Keratoacanthomas associated with sorafenib therapy

Eruptive keratoacanthomas associated with dupilumab therapy

We would like to present the case of eruptive keratoacanthomas associated with dupilumab therapy, which occurred in an 85-year-old woman receiving biologic therapy for the treatment of atopic dermatitis. With the increasing prevalence of Dupilumab usage, this is an important potential complication of which clinicians should be aware.

Sorafenib-related generalized eruptive keratoacanthomas (Grzybowski syndrome): a case report

BACKGROUND

Sorafenib is an oral multikinase inhibitor that targets Raf serine/threonine receptor tyrosine kinases and inhibits tumor cell growth and angiogenesis. Cutaneous toxicities of sorafenib are common, including cutaneous eruptions (such as truncal erythema and seborrheic-dermatitis-like changes) and hand-foot syndrome. Keratoacanthomas and squamous cell carcinomas have been reported previously; however, we report a case of multiple eruptive keratoacanthomas in the form of Grzybowski syndrome after initiation of sorafenib.

CASE PRESENTATION

We report a 63-year-old Caucasian male who developed multiple cutaneous eruptive keratoacanthomas after starting sorafenib 400 mg twice daily. He had a known history of hepatitis-C-related cirrhosis and hepatocellular carcinoma, and previously had actinic keratosis and skin squamous cell carcinoma excision. Approximately two and a half months after starting sorafenib, the patient initially developed two lesions, one on each forearm, and after excision, these lesions demonstrated histological features of squamous cell carcinoma. One month later, the patient presented with approximately 48 new skin lesions of varying size on the back, bilateral upper limbs, and face requiring excisional biopsy of a large number of these lesions. Histopathology showed eruptive invasive keratoacanthomas (Grzybowski syndrome). Sorafenib was temporarily stopped and subsequently restarted at a lower dose. Acitretin 25 mg daily was commenced after few weeks, and no further keratoacanthomas developed during his treatment.

CONCLUSIONS

We report a unique case of sorafenib-associated Grzybowski syndrome. Temporary interruption and dose reduction of sorafenib and use of acitretin appeared to prevent further development of keratoacanthomas.

Mutational profile of skin lesions in hepatocellular carcinoma patients under tyrosine kinase inhibition: a repercussion of a wide-spectrum activity

BACKGROUND/AIM

Dermatological adverse events (DAE) in hepatocellular carcinoma (HCC) patients treated with sorafenib predicts better outcome. Some turn into skin lesions (SL) requiring pathology examination. We describe incidence, characteristics and molecular profile of SL in HCC patients treated with sorafenib.

MATERIALS AND METHODS

SL were prospectively collected in 311 HCC patients who started sorafenib. SL from sorafenib cohort were compared to those from a control patient group selected to match SL type and demographics. HRAS, KRAS and BRAF mutations were analyzed by CAST-PCR, mutated p53 and MAPK pathway activation by immunohistochemistry and immune infiltration by hematoxylin-eosin staining.

RESULTS

Eighty-eight out of 311 patients developed DAE and 7.4% SL required histological assessment. Most frequent lesions were keratoacanthomas (n = 4), squamous-cell carcinomas (SCC)(n = 5), basal-cell carcinomas (BCC)(n = 3) and seborrheic keratosis (n = 5). HRAS and KRAS mutations were detected in 4 SL, while no mutations showed in control SL. Nuclear pERK immunostaining was identified in 33.3% of cases versus 5.3% of controls. Most SL (90%) from patients with DAE were proliferative with intense immune infiltration (73%).

CONCLUSIONS

The onset of SL and their molecular profile did not impact negatively on patient's prognosis, but intense proliferation of SL may reflect compensatory activation of MAPK pathway and warrants their close monitoring.

Sorafenib-induced Facial Acneiform Eruption

Sorafenib is a multikinase inhibitor that is used to treat hepatocellular carcinoma by inhibiting tumor cell growth and angiogenesis. Cutaneous adverse events of sorafenib are commonly reported, with alopecia and hand-foot skin reactions most frequently encountered. Acneiform eruptions represent rare adverse events that have only been reported at high doses of sorafenib. We present a patient who started low dose sorafenib for hepatocellular carcinoma and subsequently developed a fulminant facial acneiform eruption in the absence of other cutaneous adverse events. Treatment included topical clindamycin and tretinoin with some improvement. Facial acneiform eruption represents a rare consequence of sorafenib that has not previously been described at low doses. Additionally, acneiform papules in the absence of other cutaneous adverse events is unusual. The cutaneous mechanism is not well understood but may be related to indirect epidermal growth factor receptor inhibition or direct cytotoxic effects on eccrine glands. Topical treatment produces only minimal improvement in patients who continue sorafenib therapy. Discontinuation of the drug is usually unwarranted except in special circumstances.

BRAF inhibitor-associated cutaneous squamous cell carcinoma: new mechanistic insight, emerging evidence for viral involvement and perspectives on clinical management

Mutations in the BRAF proto-oncogene occur in the majority of cutaneous melanomas. The commonly detected valine (V) to glutamate (E) mutation (V600E) is known to drive melanomagenesis and has thus been the target of two highly selective chemotherapeutic agents: vemurafenib and dabrafenib. While BRAF inhibitor therapy has revolutionized the treatment of metastatic melanoma, unanticipated cutaneous toxicities, including the development of cutaneous squamous cell carcinomas (cSCCs), are frequently reported and hinder therapeutic durability. However, the mechanisms by which BRAF inhibitors induce cutaneous neoplasms are poorly understood, thus posing a challenge for specific therapies. In this review, we summarize the clinical and molecular profiles of BRAF inhibitor-associated cSCCs, with a focus on factors that may contribute to disease pathogenesis. In particular, we discuss the emerging evidence pointing towards viral involvement in BRAF inhibitor-induced cutaneous neoplasms and offer new perspectives on future therapeutic interventions. Continued clinical and mechanistic studies along this line will not only allow for better understanding of the pathogenic progression of BRAF inhibitor-induced cSCCs, but will also lead to development of new therapeutic and preventative options for patients receiving targeted cancer therapy.

Cutaneous complications of molecular targeted therapy used in oncology

The new molecular targeted therapy has been developed over the past decades by using the molecular targeted molecular changes discovered in specific types of cancer. Unfortunately, most of these agents (epidermal growth factor receptors, multi-targeted small molecule tyrosine kinase inhibitors, monoclonal antibodies) have severe cutaneous adverse reactions, that not only interfere with the patient's quality of life, but also are dose-limiting and may require treatment interruptions. These cutaneous complications and their management must be very well known by any oncologist and dermatologist who treat oncologic patients.

ABBREVIATIONS

EGFR = epidermal growth factor receptors, EGFRI = epidermal growth factor receptors inhibitors.

Cutaneous adverse effects of targeted therapies: Part I: Inhibitors of the cellular membrane

There has been a rapid emergence of numerous targeted agents in the oncology community in the last decade. This exciting paradigm shift in drug development lends promise for the future of individualized medicine. Given the pace of development and clinical deployment of targeted agents with novel mechanisms of action, dermatology providers may not be familiar with the full spectrum of associated skin-related toxicities. Cutaneous adverse effects are among the most frequently observed toxicities with many targeted agents, and their intensity can be dose-limiting or lead to therapy discontinuation. In light of the often life-saving nature of emerging oncotherapeutics, it is critical that dermatologists both understand the mechanisms and recognize clinical signs and symptoms of such toxicities in order to provide effective clinical management. Part I of this continuing medical education article will review in detail the potential skin-related adverse sequelae, the frequency of occurrence, and the implications associated with on- and off-target cutaneous toxicities of inhibitors acting at the cell membrane level, chiefly inhibitors of epidermal growth factor receptor, KIT, and BCR-ABL, angiogenesis, and multikinase inhibitors.

Histopathology of Keratoacanthoma Revisited

Background/Aims. Given the defining histopathologic architecture of keratoacanthoma (KA), the aim of this study was to measure the crateriform orifice (“orificial size”) in histopathologically crateriform lesions to ascertain its utility as an objective diagnostic histopathologic adjunct. Methods. This cross-sectional, retrospective study included 97 cases with a histopathologic diagnosis of KA. We measured the “orificial size” using the ocular micrometer in a BH-2 Olympus microscope at 4× magnification, in a blinded manner with respect to information. Frequency of histopathologic features observed was also recorded. Results. The average orificial size for different groups was as follows: 2.3 ± 0.2 mm for cases with a clinical presentation of KA/keratotic papule (KP) (n = 30) versus 2.9 ± 0.3 mm for other (n = 67), P = .18. Histopathologic findings in the 2 groups were as follows: crateriform architecture/epithelial lip and sharp demarcation of tumor from stroma (100% in both groups), fibrosis (29/30 vs 64/67), apoptotic keratinocytes (27/30 vs 56/67), dermal islands of “glassy” keratinocytes (26/30 vs 54/67), entrapped elastic fibers (26/30 vs 49/67), and neutrophilic abscesses (11/30 vs 21/670 [ P = not significant for all]. Conclusion. Our findings indicate that, in the appropriate clinical setting, a smaller orificial size, although predictive of a KA, in itself is not sufficient for a definitive diagnosis. Given that a major limitation is that this is a function of age of the lesion as orificial size depends on the evolution stage of the neoplasm with the largest diameter often evident in lesions at early stages of regression, for now correlation with histopathologic features such as presence of an epithelial lip, sharp demarcation of tumor from stroma, and fibrosis (present in >95% of cases of KAs) is required.

Sorafenib suppresses JNK-dependent apoptosis through inhibition of ZAK

Sorafenib is U.S. Food and Drug Adminstration-approved for the treatment of renal cell carcinoma and hepatocellular carcinoma and has been combined with numerous other targeted therapies and chemotherapies in the treatment of many cancers. Unfortunately, as with other RAF inhibitors, patients treated with sorafenib have a 5% to 10% rate of developing cutaneous squamous cell carcinoma (cSCC)/keratoacanthomas. Paradoxical activation of extracellular signal-regulated kinase (ERK) in BRAF wild-type cells has been implicated in RAF inhibitor-induced cSCC. Here, we report that sorafenib suppresses UV-induced apoptosis specifically by inhibiting c-jun-NH(2)-kinase (JNK) activation through the off-target inhibition of leucine zipper and sterile alpha motif-containing kinase (ZAK). Our results implicate suppression of JNK signaling, independent of the ERK pathway, as an additional mechanism of adverse effects of sorafenib. This has broad implications for combination therapies using sorafenib with other modalities that induce apoptosis.

Pharmacological control of receptor of advanced glycation end-products and its biological effects in psoriasis

Receptor for advanced glycation end-products is implicated in a development of chronic inflammatory response. Aim of this paper is to provide a review on commercial and experimental medicines that can interfere with RAGE and signaling through RAGE. We searched three bibliographical databases (PubMed, Web of Science and MEDLINE) for the publications from 2005 to March 2012 and identified 5 major groups of agents that can interfere with RAGE biological effects. In the first part of this paper, we discuss AGE crosslink breakers. These chemicals destroy advanced glycation end products (AGEs) that are crosslinked to the extracellular matrix proteins and can interact with RAGE as ligands. Then, we describe two non-conventional agents SAGEs and KIOM-79 that abolish certain biological effects of RAGE and have a strong anti-inflammatory potential. In the third part, we evaluate the inhibitors of the signaling cascades that underlie RAGE. Particularly, we discuss two groups of kinase inhibitors tyrphostins and the inhibitors of JAK kinases. Considering RAGE as a potential master regulator of processes that are crucial for the pathogenesis of psoriasis, we propose that these medicins may help in controlling the disease by abolishing the chronic inflammation in skin lesions.

Targeted therapy in melanoma

Since the discovery of activating mutations in the BRAF oncogene in melanoma, there has been remarkable progress in the development of targeted therapies for unresectable and metastatic melanoma. We review the latest developments in our understanding of the role of BRAF/MEK/ERK pathway signaling in melanoma, and the development of inhibitors of this pathway. We also explore alternative mutations seen in melanoma, such as NRAS, KIT, GNAQ, and GNA11, and the drug development that is ongoing based on this biology. Strategies for the management of the vexing clinical problem of BRAF inhibitor resistance, primarily via combination therapy, are outlined. With the recent approval of the BRAF inhibitor vemurafenib for stage IV metastatic melanoma, use of this agent is expanding in the United States. Thus, management of the skin toxicities of this agent, such as squamous cell carcinomas, "acneiform" eruptions, hand-foot syndrome, and panniculitis, will be a growing problem facing dermatologists today. We discuss the toxicities of targeted agents in use for melanoma, in particular the dermatologic effects and the management of these skin toxicities.

Skin cancer associated with the use of sorafenib and sunitinib for renal cell carcinoma

BACKGROUND

Several case series have reported an association between sorafenib and the development of skin cancer, but they differ in the reported rapidity of skin cancer onset and the frequency of recurrence with ongoing multikinase inhibitor (MKI) treatment.

OBJECTIVE

To compare the presentation and incidence of skin cancer in patients with renal cell carcinoma (RCC) treated with sorafenib and sunitinib.

MATERIALS AND METHODS

This retrospective study reviewed the records of 69 patients with RCC treated with sorafenib or sunitinib at the University of Colorado Hospital between January 2005 and July 2009.

RESULTS

Seven patients treated with MKI developed skin cancer (5 (13.5%) with sorafenib, 2 (6.3%) with sunitinib; 5 squamous cell carcinomas (SCC), 3 basal cell carcinomas (BCC)); all developed in sun-exposed areas during first-line MKI therapy. The median time from the start of MKI therapy until observation of a skin cancer lesion was 13.5 months.

CONCLUSION

We observed more cases of skin cancer during sorafenib treatment than during sunitinib treatment for advanced RCC; median MKI treatment duration before the identification of skin cancer was longer than 1 year.

Analysis of dermatologic events in vemurafenib-treated patients with melanoma

BACKGROUND

Vemurafenib has been approved for the treatment of patients with advanced BRAF(V600E)-mutant melanoma. This report by the Vemurafenib Dermatology Working Group presents the characteristics of dermatologic adverse events (AEs) that occur in vemurafenib-treated patients, including cutaneous squamous cell carcinoma (cuSCC).

METHODS

Dermatologic AEs were assessed from three ongoing trials of BRAF(V600E) mutation-positive advanced melanoma. Histologic central review and genetic characterization were completed for a subset of cuSCC lesions.

RESULTS

A total of 520 patients received vemurafenib. The most commonly reported AEs were dermatologic AEs, occurring in 92%-95% of patients. Rash was the most common AE (64%-75% of patients), and the most common types were rash not otherwise specified, erythema, maculopapular rash, and folliculitis. Rash development did not appear to correlate with tumor response. Photosensitivity occurred in 35%-63% of patients, and palmar-plantar erythrodysesthesia (PPE) occurred in 8%-10% of patients. The severity of rash, photosensitivity, and PPE were mainly grade 1 or 2. In all, 19%-26% of patients developed cuSCC, mostly keratoacanthomas (KAs). The majority of patients with cuSCC continued therapy without dose reduction after resection. Genetic analysis of 29 cuSCC/KA samples demonstrated HRAS mutations in 41%.

CONCLUSIONS

Dermatologic AEs associated with vemurafenib treatment in patients with melanoma were generally manageable with supportive care measures. Dose interruptions and/or reductions were required in <10% of patients.

The Use of Sorafenib in the Thyroid Cancer

There are not effective therapies for metastatic unresectable, non-RAI-avid thyroid carcinomas. Fortunately, thyroid carcinomas represent a promising paradigm for targeted therapy due to the presence of activing mutations of genes coding the kinase tyrosines which are involved in all functions of cancer cells (such as: growth or invasion). In this paper an efficacy and toxicity of sorafenib, one of the multi-kinase inhibitors in thyroid carcinomas treatment is presented.

Diverse cutaneous side effects associated with BRAF inhibitor therapy: a clinicopathologic study

BACKGROUND

Vemurafenib, a novel selective small molecule inhibitor of BRAF, has recently been shown to be effective in the treatment of melanomas harboring the BRAF V600E mutation. Similar to the broad-spectrum RAF inhibitor sorafenib, vemurafenib induces development of squamous cell carcinomas and keratoacanthomas as a side effect of therapy.

OBJECTIVE

We sought to detail additional cutaneous adverse effects of vemurafenib and a similar BRAF inhibitor, dabrafenib.

METHODS

We evaluated the clinical and histologic feature of skin side effects developing on vemurafenib or dabrafenib therapy in 14 patients.

RESULTS

Eight patients developed one or more squamous cell carcinomas, and 11 patients formed benign verrucous keratoses. Eight patients developed single lesions and/or widespread eruptions with histopathologic findings of acantholytic dyskeratosis, consistent with warty dyskeratomas and Darier- or Grover-like rashes, respectively. One patient developed palmoplantar hyperkeratosis, and darkening of existing nevi and new nevi within 2 months of starting vemurafenib. Side effects presented as early as 1 week after beginning therapy, with a mean time of onset of 12.6 weeks in our cohort.

LIMITATIONS

This study was limited by the small number of cases, all from a single institution.

CONCLUSION

Selective BRAF inhibitor therapy is associated with the development of malignant and benign growths, including keratoacanthoma-like squamous cell carcinomas, warty dyskeratomas, and verrucous keratoses, along with widespread eruptions with histologic features of acantholytic dyskeratosis. Given the potential for malignant lesions to develop on treatment, awareness of potential adverse effects of these agents is necessary, and a low threshold for biopsy of new growths is recommended.

Dermatologic toxicities in epidermal growth factor receptor and multikinase inhibitors

Targeted therapies have produced significant treatment advances for patients diagnosed with a variety of tumor types. These therapies are associated with unique dermatologic toxicities that may hamper treatment efforts and cause significant discomfort for patients. Prevention and management of these toxicities can allow patients to remain on therapy and hence receive maximum clinical benefit from the drug.

Chemotherapy-induced iatrogenic injury of skin: new drugs and new concepts

Chemotherapy and its cutaneous side effects are an increasingly common source of iatrogenic injury to the skin, hair, and nails. Cutaneous changes are among the most common side effects from treatment with particular targeted chemotherapeutic agents, especially those that target the epidermal growth factor receptor and small molecule multikinase inhibitors. Less common, but growing in recognition, are the development of secondary cutaneous neoplasms and subacute cutaneous lupus erythematosus as a result of chemotherapy. There is considerable overlap of the multiple entities described as a side effect from conventional chemotherapeutic agents; therefore, the term "toxic erythema of chemotherapy" can be used as an easily understood name.

Targeted therapies for renal cell carcinoma: review of adverse event management strategies

With the advent of targeted agents for the treatment of renal cell carcinoma (RCC), overall survival has improved, and patients are being treated continuously for increasingly long periods of time. This has raised challenges in the management of adverse events (AEs) associated with the six targeted agents approved in RCC-sorafenib, sunitinib, pazopanib, bevacizumab (in combination with interferon alpha), temsirolimus, and everolimus. Suggestions for monitoring and managing AEs have been published, but there are few consensus recommendations. In addition, there is a risk that patients will be subjected to multiple unnecessary investigations. In this review, we aimed to identify the level of supporting evidence for suggested AE management strategies to provide practical guidance on essential monitoring and management that should be undertaken when using targeted agents. Five databases were systematically searched for relevant English language articles (including American Society of Clinical Oncology abstracts) published between January 2007 and March 2011; European Society of Medical Oncology congress abstracts were hand searched. Strategies for AE management were summarized and categorized according to the level of recommendation. A total of 107 articles were identified that describe a large number of different investigations for monitoring AEs and interventions for AE management. We identify and summarize clear recommendations for the management of dermatologic, gastrointestinal, thyroid, cardiovascular, and other AEs, based predominantly on expert opinion. However, because the evidence for the suggested management strategies is largely anecdotal, there is a need for further systematic investigation of management strategies for AEs related to targeted therapies for RCC.

[New tyrosine kinase and EGFR inhibitors in cancer therapy. Cardiac and skin toxicity as relevant side effects. Part B: Skin]

Recently, inhibitors of the epidermal growth factor receptor (EGFR) and multikinase inhibitors have been successfully established in the therapy of various solid tumors. EGFR inhibitors and multikinase inhibitors are specific and selective agents that intervene with the dysfunctional regulatory processes of malignant cells. This results in a favorable safety profile and range of side effects, especially in comparison to conventional chemotherapy. The various cutaneous adverse drug reactions are considered substance class effects and are the most frequent side effects of these targeted therapies. Therapy with EGFR inhibitors is associated with acneiform rash, painful paronychia, xerosis cutis, acral fissures, hair changes, and pruritus. Treatment with tyrosin kinase inhibitors may cause hand-foot syndrome, various types of drug rash, hair loss, xerosis cutis, and pruritus. These side effects may be stigmatizing and place a huge burden on the patient's quality of life. Treatment is a challenge and best performed in interdisciplinary cooperation of dermatologists and oncologists.

Sorafenib-induced premalignant and malignant skin lesions

PURPOSE

To review characteristics of patients who develop premalignant and malignant skin lesions while on sorafenib therapy and discuss implications for subsequent treatment of their primary malignancies.

BACKGROUND

Sorafenib is a newly developed multitargeted protein kinase inhibitor reported to induce a variety of adverse cutaneous effects, rarely including actinic keratoses, keratocanthomas, and squamous cell carcinomas (SCCs).

METHODS

Published reports of individuals who have developed cutaneous lesions demonstrating atypia of the epidermis are reviewed. In addition, a 77-year-old man who developed not only an SCC but also verrucas within one month of taking sorafenib monotherapy for metastatic adenocarcinoma of the lung is described.

RESULTS

Cutaneous lesions develop most commonly in Caucasian men older than 40 years without previous histories of skin cancer, within two weeks to three years of starting sorafenib therapy. Currently there is no definitive explanation for the relationship between sorafenib and cutaneous neoplasms. Management typically involves treatment of skin lesions with cryotherapy or excision with at least a brief discontinuation of sorafenib. In patients whose primary malignancies were responding well, sorafenib therapy was continued with close follow-up.

CONCLUSIONS

The possibility of rapidly developing actinic keratoses, keratocanthomas, verrucas, and SCC during treatment with sorafenib, warrants close dermatologic follow-up and a lower threshold for biopsy and treatment of suspicious cutaneous lesions. Development of a sorafenib-induced SCC is not an absolute contraindication for continued use of sorafenib therapy; however, the drug should be briefly discontinued until lesions are treated.

[Squamous cell carcinoma in a patient receiving sorafenib]

BACKGROUND

Sorafenib is a multikinase inhibitor approved for the treatment of renal cell carcinoma and hepatocellular carcinoma. Associated short-term cutaneous adverse events are well known. Regarding long-term adverse events, keratoacanthoma has been reported more recently and, more rarely, invasive squamous cell carcinoma.

PATIENTS AND METHODS

A 56-year-old man was treated with sorafenib in December 2008 for renal cell carcinoma with cutaneous metastases. The patient had a skin phototype IV and no history of intense sun exposure. Within five months of starting sorafenib, he developed deeply invasive well-differentiated retroauricular squamous cell carcinoma.

DISCUSSION

Sorafenib modifies the immunostimulatory capacity of dendritic cells by reducing cytokine secretion and CD1a expression. Blockade of autocrine vascular endothelial growth factor (VEGF) signalling in keratinocytes can also select tumoural clones with increased oncogenic Ras mutation, increased activation of phospholipase D and modulation of the Ras/Raf/MAP kinase signalling pathway involved in cutaneous squamous cell carcinogenesis.

CONCLUSION

Cases of keratoacanthomas and deeply invasive squamous cell carcinomas reported in patients on sorafenib emphasise the need for multidisciplinary follow-up of this population and the important role of dermatologists in managing the short and long-term adverse effects of multitarget tyrosine inhibitors.

Clinical efficacy of a RAF inhibitor needs broad target blockade in BRAF-mutant melanoma

B-RAF is the most frequently mutated protein kinase in human cancers.1 The finding that oncogenic mutations in BRAF are common in melanoma2 followed by the demonstration that these tumors are dependent on the RAF/MEK/ERK pathway3 offered hope that inhibition of B-RAF kinase activity could benefit melanoma patients. Herein, we describe the structure-guided discovery of PLX4032 (RG7204), a potent inhibitor of oncogenic B-RAF kinase activity. Preclinical experiments demonstrated that PLX4032 selectively blocked the RAF/MEK/ERK pathway in BRAF mutant cells and caused regression of BRAF mutant xenografts.4 Toxicology studies confirmed a wide safety margin consistent with the high degree of selectivity, enabling Phase 1 clinical trials using a crystalline formulation of PLX4032.5 In a subset of melanoma patients, pathway inhibition was monitored in paired biopsy specimens collected before treatment initiation and following two weeks of treatment. This analysis revealed substantial inhibition of ERK phosphorylation, yet clinical evaluation did not show tumor regressions. At higher drug exposures afforded by a new amorphous drug formulation,4,5 greater than 80% inhibition of ERK phosphorylation in the tumors of patients correlated with clinical response. Indeed, the Phase 1 clinical data revealed a remarkably high 81% response rate in metastatic melanoma patients treated at an oral dose of 960 mg twice daily.5 These data demonstrate that BRAF-mutant melanomas are highly dependent on B-RAF kinase activity.

Toxicity of sorafenib: clinical and molecular aspects

IMPORTANCE OF THE FIELD

Sorafenib is a novel oral bis-aryl urea compound originally developed as an inhibitor of RAF kinase for its anti-proliferative property. Sorafenib also inhibits receptor tyrosine kinases of multiple pro-angiogenic factors such as VEGFR-1/2/3, Flt-3 and PDGFR-beta. The combination of both its anti-proliferative and anti-angiogenic properties makes sorafenib an attractive agent in cancer treatment. Sorafenib has been approved for the treatment of metastatic renal cell carcinoma as well as hepatocellular cancer. Despite its inherent selectivity, sorafenib can cause unusual adverse events whose the management represents a challenge for oncologists.

AREAS COVERED IN THIS REVIEW

Relevant literature was identified using a Pubmed search of articles published up to June 2009. Search terms included 'sorafenib' and 'toxicity'. Original articles were reviewed and relevant citations from these articles were also considered.

WHAT THE READER WILL GAIN

The clinical aspect of sorafenib-induced adverse events and the molecular basis behind this toxicity are discussed. Finally, recommendations for the management of these adverse events are proposed.

TAKE HOME MESSAGE

Although not life-threatening, toxicity of sorafenib can severely impact the physical, psychological and social well-being of patients. The management of this unusual toxicity highlights the particular need of new pluridisciplinarities linking oncologist, cardiologist and dermatologist.

Treatment with tyrosine kinase inhibitors for patients with differentiated thyroid cancer: the M. D. Anderson experience

OBJECTIVES

Until recently, treatment options for patients with progressive, radioactive iodine-resistant differentiated thyroid cancer (DTC) have been limited. In our clinical practice, we have begun to use sorafenib and sunitinib for patients with progressive DTC who are not able or willing to participate in clinical trials. In this paper, we describe the University of Texas M. D. Anderson Cancer Center's experience with the off-label use of these tyrosine kinase inhibitors for DTC.

METHODS

Adult patients were included if they had a diagnosis of radioactive iodine-refractory DTC, were treated with single agent sorafenib or sunitinib, and had both baseline and at least one follow-up scan for restaging purposes. All imaging data were collected, as well as the TSH-suppressed thyroglobulin (Tg) levels corresponding to each scan date. The primary endpoints were radiographic response and progression-free survival (PFS). Secondary objectives were tissue-specific radiographic responses and correlation of Tg with overall response.

RESULTS

We identified 33 patients from our clinical database. Fifteen patients (nine women, six men) met inclusion criteria, with a median age of 61 yr (range, 38-83 yr). Eight patients had papillary and seven had follicular thyroid carcinoma. Sorafenib was used in 13 and sunitinib in two, including one patient who failed prior sorafenib therapy. All patients had evidence of progressive disease (PD) before start of therapy, with a median PFS of only 4 months. Best response in target lesions was: partial response (PR) in three (20%), stable disease (SD) in nine (60%), and PD in three (20%). Clinical benefit (PR+SD) was 80%. The sunitinib patient previously refractory to sorafenib had a 38% reduction in tumor size. The most noticeable organ-specific response was observed in lung (median change, -22%) compared to lymph nodes (median change, 0%). Pleural disease and nonirradiated bone metastases demonstrated PD. All histological subtypes had similar responses. The median PFS was 19 months. The median overall survival has not yet been reached, but at 2 yr of follow-up, overall survival is 67%. Log Tg correlated with radiographic response (P = 0.0005).

CONCLUSIONS

Sorafenib and sunitinib appear to be effective in patients with widely metastatic, progressive DTC, with most patients achieving SD or PR, despite having PD at baseline. The most noticeable responses occurred in the lungs in contrast with minimal changes in nodal metastases and PD in pleural and nonirradiated bone metastases, suggesting a tissue-specific response to therapy. Log Tg significantly correlated with response to treatment and therefore may have value as a surrogate marker of response.

Experience with sorafenib and the elderly patient

Renal cell carcinoma primarily affects older individuals. Approximately half of all new renal cell carcinoma diagnoses are made in persons 65 years of age or older. Devising a treatment plan for the elderly patient population requires special consideration. Age-related physiological, cognitive, and social characteristics of elderly patients may influence each stage of patient care. Until recently, treatment options were limited for elderly patients with renal cell carcinoma. Sorafenib is the first multikinase inhibitor approved for use in renal cell carcinoma in the United States and Europe. In the phase III Treatment Approaches in Renal Cell Cancer Global Evaluation Trial, sorafenib significantly extended progression-free survival in patients with advanced renal cell carcinoma, regardless of age. Incidence rates of adverse events were not significantly higher in elderly patients receiving sorafenib than in younger patients. Thus, sorafenib represents an important treatment option for elderly patients with renal cell carcinoma. This report describes particular considerations for physicians to be aware of when choosing a treatment regimen for their elderly patients with renal cell carcinoma and offers recommendations on how to integrate specific management strategies into clinical practice that will optimize the use of sorafenib in the elderly. The strategies focus on patient selection, assessment of quality of life, management of adverse events, and appropriate dose modifications. The goal of these recommendations is to maximize the clinical benefit of sorafenib in the elderly patient population through appropriate use.

The histologic spectrum of epithelial neoplasms induced by sorafenib

Sorafenib is a multikinase inhibitor newly approved for the treatment of renal cell carcinoma and hepatocellular carcinoma. Multiple cutaneous adverse effects of sorafenib have been described. We present a 68-year-old patient with renal cell carcinoma who developed multiple tender hyperkeratotic papules within weeks of starting sorafenib. The degree of symptoms and size of lesions corresponded directly with his sorafenib dosing. Four biopsy specimens of representative lesions were taken. Three lesions showed keratin-filled endophytic epithelial-lined invaginations, one with a coexistent actinic keratosis. The fourth biopsy specimen revealed an invasive squamous cell carcinoma with keratoacanthoma-like features. To our knowledge, diffuse eruptions of epidermal invaginations, ectatic follicular infundibula, and follicular infundibular cysts have not been reported previously with sorafenib, although they are well known to occur with epidermal growth factor receptor inhibitor therapy. Keratoacanthoma and squamous cell carcinoma as a result of sorafenib use are only beginning to be reported in the literature. At the time of acceptance of our manuscript, sorafenib-induced keratoacanthoma was noted only once in the literature, and deeply invasive squamous cell carcinoma has been reported once in the setting of sorafenib and tipifarnib combination therapy. We review the spectrum of dermatologic side effects of sorafenib to facilitate their recognition.