Arsenic-Induced Carcinogenesis and Immune Dysregulation

Arsenic, a metal ubiquitously distributed in the environment, remains an important global health threat. Drinking arsenic-contaminated water is the major route of human exposure. Exposure to arsenic contributes to several malignancies, in the integumentary, respiratory, hepatobiliary, and urinary systems. Cutaneous lesions are important manifestations after long-term arsenic exposure. Arsenical skin cancers usually herald the development of other internal cancers, making the arsenic-induced skin carcinogenesis a good model to investigate the progression of chemical carcinogenesis. In fact, only a portion of arsenic-exposed humans eventually develop malignancies, likely attributed to the arsenic-impaired immunity in susceptible individuals. Currently, the exact pathophysiology of arsenic-induced carcinogenesis remains elusive, although increased reactive oxidative species, aberrant immune regulations, and chromosome abnormalities with uncontrolled cell growth might be involved. This review discusses how arsenic induces carcinogenesis, and how the dysregulated innate and adaptive immunities in systemic circulation and in the target organs contribute to arsenic carcinogenesis. These findings offer evidence for illustrating the mechanism of arsenic-related immune dysregulation in the progression of carcinogenesis, and this may help explain the nature of multiple and recurrent clinical lesions in arsenic-induced skin cancers.

Treatment of Arsenic-Induced Bowen’s Disease With Topical 5-Fluorouracil

Here, we present a case of arsenic-induced Bowen’s disease treated with a regimen consisting of topical 5-fluouracil and oral nicotinamide. The use of this therapy modality resulted in near complete resolution of all of the patient’s lesions except for those on her palms, soles, and scalp. Excellent wound care and treatment adherence were major factors contributing to the success of this treatment option. Our results ultimately provide an alternative approach to treating multiple arsenical keratoses in patients who are limited to a drug plan involving 5-FU and oral nicotinamide and who are able to be rigorously compliant with application of medication and wound care. J Drugs Dermatol. 2019;18(5):477-479.

Cyclin D1 promoter -56 and -54bp CpG un-methylation predicts invasive progression in arsenic-induced Bowen's disease

BACKGROUND

Patients with arsenic-induced Bowen's disease (As-BD) are at risk of developing invasive cancers in the skin, lung, and urinary bladder. However, a longitudinal follow-up study on the association between As-BD and invasive cancers is still lacking.

OBJECTIVES

This study aims to investigate the underlying molecular mechanisms of this malignant progression in the skin and internal organs.

METHODS

This is a biopsy-based follow-up study. We tested the DNA histograms, Cyclin D1 (CCND1) protein expression and CCND1 promoter DNA methylation in 40 pathologically confirmed specimens from As-BD patients to correlate with individual's invasive cancer occurrence in the 5-year follow-up.

RESULTS

Flow cytometric DNA histogram analysis of skin specimens showed aneuploid (n=15), G2/M arrest (n=22), and normal (n=3) DNA histograms. No patients with normal DNA histograms developed invasive cancers, whereas 13 developed invasive cancers in the aneuploid group and 2 developed invasive cancers in the G2/M arrest group. The aneuploid group showed a high risk of invasive cancer development. In all assessed aneuploid specimens, the CCND1 promoter hypomethylation was observed. Statistically, percentage of un-methylation more than 55.85% among 17 detected CpG sites showed extremely high predictive power in the occurrence of invasive arsenical cancers. Furthermore, the un-methylation at -56 and -54bp CpG sites was statistically significantly associated with invasive arsenical cancer development (p=1.29×10^-5).

CONCLUSIONS

As-BD lesions showing an aneuploid DNA histogram had a high risk of invasive cancer development. Un-methyaltion at -56 and -54bp CpG in the CCND1 promoter serves as a predictor for invasive progression in As-BD patients.

Role of mitochondria, ROS, and DNA damage in arsenic induced carcinogenesis

The International Agency for Research on Cancer (IARC) declared arsenic a class I carcinogen. Arsenic exposure induces several forms of human cancers, including cancers of skin, lung, liver, and urinary bladder. The majority of the arsenic-induced cancers occur in skin. Among these, the most common is Bowen's disease, characterized by epidermal hyperplasia, full layer epidermal dysplasia, leading to intraepidermal carcinoma as well as apoptosis, and moderate dermal infiltrates, which require the participation of mitochondria. The exact mechanism underlying arsenic induced carcinogenesis remains unclear, although increased reactive oxidative stresses, leading to chromosome abnormalities and uncontrolled growth, and aberrant immune regulations might be involved. Here, we highlight how increased mitochondrial biogenesis and oxidative stress lead to mitochondrial DNA damage and mutation in arsenic induced cancers. We also provide therapeutic rationale for targeting mitochondria in the treatment of arsenic induced cancers.

Cutaneous malignant and premalignant conditions caused by chronic arsenicosis from contaminated ground water consumption: a profile of patients from eastern India

Natural arsenic pollution is a major global health problem. The two worst affected areas e Bangladesh and West Bengal, India. Arsenic is a well-documented human carcinogen that affects many organs including the skin. The authors sought to find out the clinical patterns of different malignant and premalignant conditions associated with chronic arsenicosis from drinking contaminated ground water in a group of patients from eastern India. This was a clinical observational study. Patients with chronic arsenicoses with suspected cutaneous malignancies for whom dermatology service was sought were enrolled in the study. A total of 24 patients (male to female ratio, 11:1; age range, 32-71 years; mean age, 52.2 years) were evaluated. Squamous cell carcinoma (SCC) was the commonest malignancies in our series, seen in 10 (41.7%) patients. This was followed by Bowen's disease (9 [37.5%]) and basal cell carcinoma (8 [33.3%]). Three patients (12.5%) had > 1 type of cutaneous malignancies. Multicentric lesions were seen in 3 cases. The most common site of involvement was the chest (8 [33.3%]). No statistically significant correlation was found between number of lesions and arsenic content in the hairs and nails of the patients.

Use of arsenic-induced palmoplantar hyperkeratosis and skin cancers to predict risk of subsequent internal malignancy

Hyperpigmentation, hyperkeratoses, and Bowen's disease are hallmarks of chronic arsenic exposure. The association between arsenic-induced skin lesions and subsequent internal cancers is examined by using a community-based prospective study. The cohort was enrolled from an arseniasis-endemic area in southwestern Taiwan, where 2,447 residents participated in skin examinations during the late 1980s. The number of participants diagnosed with hyperpigmentation was 673; with hyperkeratosis, 243; and with skin cancer (Bowen's disease or non-melanoma skin cancer), 378. Newly diagnosed internal cancers were ascertained through linkage with National Cancer Registry profiles. Cox regression was performed to estimate hazard ratios with 95% confidence intervals for potential risk predictors. Compared with participants without skin lesions, patients affected with skin cancers had a significantly increased risk of lung cancer (hazard ratio = 4.64, 95% confidence interval: 2.92, 7.38) and urothelial carcinoma (hazard ratio = 2.02, 95% confidence interval: 1.23, 3.30) after adjustment for potential confounders and cumulative arsenic exposure. Hyperkeratosis is significantly associated with an increased lung cancer risk (hazard ratio = 2.76, 95% confidence interval: 1.35, 5.67). A significant interactive effect on lung cancer risk between hyperkeratosis and cigarette smoking was identified, which suggests that patients with hyperkeratosis who have been exposed to arsenic should cease smoking.

Analysis of p16 gene mutation, deletion and methylation in patients with arseniasis produced by indoor unventilated-stove coal usage in Guizhou, China

The aim of this study was to determine p16 gene mutation, deletion, and promoter 5' CpG island hypermethylation in peripheral blood mononuclear leukocyte of patients with arseniasis as attributed to exposure to indoor unventilated coal stove. The role of the aberrant change of p16 gene in the induction and development of carcinogenesis in endemic arsenisiasis region in China was also examined. Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP), multiplex PCR (mPCR), methylation-specific PCR (MSP), and sequencing techniques were performed to detect (1) mutation of the p16 gene exon 2, (2) homozygous deletion of the p16 gene exon 1 and exon 2, and (3) hypermethylation of the promoter CpG island in peripheral blood mononuclear leukocyte of patients with arseniasis. Results showed no mutation was found in exon 2 of p16 gene. The homozygous deletion frequency of p16 gene was 5 and 15% in control and arseniasis patients, respectively. The homozygous deletion occurred mainly in exon 2, with significant deletion frequencies of 9, 13, and 20% in mild, intermediate, and severe arseniasis groups. The significant homozygous deletion frequency was 9 and 39% in noncarcinoma and carcinoma individuals. The positive rate of p16 gene promoter CpG island hyermethylation was 42 and 2% in the exposed group and the control group, respectively. The positive rate was 26, 42, and 50% in mild, intermediate, and severe arseniasis. The marked different positive rate was 22 and 56% in noncarcinoma and carcinoma individuals, respectively. In conclusion, homozygous deletion and hypermethylation of p16 gene may play an important role in the initiation and development of manifestations seen in endemic arseniasis including carcinogenesis.

A case of Bowen's disease and small-cell lung carcinoma: long-term consequences of chronic arsenic exposure in Chinese traditional medicine

Chronic arsenic toxicity occurs primarily through inadvertent ingestion of contaminated water and food or occupational exposure, but it can also occur through medicinal ingestion. This case features a 53-year-old lifetime nonsmoker with chronic asthma treated for 10 years in childhood with Chinese traditional medicine containing arsenic. The patient was diagnosed with Bowen's disease and developed extensive-stage small-cell carcinoma of the lung 10 years and 47 years, respectively, after the onset of arsenic exposure. Although it has a long history as a medicinal agent, arsenic is a carcinogen associated with many malignancies including those of skin and lung. It is more commonly associated with non-small-cell lung cancer, but the temporal association with Bowen's disease in the absence of other chemical or occupational exposure strongly points to a causal role for arsenic in this case of small-cell lung cancer. Individuals with documented arsenic-induced Bowen's disease should be considered for more aggressive screening for long-term complications, especially the development of subsequent malignancies.

Arsenic-induced keratoses and Bowen's disease

We report a patient with arsenic-induced keratoses and Bowen's disease. Chronic arsenicism may lead to both cutaneous and systemic neoplasms and patients should undergo regular long-term examination. Our patient had widespread cutaneous disease, which responded well to acitretin.

Treatment of arsenical keratosis and Bowen's disease with acitretin

BACKGROUND

Long-term exposure to arsenic is associated with the development of arsenical keratosis, Bowen's disease, squamous cell carcinoma, and basal cell carcinoma. The efficacy of acitretin therapy was examined in two patients with cutaneous arsenical neoplasms.

METHODS

Lipid profile, hematological and liver function tests were performed regularly during the therapy at monthly intervals.

RESULTS

After the third month of treatment, improvement of lesions of arsenical keratosis and Bowen's disease were observed in both patients. For the first patient who received 1 mg/kg daily acitretin for 10 months nearly total clearing was obtained at the end of therapy. The second patient discontinued the treatment after a period of 5 months because of symptomatic side-effects. During therapy no new lesions and no laboratory side-effects were observed in either patient.

CONCLUSIONS

Although these results need to be confirmed by larger, long-term trials, it appears that acitretin is effective in the treatment of Bowen's disease related with arsenic, as well as arsenical keratosis.

Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions

Curcumin (diferuloylmethane), a yellow substance from the root of the plant Curcuma longa Linn., has been demonstrated to inhibit carcinogenesis of murine skin, stomach, intestine and liver. However, the toxicology, pharmacokinetics and biologically effective dose of curcumin in humans have not been reported. This prospective phase-I study evaluated these issues of curcumin in patients with one of the following five high-risk conditions: 1) recently resected urinary bladder cancer; 2) arsenic Bowen's disease of the skin; 3) uterine cervical intraepithelial neoplasm (CIN); 4) oral leucoplakia; and 5) intestinal metaplasia of the stomach. Curcumin was taken orally for 3 months. Biopsy of the lesion sites was done immediately before and 3 months after starting curcumin treament. The starting dose was 500 mg/day. If no toxicity > or = grade II was noted in at least 3 successive patients, the dose was then escalated to another level in the order of 1,000, 2,000, 4,000, 8,000, and 12,000 mg/day. The concentration of curcumin in serum and urine was determined by high pressure liquid chromatography (HPLC). A total of 25 patients were enrolled in this study. There was no treatment-related toxicity up to 8,000 mg/day. Beyond 8,000 mg/day, the bulky volume of the drug was unacceptable to the patients. The serum concentration of curcumin usually peaked at 1 to 2 hours after oral intake of crucumin and gradually declined within 12 hours. The average peak serum concentrations after taking 4,000 mg, 6,000 mg and 8,000 mg of curcumin were 0.51 +/- 0.11 microM, 0.63 +/- 0.06 microM and 1.77 +/- 1.87 microM, respectively. Urinary excretion of curcumin was undetectable. One of 4 patients with CIN and 1 of 7 patients with oral leucoplakia proceeded to develop frank malignancies in spite of curcumin treatment. In contrast, histologic improvement of precancerous lesions was seen in 1 out of 2 patients with recently resected bladder cancer, 2 out of 7 patients of oral leucoplakia, 1 out of 6 patients of intestinal metaplasia of the stomach, I out of 4 patients with CIN and 2 out of 6 patients with Bowen's disease. In conclusion, this study demonstrated that curcumin is not toxic to humans up to 8,000 mg/day when taken by mouth for 3 months. Our results also suggest a biologic effect of curcumin in the chemoprevention of cancer.

Arsenic-related Bowen's disease, palmar keratosis, and skin cancer

Chronic arsenical intoxication can still be found in environmental and industrial settings. Symptoms of chronic arsenic intoxication include general pigmentation or focal "raindrop" pigmentation of the skin and the appearance of hyperkeratosis of the palms of the hands and soles of the feet. In addition to arsenic-related skin diseases including keratosis, Bowen's disease, basal-cell-carcinoma, and squamous-cell carcinoma, there is also an increased risk of some internal malignancies. Arsenic-related diseases are common in areas of the world where the drinking water has a high arsenic content. In this paper, we describe a 35-year-old male patient who had arsenic-related keratosis, squamous-cell carcinoma in the palmar area of his left hand, and Bowen's disease on his left thigh. The patient worked in a borax mine for 15 years, so he was exposed to arsenic in drinking water, airborne arsenic in his workplace, and had direct contact. The patient was treated for 11 months for arsenic-related keratosis until an axillary lymph node metastasis occurred; the lesion was excised and diagnosed to be malignant. Bowen's disease was detected when the patient was being treated for cancer. No other malignancy was found. The patient is still receiving regular follow-up care.

The role of oxidative DNA damage in human arsenic carcinogenesis: detection of 8-hydroxy-2'-deoxyguanosine in arsenic-related Bowen's disease

Arsenic is widely distributed in nature in the form of either metalloids or chemical compounds, which cause a variety of pathologic conditions including cutaneous and visceral malignancies. Recently, reactive oxygen species have been hypothesized to be one of the causes of arsenic-induced carcinogenesis. 8-Hydroxy-2'-deoxyguanosine is one of the major reactive oxygen species-induced DNA base-modified products that is widely accepted as a sensitive marker of oxidative DNA damage. We studied the presence of 8-hydroxy-2'-deoxyguanosine by immunohistochemistry using N45.1 monoclonal antibody in 28 cases of arsenic-related skin neoplasms and arsenic keratosis as well as in 11 cases of arsenic-unrelated Bowen's diseases. The frequency of 8-hydroxy-2'-deoxyguanosine positive cases was significantly higher in arsenic-related skin neoplasms (22 of 28; 78%) than in arsenic-unrelated Bowen's disease (one of 11; 9%) (p < 0.001 by chi2 test). 8-Hydroxy-2'-deoxyguanosine was also detected in normal tissue adjacent to the arsenic-related Bowen's disease lesions. Furthermore, arsenic was detected by neutron activation analysis in the deparaffined skin tumor samples of arsenic-related disease (four of five; 80%), whereas arsenic was not detected in control samples. Our results strongly suggest the involvement of reactive oxygen species in arsenic-induced human skin cancer. Key word: neutron activation analysis.

Mutational spectrum of p53 gene in arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan

To understand the role of p53 tumour suppressor gene in the carcinogenesis of arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan, we collected tumour samples from 23 patients with Bowen's disease, seven patients with basal cell carcinomas (BCC) and nine patients with squamous cell carcinomas (SCC). The result showed that p53 gene mutations were found in 39% of cases with Bowen's disease (9/23), 28.6% of cases with BCC (2/7) and 55.6% of cases with SCC (5/9). Most of the mutation sites were located on exon 5 and exon 8. Moreover, the results from direct sequencing indicated that missense mutations were found at codon 149 (C-->T) in one case, codon 175 (G-->A) in three cases, codon 273 (G-->C) in three cases, codon 292 (T-->A) in one case, codon 283 (G-->T) in one case, codon 172 (T-->C) in one case and codon 284 (C-->A) in one case. In addition, silent mutations were also found in four cases. These mutations were located at codons 174, 253, 289 and 298 respectively. In immunohistochemistry analysis, p53 overexpression was found in 43.5% (10/23) of cases with Bowen's disease, 14% (1/7) of cases with BCC and 44% (4/9) of cases with SSC. These findings showed that p53 gene mutation rate in arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan is high and that the mutation types are different from those in UV-induced skin cancers.

Defective IL-2 receptor expression in lymphocytes of patients with arsenic-induced Bowen's disease

The immune function of peripheral mononuclear cells (MNC) in patients with endemic arsenic-induced Bowen's disease (BD) was investigated. Many cytokines and immune-related factors were determined in the present study. Interleukin-1beta and TNF-alpha production was used as an indicator of monocyte/macrophage function. II-2 and sIL-2R production was used as an indicator of lymphocyte activation. The release of sCD4 and sCD8 was used as an indicator of activation of respective T-cell subpopulations. Production of IFN-gamma and IL-2 reflected the cellular effector function of helper T-cells type 1. In vivo cell-mediated immunity was also assessed by estimation of the percentage of T-cells in peripheral blood MNC and the nonspecific delayed-type hypersensitivity (DTH) response to 2,4-dinitrochlorobenzene (DNCB). Both assays revealed depressed cell-mediated immunity in BD. Compared with healthy controls, spontaneous and PHA-induced IFN-gamma and TNF-alpha production was significantly decreased in BD whereas spontaneous release of IL-2, sCD4 and sCD8 was significantly increased. Although PHA stimulation increased IL-2 release, the expression of IL-2R alpha and beta chains and the release of sIL-2R were not proportionately increased in BD. In addition, IL-2-mediated [3H]-thymidine incorporation by MNC in patients with BD was significantly decreased. These findings suggest that the defective cell-mediated immune function in BD is due to impairment of membrane IL-2R expression in lymphocytes after stimulation.

Expression of bcl-2, p53 and Ki-67 in arsenical skin cancers

To investigate the regulation of apoptosis and proliferation in arsenic-induced skin cancers, we examined the expression of bcl-2, p53, and Ki-67 using immunohistochemical staining. Thirty patients with Bowen's disease (BD), ten with basal cell carcinoma (BCC), eight with squamous cell carcinoma (SCC) and eleven of perilesional normal skin (PLN) of the non-sun exposure sites from endemic area were examined. The results showed that: 1) bcl-2 was expressed in all of the BCC homogeneously, in none of the SCC, and in 12/30 of the BD focally or homogeneously; 2) p53 was expressed in all of the arsenical skin cancers with a labelling index of 75 +/- 14% of BD, 50 +/- 17% of BCC, 61 +/- 15% of SCC, and also in all of the perilesional normal skin with a labelling index of 55 +/- 24%; 3) Ki-67 was expressed in all of the skin cancers with labelling index of 58 +/- 17% of BD, 12 +/- 7% of BCC, 47 +/- 21% of SCC, and in 9/11 of PLN with a labelling index of 41 +/- 24%. Expression of bcl-2 in BCC or BD is related to the phenotype of germinative basal cell. The constant expression of bcl-2 i early dysplastic cells of BD and the earliest expression of P53 in the basal cells of perilesional normal skin indicate that the initial step of arsenic-induced carcinogenesis is from the basal germinative cells. There is no mutual relationship between bcl-2, p53 or Ki-67 expression in any type of the arsenical skin cancers, but there is a positive correlation between p53 and Ki-67 expression identified in perilesional normal skin. BD had the highest labelling index of p53 and Ki-67.

Merkel cell carcinoma, Bowen's disease and chronic occupational arsenic poisoning

We diagnosed a unique case of Merkel cell carcinoma (MCC) coexisting with Bowen's disease on the sole of the foot of a 72-year-old man who had worked for about 4 years in a factory handling inorganic arsenic. He had a past history of arsenical keratosis and multiple Bowen's disease. The tumour first appeared as a reddish macule and then showed marked growth over the next month. The tumour was excised and the specimen was examined histopathologically. The tumour consisted of two components: a group of atypical cells representing Bowen's disease in the epidermis and another group of atypical cells with a trabecular pattern characteristic of MCC in the dermis. Neither group of cells showed transitional findings, and the tumour elements were divided by a clear basement membrane. The tumour cells in the dermis were positive for neurone-specific enolase, and on electron microscopy had dense core granules in the cytoplasm. Inorganic arsenic can cause various cutaneous neoplasms, but to our knowledge, this is the first report of a case of MCC associated with Bowen's disease.

Cutaneous manifestations of chronic arsenicism: review of seventeen cases

BACKGROUND

Cutaneous complications arising from exposure to Chinese proprietary medicines known to contain inorganic arsenic have been rarely reported.

OBJECTIVE

Our purpose was to study the nature, incidence, and sequelae of patients with chronic arsenicism and to review the literature on arsenic-induced skin diseases.

METHODS

Case records of patients with cutaneous lesions related to chronic arsenicism seen from January 1990 to December 1996 were reviewed. Patients were interviewed and a complete skin and systemic examination was performed. Data on demography, history of arsenic ingestion, and type and distribution of skin lesions and visceral malignancy were collated.

RESULTS

Seventeen Chinese patients (11 men, six women) were identified; their mean age was 64.5 years. Fourteen patients (82%) had exposure to Chinese proprietary medicines known to contain inorganic arsenic, and three had environmental arsenic exposure from well water. The mean age of these 14 patients was 17.6 years; mean duration of arsenic intake was 6.4 years. Seventeen patients had Bowen's disease; of these, 70% had 2 to 10 lesions. Of the 17 patients with arsenical keratoses on the palms, 76% had 2 to 10 lesions. Of the 14 patients (82%) with plantar arsenical keratoses, 64% had 11 to more than 50 lesions. Eleven patients (65%) had macular hypopigmentation. Seven patients (41%) had 11 squamous cell carcinomas (SCCs); three of the seven had more than one lesion. Fifty-five percent of SCCs arose from preexisting keratotic lesions (n = 4) or Bowen's disease (n = 2), and 45% arose de novo. One patient each (6%) had multiple basal cell carcinomas, laryngeal carcinoma, and metastatic SCC. The latency periods for the development of arsenical keratoses, Bowen's disease, and SCC were 28, 39, and 41 years, respectively. Patients with SCC were significantly older at the start of arsenic exposure and had significantly more palmar arsenical keratoses than those without SCC.

CONCLUSION

Exposure to Chinese proprietary medicines containing inorganic arsenic poses a risk for the development of cutaneous and systemic malignancies. Long-term follow-up is necessary for tumor detection because of long latency periods. Surveillance programs are important to restrict the sale of Chinese proprietary medicines that may contain inorganic arsenic.

Merkel cell carcinoma and multiple Bowen's disease: incidental association or possible relationship to inorganic arsenic exposure?

An 81-year-old Japanese male was referred to our clinic in 1991 with multiple Bowen's disease. The associated hyperpigmentation of the trunk and extremities and palmoplantar keratotic nodules indicated that he had suffered from chronic arsenic poisoning. Interestingly, he was a native of Namikata in Ehime, Japan, where many residents have suffered from multiple Bowen's disease with internal malignancy. Arsenic exposure was strongly suspected. Two years later, Merkel cell carcinoma developed on the dorsum of his right hand, where Bowen's disease lesions were absent. Metastasis of this Merkel cell carcinoma led to his eventual death one year later. To our knowledge, this is the first report of Merkel cell carcinoma associated with multiple Bowen's disease. Chronic arsenic poisoning may be responsible for the association of these two rare skin neoplasms.

[Multiple cutaneous neoplasms in cyclosporine therapy after kidney transplantation]

We report on a 56-year-old renal allograft recipient receiving cyclosporin A immunosuppression. During this therapy he subsequently developed the following cutaneous neoplasms: squamous cell carcinomas, basal cell carcinomas, Bowen's disease, actinic keratosis, sebaceous hyperplasia, a dysplastic naevus and, finally a nodular malignant melanoma. Adverse effects of the cyclosporin A therapy are discussed, with special reference to dermatologic effects and the implications for patient and doctor.

Cutaneous carcinoma and PUVA lentigines in Thai patients treated with oral PUVA

A total of 113 Thai patients who were treated with oral PUVA from 1979 to 1992 were examined for long-term cutaneous side effects of PUVA. Two psoriatic patients developed PUVA keratosis on non-sun-exposed areas. Both were skin type IV and had had phototherapy with UVB and sunlight previously. The total doses of UVA were 909 J/cm2 and 242 J/cm2 respectively. One psoriatic patient developed Bowen's disease. He had had a cumulative dose of UVA 2207 J/cm2. He also had a past history of arsenic intake and phototherapy with UVB and sunlight. PUVA lentigines were seen in 58 patients (51.4%). It was associated with older age at starting PUVA, higher cumulative UVA dose and greater number of PUVA treatment. This study suggests that previous exposure to other risk factors is important for inducing skin cancer in populations with skin phototype III, IV and V treated with oral PUVA.

Arsenic-related Bowen's disease and paraquat-related skin cancerous lesions show no detectable ras and p53 gene alterations

We have investigated point mutations of codons 12, 13, and 61 in H-, K-, and N-ras oncogenes as well as p53 tumour suppressor gene exon 5 through exon 9 by PCR-SSCP analysis in 26 skin biopsy tissues from 16 arsenic-related Bowen's disease patients and 6 skin samples from 4 paraquat manufacturing workers. No mutation was found. These results are different from findings with UV associated skin cancers. Interestingly, a silent change at codon 27 of H-ras in one allele was detected in all 4 paraquat manufacturing workers and in 2 of 16 arsenic-related Bowen's disease patients. It is likely that the molecular mechanisms involved in arsenic and paraquat induced skin cancers differ from sunlight-related skin malignancies.

Progressive alterations of cytokeratin expressions in the process of chronic arsenism

Recent studies of an endemic occurrence of chronic arsenism in a limited area on the southwest coast of Taiwan are focusing on its cytokeratin analysis in hopes of tracing the disease's biochemical expression. Specimens were obtained from uninvolved skin and arsenical cancers including Bowen's disease, basal cell carcinoma, and squamous cell carcinoma. In this study, we used two-dimensional polyacrylamide gel electrophoresis to analyse cytokeratin expression. Progressive alterations in cytokeratin expression were found in various skin lesions. These include an expression of K16 in the uninvolved skin; K16 and K6 in Bowen's disease; and K16, K6 and K17 in squamous cell carcinoma and basal cell carcinoma. In addition, we found that the K1 isoelectric variants shifted to more acidic forms with the complete absence of K1 in basal cell carcinoma. K16 expression in uninvolved skin indicates that it is nevertheless in a hyperproliferative status. K17 was expressed in squamous cell carcinoma and basal cell carcinoma, but not in Bowen's disease. The progressive impairment of phosphorylation of K1 and K2 in the process of chronic arsenism provides us with a suitable model for studying the biological significance of phosphorylation in intermediate filaments during chemical carcinogenesis.

Alterations of mitogenic responses of mononuclear cells by arsenic in arsenical skin cancers

We have studied the endemic occurrence of chronic arsenism in a limited area on the southwest coast of Taiwan. The effects of arsenic on the mitogenic responses of mononuclear cells (MNC) derived from patients with arsenical skin cancers in that area were evaluated. The subjects enrolled in this study included patients with 1) Bowen's disease, 2) arsenical skin cancers (basal cell carcinoma and squamous cell carcinoma), 3) non-arsenical skin cancers (basal cell carcinoma and squamous cell carcinoma), 4) nasopharyngeal cancer and 5) healthy controls from endemic and non-endemic areas. Phytohemagglutinin (PHA) stimulated [3H]thymidine incorporation in MNC in all groups except the arsenical skin cancer group. However, when a low concentration of As2O3 (2.5 x 10(-7) M) was added to PHA-stimulated MNC, a tremendous amplification of the uptake of [3H]thymidine was noticed in patients with arsenical skin cancer. In this study, this phenomenon did not occur in cancers not related to arsenic. This result shows that arsenical carcinomas are hyperreactive to its specific etiology--arsenic. Arsenic seems to play a role as a co-stimulant of PHA similar to interleukin-1.

Alterations of skin-associated lymphoid tissue in the carcinogenesis of arsenical skin cancer

We investigated the skin-associated lymphoid tissue in arsenical skin cancers, including 14 Bowen's disease, 6 basal cell carcinoma and 6 squamous cell carcinoma patients from an endemic area by immunohistochemical and morphometric methods. There was a progressive decrease of Langerhans cells in the order of normal skin, normal appearing edge and arsenical cancers. A disruption of the uniform Langerhans cell dendrites was also noticed. The Langerhans cell density in arsenical tumors did not correlate with the peritumoral infiltrates. The prominent infiltrated cells in the peritumoral area had T cell markers. The number of peritumoral T lymphocytes in squamous cell carcinoma was significantly less than that of Bowen's disease and basal cell carcinoma. Peritumoral mononuclear infiltrates in Bowen's disease and squamous cell carcinoma showed a higher helper/suppressor T cell ratio than that in basal cell carcinoma. This may be accounted for by a selective increased recruitment of helper T cells to the tumor infiltrates in Bowen's disease and squamous cell carcinoma.

Quantitative and morphological changes of Langerhans cells in Bowen's disease from patients with chronic arsenicism

Langerhans cells (LCs) are considered to be responsible for the immunologic presentation of tumor-associated antigens and play a role in the elimination of neoplastic clones. Ultraviolet light B can cause dysfunction and loss of LCs. Both the number and dendritic morphology of LCs are known to be diminished in squamous cell carcinomas from sun-exposed skin. The effects of arsenics on LCs are unknown. Using an OKT-6 monoclonal antibody to stain intraepithelial LCs, we compared their number and morphology in Bowen's lesions and in the perilesional skin from sun-protected sites in ten patients with chronic arsenicism. There was a significant reduction in the numbers of LCs in the Bowen's lesions as compared to the perilesional skin specimens. Loss of dendrites was observed in all Bowen's lesions and in seven of the perilesional skin specimens. Ultrastructurally, the LCs showed an absence of dendrites, but the Birbeck granules were preserved. Since the specimens were not from sun-exposed skin in our study, the findings may be related to chronic arsenic intoxication. The morphologic alteration of LCs observed in the perilesional skin further suggests an arsenic-related systemic dysfunction of the LCs, which in turn may contribute to the development of skin cancers in these patients.

Ureteral tumor with multiple Bowen's disease forty-two years after exposure to arsenic

We report a case of ureteral tumor associated with Bowen's disease in a 67-year-old man. The patient has a history of occupational exposure to arsenic 42 years before. Arsenic produces multiple cancers and these cancers are characterized by a long period of latency.

Arsenic exposure followed by the development of dermatofibrosarcoma protuberans

A case of documented significant arsenic exposure followed by the development of dermatofibrosarcoma protuberans is reported. Exposure to arsenic is associated with an increased chance of the subsequent development of a variety of neoplasms. It is possible that dermatofibrosarcoma protuberans may be one such tumor.

Small cell lung carcinoma and Bowen's disease 40 years after arsenic ingestion

A non-smoking woman presented with ectopic ACTH syndrome associated with disseminated small cell carcinoma of lung. The patient had Bowen's disease and had taken oral arsenic for psoriasis 40 years ago. It is postulated that the previous therapeutic arsenic ingestion caused both her arsenical dermatosis and her small cell carcinoma of lung.

Bowen's disease of the palm

Bowen's disease is a squamous cell carcinoma characterized by isolated, grouped or confluent nodules, either flat, scaling, or crusted, with an arcuate or serpiginous configuration. Malignant dyskeratosis throughout the epidermis, the bowenoid hallmark, is not sufficient by itself to identify a lesion as Bowen's disease. It has been suggested, but not proven, that arsenic has a role in the etiology of Bowen's disease. A case of Bowen's disease affecting the palm, an unusual location, is reported.

Electron microscopic observations of arsenical keratosis and Bowen's disease associated with chronic arsenicism

A 57-year-old man, who had received injections of an arsenide for the treatment of syphilis, developed a tumor on his lower lip and a patchy pigmented lesion on his neck 2 years before the present examination. The lesions enlarged progressively. Under a diagnosis of arsenical keratosis and Bowen’s disease associated with chronic arsenicism, light and electron microscopic observations were made of the lesions. Vacuolated cells were demonstrated by light microscopy, while the characteristic electron microscopic features of both lesions were the appearance of nuclear bodies and the presence of radially arranged, intranuclear inclusion bodies of high electron density.

Premalignant and neoplastic skin lesions associated with occupational exposure to "tarry" byproducts during manufacture of 4,4'-bipyridyl

ABSTRACT Skin lesions have been identified in 20 workers manufacturing 4,4'-bipyridyl. The lesions were on the face, neck, and backs of the hands and arms. Larger localised lesions were removed surgically and examined histopathologically, but other lesions have been treated topically with fluorouracil cream. Histological diagnosis showed a progression from keratosis to Bowen's disease and, in six cases, to squamous cell carcinoma. Over 550 individuals associated with 4,4'-bipyridyl processes between 1961 and 1980 have been examined or questioned. All 20 patients identified worked in now obsolete production plants; 15 of whom were found among the 147 shift process operators. The time taken for the lesions to appear from first working on a 4,4'-bipyridyl plant was 6-19 years (average 12 years). Starting in the early 1960s three processes have been successively used to convert pyridine into 4,4'-bipyridyl. These differ in the reaction conditions used and in the efficiency of the conversion. In the two earlier plants a substantial quantity of pyridine was converted into polypyridyls and “tarry” byproducts, which caused operating difficulties and increased the risk of worker exposure. The exposure and occupational histories of the cases, including the fact that two had worked only on the obsolete production plants, indicates that the causative agent was present in these earlier processes. In-vitro tests for potential carcinogenicity on materials from the present plant and from an earlier process gave positive tests on the tarry byproducts from the earlier process, suggesting that they were the cause of the lesions. Tar impurity production on the present plant is minimal, and worker exposure to chemicals is low. No similar skin lesions have been seen in those who have worked only on the present plant. This observation supports the view that the causative agent was present only on the earlier plants but is not conclusive because of the shorter time that has elapsed since first exposure of personnel who have worked only on the present plant. Medical surveillance of past and present 4,4'-bipyridyl workers is continuing.

Noncirrhotic portal hypertension after arsenic ingestion

Five years after arsenic therapy, the patient described had noncirrhotic portal hypertension, for which he had splenectomy and anastomosis of the splenic vein to the left renal vein. During the 12-year postoperative period he had Bowen's disease (skin carcinoma), but has had normal liver function and no further gastrointestinal bleeding. Arsenic exposure in humans is common throughout the world and may lead to late complications such as noncirrhotic portal hypertension and skin carcinoma, as well as malignancies of the lungs, liver, and lymphatic systems. It may also lead to severe arteriosclerosis with involvement of the heart and extremities.

Bowen's disease of the plantar arch

Bowen's disease has previously been associated with the development of other malignancies particularly in patients with a history of arsenic exposure. A review of the literature is combined with a discussion of current theories regarding arsenic exposure, lesion differentiation, and prognostic implications. This report of a bowenoid lesion of the plantar arch emphasizes the importance of close follow-up of patients with Bowen's disease, especially on unexposed surfaces.

[Syntopy of Bowen's disease and Lewisite scar]

Description of a case of Bown's disease in an area of the right lower leg after lewisite contamination 30 years ago. The possible influence of lost derivatives on carcinogenesis is discussed.