Higher mycophenolate dosage is associated with an increased risk of squamous cell carcinoma in kidney transplant recipients.

BACKGROUND: Kidney transplant recipients are at increased risk of keratinocyte cancers, namely squamous cell and basal cell carcinomas (SCCs and BCCs). This is primarily due to the high levels of immunosuppression that are required to prevent allograft rejection. Different immunosuppressive medications confer different risks, and the effect of mycophenolate mofetil on SCC and BCC risk is unclear. We explored the relationship between mycophenolate dose prescribed over the entire transplant period and the risk of SCC and BCC. METHODS: Kidney transplant recipients from Queensland, Australia, were recruited between 2012 and 2014 and followed until mid-2016. During this time transplant recipients underwent regular skin examinations to diagnose incident SCCs and BCCs. Immunosuppressive medication regimens were obtained from hospital records, and the average mycophenolate dose/day over the entire transplantation period was calculated for each patient. Doses were divided into three ranked groups, and adjusted relative risks (RRadj) of developing SCC and BCC tumours were calculated using negative binomial regression with the lowest dosage group as reference. Recipients who had used azathioprine previously were excluded; further sub-group analysis was performed for other immunosuppressant medications. RESULTS: There were 134 kidney transplant recipients included in the study. The average age was 55, 31% were female and 69% were male. At the highest median mycophenolate dose of 1818 mg/day the SCC risk doubled (RRadj 2.22, 95% CI 1.03-4.77) when compared to the reference group of 1038 mg/day. An increased risk persisted after accounting for ever-use of ciclosporin, ever-use of tacrolimus, and when excluding mammalian target of rapamycin users. This increased risk was mainly carried by kidney transplant recipients immunosuppressed for five or more years (RRadj = 11.05 95% CI 2.50-48.81). In contrast, there was no significant association between BCC incidence and therapy with the highest compared with the lowest mycophenolate dosage (RRadj = 1.27 95% CI 0.56-2.87). CONCLUSION: Higher mycophenolate dosage is associated with increased SCCs in kidney transplant recipients, particularly those immunosuppressed for more than five years. The increased SCC risk persists after accounting for usage of other immunosuppressant medications.

Skin cancer multiplicity in lung transplant recipients: a prospective population-based study.

BACKGROUND: Lung transplant recipients are at high risk of skin cancer, but precise annual incidence rates of treated skin cancers per patient are unknown. OBJECTIVES: To perform a prospective assessment of the total burden of histologically confirmed squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) and associated factors in lung transplant recipients. METHODS: A population-based cohort of 125 Queensland lung transplant recipients aged 18 years and over, recruited between 2013 and 2015, were followed to the end of 2016. All underwent dermatological skin examinations at baseline and annually thereafter and patients self-reported all interim treated skin cancers, which were verified against pathology databases. Standard skin cancer risk factors were obtained via questionnaire, and details of medications were acquired from hospital records. RESULTS: During a median follow-up time of 1·7 years, 29 (23%) and 30 (24%) lung transplant recipients with a median duration of immunosuppression of 3·3 years developed SCC and BCC, respectively. The general population age-standardized incidence rates of SCC and BCC were 201 and 171 per 1000 person-years, respectively (based on first primary SCC or BCC during follow-up); however, on accounting for multiple primary tumours, corresponding incidence rates were 447 and 281 per 1000 person-years. Risk of multiple SCCs increased around sixfold in those aged ≥ 60 years and in those with previous skin cancer, and increased around threefold in those treated with the antifungal medication voriconazole. Multiple BCC risk rose threefold from age 60 years and tenfold for patients with previous skin cancer. CONCLUSIONS: Lung transplant recipients have very high incidence of multiple primary skin cancers. Close surveillance and assiduous prevention measures are essential. Linked Comment: Proby and Harwood. Br J Dermatol 2020; 183:416-417.

Cutaneous squamous cell carcinoma (cSCC) and immunosurveillance - the impact of immunosuppression on frequency of cSCC.

Solid organ transplant recipients (OTR) are at extreme risk of developing cutaneous squamous cell carcinomas (cSCC) post-transplantation due to the immunosuppressive medication needed to retain the transplanted organ. The early classical immunosuppressive drugs, azathioprine and cyclosporine, have largely been replaced by modern immunosuppressants, namely mycophenolate mofetil and tacrolimus, as well as sirolimus and everolimus. Although still very high, the risk of cSCC in OTR seems to be decreasing which suggests that cSCC risk may be lower in OTR treated with these modern immunosuppressive drugs and that cSCC preventive measures may be effective. OTR should be closely monitored so that cSCC can be treated at an early stage. (Chemo)prevention of cSCC as well as changing immunosuppression to more favourable regimens will be important in future to reduce skin cancer incidence.

Metastasis of cutaneous squamous cell carcinoma in organ transplant recipients and the immunocompetent population: is there a difference? a systematic review and meta-analysis.

BACKGROUND: Organ transplant recipients (OTR) have a higher risk of developing cutaneous squamous cell carcinoma (cSCC) compared to the immunocompetent population. Immunosuppression is often stated as a risk factor for metastasis. However, evidence for this is scarce. OBJECTIVES: To investigate the cSCC metastasis risk in OTR and the immunocompetent population by systematically reviewing the literature. METHODS: A systematic review of the literature was performed up to January 2018 using: Medline; Embase; Web of Science and ISI Science Citation Index. Studies assessing cSCC metastasis risk in ORT or immunocompetent cohorts were considered. A pooled risk estimate for metastasis was calculated for the immunocompetent population and OTR separately. RESULTS: The pooled metastasis risk estimate for OTR was, respectively, 7.3% (95% CI 6.2-8.4) for cSCC on total body, and 11.0% (95% CI 7.7-14.8) for cSCC of the head neck area. For the immunocompetent population reported risk estimate analysis showed a pooled metastatic risk of 3.1% (95% CI 2.8-3.4) in total body cSCC and of 8.5% (95% CI 7.3-9.8) in cSCC of the head and neck area. Pooled risk estimate per single cSCC in OTR was 1.3% (95% CI 1.0-1.7) in total body cSCC and 4.0% (95% CI 2.7-5.5) in cSCC of the head and neck area. In the immunocompetent population, these pooled risk estimates were, respectively, 2.4% (95% CI 2.1-2.6) and 6.7% (95% CI 5.7-7.8). CONCLUSIONS: Organ transplant recipients show a higher overall risk of cSCC metastasis compared to the immunocompetent population. Metastasis risks per single cSCC were substantially lower in both groups. However, due to heterogeneity and differences between studies, comparisons are difficult. Comprehensive follow-up studies with defined cohorts are necessary to adequately asses the risk for cSCC metastasis.

Epidemiology of keratinocyte carcinomas after organ transplantation.

Keratinocyte carcinoma (KC) is the most common type of cancer among white populations, but it is even more common among solid organ transplant recipients (OTRs). The most frequent histological type of KC among OTRs is cutaneous squamous cell carcinoma (cSCC), followed by basal cell carcinoma, although the reverse is seen in the general population. Metastatic cSCCs are more frequent, and mortality is increased compared with immunocompetent populations. There is strong evidence that the risk of KC among OTRs rises with increasing time after transplantation and older age at transplantation, and that KC is enhanced in those with sun-damaged skin. This evidence suggests that accelerated accumulation of genetic damage from several sources leads to excess KC in OTRs. We describe international variation in KC and focus on trends in immunosuppressive regimens, the role of ultraviolet susceptibility and exposure, and the contribution of genetics to tumour development. Further epidemiological studies are needed to address gaps in our understanding of the mediation of excess KC by immunosuppressive drugs, viral infection, genetic susceptibility, timing of relevant ultraviolet exposure or some combination of these factors.

Pain identifies squamous cell carcinoma in organ transplant recipients: the SCOPE-ITSCC PAIN study.

Organ transplant recipients (OTR) are at high risk for cutaneous squamous cell carcinomas (SCC). We aimed to define clinically meaningful patient-reported warning signals predicting the presence of invasive SCC.Patient-reported signs and symptoms of 812 consecutively biopsied skin lesions from 410 OTR were determined by questionnaire and physical examination and related to the subsequent biopsy-proven diagnoses. Receiver-operating characteristic (ROC) curve analyses were used as a measure of distinction between the predictive values of patient-reported warning signals and the occurrence of SCC. Pain was an independent predictive patient-reported warning signal for a biopsy-proven invasive SCC. The odds ratio from the fully adjusted model predicting SCC was 4.4(95% confidence interval: 2.4­8.2). Higher scores on the visual analog scale (VAS) for pain were associated witha greater likelihood for the presence of SCC compared to none or mild pain. The for scores on the VAS from 1to 3, 4 to 6 and 7 to 10 were 4.9 (2.2­10.5), 2.3 (0.96­5.5)and 16.5 (3.6­75.8), respectively. Pain is the most powerful patient-reported warning signal for invasive cutaneous SCC in OTR. Empowerment of patients by education could accelerate diagnosis and treatment of cutaneous SCC.