Nodular malignant melanoma and multiple cutaneous neoplasms under immunosuppression with azathioprine

[DMARD treatment and skin cancer : Recognition, state of knowledge and prevention]

BACKGROUND AND OBJECTIVE

Epithelial tumors differ in cellular origin, risk factors, incidence, and treatment. This article discusses the extent to which the use of disease-modifying antirheumatic drugs (DMARD) is associated with an increased risk for the development of skin tumors and for which substances the risk may be increased. In addition, some practical dermatological recommendations for rheumatologists are presented.

METHODS

The most frequent tumors of the skin are classified according to their cellular origin into malignant melanoma (MM) and so-called keratinocyte cancer (KC). The clinical presentation of these tumors differs and also the risk for the development of these epithelial skin tumors under DMARD treatment varies depending on the drug and tumor entity. As rheumatologists frequently see these patients for follow-up, it is essential to know the clinical findings as well as the corresponding risk factors of the specific tumor entities.

RESULTS

A generally valid and reliable estimation of the risk for the development of epithelial skin tumors under DMARD treatment can only be formulated in the form of tendencies at the present time due to the lack of data. The relevant literature shows that regular intensive dermatological screening is recommended.

CONCLUSION

Patients undergoing immunosuppressive or immune-modulating treatment should be instructed in self-inspection of the skin, receive regular dermatological check-ups and be instructed in strict UV protection methods. Lesions that do not heal or recurrently bleed should be referred for a punch biopsy to rule out or diagnose an epithelial skin tumor, as should atypical inflammatory lesions that do not heal with the use of topical glucocorticoids. An interdisciplinary approach in patient management is the key to success in ensuring the maximum quality of life with the lowest possible risk of developing epithelial skin tumors for these patients.

Systematic analysis of new drug indications by drug-gene-disease coherent subnetworks

Drug targets and disease genes may work as driver factors at the transcriptional level, which propagate signals through gene regulatory network and cause the downstream genes' differential expression. How to analyze transcriptional response data to identify meaningful gene modules shared by both drugs and diseases is still a critical issue for drug-disease associations and molecular mechanism. In this article, we propose the drug-gene-disease coherent subnetwork concept to group the biological function related drugs, diseases, and genes. It was defined as the subnetwork with drug, gene, and disease as nodes and their interactions coherently crossing three data layers as edges. Integrating differential expression profiles of 418 drugs and 84 diseases, we develop a computational framework and identify 13 coherent subnetworks such as inflammatory bowel disease and melanoma relevant subnetwork. The results demonstrate that our coherent subnetwork approach is able to identify novel drug indications and highlight their molecular basis.

Inflammatory bowel disease is associated with an increased risk of melanoma: a systematic review and meta-analysis

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) has been associated with an increased risk of nonmelanoma skin cancer, particularly among patients treated with thiopurines. It is unclear whether IBD affects risk for melanoma. We performed a systematic review and meta-analysis of cohort studies to determine the risk of melanoma in patients with IBD.

METHODS

We conducted a systematic search of bibliographic databases through March 2013. Cohort studies reporting incident melanoma after IBD diagnosis and an estimate of incidence rate ratio or standardized incidence rate were included in the analysis. Pooled relative risk (RR) estimates with 95% confidence intervals (CIs) were calculated using the random-effects model.

RESULTS

Our analysis included 12 studies, comprising a total of 172,837 patients with IBD; 179 cases of melanoma were reported from 1940 to 2009. The pooled crude incidence rate of melanoma in patients with IBD was 27.5 cases/100,000 person-years (95% CI, 19.9-37.0). Overall, IBD was associated with a 37% increase in risk of melanoma (12 studies: RR, 1.37; 95% CI, 1.10-1.70). The risk was increased among patients with Crohn's disease (7 studies: RR, 1.80; 95% CI, 1.17-2.75) and ulcerative colitis (7 studies: RR, 1.23; 95% CI, 1.01-1.50). The risk of melanoma was higher in studies performed before introduction of biologic therapies (before 1998) (8 studies: RR, 1.52; 95% CI, 1.02-2.25) but not in studies performed after 1998 (2 studies: RR, 1.08; 95% CI, 0.59-1.96).

CONCLUSIONS

Based on a meta-analysis, IBD has been associated with an increased risk of melanoma, independent of the use of biologic therapy. Patients diagnosed with IBD should be counseled on their risk for melanoma.

Review article: dermatological complications of immunosuppressive and anti-TNF therapy in inflammatory bowel disease

BACKGROUND

With the expanding list of medications available to treat patients with inflammatory bowel disease (IBD), it is important to recognise adverse events, including those involving the skin. Dermatological adverse events may be confused with extra-intestinal manifestations of IBD.

AIM

To review drug-related dermatological manifestations associated with immunosuppressive and anti-tumour necrosis factor (anti-TNF) therapy.

METHODS

The literature was searched on PubMed for dermatological adverse events in IBD.

RESULTS

Present thiopurine exposure was associated with a 5.9-fold [95% confidence interval (CI), 2.1-16.4] increased risk of developing non-melanoma skin cancer (NMSC). The peak incidence is highest in Caucasians over the age of 65 years with crude incidence rates of 4.0 and 5.7/1000 patient-years for present and previous use. In anti-TNF-exposed subjects, drug-induced lupus was reported in 1% of the cases and a psoriatic rash in up to 3% of the cases. Anti-TNF monotherapy increases the risk of NMSC ~2-fold to a rate of 0.5 cases per 1000 person-years. Cutaneous lymphomas have been rarely reported in subjects on thiopurine or anti-TNF drug monotherapy. Combination therapy seems to have an additive effect on the risk of developing NMSC and lymphoma.

CONCLUSIONS

Physicians need to be aware of the wide spectrum of dermatological complications of immunosuppressive and anti-TNF therapy in IBD, especially psoriasis and non-melanoma skin cancer. Vigilance and regular screening for non-melanoma skin cancer is recommended. Case discussions between gastroenterologists and dermatologists should be undertaken to best manage dermatological adverse events.

Donor transmission of melanoma following renal transplant

Donor transmission of melanoma is one of the more common and lethal of recipient malignancies, often presenting with systemic disease. Although some patients may receive durable remission of melanoma following explantation of the allograft and withdrawal of immunosuppression, donor transmission of melanoma is fatal in most patients. Here we present a case of a 44-year-old male who developed metastatic melanoma following renal transplant.

Thiopurine methyltransferase predicts the extent of cytotoxicty and DNA damage in astroglial cells after thioguanine exposure

Thiopurine methyltransferase (Tpmt) is the primary enzyme responsible for deactivating thiopurine drugs. Thiopurine drugs (i.e., thioguanine [TG], mercaptopurine, azathioprine) are commonly used for the treatment of cancer, organ transplant, and autoimmune disorders. Chronic thiopurine therapy has been linked to the development of brain cancer (most commonly astrocytomas), and Tpmt status has been associated with this risk. Therefore, we investigated whether the level of Tpmt protein activity could predict TG-associated cytotoxicity and DNA damage in astrocytic cells. We found that TG induced cytotoxicity in a dose-dependent manner in Tpmt^+/+, Tpmt^+/− and Tpmt^−/− primary mouse astrocytes and that a low Tpmt phenotype predicted significantly higher sensitivity to TG than did a high Tpmt phenotype. We also found that TG exposure induced significantly more DNA damage in the form of single strand breaks (SSBs) and double strand breaks (DSBs) in primary astrocytes with low Tpmt versus high Tpmt. More interestingly, we found that Tpmt^+/− astrocytes had the highest degree of cytotoxicity and genotoxicity (i.e., IC₅₀, SSBs and DSBs) after TG exposure. We then used human glioma cell lines as model astroglial cells to represent high (T98) and low (A172) Tpmt expressers and found that A172 had the highest degree of cytoxicity and SSBs after TG exposure. When we over-expressed Tpmt in the A172 cell line, we found that TG IC₅₀ was significantly higher and SSB's were significantly lower as compared to mock transfected cells. This study shows that low Tpmt can lead to greater sensitivity to thiopurine therapy in astroglial cells. When Tpmt deactivation at the germ-line is considered, this study also suggests that heterozygosity may be subject to the greatest genotoxic effects of thiopurine therapy.

Regression of advanced melanoma upon withdrawal of immunosuppression: case series and literature review

We report two cases of stage IV malignant melanoma arising in patients treated with azathioprine for myasthenia gravis. In both cases, the melanoma metastases regressed upon withdrawal of immunosuppression. One patient remains melanoma free at 10 years, and the second patient experienced an 18-month disease free period. There is one prior case report in the medical literature to support full immune reconstitution for treatment in advanced immunosuppression-related melanoma, and one case series suggesting that transplant patients developing melanoma may benefit from a switch to sirolimus. Virtually, no data exist for the medical management of early stage melanoma in the immunosuppressed patients. We review the limited preclinical data in support of immune reconstitution and the data on immunosuppression as a risk factor for melanoma. We conclude that reduction or withdrawal of immunosuppression may be beneficial in patients with advanced stage melanoma and warrants further consideration in patients with early stage melanoma.