Epidermal growth factor receptor inhibitors: a review of cutaneous adverse events and management

LC-OCT for early diagnosis and characterization of dermatologic adverse events to oncologic drugs and correlation to histopathology

BACKGROUND

Targeted and immune therapies have recently been associated with the occurrence of multiple cutaneous toxicities, often challenging to differentiate by clinical examination alone without histology. Line-field confocal optical coherence tomography (LC-OCT) is a non-invasive and innovative imaging technique that has been shown to be almost as effective as histology in diagnosing several skin conditions. Our study aimed to assess the effectiveness of LC-OCT in predicting the clinical evolution of early maculopapular eruptions related to antineoplastic targeted therapy and immunotherapy.

METHODS

In the period between May 2023 and December 2023, consecutive patients with clinical cutaneous maculopapular reactions caused by oncologic targeted therapy or immunotherapy were enrolled at the dermatologic outpatient clinic of the Fondazione Policlinico A. Gemelli IRCCS, Rome. Patients underwent clinical dermatological examination, video-dermoscopy, LC-OCT, and incisional skin biopsy of a target cutaneous lesion. To investigate the evolutionary pattern of maculopapular lesions (psoriasic eruption, lichenoid eruption, eczematous eruption, bullous eruption), LC-OCT and histopathological images have been compared based on specific characteristics (hyperkeratosis, acanthosis, spongiosis; papillomatosis; lichenoid inflammatory infiltrate; presence of intraepidermal/subepidermal cleavage plan with formation of a bulla).

RESULTS

Eighteen patients were included in this study (11 males, 7 females, median age 64.5). LC-OCT demonstrated an overall concordance with histology of 77.8%, with a Cohen's Kappa of 0.69 (P < 0.0001). Sensitivity exceeded 70%, and specificity was ≥88.2%. The Area Under the Curve (AUC) ranged from 0.9 to 1 for psoriasis and lichenoid eruption and from 0.7 to 0.9 for eczematous and bullous eruption.

CONCLUSIONS

LC-OCT appears to be a promising tool for the early differential diagnosis of adverse skin reactions related to targeted therapy and immunotherapy, offering the potential to avoid skin biopsies in fragile cancer patients.

Panitumumab-Induced Periorbital Dermatitis: A Case Report

Panitumumab is a recombinant, fully humanized immunoglobulin G2 monoclonal antibody targeting the epidermal growth factor receptor (EGFR). It is approved for the first- and second-line treatment of advanced wild-type KRAS colorectal cancer. Although common cutaneous side effects include acneiform dermatitis, folliculitis, and xerosis, ocular toxicities have occasionally been reported. Herein, we report the case of an 81-year-old Thai female with chemorefractory advanced stage sigmoid colon cancer who developed isolated periorbital dermatitis following treatment with panitumumab plus modified FOLFOX6. The cutaneous adverse reaction recurred after subsequent infusions; however, it was alleviated by topical therapy. To our knowledge, panitumumab-induced periorbital dermatitis is exceptionally rare. To raise awareness of potential periocular cutaneous side effects in patients taking EGFR inhibitors, the published literature regarding periorbital dermatitis induced by these agents has also been reviewed in this article. Periorbital dermatitis should be considered as a potential cutaneous reaction following panitumumab administration, and should be promptly treated.

Mechanism of action of adapalene for treating EGFR-TKI-induced skin disorder

BACKGROUND

Skin disorders are the most common side effect associated with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. It is important to manage skin lesions. Adapalene has been used to treat skin lesions caused by EGFR-TKIs in some cases. The aim of this study was to investigate the functional mechanism of adapalene in erlotinib-induced skin disorder.

METHODS

To analyze the effect of adapalene on skin rash, afatinib and adapalene were administered to mice. The relationship between the concentration of adapalene and skin disorders was also examined by analyzing AQP3 expression. A skin lesion model was experimentally established in human skin keratinocytes (HaCaT) by using erlotinib with TNF-α and IL-1β. We used qRT-PCR to analyze chemokine-induced inflammation and western blotting to analyze the effects of adapalene on the NF-κB signaling pathway. Antimicrobial peptides and adhesion factors were also examined using qRT-PCR.

RESULTS

Mice administered 0.01% adapalene had less skin inflammation than mice treated with afatinib alone. The expression level of AQP3 decreased in an adapalene concentration-dependent manner. The mRNA levels of proinflammatory cytokines such as CCL2 and CCL27 in HaCaT cells were significantly reduced by adapalene. The expression of an antimicrobial peptide, hBD3, was upregulated after adapalene treatment. Adhesion factors, such as E-cadherin, were significantly downregulated by EGFR-TKI and significantly upregulated by adapalene treatment. Western blot analysis suggested that erlotinib-induced phosphorylation of p65 was decreased by adapalene.

CONCLUSION

We suggest that adapalene may be a possible treatment option for skin disorders induced by EGFR-TKIs.

A Cost-effectiveness Analysis of Adding Cetuximab to the First-line Treatment of Metastatic Colorectal Carcinoma in Iran; Considering Genetic Screening for Precision Medicine

PURPOSE

This study aimed to evaluate the cost-effectiveness of cetuximab in different genetic populations of metastatic colorectal carcinoma patients, including KRAS and RAS wild types and mutants, when added to FOLFIRI treatment regimens for evidence-based disease management in Iran.

METHOD

A Markov decision model was designed in TreeAge software with the three states of stable, progress, and death. Clinical outcomes were extracted from published clinical studies, and costs were extracted from the Iranian local data. The primary outcome was an incremental cost-effectiveness ratio (ICER) in the simulated population.

RESULTS

The cost-utility model from the perspective of the health system indicated that the average direct medical costs of a patient that has not been genetically screened are $56,985.27 and $20,767.74 in FOLFIRI + cetuximab and FOLFIRI regimens, respectively. However, costs per patient in the KRAS wild-type population were $21,845.52 in FOLFIRI and $78,321.22 in FOLFIRI + cetuximab. In RAS wild-type patients, FOLFIRI and FOLFIRI + cetuximab costs per patient were $23,111.62 and $84,976.39, respectively. Incremental QALYs for the above scenarios were 0.069, 0.193, and 0.285, respectively. Therefore, the ICER of add-on cetuximab in Iran compared to the treatment alternatives in the scenarios with and without KRAS screening was $520,771.55/QALY, $292,768.16/QALY, and $217,460.51/QALY.

CONCLUSION

Although genetic screening in precision medicine reduces costs per outcome, according to the willingness-to-pay threshold of $4349.50 in the Iranian health system, add-on cetuximab to the FOLFIRI regimen is not a cost-effective strategy even with genetic screening and a 20% price reduction.

Ocular complications of antineoplastic therapies

Ocular complications of antineoplastic agents can have a profound effect on the quality of life of cancer patients. New oncologic treatments like monoclonal antibodies, immunotherapies, antibody-drug conjugates, checkpoint inhibitors and growth factor receptors have resulted in increased ocular complications. These ocular complications differs in respect to distinct mechanisms of actions and lead to significant challenges in the management of cancer patients. In this review, we reviewed literature, clinical studies and cases detailing ocular complications due to administration of antineoplastic agents and emphasized the need for communication between oncologists and ophthalmologists toward early detection and management of ocular complications.

A phase 2 study for evaluating doxycycline 50 mg once daily and 100 mg once daily as preemptive treatment for skin toxicity in patients with metastatic colorectal cancer treated with an anti-EGFR and chemotherapy

PURPOSE

To assess the efficacy, safety, and quality-of-life outcomes of doxycycline 50 or 100 mg once daily in the prevention of skin toxicity in patients undergoing chemotherapy plus anti-EGFR therapy as first-line treatment of metastatic colorectal cancer (mCRC).

METHODS

Phase II, multicenter, single-arm, exploratory study was conducted in 7 Spanish hospitals. The primary study outcome was the incidence of ≥ grade 2 skin toxicities during the 6-week skin treatment period. Quality of life was assessed with the Dermatology Life Quality Index (DLQI) questionnaire. Patients had to receive either doxycycline 50 mg once daily in a first stage with 10 patients, or, if more than three patients presented ≥ grade 2 skin toxicities, the next 30 patients had to receive 100 mg once daily.

RESULTS

Thirty-four patients with RAS wild-type mCRC were enrolled in the study. Ten patients were first treated with doxycycline 50 mg once daily, and the following 24 were treated with doxycycline 100 mg once daily. A total of 60.0% (95% CI 29.6-90.0) and 20.8% (95% CI 4.6-37.0) of patients who received doxycycline 50 mg/day and 100 mg/day, respectively, had at least one ≥ grade 2 skin toxicity. Patients treated with doxycycline 100 mg once daily experienced less QoL deterioration. Only 1 patient reported a mild doxycycline-related gastrointestinal adverse event.

CONCLUSION

Our results suggest that doxycycline doses as low as 100 mg once daily are efficacious and well tolerated for the prevention of skin toxicity in patients with mCRC who undergo treatment with chemotherapy plus EGFR-targeted therapies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03448731.

Immunotherapy and Systemic Treatment of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinomas (cSCC) represent one of the most diagnosed non-melanoma skin cancers and its incidence is increasing globally. Whereas early stage and low risk cSCC is typically treated with surgery, and in some cases other localized therapeutic modalities, locally advanced or metastatic cSCC is a cause of significant morbidity and mortality that requires a different approach to therapy. Therapeutic attempts at treating advanced cSCC include a multi-disciplinary approach with considerations for surgery, radiation, and systemic therapies. In this review, we will discuss the various systemic therapies that have been trialed for advanced cSCC, beginning with the early cytotoxic and platinum-based agents as well as their corresponding limitations. We will then review the targeted approaches using EGFR inhibitors prior to discussing the more recent immunotherapeutics that have shown good tumor responses in this often-lethal disease.

Pre-emptive oral clarithromycin reduces the skin toxicity of panitumumab treatment for metastatic colorectal cancer

PURPOSE

Chemotherapy with panitumumab is expected to be well tolerated and improve survival in patients with metastatic colorectal cancer (mCRC). However, skin toxicities are its most common adverse events. The aim of this trial was to evaluate the efficacy and safety of pre-emptive antibiotic treatment with clarithromycin (CAM) to prevent panitumumab skin toxicities.

METHODS

We conducted a phase lll, multicenter, open-label, randomized clinical trial on mCRC patients treated with panitumumab. Eligible patients were randomly assigned 1:1 to pre-emptive antibiotic and control groups. In the pre-emptive group, CAM administration (200 mg twice per day) continued daily through the panitumumab treatment period. The control regimen consisted of skin care only. The primary end point was the incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period.

RESULTS

Of 156 enrolled patients, 78 received pre-emptive antibiotic treatment, and 78 received reactive treatment. The number and incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period were 16 (21.3%) and 41 (54.7%) for the pre-emptive and control groups, respectively (HR, 0.32; 95% CI, 0.17-0.56). There was almost no difference in the rate of other adverse events between the two groups, but the incidence of grade ≥ 3 diarrhea in the pre-emptive group was high, at 8% vs. 1.3% in the control group. There were no treatment-related deaths.

CONCLUSION

Prophylactic oral CAM together with relatively simple skin care was found to be effective in suppressing the development of grade ≥ 2 skin toxicities induced by panitumumab.

CLINICAL TRIAL REGISTRATION

UMIN000011485 DATE OF REGISTRATION: Sep 1st, 2013.

Role of sex hormones in lung cancer

Lung cancer represents the world's leading cause of cancer deaths. Sex differences in the incidence and mortality rates for various types of lung cancers have been identified, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined. While some cancers such as lung adenocarcinoma are more commonly found among women than men, others like squamous cell carcinoma display the opposite pattern or show no sex differences. Associations of tobacco product use rates, susceptibility to carcinogens, occupational exposures, and indoor and outdoor air pollution have also been linked to differential rates of lung cancer occurrence and mortality between sexes. While roles for sex hormones in other types of cancers affecting women or men have been identified and described, little is known about the influence of sex hormones in lung cancer. One potential mechanism identified to date is the synergism between estrogen and some tobacco compounds, and oncogene mutations, in inducing the expression of metabolic enzymes, leading to enhanced formation of reactive oxygen species and DNA adducts, and subsequent lung carcinogenesis. In this review, we present the literature available regarding sex differences in cancer rates, associations of male and female sex hormones with lung cancer, the influence of exogenous hormone therapy in women, and potential mechanisms mediated by male and female sex hormone receptors in lung carcinogenesis. The influence of biological sex on lung disease has recently been established, thus new research incorporating this variable will shed light on the mechanisms behind the observed disparities in lung cancer rates, and potentially lead to the development of new therapeutics to treat this devastating disease.

Cetuximab-induced rash is associated with overall survival in patients with recurrent/metastatic squamous cell carcinoma of head and neck

PURPOSE

In this study, we looked for whether treatment-induced rash predicts treatment efficacy in patients with recurrent/metastatic HNSCC treated with Cetuximab and chemotherapy.

METHODS

Patients who were treated with platinum-based chemotherapy and cetuximab for the first line treatment of recurrent/metastatic HNSCC were recruited. Presence of rash, hypomagnesemia, hypopotassemia, anemia, neutropenia, thrombocytopenia during treatment and treatment response, date of progression, date of last visit and death were recorded.

RESULTS

A total of 138 patients' data were available for analysis. Any grade of rash was detected in 57 (44.5%) of the patients. The incidence of rash was significantly higher in patients with objective response than in patients with disease progression (%56.8 vs %14.3, p < 0.001). Progression free survival was 7.06 months (4.98-9.15) in patients treated with cetuximab and chemotherapy as first line treatment. In the multivariate analysis; rash was significantly correlated with longer PFS (HR 2.136; 95% CI 1.067-4.278; p = 0.032). Progression free survival was 9.65 months in patients who experienced rash, and 6.02 months in patients without rash, (p = 0.019, log-rank test). Overall survival was 11.24 months (9.65-12.82). In multivariate analysis, the survival of patients with rash was significantly longer than patients without rash (HR 1.954; 95% CI 1.162-3.285; p = 0.012). Overall survival was 15.08 months in patients who experienced rash, and 8.61 months in patients without rash (p = 0.05, log-rank test).

CONCLUSION

Cetuximab-induced rash is associated with better ORR and longer PFS and OS in patients with recurrent/metastatic HNSCC treated with Cetuximab and platinum-based chemotherapy.

[Alopecia and cancers: From basics to clinical practice]

Alopecia, although long considered an unavoidable consequence of cancer therapy, currently presents a multifaceted challenge. The knowledge of the physiology of the hair and consequently of the pathophysiology of alopecia has led to show that there is not one but several types of alopecia. Transposed to the world of oncology, different types of alopecia and subsequently molecular pathways have been characterized, allowing a better understanding of the underlying mechanisms. Thus, in patients with cancer, alopecia can be iatrogenic (chemotherapies, endocrine therapies, targeted therapies, immunotherapies, radiotherapy, surgery) or directly the consequence of the disease itself (malnutrition, scalp metastases, paraneoplastic syndromes). Knowledge of the incriminated mechanism(s) could thus make it possible to deploy an appropriate care component, whether on the preventive or curative sides or in terms of supportive care. These are particularly essential regarding the psychological repercussions caused by alopecia, with significant consequences on the quality of life of patients and with a potential impact on treatment compliance. On the preventive side, the last few years have seen the advent of the automated scalp cooling therapy, supported by several randomized clinical trials. On the curative side, several therapeutic proposals are currently deployed or under development in order to provide relevant treatments.

The Impact of Long-Term Antibiotic Therapy of Cutaneous Adverse Reactions to EGFR Inhibitors in Colorectal Cancer Patients

Colorectal cancer (CRC) is an important public health issue, in terms of incidence and mortality, with approximately 1.8 million new cases reported worldwide in 2018. Advancements in understanding pathophysiological key steps in CRC tumorigenesis have led to the development of new targeted therapies such as those based on epidermal growth factor receptor inhibitors (EGFR inhibitors). The cutaneous adverse reactions induced by EGFR inhibitors, particularly papulopustular rash, often require long-term antibiotic treatment with tetracycline agents (mostly minocycline and doxycycline). However, this raises several issues of concern: possible occurrence of gut dysbiosis in already vulnerable CRC patients, selection of highly antibiotic resistant and/or virulent clones, development of adverse reactions related to tetracyclines, interference of antibiotics with the response to oncologic therapy, with a negative impact on disease prognosis etc. In the context of scarce information regarding these issues and controversial opinions regarding the role of tetracyclines in patients under EGFR inhibitors, our aim was to perform a thorough literature review and discuss the main challenges raised by long-term use of tetracyclines in advanced CRC patients receiving this targeted therapy.

Efficacy and Safety of Modified Huang-Lian-Jie-Du Decoction Cream on Cancer Patients with Skin Side Effects Caused by EGFR Inhibition

(1) Background: The epidermal growth factor inhibitors (EGFRIs)/tyrosine kinase inhibitors (TKIs) are effective for cancer target therapy, but acneiform rashes or so-called inflammatory papulopustular exanthemas are common (50% to 90%). The conventional therapy for EGFRIs/TKIs-induced skin toxicity is steroids and antibacterial drugs, but it is still ineffective for some patients, and EGFRIs/TKIs dose reduction/interruption may be needed. In this study, a modified Chinese herbal medicine, Huang-Lian-Jie-Du decoction cream with Yin-Cold (YC) medicine characteristic, was investigated for the effect on patients suffering EGFRIs/TKIs-induced skin toxicity. (2) Methods: The modified Huang-Lian-Jie-Du (mHLJD) decoction cream was made from 10 herbal medicines, including 4 major medicines (Huanglian, Huangqin, Huangbo, and Zhizi) in traditional HLJD decoction. Patients with EGFRIs/TKIs-induced skin toxicity were enrolled. Patients were excluded if they also used other cream for skin toxicity. Skin conditions were monitored by follow up every 2 weeks. The patients’ characteristics, the skin toxicities, treatment response, and adverse events were recorded and analyzed until skin problems resolved or the study ended. (3) Results: The mHLJD decoction cream and its sub-packages were stored at 4 °C before use. Thirty-four patients who had grade 1–3 skin toxicities after receiving EGFRIs/TKIs were enrolled. Seven patients withdrew or were excluded. Finally, data from 27 patients were analyzed. The mean grade of rash acneiform was significantly decreased from 2.19 (ranged 1 to 3) to 0.88 (ranged 0 to 2) after mHLJD decoction cream treatment for 4 weeks and to 0.55 (ranged 0 to 2) after mHLJD decoction cream treatment for 8 weeks. Additionally, the mean grade of dry skin was also significantly decreased from 1.57 (ranged 1 to 2) to 0.71 (ranged 0 to 1) after mHLJD decoction cream treatment for 4 weeks. The changes of skin toxicity were significant, with no obvious adverse events. (4) Conclusions: In summary, the mHLJD decoction cream provides benefits for alleviation of EGFRIs/TKIs-induced skin rash acneiform and dry skin. Additionally, no obvious side effects were found in patients using mHLJD decoction cream.

Panitumumab-Induced Paronychia: A Case Report and a Brief Review of the Literature

Panitumumab is a recombinant, fully humanized IgG2 monoclonal antibody targeting the epidermal growth factor receptor (EGFR). Panitumumab is indicated for patients with metastatic colorectal cancer with progressive refractory disease. Targeted therapies are well known to be well tolerated; however, they may induce toxicities that are distinct from those of classical chemotherapeutic agents. For instance, EGFR inhibitors (EGFRIs) are associated with some specific dermatological adverse effects, one of which is nail toxicity. Since panitumumab is fully humanized, unlike most of the other EGFRIs, it has been reported to have reduced incidence of adverse reactions. Nail-related adverse effects are frequently observed with EGFRIs. A literature search has yielded a list of reviews describing panitumumab-induced nail toxicity. However, as far as we know, there is no case report detailing this adverse effect of panitumumab. Here, we present a case of panitumumab-induced paronychia in a 60-year-old woman with metastatic colon cancer. With this case report, we would like to review the literature and discuss the possible underlying mechanisms of this condition.

Oxidative stress induces EGFR inhibition-related skin cell death

Cutaneous side effects are often observed in patients treated with chemotherapeutic agents, including those treated with epidermal growth factor receptor (EGFR) inhibitors. These side effects are not fatal but often require dose reduction of chemotherapies. The mechanisms of epidermal growth factor receptor inhibition-related dermatologic toxicities are unclear, and prophylactic approaches are not well-established. To explore the mechanisms of the cutaneous side effects induced by epidermal growth factor receptor inhibition, we analyzed the metabolome using human keratinocyte cells. We first demonstrated that afatinib and lapatinib induced apoptosis in HaCaT cells. Using liquid chromatography-mass spectrometry, we detected 676 and 482 metabolites and compounds in the cells and media, respectively. We observed diverse metabolic alterations, including glycolysis, TCA metabolism, and polyamine metabolism, and also found a change in glutathione metabolites after epidermal growth factor receptor inhibition, which led to the accumulation of reactive oxygen species. Supplementation of N-acetyl cysteine partly rescued the afatinib-induced apoptosis, suggesting that reactive oxygen species are involved in the cytotoxicity of skin cells. We observed epidermal growth factor receptor inhibitor-associated comprehensive metabolic changes in human keratinocyte cells, suggesting that oxidative stress evokes cutaneous side effects induced by EGFR inhibition.

Characterization and management of ERK inhibitor associated dermatologic adverse events: analysis from a nonrandomized trial of ulixertinib for advanced cancers

Background Ulixertinib is the first-in-class ERK1/2 kinase inhibitor with encouraging clinical activity in BRAF- and NRAS-mutant cancers. Dermatologic adverse events (dAEs) are common with ulixertinib, so management guidelines like those established for epidermal growth factor receptor inhibitor (EGFRi)-associated dAEs are needed. Patients and Methods This was an open-label, multicenter, phase I dose escalation and expansion trial of ulixertinib evaluating data from 135 patients with advanced malignancies enrolled between March 2013 and July 2017. Histopathological features, management, and dAEs in 34 patients are also reported. Twice daily oral ulixertinib was administered at 10 to 900 mg in the dose escalation cohort (n = 27) and at 600 mg in 21-day cycles in the expansion cohort (n = 108). Results The incidence of ulixertinib-induced dAEs and combined rash were 79% (107/135) and 76% (102/135). The most common dAEs included acneiform rash (45/135, 33%), maculopapular rash (36/135, 27%), and pruritus (34/135, 25%). Grade 3 dAEs were observed in 19% (25/135) of patients; no grade 4 or 5 dAEs were seen. The presence of at least 1 dAE was associated with stable disease (SD) or partial response (PR) (OR = 3.64, 95% CI 1.52-8.72; P = .003). Acneiform rash was associated with a PR (OR = 10.19, 95% CI 2.67-38.91; P < .001). Conclusion The clinical spectrum of ulixertinib-induced dAEs was similar to EGFR and MEK inhibitors; dAEs may serve as a surrogate marker of tumor response. We propose treatment algorithms for common ERK inhibitor-induced dAEs to maintain patients' quality of life and dose intensity for maximal clinical benefit. Clinical Trial Registration: NCT01781429.

Genetic Predictors of Severe Skin Toxicity in Patients with Stage III Colon Cancer Treated with Cetuximab: NCCTG N0147 (Alliance)

BACKGROUND

Cetuximab, an EGFR inhibitor used to treat multiple cancer types, including colon cancer, causes severe skin toxicity in 5%-20% of patients, leading to decreased quality of life and treatment delays. Our understanding of which patients have an increased risk of severe toxicities is limited. We conducted a genome-wide association study to identify germline variants predictive of cetuximab-induced severe skin toxicity.

METHODS

Our study included 1,209 patients with stage III colon cancer randomized to receive cetuximab plus 5-fluorouracil and oxaliplatin as part of the NCCTG N0147 (Alliance) clinical trial. Skin toxicity outcomes were collected using the Common Toxicity Criteria for Adverse Events version 3.0. We performed genotyping, evaluating approximately 10 million genetic variants. We used logistic regression to evaluate the association of each genetic variant and severe (grade ≥ 3) skin toxicity, adjusting for age, sex, and genetic ancestry. Genome-wide significance was defined as P < 5 × 10^-8.

RESULTS

Participants were predominantly middle-aged white men; 20% (n = 243) experienced severe skin toxicity. Two genetic variants in the retinoic acid receptor alpha (RARA) gene were significantly associated with severe skin toxicity [OR, 3.93; 95% confidence interval (CI), 2.47-6.25; P < 7.8 × 10^-9]. Functional annotations indicate these variants are in the RARA promoter. Additional significantly associated variants were identified in chromosome 2 intergenic regions.

CONCLUSIONS

Identified variants could represent a potential target for risk stratification of patients with colon cancer receiving cetuximab.

IMPACT

Retinoids have shown promise in the treatment of cetuximab-induced skin toxicity, so follow-up work could evaluate whether individuals with the RARA variant would benefit from retinoid therapy.

A Comprehensive Review of Contemporary Literature for Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer and Their Toxicity

Mutations in the epidermal growth factor receptor (EGFR) are common amongst those with non-small cell lung cancer and represent a major factor in treatment decisions, most notably in the advanced stages. Small molecule tyrosine kinase inhibitors (TKIs) that target the EGFR, such as erlotinib, gefitinib, icotinib, afatinib, dacomitinib and osimertinib, have all shown to be effective in this setting. Osimertinib, a third-generation EGFR TKI, is a favorable option, but almost all patients develop resistance at some time point. There are no effective treatment options for patients who progress on osimertinib, but ongoing trials will hopefully address this unmet need. The aim of this review is to provide a comprehensive review of the data with EGFR TKIs, management of the toxicities and the ongoing trials with this class of agents.

Safety, Efficacy, and Pharmacokinetics of Almonertinib (HS-10296) in Pretreated Patients With EGFR-Mutated Advanced NSCLC: A Multicenter, Open-label, Phase 1 Trial

INTRODUCTION

Almonertinib (HS-10296) is a novel, third-generation EGFR tyrosine kinase inhibitor (EGFR TKI) that targets both EGFR-sensitizing and T790M resistance mutations. This first-in-human trial aimed to evaluate the safety, efficacy, and pharmacokinetics of almonertinib in patients with locally advanced or metastatic EGFR mutation-positive NSCLC that had progressed after pevious EGFR TKI therapy.

METHODS

This phase 1, open-label, multicenter clinical trial (NCT0298110) included dose-escalation (55, 110, 220, and 260 mg) and dose-expansion cohorts (55, 110, and 220 mg) with once daily oral administration of almonertinib. In each expansion cohort, tumor biopsies were obtained for the determination of EGFR T790M status. The safety, tolerability, antitumor activity, and pharmacokinetics of almonertinib were evaluated.

RESULTS

A total of 120 patients (26 patients in the dose-escalation cohort and 94 patients in the dose-expansion cohort) were enrolled. The maximum tolerated dose was not defined in the dose-escalation phase; the 260 mg regimen was not further evaluated in the dose-expansion phase owing to safety concerns and saturation of exposure. The most common treatment-related grade greater than or equal to 3 adverse events were increased blood creatine phosphokinase (10%) and increased alanine aminotransferase (3%). Among 94 patients with the EGFR T790M mutation in the dose-expansion cohort, the investigator-assessed objective response rate and disease control rate were 52% (95% confidence interval [CI]: 42-63) and 92% (95% CI: 84-96), respectively. Median progression-free survival was 11.0 months (95% CI: 9.5-not reached) months.

CONCLUSIONS

Almonertinib is safe, tolerable and effective for patients with locally advanced or metastatic NSCLC harboring the EGFR T790M mutation who were pretreated with EGFR TKIs.

A Comparative Clinical Study between Concentrated Growth Factor and Low-Level Laser Therapy in the Management of Dry Socket

OBJECTIVE

 A dry socket is a well-recognized complication of wound healing following tooth extraction. Its etiology is poorly understood and commonly occur among healthy patients. As such, management strategies for dry socket has always been empirical rather than scientific with varying outcome. The aim of this study is to investigate the efficacy of concentrated growth factor (CGF) and low-level laser therapy (LLLT) and compared them to the conventional treatment in the management of dry socket.

MATERIALS AND METHODS

 Sixty patients with one dry socket each, at University Dental Hospital Sharjah, were divided into three treatment groups based on their choice. In group I (n = 30), conventional treatment comprising of gentle socket curettage and saline irrigation was done. Group II (n = 15) dry sockets were treated with CGF and group III (n = 15) sockets were lased with LLLT. All dry socket patients were seen at day 0 for treatment and subsequently followed-up at 4, 7, 14, and 21 days. Pain score, perisocket inflammation, perisocket tenderness, and amount of granulation tissue formation were noted.

STATISTICAL ANALYSIS

 Data were analyzed as mean values for each treatment group. Comparisons were made for statistical analysis within the group and among the three groups to rank the efficacy of treatment using one-way analysis of variance (ANOVA). Statistically significant difference is kept at p < 0.05.

RESULTS

 Conventional treatment group I took more than 7 days to match the healing phase of group II CGF treated socket and group III LLLT irradiated socket (p = 0.001). When healing rate between CGF and LLLT are compared, LLLT group III showed a delay of 4 days compared with CGF in granulation tissue formation and pain control.

CONCLUSION

 CGF treated socket was superior to LLLT in its ability to generate 75% granulation tissue and eliminate pain symptom by day 7 (p = 0.001).

Management of dermatologic adverse events from cancer therapies: recommendations of an expert panel

With the development of new cancer therapies, systemic toxicity profile and effects on survival achieved an important improvement. However, a constellation of toxicities has emerged, even more remarkably, cutaneous adverse events. This report, developed by a board of Brazilian experts in oncodermatology, aims to establish a guideline for the dermatological care of oncologic patients. When possible, evidence-based recommendations were made, but in many cases, when strong evidence was not available, a consensus was reached, based on some data supporting therapies combined with personal experiences.

Proteomic and Phosphoproteomic Analysis Reveals that Neurokinin-1 Receptor (NK1R) Blockade with Aprepitant in Human Keratinocytes Activates a Distinct Subdomain of EGFR Signaling: Implications for the Anti-Pruritic Activity of NK1R Antagonists

Background: Epidermal growth factor receptor (EGFR) inhibitors can cause serious cutaneous toxicities, including pruritus and papulopustular acneiform skin eruptions. Increasingly, the neurokinin-1 receptor (NK1R) antagonist aprepitant is being utilized as an anti-pruritic agent in the treatment of EGFR-inhibitor induced pruritus. Aprepitant is believed to reduce itching by blocking NK1R on the surface of dermal mast cells. However, the effects of aprepitant on human keratinocytes remains unexplored. Methods: Herein, we examine the effects of aprepitant on EGFR stimulation in HaCaT cells using a phosphoproteomic approach including reverse phase protein arrays and Ingenuity Pathway Analysis. Changes in EGFR phosphorylation were visualized using Western blotting and the effect of EGF and aprepitant on the growth of HaCaT cells was determined using the WST-1 Cell Proliferation Assay System. Results: We found that aprepitant increased the phosphorylation of EGFR, as well as 10 of the 23 intracellular proteins phosphorylated by EGF. Analysis of phosphoproteomic data using Ingenuity Pathway Analysis software revealed that 5 of the top 10 pathways activated by EGF and aprepitant are shared. Conclusions: We propose that aprepitant produces its antipruritic effects by partially activating EGFR. Activation of EGFR by aprepitant was also seen in primary human keratinocytes. In addition to itch reduction through partial activation of shared EGFR pathways, aprepitant exerts a dose-dependent cytotoxicity to epithelial cells, which may contribute to its antitumor effects.

Mechanisms and Antitumor Activity of a Binary EGFR/DNA-Targeting Strategy Overcomes Resistance of Glioblastoma Stem Cells to Temozolomide

PURPOSE

Glioblastoma (GBM) is a fatal primary malignant brain tumor. GBM stem cells (GSC) contribute to resistance to the DNA-damaging chemotherapy, temozolomide. The epidermal growth factor receptor (EGFR) displays genomic alterations enabling DNA repair mechanisms in half of GBMs. We aimed to investigate EGFR/DNA combi-targeting in GBM.

EXPERIMENTAL DESIGN

ZR2002 is a "combi-molecule" designed to inflict DNA damage through its chlorethyl moiety and induce irreversible EGFR tyrosine kinase inhibition. We assessed its in vitro efficacy in temozolomide-resistant patient-derived GSCs, mesenchymal temozolomide-sensitive and resistant in vivo-derived GSC sublines, and U87/EGFR isogenic cell lines stably expressing EGFR/wild-type or variant III (EGFRvIII). We evaluated its antitumor activity in mice harboring orthotopic EGFRvIII or mesenchymal TMZ-resistant GSC tumors.

RESULTS

ZR2002 induced submicromolar antiproliferative effects and inhibited neurosphere formation of all GSCs with marginal effects on normal human astrocytes. ZR2002 inhibited EGF-induced autophosphorylation of EGFR, downstream Erk1/2 phosphorylation, increased DNA strand breaks, and induced activation of wild-type p53; the latter was required for its cytotoxicity through p53-dependent mechanism. ZR2002 induced similar effects on U87/EGFR cell lines and its oral administration significantly increased survival in an orthotopic EGFRvIII mouse model. ZR2002 improved survival of mice harboring intracranial mesenchymal temozolomide-resistant GSC line, decreased EGFR, Erk1/2, and AKT phosphorylation and was detected in tumor brain tissue by MALDI imaging mass spectrometry.

CONCLUSIONS

These findings provide the molecular basis of binary EGFR/DNA targeting and uncover the oral bioavailability, blood-brain barrier permeability, and antitumor activity of ZR2002 supporting potential evaluation of this first-in-class drug in recurrent GBM.

Phospholipase Cγ1 is required for normal irritant contact dermatitis responses and sebaceous gland homeostasis

Differentiation and proliferation of keratinocyte are controlled by various signalling pathways. The epidermal growth factor receptor (EGFR) is known to be an important regulator of multiple epidermal functions. Inhibition of EGFR signalling disturbs keratinocyte proliferation, differentiation and migration. Previous studies have revealed that one of the EGFR downstream signalling molecules, phospholipase Cγ1 (PLCγ1), regulates differentiation, proliferation and migration of keratinocytes in in vitro cell culture system. However, the role of PLCγ1 in the regulation of keratinocyte functions in animal epidermis remains unexplored. In this study, we generated keratinocyte-specific PLCγ1 knockout (KO) mice (PLCγ1 cKO mice). Contrary to our expectations, loss of PLCγ1 did not affect differentiation, proliferation and migration of interfollicular keratinocytes. We further examined the role of PLCγ1 in irritant contact dermatitis (ICD), in which epidermal cells play a pivotal role. Upon irritant stimulation, PLCγ1 cKO mice showed exaggerated ICD responses. Further study revealed that epidermal loss of PLCγ1 induced sebaceous gland hyperplasia, indicating that PLCγ1 regulates homeostasis of one of the epidermal appendages. Taken together, our results indicate that, although PLCγ1 is dispensable in interfollicular keratinocyte for normal differentiation, proliferation and migration, it is required for normal ICD responses. Our results also indicate that PLCγ1 regulates homeostasis of sebaceous glands.

Topical doxycycline foam 4% for prophylactic management of epidermal growth factor receptor inhibitor skin toxicity: an exploratory phase 2, randomized, double-blind clinical study

PURPOSE

Acneiform rash, a common toxicity of epidermal growth factor receptor inhibitors (EGFRIs), can cause patient discomfort, warranting changes in treatment. This study investigated the safety, tolerability, and efficacy of a novel doxycycline foam, FDX104 4%, for managing EGFRI-related skin toxicity.

METHODS

This was an exploratory phase 2, randomized, double-blind, placebo-controlled study. Subjects had metastatic colorectal cancer and were being treated with either cetuximab or panitumumab plus chemotherapy. Treatment (twice-daily topical FDX104 4% on one side of the face and vehicle foam on the other for 5 weeks) was initiated 7 ± 3 days prior to EGFRI therapy. Rash severity, safety, and tolerability were evaluated at 2 and 4 weeks after EGFRI start.

RESULTS

The mean maximal rash grade was lower with FDX104 4% vs vehicle, and fewer subjects developed moderate-to-severe (grades 2-3) rash. On the Global Severity Score scale, a statistically significant difference favored FDX104 4% over vehicle (P = .047). Adverse events (AEs) (n = 68) occurred in 20 subjects; most were mild or moderate. The most common AEs were oral mucositis, nausea, and vomiting, common to chemotherapy and EGFRI treatment. Study-drug-related AEs were experienced by five subjects and consisted of mild, local skin reactions. No study-drug-related systemic side effects were reported.

CONCLUSION

Twice-daily, topical administration of FDX104 4% as an adjunct to either cetuximab or panitumumab was safe and well tolerated, and appeared to prevent the onset of rash, especially severe rash. CLINICALTRIALS.

GOV IDENTIFIER

Trial Registration NCT02239731.

Alopecia in Association with Malignancy: A Review

The interaction between hair and malignancy is complicated. Various hair abnormalities can manifest in oncology patients as a clinical manifestation, the result of cancer therapy, or due to a paraneoplastic condition. The mechanisms of these changes remain unclear. Alopecia is one of the common clinical presentations occurring in oncology patients that affects their quality of life. The condition can concomitantly develop during the course of malignancy or when patients undergo cancer treatment. It is important for physicians to understand alopecia in association with malignancy as it may be an important associated finding or provide the clues to aid diagnosis. The aim of this review is to summarize the clinical characteristics of alopecia that occur in cancer patients and their relationship with the type of malignancy and its treatment.

Instrumental evaluation sensitively detects subclinical skin changes by the epidermal growth factor receptor inhibitors and risk factors for severe acneiform eruption

Epidermal growth factor receptor inhibitors (EGFRI), EGFR tyrosine kinase inhibitors (TKI) and anti-EGFR antibodies commonly develop skin toxicities including acneiform eruption (AfE). However, precise skin changes and risk factors for severe AfE are still unclear. The objective of the current study was elucidation of the useful parameters for early and sensitive detection of the skin changes by EGFRI. Transepidermal water loss (TEWL), skin surface hydration, skin surface lipid levels and erythema/melanin index were serially measured for 2 weeks in 19 EGFR-TKI afatinib/erlotinib-treated patients and for 8 weeks in 20 anti-EGFR antibody cetuximab-treated patients. The TEWL levels of the cheek in the patients who developed AfE of grade 2 and more (AfE ≥ Gr2) were already elevated at 7 days after the initiation of afatinib/erlotinib therapy compared with those before therapy as well as in patients with grade 1 or less (AfE ≤ Gr1). In patients treated with cetuximab, the skin surface hydration on the cheek in AfE ≥ Gr2 patients significantly decreased compared with that of AfE ≤ Gr1 patients at the 2nd and 6th week. Baseline skin surface lipid levels and erythema index on the cheek of patients with AfE ≥ Gr2 were significantly higher than those with AfE ≤ Gr1. The small sample size of the present study, especially for logistic regression analysis, is a limitation. In conclusion, instrumental evaluation declared rapid inflammatory changes of the skin by EGFRI and elucidated oily skin as a risk for severe AfE.

Osimertinib: A Novel Dermatologic Adverse Event Profile in Patients with Lung Cancer

Dermatologic adverse events (dAEs) are common with the use of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. First- and second-generation agents (erlotinib, gefitinib, and afatinib) are frequently associated with acneiform rash, pruritus, xerosis, and paronychia; the incidence and characterization of these dAEs have been well described. However, there is evidence that the dAE profile is different with third-generation EGFR-TKIs. Herein, we describe the dAEs associated with third-generation EGFR-TKIs and our clinical experience with osimertinib, a third-generation EGFR-TKI approved by the U.S. Food and Drug Administration for the treatment of metastatic, EGFR T790M mutation-positive non-small cell lung cancer in patients whose disease has progressed on or after EGFR-TKI therapy. Case summaries of patients from two of our institutions who received osimertinib and were referred to a dermatologist for dAEs are also presented. Overall, the evidence suggests that osimertinib is associated with less severe and less frequent dAEs than first- and second-generation EGFR-TKIs and that therefore a different approach is warranted. Finally, we outline dAE management approaches for osimertinib in the context of those typically employed with first- and second-generation EGFR-TKIs.

IMPLICATIONS FOR PRACTICE

Appropriate prevention and management of dermatologic adverse events (dAEs) associated with the use of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) may help patients to continue therapy and lessen any negative impact on their quality of life. EGFR-TKIs are frequently associated with acneiform rash, pruritus, xerosis, and paronychia; however, dAEs associated with third-generation EGFR-TKIs are lower in frequency and severity. Before therapy, health care providers should discuss the potential osimertinib-associated dAEs and encourage patients to report their dAEs. Patients should also be educated on prophylactic measures to minimize the severity of dAEs and the importance of adherence to the treatment regimen.

Management of skin toxicity caused by epidermal growth factor receptor inhibitors: an evidence-based implementation project

BACKGROUND

Epidermal growth factor receptor inhibitors (EGFRIs) bind to and inhibit epidermal growth factor receptors (EGFRs) in cancer cells, slowing/preventing tumor growth. As a type of "targeted therapy", they have demonstrated therapeutic effects on solid tumors including colorectal, lung, and head and neck cancers. While effective, various skin reactions are associated with EGFRI therapy which can lead to dose modification or discontinuation as well as discomfort, pain and reduced quality of life. With adequate knowledge and skills, EGFRI-induced skin toxicity can be effectively managed collaboratively by clinicians and people affected by cancer.

OBJECTIVES

This project aimed to improve management of skin toxicity caused by EGFRIs by implementing evidence-informed practice within a chemotherapy department.

METHODS

Evidence-informed recommendations for practice and corresponding audit criteria were developed based on a series of literature reviews. Current practice was reviewed against these criteria with 19 nurses and 21 patients within a chemotherapy department. Barriers to adherence to evidence-informed practice were identified and strategies to improve compliance were implemented with clinicians and patients. A follow-up audit against the criteria was used to measure changes in clinical practice.

RESULTS

Multiple strategies for getting research into practice appear to have been successful. The follow-up audit demonstrated large improvements in compliance across all audit criteria in comparison with baseline results with all but one criterion achieving 100% compliance. Low rates of suspected infection meant that clinical practice could not be measured for criterion 7.

CONCLUSIONS

Auditing current practice and implementation of strategies to improve compliance with evidence-informed practice were effective. Sustaining these improvements is vital to ensure clinical practice continues to support better patient outcomes.

Cancer Pain Syndromes

Patients with cancer experience many acute and chronic pain syndromes, the identification of which may be helpful in the assessment and treatment of pain. Syndromes are defined by the relationship with the cancer, the pain pathophysiology, and the clinical characteristics of the pain. The most common pain syndromes are directly related to the tumor; bone pain syndromes are most common. Neuropathic pain syndromes may involve cancer-related injury at any level of the peripheral nervous system. Treatment-related pain syndromes may follow any type of antineoplastic therapy. This article reviews the phenomenology of common acute and chronic cancer pain syndromes.

Clinical impact of minocycline on afatinib-related rash in patients with non-small cell lung cancer harboring epidermal growth factor receptor mutations

BACKGROUND

The management of skin toxicity is crucial for efficient afatinib treatment, but the role of tetracycline class antibiotics (TCs) in managing these rashes is relatively unknown.

METHODS

We reviewed the clinical records of patients who were administered afatinib for the treatment of non-small cell lung cancer harboring epidermal growth factor receptor mutations between October 2014 and November 2016. Twenty-five patients, who received TCs for the management of afatinib-related skin disorders, were enrolled.

RESULTS

Minocycline was administered orally to participants. Afatinib-related toxic effects, such as rash, diarrhea, and paronychia, were observed in 92%, 92%, and 40% of cases, respectively. Although 24% of diarrhea and 4% of paronychia cases were rated grade 3 or higher, no severe cases of rash were observed during afatinib treatment. Of the 18 afatinib dose reductions, 14 (78%), three (17%), and one (6%) resulted from diarrhea, paronychia, and stomatitis, respectively; no patients required a dose reduction because of rash. When minocycline treatment started, 21 patients (84%) had a rash of grade 1 or less, and three patients had a grade 2 rash. A response to afatinib was observed in 18 patients (72%) and the median duration of afatinib administration was 501 days. An adverse event related to minocycline (grade 1 nausea) was observed in one patient.

CONCLUSIONS

A large proportion of the study patients started minocycline before grade 2 rash development and the severity of afatinib-related rash was lower than that previously reported. Oral TCs may be beneficial, especially if started early.

The incidence and management of cutaneous adverse events of the epidermal growth factor receptor inhibitors

Overexpression of the epidermal growth factor receptor (EGFR) is found in many cancers, including those of the head and neck area, non-small-cell lung cancer, and colorectal, cervical, prostate, breast, ovary, stomach, and pancreatic cancer. The EGFR inhibitors are used at present in the treatment of such cancers. Skin lesions that develop during and after cancer treatment may be due to specific cytostatics, molecular-targeted drugs, radiation therapy, complementary therapy, or the cancer itself, and hence knowledge is essential to distinguish between them. The mechanism through which skin toxicity arises during treatment with EGFR inhibitors is not well known, but seems to be due to the modification of the RAS/RAF/MEK/ERK signal path associated with its activation, which results in the similarity between the adverse effects of EGFR inhibitors and the treatment of melanoma with BRAF and MEK inhibitors. The most common side effects are pruritus, xerosis, papulopustular rash, hand-foot skin reaction, alopecia and dystrophy of the hair, and paronychia. This work presents options for prevention and suggestions for managing these adverse events, which are of importance in the care of patients undergoing oncological treatment.

Exposure-Response Analysis of Necitumumab Efficacy in Squamous Non-Small Cell Lung Cancer Patients

We sought to describe the exposure-response relationship of necitumumab efficacy in squamous non-small cell lung cancer patients and evaluate intrinsic and extrinsic patient descriptors that may guide dosing. SQUIRE was a phase III study comparing necitumumab in combination with gemcitabine and cisplatin vs. gemcitabine and cisplatin alone in 1,014 patients. An integrated model for tumor size dynamics and overall survival was developed, where reduction in tumor size results in a decrease in survival hazard. The change in tumor size was characterized using linear growth and first-order shrinkage. Overall survival was described using a combination of a Weibull function and Gompertz function for the hazard, with dynamic tumor size being a predictor for the hazard. Although body weight resulted in higher clearance and lower exposure, simulations showed that an 800 mg flat dose provided optimal response regardless of body weight.

Management of adverse events during treatment of gastrointestinal cancers with epidermal growth factor inhibitors

The epidermal growth factor receptor (EGFR) is involved in development and progression of some gastrointestinal cancers, and is targeted by monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs) used to treat these conditions. Targeted agents are generally better tolerated than conventional chemotherapy, but have characteristic toxicities that can affect adherence, dosing, and outcomes. Skin conditions are the most common toxicities associated with EGFR inhibitors, particularly papulopustular rash. Other common toxicities include mucosal toxicity, electrolyte imbalances (notably hypomagnesaemia), and diarrhoea, while the chimaeric mAb cetuximab is also associated with increased risk of infusion reactions. With appropriate prophylaxis, the incidence and severity of these events can be reduced, while management strategies tailored to the patient and the degree of toxicity can help to ensure continuation of anti-cancer therapy. Here, we review the main toxicities associated with EGFR-inhibiting mAbs and TKIs in patients with gastrointestinal cancers, and provide recommendations for prophylaxis and treatment.

Patient considerations in metastatic colorectal cancer - role of panitumumab

Epidermal growth factor receptor (EGFR) is overexpressed in many malignancies, including colorectal cancer (CRC), making EGFR an attractive treatment option. Panitumumab and cetuximab, monoclonal antibodies (mAbs) directed at EGFR, are both currently utilized in the management of metastatic CRC (mCRC). Through the development of these agents in mCRC, key issues surrounding each mAbs use have been revealed. These key issues include negative patient outcome avoidance when determining use, the economic burden with high-cost medication, predictive biomarkers, tumor location, patient geographic location, patient quality of life, and the prevention of debilitating adverse effects. CRC remains a common malignancy, with many of these patients expected to receive targeted therapy, including EGFR mAb therapy. Oncologists must recognize these EGFR mAb factors in order to improve outcomes. This review aims to provide a chronological timeline on the development of panitumumab, clinical pearls, and guidance on the current use of panitumumab in mCRC.

ADAM17/EGFR axis promotes transglutaminase-dependent skin barrier formation through phospholipase C γ1 and protein kinase C pathways

The vitally important skin barrier is formed by extensive cross-linking activity of transglutaminases (TGs) during terminal epidermal differentiation. We have previously shown that epidermal deficiency of a disintegrin and metalloproteinase 17 (ADAM17), the principal EGFR ligand sheddase, results in postnatal skin barrier defects in mice due to impeded TG activity. However, the mechanism by which ADAM17/EGFR signalling maintains TG activity during epidermal differentiation remains elusive. Here we demonstrate that ADAM17-dependent EGFR signalling promotes TG activity in keratinocytes committed to terminal differentiation by direct induction of TG1 expression. Restored TG1 expression of EGF-stimulated differentiated Adam17-/- keratinocytes was strongly repressed by inhibitors for PLCγ1 or protein kinase C (PKC) pathways, while treatment with the PKC stimulator 12-O-tetradecanoylphorbol-13-acetate restored TG activity in the epidermis of keratinocyte-specific Adam17-/- (AD17ΔKC) mice. Further investigations emphasized the expression of PKCη, a mediator of TGM1 transcription, to be sensitive to EGFR activation. In agreement, topical skin application of cholesterol sulfate, an activator of PKCη, significantly improved TG activity in epidermis of AD17ΔKC mice. Our results suggest ADAM17/EGFR-driven PLCγ1 and PKC pathways as important promoters of TG1 expression during terminal keratinocyte differentiation. These findings may help to identify new therapeutic targets for inflammatory skin diseases related to epidermal barrier defects.

Erlotinib-induced purpuric papulopustular eruption treated with pulsed azithromycin

Erlotinib belongs to the targeted cancer treatments acting through epidermal growth factor receptor inhibition. Papulopustular eruption is the most common cutaneous toxicity. The pathogenesis of the rash is not clear. There is no consensus on treatment. In this report, we describe a 73-year-old female patient who was referred to our outpatient clinic for evaluation and treatment of a widespread acneiform eruption. She was put on erlotinib therapy for 3 months for the treatment of lung adenocarcinoma. The patient has developed nonpruritic papules and pustules widespread over the body except the face for the past 2 weeks. Bacterial culture obtained from a pustule on the back grew methicillin-sensitive Staphylococcus aureus (SA). Histopathological examination of a papule demonstrated vacuolar degeneration of basal layer, prominent walls of vessels, a mixed infiltration of eosinophils, and lymphocytes and erythrocyte extravasation. The eruption was successfully treated with two weekly pulses of azithromycin 500 mg for 3 consecutive days. This case demonstrated that erlotinib may cause purpuric papular eruption secondarily infected with SA. Routine bacterial culture should be performed from pustules before any treatment.

Skin Barrier Defects Caused by Keratinocyte-Specific Deletion of ADAM17 or EGFR Are Based on Highly Similar Proteome and Degradome Alterations

Keratinocyte-specific deletion of ADAM17 in mice impairs terminal differentiation of keratinocytes leading to severe epidermal barrier defects. Mice deficient for ADAM17 in keratinocytes phenocopy mice with a keratinocyte-specific deletion of epidermal growth factor receptor (EGFR), which highlights the role of ADAM17 as a "ligand sheddase" of EGFR ligands. In this study, we aim for the first proteomic/degradomic approach to characterize the disruption of the ADAM17-EGFR signaling axis and its consequences for epidermal barrier formation. Proteomic profiling of the epidermal proteome of mice deficient for either ADAM17 or EGFR in keratinocytes at postnatal days 3 and 10 revealed highly similar protein alterations for ADAM17 and EGFR deficiency. These include massive proteome alterations of structural and regulatory components important for barrier formation such as transglutaminases, involucrin, filaggrin, and filaggrin-2. Cleavage site analysis using terminal amine isotopic labeling of substrates revealed increased proteolytic processing of S100 fused-type proteins including filaggrin-2. Alterations in proteolytic processing are supported by altered abundance of numerous proteases upon keratinocyte-specific Adam17 or Egfr deletion, among them kallikreins, cathepsins, and their inhibitors. This study highlights the essential role of proteolytic processing for maintenance of a functional epidermal barrier. Furthermore, it suggests that most defects in formation of the postnatal epidermal barrier upon keratinocyte-specific ADAM17 deletion are mediated via EGFR.

Extreme Phenotype of Epidermal Growth Factor Receptor Inhibitor-induced Destructive Folliculitis

Due to the increasingly widespread use and side effect profile of epidermal growth factor receptor inhibitors (EGFRIs), cutaneous side effects of these drugs are frequently encountered. The EGFR is expressed on keratinocytes and fibroblasts. Inhibition of EGFR can produce a range of cutaneous adverse effects, the most frequent being a characteristic acneiform skin eruption. As the latter is associated with good anti-neoplastic responses, the onset of EGFRI-induced acneiform skin eruption is typically viewed as a positive sign by patients and physicians. It can usually be treated well with standard acne drugs, but in rare cases, the skin eruption can be so severe that systemic therapy and/or interruption of EGFRI treatment are required. One of the severest forms of EGFRI-induced skin eruption occurring on the head and neck area resembles folliculitis decalvans. Here, we discuss the management of such a case seen in our department. In addition, we present an analysis of tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-17A expression based on immunohistochemical stains and qPCR.

Erlotinib-associated rash in patients with EGFR mutation-positive non-small-cell lung cancer treated in the EURTAC trial

AIM

This analysis investigates incidence and time course of rash in the EURTAC study.

MATERIALS & METHODS

Patients with EGFR mutation-positive non-small-cell lung cancer were randomized 1:1 to receive once daily erlotinib or 3-weekly cycles of chemotherapy.

RESULTS

Of the 86 erlotinib-treated patients, 71 reported rash. Median time to first rash appearance was 0.7 months. Most patients (n = 65) had the same or lower grade rash at final assessment compared with initial assessment. Of the 21 patients with decreased rash grade between initial and final assessments, 61.9% received no erlotinib dose modification, 42.8% had no concomitant rash treatment.

CONCLUSION

Most rash cases were mild, occurred within 1 month of erlotinib treatment, and rapidly improved without the need for erlotinib dose alterations.