Nail changes with chemotherapeutic agents and targeted therapies

Patients on Cancer chemotherapeutic agents often develop nail changes most of which are only cosmetic concern and disappear on drug withdrawal. But some nail changes can be painful and disabling thereby affecting quality of life substantially. Different components of the nail unit include the nail matrix, nail bed, nail plate, the hyponychium, lunula, the proximal and lateral nail folds. In this article we review the nail changes induced by chemotherapeutics and targeted anticancer drugs, preventive measures and treatment options available.

Drug reactions affecting hair and nails

Drug-induced changes of hair and nails have been observed with a variety of different pharmaceutical agents, both topical and systemic. These compounds or their metabolites may interfere with hair cycling and texture, nail matrix, nail bed, nail folds, and microvasculature. Phototoxic reactions may also occur. Before initiating treatment, physicians and patients should be aware of possible adverse events to hair and nails and should be aware of the preventive measures, if available, as quality of life can be reduced, and adherence and compliance to treatment may be impaired.

Cornification of nail keratinocytes requires autophagy for bulk degradation of intracellular proteins while sparing components of the cytoskeleton

Epidermal keratinocytes undergo cornification to form the cellular building blocks of hard skin appendages such as nails and the protective layer on the surface of the skin. Cornification requires the cross-linking of structural proteins and the removal of other cellular components to form mechanically rigid and inert corneocytes. Autophagy has been proposed to contribute to this intracellular remodelling process, but its molecular targets in keratinocytes, if any, have remained elusive. Here, we deleted the essential autophagy factor Atg7 in K14-positive epithelia of mice and determined by proteomics the impact of this deletion on the abundance of individual proteins in cornified nails. The genetic suppression of autophagy in keratinocytes resulted in a significant increase in the number of proteins that survived cornification and in alterations of their abundance in the nail proteome. A broad range of enzymes and other non-structural proteins were elevated whereas the amounts of cytoskeletal proteins of the keratin and keratin-associated protein families, cytolinker proteins and desmosomal proteins were either unaltered or decreased in nails of mice lacking epithelial autophagy. Among the various types of non-cytoskeletal proteins, the subunits of the proteasome and of the TRiC/CCT chaperonin were most strongly elevated in mutant nails, indicating a particularly important role of autophagy in removing these large protein complexes during normal cornification. Taken together, the results of this study suggest that autophagy is active during nail keratinocyte cornification and its substrate specificity depends on the accessibility of proteins outside of the cytoskeleton and their presence in large complexes.

Transient yellow discoloration of the nails for differential diagnosis with yellow nail syndrome

A differential diagnosis must be made between transient yellow discoloration of the nails and yellow nail syndrome. We highlight some practical aspects of yellow nail discoloration.

Pigmentary changes in patients treated with targeted anticancer agents: A systematic review and meta-analysis

BACKGROUND

The discovery of signaling networks that drive oncogenic processes has led to the development of targeted anticancer agents. The burden of pigmentary adverse events from these drugs is unknown.

OBJECTIVE

To conduct a systematic review and meta-analysis of published clinical trials and determine the incidence and risk of development of targeted therapy-induced pigmentary changes.

METHODS

A comprehensive search was conducted to identify studies reporting targeted therapy-induced pigmentary changes. The incidence and relative risk were calculated. Case reports and series were reviewed to understand clinical characteristics.

RESULTS

A total of 8052 patients from 36 clinical trials were included. The calculated overall incidences of targeted cancer therapy-induced all-grade pigmentary changes in the skin and hair were 17.7% (95% confidence interval [CI], 11.9-25.4) and 21.5% (95% CI, 14.9-30.1), respectively. The relative risk of all-grade pigmentary changes of skin and hair were 93.7 (95% CI, 5.86-1497.164) and 20.1 (95% CI, 8.35-48.248). Across 53 case reports/series (N = 75 patients), epidermal growth factor receptor and breakpoint cluster region-abelson inhibitors were the most common offending agents.

LIMITATIONS

Potential under-reporting and variability in oncologists reporting these events.

CONCLUSION

There is a significant risk of development of pigmentary changes during treatment with targeted anticancer therapies. Appropriate counseling and management are critical to minimize psychosocial impairment and deterioration in quality of life.

Nail toxicities induced by systemic anticancer treatments

Patients treated with systemic anticancer drugs often show changes to their nails, which are usually well tolerated and disappear on cessation of treatment. However, some nail toxicities can cause pain and functional impairment and thus substantially affect a patient's quality of life, especially if they are given taxanes or EGFR inhibitors. These nail toxicities can affect both the nail plate and bed, and might present as melanonychia, leukonychia, onycholysis, onychomadesis, Beau's lines, or onychorrhexis, as frequently noted with conventional chemotherapies. Additionally, the periungual area (perionychium) of the nail might be affected by paronychia or pyogenic granuloma, especially in patients treated with drugs targeting EGFR or MEK. We review the nail changes induced by conventional chemotherapies and those associated with the use of targeted anticancer drugs and discuss preventive or curative options.

Advances in the therapeutic use of mammalian target of rapamycin (mTOR) inhibitors in dermatology

Significant developments in the use of mammalian target of rapamycin (mTOR) inhibitors (mTORIs) as immunosuppressant and antiproliferative agents have been made. Recent advances in the understanding of the mTOR signaling pathway and its downstream effects on tumorigenesis and vascular proliferation have broadened the clinical applications of mTORIs in many challenging disorders such as tuberous sclerosis complex, pachyonychia congenita, complex vascular anomalies, and inflammatory dermatoses. Systemic mTORI therapy has shown benefits in these areas, but is associated with significant side effects that sometimes necessitate drug holidays. To mitigate the side effects of systemic mTORIs for dermatologic applications, preliminary work to assess the potential of percutaneous therapy has been performed, and the evidence suggests that percutaneous delivery of mTORIs may allow for effective long-term therapy while avoiding systemic toxicities. Additional large placebo-controlled, double-blinded, randomized studies are needed to assess the efficacy, safety, duration, and tolerability of topical treatments. The objective of this review is to provide updated information on the novel use of mTORIs in the management of many cutaneous disorders.

Dermatological toxicity associated with targeted therapies in cancer: optimal management

Targeted therapies have developed rapidly over the last few years in the field of oncology thanks to a better understanding of carcinogenesis. They target pathways involved in signal transduction (EGFR, HER2, HER3, HER4, FLT3, RAS, RAF, MEK, KIT, RET, mTOR, SRC, EPH, SCF), tumor angiogenesis (VEGFR, TIE2), and tumor microenvironment (PDGFR, FGFR). They rarely cause the systemic adverse reactions generally associated with chemotherapy, but frequently cause disabling and specific skin toxicity. The impact on patient quality of life can be important both in terms of symptoms caused and of potentially aesthetic consequences. Inappropriate management can increase the risk of dose reduction or discontinuation of the cancer treatment. In this review, we will discuss skin toxicity associated with the main drug classes-EGFR, BRAF, MEK, mTOR, c-KIT, CTLA4, and SMO inhibitors, and anti-angiogenic agents. Targeted therapy-induced skin toxicities will be detailed in terms of symptoms, frequency, evolution, complications, and topical and oral treatments in order to improve their diagnosis and management.

Incidence and risk of treatment-related mortality in cancer patients treated with the mammalian target of rapamycin inhibitors

BACKGROUND

Inhibition of the mammalian target of rapamycin (mTOR) is an established treatment for multiple malignancies. We carried out an up-to-date meta-analysis to determine the risk of fatal adverse events (FAEs) in cancer patients treated with mTOR inhibitors.

PATIENTS AND METHODS

PubMed, conferences and clinicaltrials.gov databases were searched for articles reported from January 1966 to June 2012. Eligible studies were limited to approved mTOR inhibitors (everolimus and temsirolimus) and reported on patients with cancer, randomized design and adequate safety profiles. Data extraction was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

In all, 3193 patients from eight randomized, controlled trials (RCTs) were included, 2236 from everolimus trials and 957 from temsirolimus trials. The relative risk (RR) of FAEs related to mTOR inhibitors use was 2.20 (95% CI, 1.25-3.90; P = 0.006) compared with control patients. On subgroup analysis, no difference in the rate of FAEs was found between everolimus and temsirolimus or between tumor types [renal cell carcinoma (RCC) versus non-RCC]. No evidence of publication bias was observed.

CONCLUSION

The use of mTOR inhibitors is associated with a small but higher risk of FAEs compared to control patients. In the appropriate clinical scenario, the use of these drugs remains justified in their approved indications.