Sir,

Adult renal transplantation has become the treatment of choice for end-stage renal disease as it improves the quality of life of the patient as well as their life expectancy [1,2].

Chronic and potent systemic immunosuppression, which has ensured prolonged survival for most organ transplant patients, has given rise to a new set of challenges for patients and providers, manifested by an alarming increase in the incidence of skin infections and neoplasia, responsible for 12% and 16% of deaths, respectively, in patients with a functional graft, hence the need for systematic and regular dermatology follow-up of this population [3].

In order to conduct our retro-prospective study, we established the following objectives:

We collected all renal transplant patients who consulted in dermatology for a case of skin manifestations or were in the framework of the systematic biannual follow-up of renal transplant patients.

All patients were subjected to a detailed interrogation:

A complete dermatological examination was performed to detect the different tumor manifestations.

One hundred forty-four patients were collected. The mean age at transplantation was 41.93 years (extremes: 14 and 82 years). There was a male predominance (male-to-female ratio: 1.21).

Fifty-four percent of our patients had phototype IV, 30% had phototype III, 12% had phototype II, and two patients had phototype V.

One hundred forty-one of our patients were under polychemotherapy and three were under monochemotherapy.

The first transplant was performed in France in 1981 and it was only in 1998 that renal transplantation was started at the Ibn Sina University Hospital. Sixty-seven percent were transplanted in Rabat.

Seventy-two percent of the patients presented with cutaneous and mucosal manifestations with a median delay of twelve months (1 week to 148 months).

During the study period, five skin cancers were identified in five patients. Table 1 summarizes the clinical characteristics of the five patients who developed a malignant tumor during the study period.

Table 1: Clinical characteristics of kidney transplant patients who developed a skin cancer during the observation period.

Renal transplantation remains the only radical treatment for chronic end-stage renal disease. However, as in the case of any treatment, renal transplantation has its drawbacks, risks, and constraints [4]. Indeed, organ transplantation is necessarily accompanied by immunosuppressive treatment, which may be responsible for short- and long-term adverse effects. The risk of cancer in transplanted patients is at least three times higher than in the general population, yet varies greatly with the type of cancer, which also determines the latency (from several months to, sometimes, twenty years). It is estimated that 17% of patients develop cancer after transplantation, including 9% of cutaneous squamous cell carcinomas and 7% of basal cell carcinomas. The cumulative incidence of all cancers combined is 13%, 33%, and 47% at 10, 20, and 30 years, respectively [5]. Other tumors have been reported, such as Kaposi’s disease, the frequency of which is 500 times higher than in the general population. Rarely, lymphomas, melanomas, sarcomas, and Merkel tumors have been reported [6].

Several factors are incriminated: immune status, duration and intensity of immunosuppression, sun exposure, genetic susceptibility, and pre-existing HPV lesions [7].

The average time to the onset of skin tumors was nine years. Only five of our patients presented tumor lesions. This was probably due to insufficient follow-up after transplantation in our series.

The main finding of our study was the low cumulative incidence of skin cancers (2.7%), particularly carcinomas, which, subject to the limited duration of the observation period, was lower than the incidences found in other cohorts of transplant patients.

Despite these limitations, the types of cancers developed during our observation period corresponded to those most frequently reported in transplant patients.

Patients should be informed about the risk of developing skin tumors and should be encouraged to consult regularly, thus enabling the dermatologist to detect lesions at an early stage.

A skin examination for the early detection of lesions should be performed regularly at a rate of once per year in the absence of complications or even more often in the case of pre-existing cancerous lesions.

REFERENCES

1. Park GH, Chang SE, Won CH, Lee MW, Choi JH, Moon KC, et al. Incidence of primary skin cancer after organ transplantation:An 18-year single-center experience in Korea. J Am Acad Dermatol. 2014;70:465-72.

2. Chapman JR, Webster AC, Wong G. Cancer in the transplant recipient. Cold Spring Harb Perspect Med. 2013;1:3.

3. Thet Z, Lam AK, Ranganathan D, Aung SY, Han T, Khoo TK. Reducing non-melanoma skin cancer risk in renal transplant recipients. Nephrology (Carlton, Vic.). 2021;26:907-19.

4. Asch WS, Bia MJ. Oncologic issues and kidney transplantation:A review of frequency, mortality, and screening. Adv Chronic Kidney Dis. 2014;21:106-13.

5. Ponticelli C, Cucchiari D, Bencini P. Skin cancer in kidney transplant recipients. J Nephrol. 2014;27:385-394.

6. Krynitz B, Edgren G, Lindelöf B, Baecklund E, Brattström C, Wilczek H, et al. Risk of skin cancer and other malignancies in kidney, liver, heart and lung transplant recipients 1970 to 2008:A Swedish population-based study. Int J Cancer. 2013;132:1429-38.

7. SkovDalgaard L, Fassel U, Østergaard LJ, Jespersen B, SchmeltzSøgaard O, Jensen-Fangel S. Risk of human papillomavirus-related cancers among kidney transplant recipients and patients receiving chronic dialysis:An observational cohort study. BMC Nephrol. 2013;14:137.