Cutaneous ulcers associated with hydroxyurea therapy in myeloproliferative disorders

Drug-Related Cutaneous Adverse Events in Philadelphia Chromosome-Negative Myeloproliferative Neoplasms: A Literature Review

Since myeloproliferative neoplasms (MPN) pose a significant risk for vascular and thrombotic complications, cytoreductive therapies, such as hydroxyurea (HU), interferon (IFN) inhibitors, and Janus kinase (JAK) inhibitors are recommended for patients at high risk. However, these agents also place patients at increased risk for drug-related cutaneous adverse events. Herein, we review the literature on skin toxicity related to the use of drugs for the treatment of MPN. Overall, the cytoreductive agents used for MPN are generally well tolerated and considered to be safe, except IFN, for which dropout rates as high as 25% have been reported. While IFN is known to give rise to flu syndrome, it rarely leads to hematological alterations. The most common hematological side effects of HU are mild and include granulocytopenia, anemia, and thrombocytopenia. The JAK inhibitor ruxolitinib has been associated with cytopenia and a higher incidence of viral infections, as well as increased risk for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Based on the present analysis, it can be concluded that cutaneous toxicity is not a negligible complication of commonly used treatments for MPN. While further research is needed, patients on these agents, and especially those with a history of cutaneous malignancies, should undergo thorough skin examination before and during therapy. In addition, detailed history is critical since many patients who develop non-melanoma skin cancer have multiple preexisting risk factors for cutaneous carcinogenesis.

Hydroxyurea Associated Cutaneous Lesions: A Case Report

BACKGROUND

Hydroxyurea (HU) is an antimetabolite agent that interferes with the S-phase of cellular replication and inhibits DNA synthesis, with little or no effect on RNA or protein synthesis. It is used in the treatment of many myeloproliferative disorders (MD) and is particularly a first line treatment drug for intermediate to high-risk essential thrombocythemia. Although safe and very well tolerated by the patients suffering from MD, there have been numerous reports of a broad palette of cutaneous side effects associated with prolonged intake of the medication. These may include classical symptoms such as xerosis, diffuse hyperpigmentation, brown-nail discolouration, stomatitis and scaling of the face, hands, and feet or more serious side effects such as actinic keratosis lesions, leg ulcers and multiple skin carcinomas.

CASE REPORT

We report a case of a 52-year-old man, on long-term therapy with HU for essential thrombocytosis, with several concurrent skin lesions. Despite the perennial use of HU, the cutaneous changes were neglected. The local dermatological examination revealed oval perimalleolar ulcer on the right leg, with dimensions 6 x 4 cm, clearly demarcated from the surroundings with regular margins, periulcerous erythema, with very deep and highly fibrinous bed of the ulcer, positive for bacterial infection. The ulcer was treated with topical wound therapy with alginate and parenteral antibiotics. The extended dermatological screening also showed two nummular lesions in the right brachial region, presenting as erythematous papules with sharp margins from the surrounding skin, gritty desquamation and dotted hyperpigmentations inside the lesion. Further dermoscopy and biopsy investigations confirmed a diagnosis of basal cell carcinoma. Nasal actinic keratosis was also noted. The patient was advised for discontinuing or substituting the HU therapy.

CONCLUSION

We present this case to draw attention to the various cutaneous side effects that occur with perennial HU use and suggest an obligatory reference to a dermatological consult.

Critical Reviews: How we treat sickle cell patients with leg ulcers

The past five decades have seen an improvement in the mortality and morbidity of sickle cell disease (SCD) because of prophylaxis against infectious complications, improved and expanded red cell transfusions, implementation of hydroxyurea therapy, and advances in supportive care. Now that the majority of patients in the western hemisphere reaches adulthood, end organ diseases are frequent, which include vasculopathic complications such as chronic leg ulcers. The management of patients with leg ulcers requires the hematologist to lead a team of health care professionals, and investigates the presence of associated, but potentially still occult signs of vasculopathy, such as pulmonary hypertension, renal disease, priapism and retinopathy. These complications may be asynchronous, and long term careful screening is indicated, in order to ensure early diagnosis and intervention. It is crucial to address both the immediate consequences of pain, infection and disability, and long term effects on quality of life, employment and stigma associated with chronic ulceration. Recent insights into their pathophysiology may have practical implications. We propose a holistic approach to the management of patients' physical and emotional problems and mechanisms of ulcers formation and delayed healing. An overview of topical and systemic therapies for chronic ulcers is given, with the understanding that wound care therapy is best left to the wound specialists, medical and surgical, with whom the hematologist must keep an open line of communication. In the absence of evidence-based guidelines, our opinion is based on both a critical review of the literature and our personal clinical and research experience.

Advances and challenges in the management of essential thrombocythemia

The new World Health Organization (WHO) diagnostic criteria for essential thrombocythemia (ET) issued in 2008 made an important distinction between true ET and early myelofibrosis (MF), which has helped to identify a more homogenous population for the diagnosis with longer survival and much less transformation to overt MF. The recent finding of a new mutation (CALR), which is mutually exclusive with JAK2 and MPL mutations, adds to the characterization of ET patients, since there are important phenotypic differences between the mutation types. CALR patients are younger, have lower white blood cell counts (WBC) and a lower thrombosis incidence. A growing field of interest is the state of hypercoagulation due to dysfunction of hemostatic systems, cell-cell interaction and hereditary prothrombotic traits. Activation of platelets, WBC and endothelial cells has been found, making the whole intravascular milieu prothrombotic. Several risk score models, based on retrospective studies, have been developed lately, distinguishing patient groups with graded risk for complications and death. Even if these may be helpful in evaluating patients, they have not been validated in prospective studies and there are not enough data to support their use as a basis for treatment algorithms. The traditional risk factors age, previous thrombosis and platelets >1500 × 10(9)/l are still recommended for the distinction between high risk and low risk ET and the decision to give cytoreductive therapy. However, cardiovascular (CV) risk factors add to thrombosis risk and should be considered both for specific treatment in any risk group and for upgrading low risk patients with high CV risk to an intermediary group where active therapy with aspirin and cytoreduction may be considered. First-line cytoreductive therapy differs with age; in younger patients interferon (IFN) or anagrelide are preferable, in older patients hydroxycarbamide (HC). Second-line therapy for younger patients is HC, for older patients IFN or anagrelide (ANA). JAK2 inhibitors may be suitable in rare cases with symptoms not responding to other therapy.

Pharmacological management of essential thrombocythemia

INTRODUCTION

Two factors have deeply influenced the area of essential thrombocythemia (ET). A gain-of-function mutation in the pseudokinase region of the JAK2 gene, which partly explains the pathophysiology of myeloproliferative neoplasms (MPNs), was discovered in 2005 and is present in 50 - 60% of ET patients. Furthermore, the 2008 WHO MPN classification outlined criteria for the separation of ET and early or prefibrotic primary myelofibrosis (PMF). However, these and other new findings have not yet changed the pharmacotherapy of ET, which is based on risk stratification for thrombohemorrhagic risk and aims to reduce thrombosis and bleeding.

AREAS COVERED

Studies on the basis for and the validation of the WHO classification as well as studies on possible new risk factors are covered. The most important drugs for ET treatment and consensus recommendations for management of ET are also presented.

EXPERT OPINION

The new WHO classification should be used for both ET studies and clinical practice, since true ET has a different prognosis than early PMF. The management of patients should be based on risk stratification. Age > 60 years or previous throbosis (high risk) and platelet counts > 1500 × 10(9)/l warrant cytoreductive treatment, and high risk patients and selected low risk patients should be given anti-aggregation therapy.

Leg ulcers in elderly on hydroxyurea: a single center experience in Ph- myeloproliferative disorders and review of literature

Hydroxyurea (HU) is effective in controlling thrombocytosis while reducing the risk of thrombosis in essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF). However, HU may carry more or less severe side-effects. Rare cases of patients with painful leg ulcers have been published. We report our experience on such a side-effect in a large cohort of patients with ET and PV treated with HU and review the literature on the topic. Five (4%) out of our 124 patients (69 ET, 51 PV, 4 MF; 49 males, 75 females; mean age at diagnosis 59.1+/-11.8 years) treated with HU developed painful leg ulcers. Sixty-one other patients affected with Phmyeloproliferative disorders (Ph- MPD) developing HU-related painful leg ulcers are described in the English literature. All our five patients were women and developed leg ulcers over the age of 75. Sixty-five percent of all described cases are women; 59% were over 65 years of age and 45% over 70. Most cases received over 1 gr HU per day for at least 1 year. The pathogenesis of HU-induced skin ulcers remains elusive. Treatment is difficult and requires prompt cessation of HU therapy.

Hydroxyurea-associated squamous dysplasia

We report 2 cases of squamous dysplasia associated with long-term hydroxyurea therapy. The association between hydroxyurea and multiple aggressive squamous cell carcinomas, Bowen's disease, and multiple actinic keratoses in sun-exposed areas after a variable latency period has been increasingly reported. On reviewing the literature, 17 cases were identified and are reviewed, with emphasis on possible pathogenetic mechanisms of carcinogenicity. Squamous dysplasia, a precursor state to a more aggressive condition of multiple squamous cell carcinomas in photoexposed areas, should be added to the well-known cutaneous toxicities of hydroxyurea therapy.

Development of large genital ulcer due to hydroxyurea treatment in a patient with chronic myeloid leukemia and Behcet's disease

Chronic myeloid leukemia (CML) is a myeloproliferative disease arising from abnormal stem cells and associated with splenomegaly and leukocytosis. Hydroxyurea and interferon alpha are used in treatment very frequently. Behcet's disease (BD) is a chronic, repetitive disease of unknown etiology and associated with mucocutaneous, ocular, vascular and central nervous system involvement. Cases with symptoms of BD have been reported during interferon alpha treatment of CML. However, similar symptoms due to hydroxyurea treatment have been reported in only one case until now. A 32-year-old female patient under follow up because of CML and BD, developed a large genital ulcer during hydroxyurea treatment. Ulcers due to hydroxyurea treatment and the co-existence of these two diseases has been reported in only one case in the literature while large genital ulcers have not been reported previously.

Modern treatment strategies in polycythemia vera

Polycythemia vera (PV), one of the chronic myeloproliferative disorders (MPD), is characterized by predominant erythroid proliferation and secondary platelet proliferation, and by progression from a proliferative stage to a metastatic phase and finally a malignant phase. These characteristics expose patients to increased risk for thrombohemorrhagic complications, myeloid metaplasia, myelofibrosis, and acute leukemic conversion irrespective of treatments. Currently, there are three agents-hydroxyurea (HU), interferon-alfa (IFN-alpha), and anagrelide-that differ in mechanisms of action and in treating specific phenotypic manifestations of PV, suggesting a potential role for combination therapy. They also differ widely in side effects profiles and severity. Because of the differing risks for long-term complications associated with these agents, age is an important variable in selecting treatments. Patients at high risk for thrombohemorrhagic complications all require cytoreduction, as do patients at intermediate risk who are not effectively managed by phlebotomy and low-dose aspirin. In younger patients, the safest and most effective combination treatment appears to be anagrelide plus IFN-alpha, while in older patients anagrelide plus hydroxyurea may be effective. HU is used sparingly in younger patients because of the long-term increased risk of mutagenicity and possibly leukemogenesis. IFN-alpha is particularly indicated for patients with myeloid metaplasia evidenced by splenomegaly. Anagrelide, which acts on the mature megakaryocyte to prevent platelet budding, is uniquely efficacious in the control of platelet counts.

Mucocutaneous adverse effects of hydroxyurea: a prospective study of 30 psoriasis patients

Hydroxyurea is an anti-tumour agent most commonly used to treat chronic myeloproliferative disorders in doses up to 4 g per day. Dermatological adverse effects reported so far have been observed predominantly in these patients. As we are treating selected psoriasis patients with low dose hydroxyurea we attempted to define the spectrum and chronology of dermatological adverse effects in this group of patients prospectively. Of the 29 evaluable patients, 19 (65.5%) developed a mucocutaneous adverse reaction after a mean duration of 6.4 weeks of treatment. Pigmentation of nails, skin or mucosa was the most common observation and was seen in 17 (58.6%) patients. Other less common findings were xerosis, diffuse alopecia, oedema of the legs, oral ulcers and actinic psoriasis. Adverse effects subsided in 11 (57.9%) patients during a mean follow up of 18 weeks. Three hitherto unreported side-effects - scleral pigmentation, acquired ichthyosis and pigmentation of lunula of the nails - were noted. This first study of dermatological adverse effects of hydroxyurea therapy on Asian psoriatic patients reveals several new findings. Pigmentation of skin, nails and mucosa appears to be very common and occurs early. Serious dermatological side-effects probably do not occur with low dose (up to 1.5 g per day) hydroxyurea in patients with psoriasis.

Hydroxyurea induces site-specific DNA damage via formation of hydrogen peroxide and nitric oxide

Hydroxyurea is a chemotherapeutic agent used for the treatment of myeloproliferative disorders (MPD) and solid tumors. The mutagenic and carcinogenic potential of hydroxyurea has not been established, although hydroxyurea has been associated with an increased risk of leukemia in MPD patients. To clarify whether hydroxyurea has potential carcinogenicity, we examined site-specific DNA damage induced by hydroxyurea using (32)P-5'-end-labeled DNA fragments obtained from the human p53 and p16 tumor suppressor genes and the c-Ha-ras-1 protooncogene. Hydroxyurea caused Cu(II)-mediated DNA damage especially at thymine and cytosine residues. NADH efficiently enhanced hydroxyurea-induced DNA damage. The DNA damage was almost entirely inhibited by catalase and bathocuproine, a Cu(I)-specific chelator, suggesting the involvement of hydrogen peroxide (H(2)O(2)) and Cu(I). Typical free hydroxyl radical scavengers did not inhibit DNA damage by hydroxyurea, but methional did. These results suggest that crypto-hydroxyl radicals such as Cu(I)-hydroperoxo complex (Cu(I)-OOH) cause DNA damage. Formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) was induced by hydroxyurea in the presence of Cu(II). An electron spin resonance spectroscopic study using N-(dithiocarboxy)sarcosine as a nitric oxide (NO)-trapping reagent demonstrated that NO was generated from hydroxyurea in the presence and absence of catalase. In addition, the generation of formamide was detected by both gas chromatography-mass spectrometry (GC-MS) and time-of-flight-mass spectrometry (TOF-MS). A high concentration of hydroxyurea induced depurination at DNA bases in an H(2)O(2)-independent manner, and endonuclease IV treatment led to chain cleavages. These results suggest that hydroxyurea could induce base oxidation as the major pathway of DNA modification and depurination as a minor pathway. Therefore, it is considered that DNA damage by hydroxyurea participates in not only anti-cancer activity, but also carcinogenesis.