Comparative Epidemiology and Pathogenic Factors for Nonmelanoma Skin Cancer in Organ Transplant Patients:

Medical care of liver transplant patients

INTRODUCTION

Liver transplantation is a life-changing event for patients and survival following transplantation has improved significantly since the first transplantation in 1967. Following liver transplantation, patients face a unique set of healthcare management decisions including transplantation-specific complications, recurrence of primary liver disease, as well as metabolic and malignancy concerns related to immunosuppression. As more patients with liver disease receive transplantation and live longer, understanding and managing these patients will require not only transplant specialist but also local subspecialist and primary care physicians.

AREAS COVERED

This review covers common issues related to the management of patients following liver transplantation including immunosuppression, liver allograft dysfunction, metabolic complications, as well as routine health maintenance such as immunizations and cancer screening.

EXPERT OPINION

Optimizing medical care for patients following liver transplant will benefit from ensuring all providers, not just transplant specialist, have a basic understanding of the common issues encountered in the post-transplant patient. This review provides an overview of common healthcare concerns and management options for patients following liver transplantation.

Risk Factors for Developing Nonmelanoma Skin Cancer after Lung Transplantation

Background

Nonmelanoma skin cancer (NSMC) is the most common malignancy after organ transplantation. Lung transplant recipients (LTRs) are particularly prone to develop NMSC as compared to renal or hepatic transplant recipients due to higher dosages of immunosuppression needed. Everolimus, an immunosuppressant used in organ transplant recipients, is thought to inherit a lower risk for NMSC than calcineurin inhibitors, especially in renal transplant recipients. It is currently unknown whether this also applies to LTRs.

Objectives

To determine risk factors for NMSC and precancerous lesions after lung transplantation (LTx) and to characterize the effect of everolimus-based regimens regarding this risk.

Materials and Methods

90 LTRs and former participants of the interventional trial “Immunosuppressive Therapy with Everolimus after Lung Transplantation”, who were randomized to receive either an everolimus- or mycophenolate mofetil- (MMF-) based regimen, were enrolled and screened in this retrospective, single-center cohort study.

Results

After a median follow-up of 101 months, we observed a prevalence of 38% for NMSC or precancerous lesions. 33% of the patients continuously receiving everolimus from LTx to dermatologic examination compared to 39% of all other patients, predominantly receiving an MMF-based regimen, were diagnosed with at least one NMSC or precancerous lesion (P=.66). Independent risk factors for NMSC or precancerous lesions after LTx were male sex and duration of voriconazole therapy.

Conclusion

NMSC or precancerous lesions were very common after LTx, and risk factors were similar to previous reports on LTRs. Everolimus did not decrease this risk under the given circumstances of this study. Patients should be counseled regarding their risk, perform vigorous sunscreen, and undergo regular dermatological controls, regardless of their immunosuppressive regimen.

Cancer stem cell immunology: key to understanding tumorigenesis and tumor immune escape?

Cancer stem cell (CSC) biology and tumor immunology have shaped our understanding of tumorigenesis. However, we still do not fully understand why tumors can be contained but not eliminated by the immune system and whether rare CSCs are required for tumor propagation.

Long latency or recurrence periods have been described for most tumors. Conceptually, this requires a subset of malignant cells which is capable of initiating tumors, but is neither eliminated by immune cells nor able to grow straight into overt tumors. These criteria would be fulfilled by CSCs. Stem cells are pluripotent, immune-privileged, and long-living, but depend on specialized niches. Thus, latent tumors may be maintained by a niche-constrained reservoir of long-living CSCs that are exempt from immunosurveillance while niche-independent and more immunogenic daughter cells are constantly eliminated.

The small subpopulation of CSCs is often held responsible for tumor initiation, metastasis, and recurrence. Experimentally, this hypothesis was supported by the observation that only this subset can propagate tumors in non-obese diabetic/scid mice, which lack T and B cells. Yet, the concept was challenged when an unexpectedly large proportion of melanoma cells were found to be capable of seeding complex tumors in mice which further lack NK cells. Moreover, the link between stem cell-like properties and tumorigenicity was not sustained in these highly immunodeficient animals. In humans, however, tumor-propagating cells must also escape from immune-mediated destruction. The ability to persist and to initiate neoplastic growth in the presence of immunosurveillance – which would be lost in a maximally immunodeficient animal model – could hence be a decisive criterion for CSCs.

Consequently, integrating scientific insight from stem cell biology and tumor immunology to build a new concept of “CSC immunology” may help to reconcile the outlined contradictions and to improve our understanding of tumorigenesis.

Merkel cell carcinoma of the head and neck: a single institutional experience

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy occurring mostly in older immunocompromized Caucasian males. A growing incidence of MCC has been reported in epidemiological studies. Treatment of MCC usually consists of surgical excision, pathological lymph node evaluation, and adjuvant radiotherapy. This paper reports the experience of a single tertiary center institution with 17 head and neck Merkel cell carcinoma patients. Median followup for the cohort was 37.5 months. After five years, recurrence-free survival, disease specific survival, and overall survival were 85%, 90%, and 83%, respectively. Our limited data support the use of adjuvant radiotherapy. We also report two cases of MCC located at the vestibule of the nose and two cases of spontaneous regression after diagnostic biopsy. About 40% of our patients were referred to our center for surgical revision and pathological lymph node evaluation. Increased awareness of MCC and an interdisciplinary approach are essential in the management of MCC.

Molecular markers in cutaneous squamous cell carcinoma

Nonmelanoma skin carcinoma (NMSC) is the most frequent cancer in the USA with over 1.3 million new diagnoses a year; however due to an underappreciation of its associated mortality and growing incidence and its ability to be highly aggressive, the molecular mechanism is not well delineated. Whereas the molecular profiles of melanoma have been well characterized, those for cutaneous squamous cell carcinoma (cSCC) have trailed behind. This importance of the new staging paradigm is linked to the ability currently to better clinically cluster similar biologic behavior in order to risk-stratify lesions and patients. In this paper we discuss the trends in NMSC and the etiologies for the subset of NMSC with the most mortality, cutaneous SCC, as well as where the field stands in the discovery of a molecular profile. The molecular markers are highlighted to demonstrate the recent advances in cSCC.

Focus Issue on Squamous Cell Carcinoma: Practical Concerns Regarding the 7th Edition AJCC Staging Guidelines

The 7th edition of the AJCC Cancer Staging Manual represents a dramatic shift in the way that cutaneous squamous cell carcinoma (cSCC) is staged, in that it is first attempt to incorporate evidence-based medicine into the staging guidelines for cSCC. In our opinion, the changes made to the seventh edition represent a significant improvement over previous editions and will ultimately lead to improved patient stratification, more accurate prognostic data, and a better framework to guide clinical decision making. However, there are a number of issues within the latest guidelines that require clarification or are impractical for clinical practice. The purpose of this paper is to highlight the key changes to the 6th edition staging manual as they pertain to cSCC, to point out impractical component of the 7th edition and/or aspects that require further clarification, and to make recommendations that address any current shortcomings to improve subsequent editions. Specific focus will be given to the inclusion of separate guidelines for cSCC and Merkel cell carcinoma (MCC), the incorporation of high-risk factors as modifiers of T stage, the addition of new guidelines for advanced T stage, and the changes in stratification of lymph node status. This paper is modified from a more comprehensive treatment of the staging of nonmelanoma skin cancer by Warner and Cockerell entitled "The new 7th edition American joint committee on cancer staging of cutaneous nonmelanoma skin cancer: a critical review," in the American Journal of Clinical Dermatology (paper accepted, pending publication).