerodigestive tract cancer (SIR = 3.05, 95% CI 1.74-5.32), urinary tract cancer (SIR = 1.31, 95% CI 1.11-1.55) and liver cancer (SIR = 1.90, 95% CI 1.48-2.44). The risk of non-Hodgkin lymphoma appears slightly increased in psoriasis (SIR = 1.40, 95% CI 1.06-1.86). Psoriasis patients have an increased risk of squamous cell carcinoma (SIR = 5.3, 95% CI 2.63-10.71) and basal cell carcinoma (SIR = 2.00, 95% CI 1.83-2.20), whereas the risk of melanoma is not increased. There was a large heterogeneity in studies assessing cancer risk in psoriasis preventing from including all studies in meta-analysis. This systematic literature review shows a small increased risk of some solid cancers in psoriasis, especially those linked to alcohol drinking and cigarette smoking. A higher risk of non-melanoma skin cancers, especially squamous cell carcinoma, is shown, mainly due to previous exposure to 8-methoxypsoralen-ultraviolet-A (PUVA), ciclosporin and possibly methotrexate.

Psoriasis, cardiovascular events, cancer risk and alcohol use: evidence-based recommendations based on systematic review and expert opinion

The relationship between psoriasis, chronic inflammation, cardiovascular risk and risk of cancer has long been debated. In addition, it has been suggested that alcohol consumption may be a risk factor for psoriasis onset and severity. The aim of this study was to develop evidence-based recommendations on the risk of comorbidities and its management for daily clinical use, focusing on cardiovascular risk, risk of cancer and alcohol use in psoriasis. A scientific committee identified and selected through the Delphi method clinically relevant questions about cardiovascular risk, risk of cancer and alcohol use in psoriasis. To address these questions, a systematic literature search was performed in Medline, Embase and the Cochrane Library databases. Systematic literature reviews including meta-analysis whenever possible were performed. Subsequently, an Expert board meeting involving 39 dermatologists took place to analyse the evidence and to elaborate recommendations on the selected questions. Recommendations were graded according to the Oxford level of evidence grading system. The degree of agreement of these recommendations was assessed on a 10-point scale, as well as their potential impact on daily clinical practice. A total of 3242 articles were identified through the systematic literature searches, among which 110 were included in the systematic reviews. Overall, 12 recommendations were elaborated regarding comorbidities management in psoriasis patients. A moderate increased risk of cardiovascular diseases (CVD), mainly myocardial infarction (MI) [meta-analysis of cohort studies: OR = 1.25 (95% CI 1.03-1.52) and of cross-sectional studies: OR = 1.57 (95% CI 1.08-2.27)], and coronary artery disease (CAD) [meta-analysis of cross-sectional: OR = 1.19 (95% CI 1.14-1.24), of cohort studies: OR = 1.20 (95% CI 1.13-1.27) and of case-control studies: OR = 1.84 (95% CI 1.09-3.09)] was acknowledged. This increased cardiovascular risk requires appropriate prevention measures. There was a lack of substantial evidence that conventional systemic treatment has any effect on cardiovascular risk although methotrexate might be cardioprotective. An increased risk of solid cancer potentially associated with smoking and alcohol use was identified. The role of systemic treatment on cancer risk could not be assessed thoroughly due to limited long-term follow-up data. A higher risk of non-melanoma skin cancers especially squamous cell carcinoma was shown, mainly due to previous exposure to oral 8-methoxypsoralen-ultraviolet-A (PUVA), ciclosporin and possibly methotrexate. No firm conclusion could be drawn regarding alcohol and psoriasis due to high variability in alcohol usage assessment in studies. Clinical experience suggests higher alcohol consumption among psoriasis patients compared to the general population. The mean expert participants' level of agreement on these recommendations varied from 6.8 to 9.4. These 12 recommendations are evidence based and supported by a panel of expert dermatologists. The next step is now to disseminate these recommendations to dermatologists who did not participate in the Expert board meeting and to assess their opinion about the recommendations.

The risk of cancer in patients with psoriasis: a population-based cohort study in Taiwan

BACKGROUND

An association between psoriasis and malignancy has been explored. However, no studies have been reported regarding cancer risk in Asian psoriasis populations.

OBJECTIVES

The aim of this study was to investigate the risk of cancer development in association with psoriasis. The effects of age at diagnosis, treatment modalities, and observation time were also evaluated.

METHODS

Data for this retrospective population-based cohort study were obtained from the Taiwan National Health Insurance Research Database (NHIRD). This study included 3,686 patients with first-time diagnosis of psoriasis between 1996 and 2000. Another 200,000 patients without psoriasis served as the comparison group. All enrolled subjects were followed-up until the end of 2007. Cumulative incidences and hazard ratios (HRs) of cancer development were determined.

RESULTS

Among the 3,686 psoriasis patients, 116 had incident cancers. The 7-year cumulative incidence of cancer among psoriasis patients was 4.8%. The adjusted HR for developing a cancer in association with psoriasis was 1.66 (95% confidence interval [CI], 1.38-2.00). Cancer risk was higher in male patients than in female patients (adjusted HR 1.86 vs.1.14, respectively). Certain cancers were significantly associated with psoriasis, including those of the urinary bladder and skin, followed by oropharynx/larynx, liver/gallbladder, and colon/rectum. Patients with psoriasis had an increased adjusted HR for cancer that varied by age. Younger patients with psoriasis tended to have the greatest risk of cancer. Finally, systemic phototherapy and oral medication did not significantly increase the risk of cancer. Phototherapy with UVB appeared to reduce the risk of cancer in psoriasis (adjusted HR, 0.52; 95% CI, 0.29-0.95; P = .03).

LIMITATIONS

NHIRD did not contain information regarding severity of psoriasis, status of smoking, alcohol use, family history of cancer, or diet. Misclassification of disease cannot be ruled out in a registry-based database.

CONCLUSIONS

Psoriasis carries an elevated risk of malignancies, especially in younger and in male patients. This effect is independent of systemic treatment for psoriasis. Finally, phototherapy with UVB did not increase, but rather reduced, the risk of cancer in psoriasis.

Update on the epidemiology and systemic treatment of psoriasis

Recent epidemiological observations reveal that the prevalence of psoriasis increases more rapidly in young women compared with young men, and that the prevalence of psoriasis may decrease in the elderly. Emerging evidence suggests that some potentially modifiable exposures, such as smoking, stress and obesity, may increase a patient's risk of developing psoriasis. The evolving literature suggests that psoriasis is associated with multiple other diseases, including cancer, cardiovascular disease, diabetes and psychiatric disease, and that psoriasis itself may be an independent risk factor for developing atherosclerosis and myocardial infarction. The treatment of moderate-to-severe psoriasis is undergoing a revolution with the advent of biological therapies that target the immunopathogenesis of psoriasis, such as tumor necrosis factor-alpha and T-cell function. The pharmacokinetics, pharmacodynamics, efficacy and safety profiles vary among biologicals and, therefore, drug and patient factors are important in selecting the optimum therapy. In this article, we focus on recent developments in the epidemiology and systemic treatment of psoriasis.

Coal tar in dermatology

Coal tar is one of the oldest treatments for psoriasis and eczema. It has anti-inflammatory, antibacterial, antipruritic and antimitotic effects. The short-term side effects are folliculitis, irritation and contact allergy. Coal tar contains carcinogens. The carcinogenicity of coal tar has been shown in animal studies and studies in occupational settings. There is no clear evidence of an increased risk of skin tumors or internal tumors. Until now, most studies have been fairly small and they did not investigate the risk of coal tar alone, but the risk of coal tar combined with other therapies. New, well-designed, epidemiological studies are necessary to assess the risk of skin tumors and other malignancies after dermatological use of coal tar.

Psoriasis and risk of incident cancer: an inception cohort study with a nested case-control analysis

Psoriasis has been associated with lymphohematopoietic and solid cancers; however, reports have been inconsistent. Cancer incidence was compared between psoriasis and psoriasis-free patients, and the roles of psoriasis duration and treatment were explored in this observational study using the UK General Practice Research Database. Among 67,761 patients, 1,703 patients had incident cancer; of whom 54% had a history of psoriasis. Incidence rate ratios for lymphohematopoietic and pancreatic cancers were 1.81 (95% confidence interval (CI) 1.35-2.42) and 2.20 (95% CI 1.18-4.09), respectively. In a nested case-control analysis, adjusted odds ratios (ORs) for cancer overall were 1.50 (95% CI 1.30-1.74) for psoriasis of >or=4 years duration and 1.53 (95% CI 0.97-2.43) for patients receiving systemic treatment (marker of disease severity). Lymphohematopoietic malignancy risk was highest in patients with systemic treatment. The OR for patients without systemic treatment was 1.59 (95% CI 1.01-2.50) for psoriasis of <2 years and 2.12 (95% CI 1.45-3.10) for that of >or=2 years duration. Risks of bladder/kidney and colorectal cancers were increased with longer-duration psoriasis. Psoriasis patients may have an increased overall risk of incident cancer (mainly lymphohematopoietic and pancreatic). Longer-term psoriasis and more severe disease may increase the risk of some cancers. These observations need further confirmation, particularly because of the potential of findings by chance in observational studies with subgroup analyses.

Autoimmune and inflammatory disorders and risk of malignant lymphomas--an update

As specific autoimmune disorders now constitute established risk factors for malignant lymphomas, we describe this association. We review reported risk levels, risk determinants, lymphoma subtypes and biological mechanisms in autoimmunity/inflammation, emphasizing on recent findings. Whilst numerous reports describe average lymphoma risks in large patient groups, there's a recent shift of focus to risk determinants and the role of inflammatory activity. Studies highlight associations with diffuse large B-cell lymphoma, apart from lymphoma development in target organs of inflammation. Future studies of high-risk patient subsets using detailed assessments of autoimmunity/inflammation and lymphoma may give important clues to lymphomagenesis.

Pathogenesis and clinical features of psoriasis

Psoriasis, a papulosquamous skin disease, was originally thought of as a disorder primarily of epidermal keratinocytes, but is now recognised as one of the commonest immune-mediated disorders. Tumour necrosis factor alpha, dendritic cells, and T-cells all contribute substantially to its pathogenesis. In early-onset psoriasis (beginning before age 40 years), carriage of HLA-Cw6 and environmental triggers, such as beta-haemolytic streptococcal infections, are major determinants of disease expression. Moreover, at least nine chromosomal psoriasis susceptibility loci have been identified. Several clinical phenotypes of psoriasis are recognised, with chronic plaque (psoriasis vulgaris) accounting for 90% of cases. Comorbidities of psoriasis are attracting interest, and include impairment of quality of life and associated depressive illness, cardiovascular disease, and a seronegative arthritis known as psoriatic arthritis. A more complete understanding of underlying pathomechanisms is leading to new treatments, which will be discussed in the second part of this Series.

[CARIMS (Cancer Risk In Multiple Sclerosis) project: impact of long-term treatment]

Controversial results have been published on potential link between cancer and multiple sclerosis. Multiple sclerosis has been linked to reduced rates of cancer prior to the era of immunomodulating or immunosuppressive treatments and until today, only 9 studies can be found in the literature. New strategies and early use of IM or IS drugs in MS justify to study and follow patients to detect a potential increase of cancer's incidence in treated patients. It is important to follow and collect prospectively in MS centers, patients with history of cancer, to document histologies, and potential relations with repeated IM or IS treatments. A prospective study is in progress in French MS centers on behalf the Club Francophone de la SEP (CARIMS Project).

Epidemiology of psoriasis. Review and the German perspective

According to population-based European studies, 2-3% of the population are affected by psoriasis. However, commonly accepted and validated diagnostic criteria are lacking. Psoriasis patients, compared to those with other dermatological disorders, are among those who suffer the highest impact on their quality of life, and this affection is comparable to other common diseases. Several lifestyle factors including alcohol and smoking have been associated with psoriasis. There is also evidence for associations with other diseases including cancer. Treatment of psoriasis engenders considerable costs, which should always be taken into account together with the relevant clinical outcome parameters. Prevention of psoriasis is crucial, as in the case of other common chronic diseases where causative treatments are lacking, but has barely been studied.

Malignant lymphomas in autoimmunity and inflammation: a review of risks, risk factors, and lymphoma characteristics

Certain autoimmune and chronic inflammatory conditions, such as Sjögren's syndrome and rheumatoid arthritis (RA), have consistently been associated with an increased risk of malignant lymphomas, but it is unclear whether elevated lymphoma risk is a phenomenon that accompanies inflammatory conditions in general. Likewise, it is debated whether the increased risk identified in association with some disorders pertains equally to all individuals or whether it varies among groups of patients with different phenotypic or treatment-related characteristics. It is similarly unclear to what extent the increased lymphoma occurrence is mediated through specific lymphoma subtypes. This update reviews the many findings on risks, risk levels, and lymphoma characteristics that have been presented recently in relation to a broad range of chronic inflammatory, including autoimmune, conditions. Recent results clearly indicate an association between severity of chronic inflammation and lymphoma risk in RA and Sjögren's syndrome. Thus, the average risk of lymphoma in RA may be composed of a markedly increased risk in those with most severe disease and little or no increase in those with mild or moderate disease. The roles of immunosuppressive therapy and EBV infection seem to be limited. Furthermore, RA, Sjögren's syndrome, systemic lupus erythematosus, and possibly celiac disease may share an association with risk of diffuse large B-cell lymphoma, in addition to well-established links of Sjögren's syndrome with risk of mucosa-associated lymphoid tissue lymphoma and of celiac disease with risk of small intestinal lymphoma. However, there is also obvious heterogeneity in risk and risk mediators among different inflammatory diseases.

The Risk of Lymphoma in Patients with Psoriasis

Psoriasis is a common, chronic, inflammatory disease. Psoriasis has been hypothesized to be associated with an increased risk of lymphoma due to its pathophysiology, its treatments, or a combination of these factors. We performed a large population-based cohort study of the risk of lymphoma in psoriasis patients using the General Practice Research Database. We identified 153,197 patients with psoriasis and 765,950 corresponding subjects without psoriasis. Psoriasis patients who received a systemic treatment consistent with extensive disease were classified as severe (N=3,994) and those who did not receive systemic therapies were classified as mild (N=149,203). The analyses were adjusted for age, gender, and person-time using a Cox proportional hazards model. For mild and severe psoriasis patients, the respective adjusted relative risks for lymphoma and its subtypes were as follows: all lymphoma 1.34 (1.16, 1.54) and 1.59 (0.88, 2.89); non-Hodgkin's lymphoma 1.15 (0.97, 1.37) and 0.73 (0.28, 1.96); Hodgkin's lymphoma (HL) 1.42 (1.00, 2.02) and 3.18 (1.01, 9.97); cutaneous T-cell lymphoma (TCL) 4.10 (2.70, 6.23) and 10.75 (3.89, 29.76). Psoriasis is associated with an increased risk of lymphoma. The association is strongest for HL and CTCL. The excess risk of lymphoma attributed to psoriasis was 7.9/100,000 psoriasis patients per year. Although patients with psoriasis have an increased relative risk of lymphoma, the absolute risk attributable to psoriasis is low given that lymphoma is a rare disease and the magnitude of association is modest.

Incidence and risk factors associated with a second squamous cell carcinoma or basal cell carcinoma in psoralen + ultraviolet a light-treated psoriasis patients

Psoralen + ultraviolet A-treated psoriasis patients are at increased risk for squamous cell carcinomas and basal cell carcinomas; however, the incidence and risk factors associated with second squamous cell carcinomas and basal cell carcinomas in this population are not well qualified. Incidence and risk factors for second squamous cell carcinomas and basal cell carcinomas were studied in a cohort of 1380 psoralen + ultraviolet A-treated psoriasis patients prospectively followed for over 20 y; 264 had a squamous cell carcinoma and 258 a basal cell carcinoma after beginning psoralen + ultraviolet A therapy. After a first squamous cell carcinoma, the risk of a second squamous cell carcinoma was 26% at 1 y, 62% at 5 y, and 75% at 10 y. Risk increased with high psoralen + ultraviolet A exposure prior to the first squamous cell carcinoma (hazard ratio 3.32, 95% confidence interval 1.53, 7.18). Higher rates of post-first squamous cell carcinoma psoralen + ultraviolet A treatment also were associated with greater risk (hazard ratio 1.56 for every additional 10 treatments per year for patients with low pre-first squamous cell carcinoma psoralen + ultraviolet A exposure, 95% confidence interval 1.35, 1.81). Patients exposed to high levels of tar and/or ultraviolet B before a first squamous cell carcinoma were also at higher risk (hazard ratio 1.72, 95% confidence interval 1.14-2.60). Risk of a second basal cell carcinoma was 21% at 1 y, 49% at 5 y, and 61% at 10 y. There was some evidence that high exposure to psoralen + ultraviolet A before a first basal cell carcinoma was associated with increased risk of second basal cell carcinoma (hazard ratio 1.45, 95% confidence interval 0.97-2.17). Higher post-first tumor psoralen + ultraviolet A treatment rates also increased risk (hazard ratio 1.24 for every additional 10 treatments per year, 95% confidence interval 1.06-1.47). Psoralen + ultraviolet A-treated psoriasis patients appear to have a greatly increased incidence of second squamous cell carcinoma compared with the general population. Patients who develop a squamous cell carcinoma after starting psoralen + ultraviolet A therapy should be closely monitored for a subsequent squamous cell carcinoma.

Cancer risk in a population-based cohort of patients hospitalized for psoriasis in Sweden

Studies of clinical series of psoriasis patients have suggested an increased risk of nonmelanoma skin cancer and melanoma; the risk of other neoplasms has rarely been studied. In order to assess the incidence of cancer in a nationwide series of psoriasis patients from Sweden, we followed up, for the years 1965-89, 9773 patients with a hospital discharge diagnosis of psoriasis made during 1965-83, who were alive and free from malignancy 1 y after first discharge. We compared their incidence of neoplasms with that of the national population by computing standardized incidence ratios (SIR). We observed a total of 789 neoplasms [SIR 1.37, 95% confidence interval (CI) 1.28, 1.47]. There was an increase in the risk of cancers of the oral cavity and pharynx (SIR 2.80, 95% CI 1.96, 3.87), liver (SIR 1.91, 95% CI 1.28, 2.74), pancreas (SIR 1.56, 95% CI 1.02, 2.23), lung (SIR 2.13, 95% CI 1.71, 2.61), skin (squamous cell carcinoma, SIR 2.46, 95% CI 1.82, 3.27), female breast (SIR 1.27, 95% CI 1.00, 1.58), vulva (SIR 3.24, 95% CI 1.18, 7.06), penis (SIR 4.66, 95% CI 1.50, 10.9), bladder (SIR 1.43, 95% CI 1.03, 1.92), and kidney (SIR 1.56, 95% CI 1.04, 2.25). The risk of malignant melanoma was decreased (SIR 0.32, 95% CI 0.10, 0.74). Despite some limitations (possible diagnostic misclassification, lack of data on treatment, relatively short follow-up), our study provides evidence against an increased risk of melanoma among patients hospitalized for psoriasis. In addition to nonmelanoma skin and genital cancers, patients hospitalized for psoriasis were at increased risk of several malignancies, in particular those associated with alcohol drinking and tobacco smoking.

Creation of psoriatic plaques: the ultimate tumor suppressor pathway. A new model for an ancient T-cell-mediated skin disease. Viewpoint

From an oncological and immunological perspective, the T-cell-mediated induction of psoriatic plaques should be prone to malignant transformation as the phenotype of psoriatic plaques includes: chronic inflammation, epidermal hyperplasia, prolonged survival and elevated telomerase levels in lesional keratinocytes, as well as angiogenesis, exposure to carcinogens and immunosuppressants. However, conversion of a psoriatic plaque to squamous cell carcinoma is exceedingly rare. This paper explores the possible molecular mechanism for the tumor suppressor pathway in psoriatic lesions, with an emphasis on a putative senescence-switch involving p16.

PUVA and cancer risk: the Swedish follow-up study

There is concern about the long-term carcinogenic effects of psoralen and ultraviolet A radiation (PUVA) for treatment of skin disorders. Many authors have found an increased risk for cutaneous squamous cell carcinoma (SCC). Except in anecdotal reports, malignant melanoma had not been observed in patients treated with PUVA until recently. In the U.S.A., a 16-centre prospective study of 1380 patients showed for the first time that there might also be an increased risk for malignant melanoma in patients treated with high cumulative dosages of PUVA. We have therefore followed up the Swedish PUVA cohort until 1994. This cohort had previously been followed up until 1985. Information from 4799 Swedish patients (2343 men, 2456 women) who had received PUVA between 1974 and 1985 was linked to the compulsory Swedish Cancer Registry in order to identify individuals with cancer. The average follow-up period was 15.9 years for men and 16.2 for women. We did not find any increased risk for malignant melanoma in our total cohort of 4799 patients treated with PUVA or in a subcohort comprising 1867 patients followed for 15-21 years. For cutaneous SCC there was an increase in the risk: the relative risk was 5.6 (95% confidence interval, CI 4. 4-7.1) for men and 3.6 (95% CI 2.1-5.8) for women. Significant (P < 0.05) increases were also found in the incidence of respiratory cancer in men and women and of kidney cancer in women. In conclusion, we did not find any increased risk for malignant melanoma in our patients treated with high doses of PUVA and followed up for a long time. We confirm previous reports of an increase in the incidence of cutaneous SCC in patients treated with PUVA, and recommend that patients should be carefully selected for PUVA and rigorously followed up.

p53 mutation in squamous cell carcinomas from psoriasis patients treated with psoralen + UVA (PUVA)

Individuals suffering from psoriasis are treated with a combination of psoralen and UVA radiation, commonly referred to as "PUVA" therapy. Epidemiologic studies have shown that PUVA therapy is a risk factor for skin cancer in psoriasis patients. Although PUVA treatment induces skin cancer in laboratory animals, it is unknown whether the increased incidence of skin cancer reported in PUVA-treated psoriasis patients is due to the carcinogenic effects of PUVA or due to other factors such as UVB. Because UV and PUVA induce different types of DNA damage resulting in unique types of p53 mutation, we investigated whether skin cancers from PUVA-treated psoriasis patients have PUVA-type or UV-type p53 mutations. Analysis of 17 squamous cell carcinomas (SCCs) from Austrian PUVA-treated patients revealed a total of 25 p53 mutations in 11 SCCs. A majority of p53 mutations occurred at 5'TpG sites. Although previous studies have shown that 5'TpA sites are the primary targets for PUVA mutagenesis, substitutions at 5'TpG sites are also quite common. Interestingly, a sizable portion of p53 mutations detected were C-->T or CC-->TT transitions, characteristic of UV-induced mutations. Because some psoriasis patients had substantial exposure to UVB before PUVA therapy and because the light sources used in PUVA therapy contained small but significant wavelengths in the UVB region, it is possible that the C-->T and CC-->TT transitions detected in SCCs from PUVA-treated patients were induced by UVB. Nonetheless, our results indicate that both PUVA and UVB may play a role in the development of skin cancer in Austrian psoriasis patients who undergo PUVA therapy.

Noncutaneous malignant tumors in the PUVA follow-up study: 1975-1996

There is concern about possible association between PUVA treatment and an increased risk of noncutaneous cancer. An alteration in the risk of cancer among persons with psoriasis has also been postulated. To test this hypothesis, for nearly two decades we have prospectively followed 1380 patients who first began PUVA treatment for psoriasis in 1975-1976. We compare the risk of noncutaneous cancer in our cohort with that expected based on general population incidence rates. The overall risk of noncutaneous cancer was nearly identical to that expected in general population. For three separate sites, we noted significant increases: thyroid cancer (RR = 3.57, 95% CI = 1.16-8.34), breast cancer (RR = 1.81, 95% CI = 1.19-2.64), and central nervous system neoplasms (RR = 2.80, 95% CI = 1.13-5.57). Since 1987, however, the risk of central nervous system neoplasms has not been elevated (RR = 0.00, 95% CI = 0.00-3.35) and the relative risk of breast cancer was lower than in the prior decade and not statistically significant. There was no association between higher levels of exposure to PUVA and the risk of any of these cancers. We did not detect any significant increase in the risk of lymphoma or leukemia. Our study does not support the hypothesis that long-term PUVA treatment increases the risk of noncutaneous cancer.

Cancer incidence among Finnish patients with psoriasis treated with trioxsalen bath PUVA

BACKGROUND

Systemic methoxsalen PUVA increases nonmelanoma skin cancer risk in a dose-dependent manner, whereas trioxsalen bath PUVA treatment has been suggested to be less carcinogenic.

OBJECTIVE

Our purpose was to study the carcinogenicity of topical trioxsalen PUVA.

METHODS

We performed a record linkage study of 337 male and 190 female patients with psoriasis treated with trioxsalen bath PUVA during the period 1977 to 1988 and the Finnish Cancer Registry (cancer incidence in the period 1977 to 1993). The mean follow-up period per person was approximately 11 years. Data on the total cumulative UVA dose and other potentially carcinogenic treatments were collected from the patients' files. The standardized incidence ratio (SIR) was calculated, in which the expected number of cases was based on the national cancer incidence rates.

RESULTS

During the follow-up, 26 cancer cases were observed in the cohort versus 30 expected (SIR, 0.88; 95% confidence interval [CI], 0.57-1.28). The only primary sites showing high SIRs were cancer of the kidney (SIR, 3.56; 95% CI, 0.97-9.10) and non-Hodgkin's lymphoma (SIR, 2.94; 95% CI, 0.36-10.6). There was only one case of nonmelanoma skin cancer; the expected number was 0.8 (SIR, 1.26; 95% CI, 0.03-7.04). The average cumulative UVA dose was 65 J/cm2; 40 patients had received more than 200 J/cm2. The average number of treatments was 112; 65 patients had received more than 200 treatments.

CONCLUSION

No excess of squamous cell carcinoma of the skin was found in patients treated with trioxsalen bath PUVA. However, because of the small size of the cohort, only a sevenfold excess risk can be excluded. The possible associations between psoriasis or its treatment and kidney cancer and lymphoma need to be studied further in larger series.

PUVA, UVB, psoriasis, and nonmelanoma skin cancer

This article reviews the English-language literature on the risk of nonmelanoma skin cancer from phototherapy (UVB) or photochemotherapy (PUVA) in the treatment of psoriasis. The evolution of the debate on the carcinogenic potential of these treatment is discussed, particularly with reference to PUVA. Available data indicate that therapeutic UVB has a low risk of producing cutaneous cancers, with the possible exception of those on male genital skin. However, there is a definite cutaneous carcinogenic risk from oral PUVA. The major associated risk factors are reviewed. We provide recommendations for the assessment and treatment of patients to minimize this risk.

p53 immunoreactivity in cutaneous PUVA tumors is similar to that in other non-melanoma skin neoplasms

Expression of the p53 tumor suppressor gene product was determined in keratoses and skin cancers associated with psoralen photochemotherapy (PUVA). An immunocytochemical study was employed using CM-1 (polyclonal) and Do-1 (monoclonal) antibodies to human wild-type p53. Thirty-two cutaneous lesions and 20 perilesional PUVA-irradiated skin biopsies were examined from 7 patients, all of whom had received more than 200 PUVA treatments and/or a cumulative UVA dose of greater than 1000J/cm2 as treatment for widespread plaque psoriasis. p53 immunoreactivity was seen in 7 of 15 squamous cell carcinomas (46.7%), 5 of 8 dysplastic keratoses (62.5%) and in no basal cell carcinomas or benign keratoses. The overall prevalence of p53 immunoreactivity in 46.2% of malignant or dysplastic PUVA-associated skin tumors is similar to that previously found by our group in comparable skin tumors from the general population. Most patients with lesions showing positive p53 immunoreactivity had, however, been exposed to additional risk factors before receiving PUVA therapy. p53 gene sequencing of PUVA-associated non-melanoma skin cancer (NMSC) may clarify whether p53 mutation contributes to the development of these tumors and whether this relates to PUVA therapy or prior carcinogen exposure.

Review article: epidemiology of male breast cancer. A meta-analysis of published case-control studies and discussion of selected aetiological factors

Male breast cancer is a rare tumour in all parts of the world. About 1% of all breast cancers occur in men, but the male/female ratio is higher among black than among white populations. This effect can be seen in US cancer registries and even more markedly in African data. A positive correlation exists on a population scale between male breast cancer and prostate cancer. Seven case-control studies of male breast cancer are available, and a pooled analysis was conducted of the most commonly suspected risk factors. Male breast cancer appears to be associated with marital status: Mantel-Haenszel exposure odds ratio (EOR) for never married = 1.6; 95% confidence limits (CL) = 1.1, 2.3, religion (EOR for being Jewish = 2.1; 95% CL = 1.4, 3.2), previous breast pathology (EOR for positive history of benign breast disease = 2.7; 95% CL = 1.7, 4.2), gynaecomastia (EOR for positive history = 6.2, 95% CL = 3.4, 11.4), previous testicular pathology (EOR for positive history = 2.2; 95% CL = 1.5, 3.3), previous liver diseases (EOR for positive history = 1.6; 95% CL = 1.0, 2.4) and family history of breast cancer (EOR for first-degree relative with breast cancer = 2.5; 95% CL = 1.7, 3.7). No association is found with smoking history. Other potential risk factors such as reproductive history, education, occupation, anthropometric variables, association with various diseases, and specific exposures such as drug use, were not systematically evaluated in all studies and provide sometimes contradictory results, possibly due to small numbers of exposed subjects. Overall, the analytical epidemiology of male breast cancer presents similarities with the epidemiology of female breast cancer, with a potential role of factors related to hormonal status, relative hyperoestrogeny in men being potentially linked to increased risk of disease. Genetics may also play a role, with high risk linked to a familial history of breast cancer, and with a major risk in patients with Klinefelter's syndrome.

The relationship of psoriasis to malignancy: a clinical report

A large variety of cutaneous reactions to malignancy have been described but to our knowledge none include psoriasis. Two cases of psoriasiform reactions in association with malignancy were first documented by Braverman, and Bazex's syndrome is now well documented in the literature. Both conditions, although clinically psoriasiform, are said to demonstrate an eczematous histology. A number of patients with psoriasis and malignancy have presented to us in the Dermatology Department. The appearance or behaviour of their psoriasis appeared to be linked to their malignancy. We have collected them together to report on this phenomenon which appears infrequently in the literature.

Malignant tumors in patients with psoriasis

BACKGROUND

There is strong epidemiologic evidence that psoriasis treatments may cause nonmelanoma skin cancer and possibly other types of cancer.

OBJECTIVE

This study from Denmark reports the cancer incidence in 6910 patients with psoriasis discharged from the hospital from 1977 through 1987.

METHODS

Patients were identified in the National Hospital Discharge Register and information on cases of cancer was obtained through the files of the Danish Cancer Registry; observed figures were compared with those expected on the basis of cancer incidence rates for the national population.

RESULTS

A 2.5-fold increased risk was observed for nonmelanoma skin cancer in men and women, with no preponderance of any specific histologic subtype of cancer. In addition, excesses were seen of lung cancer in men (relative risk [RR] = 1.4) and women (RR = 1.6), of cancer of the larynx and pharynx in men (RR = 2.8 and 3.9), and of colon and kidney cancer in women (RR = 1.6 and 2.3).

CONCLUSION

The effect of cigarette smoking on the risk for noncutaneous cancer could not be assessed in this study; however, antipsoriatic treatment such as ionizing radiation and oral arsenicals must be considered as a possible cause of colon cancer, which has been observed in excess in two other studies of psoriatic patients.