990 resultados para Malignant Skin Melanoma
Resumo:
Objective: Whole-body skin self-examination (SSE) with presentation of suspicious lesions to a physician may improve early detection of melanoma. The aim of this study was to establish the prevalence and determinants of SSE in a high-risk population in preparation for a community-based randomised controlled trial of screening for melanoma. Methods: A telephone survey reached 3110 residents older than 30 years (overall response rate of 66.9%) randomly selected from 18 regional communities in Queensland, Australia. Results: Overall, 804 (25.9%) participants reported whole-body SSE within the past 12 months and 1055 (33.9%) within the past three years. Whole-body SSE was associated in multivariate logistic regression analysis with younger age (< 50 years); higher education; having received either a whole-body skin examination, recommendation or instruction on SSE by a primary care physician; giving skin checks a high priority; concern about skin cancer and a personal history of skin cancer. Conclusion: Overall, the prevalence of SSE in the present study is among the highest yet observed in Australia, with about one-third of the adult population reporting whole-body SSE in the past three years. People over 50 years, who are at relatively higher risk for skin cancer, currently perform SSE less frequently than younger people.
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Community responses (n = 925, response rate = 71%) of a series of eight photographs of pigmented skin lesions were compared against those of general practitioners (n = 114, response rate = 77%), considered to be the most relevant gold standard. The eight photographs included three melanomas, two potentially malignant lesions and three benign pigmented lesions. Over the pool of lesions examined, the average probability that community members thought a lesion was likely to be skin cancer (0.68 [99% CI = 0.66-0.69]) was higher (p < 0.0001) than that of the comparison general practitioners 0.58 [99% CI = 0.55-0.62]. This reflects a general (but not consistent) inflated propensity to over-diagnose among community members. The average probability that respondents indicated they would seek medical advice for a lesion was 0.71 [99% CI = 0.70-0.73]. As expected, this was strongly associated with their perceptions of the skin lesion. These results suggest that the community can play a valuable role in assessing the need for medical evaluation of pigmented skin lesions. (c) 2004 International Society for Preventive Oncology. Published by Elsevier Ltd. All rights reserved.
Resumo:
Caucasian renal transplant recipients from Queensland, Australia have the highest non-melanoma skin cancer (NMSC) risk worldwide. Although ultraviolet light (UVR) exposure is critical, genetic factors also appear important. We and others have shown that polymorphism in the glutathione S-transferases (GST) is associated with NMSC in UK recipients. However, the effect of high UVR exposure and differences in immunosuppressive regimen on these associations is unknown. In this study, we examined allelism in GSTM1, GSTM3, GSTT1 and GSTP1 in 361 Queensland renal transplant recipients. Data on squamous (SCC) and basal cell carcinoma (BCC), UVR/tobacco exposure and genotype were obtained. Associations with both NMSC risk and numbers were examined using logistic and negative binomial regression, respectively. In the total group, GSTM1 AB [P = 0.049, rate ratio (RR) = 0.23] and GSTM3 AA (P = 0.015, RR = 0.50) were associated with fewer SCC. Recipients were then stratified by prednisolone dose (less than or equal to7 versus >7 mg/day). In the low-dose group, GSTT1 null (P = 0.006, RR = 0.20) and GSTP1 Val/Val (P = 0.021, RR = 0.20) were associated with SCC numbers. In contrast, in the high-dose group, GSTM1 AB (P = 0.009, RR = 0.05), GSTM3 AB (P = 0.042, RR = 2.29) and BB (P = 0.014, RR = 5.31) and GSTP1 Val/Val (P = 0.036, RR = 2.98) were associated with SCC numbers. GSTM1 AB (P = 0.016) and GSTP1 Val/Val (P = 0.046) were also associated with fewer BCC in this group. GSTP1 associations were strongest in recipients with lower UVR/tobacco exposure. The data confirm our UK findings, suggesting that protection against UVR-induced oxidative stress is important in NMSC development in recipients, but that this effect depends on the immunosuppressant regimen.
Resumo:
Background : Within a randomized trial of population screening for melanoma, primary care physicians conducted whole-body skin examinations and referred all patients with suspect lesions to their own doctor for further treatment. Objective: Our aim was to describe characteristics of skin screening participants, clinical screening diagnoses, management following referral, and specificity and yield of screening examinations. Methods: Information collected from consent forms, referral forms, and histopathological reports of lesions that had been excised or undergone biopsy was analyzed by means of descriptive statistics. Results: A total of 16,383 whole-body skin examinations resulted in 2302 referrals (14.1% overall; 15.5% men, 18.2% >= 50 years of age) for 4129 suspect lesions (including 222 suspected melanoma, 1101 suspected basal cell carcinomas [BCCs], 265 suspected squamous cell carcinomas [SCCs]). Histopathologic results were available for 94.8% of 1417 lesions excised and confirmed 33 melanomas (23 in men; 24 in participants ? 50 years of age), 259 BCCs, and 97 SCCs. The probability of detecting skin cancer of any type within the program was 2.4%. The estimated specificity of whole-body skin examinations for melanoma was 86.1% (95% confidence interval = 85.6-86.6). The positive predictive value (number of confirmed/number of lesions excised or biopsied x 100) for melanoma was 2.5%, 19.3% for BCC, and 7.2% for SCC (overall positive predictive value for skin cancer, 28.9%). Limitations: Follow-up of participants with a negative screening examination has not been conducted for the present investigation. Conclusions: The rate of skin cancer detected per 100 patients screened was higher than previously reported and men and attendees older than 50 years more frequently received a referral and diagnosis of melanoma. The specificity for detection of melanoma through whole-body skin examination by a primary care physician was comparable to that of other screening tests, including mammography.
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Objective: To describe the workload profile in a network of Australian skin cancer clinics. Design and setting: Analysis of billing data for the first 6 months of 2005 in a primary-care skin cancer clinic network, consisting of seven clinics and staffed by 20 doctors, located in the Northern Territory, Queensland and New South Wales. Main outcome measures: Consultation to biopsy ratio (CBR); biopsy to treatment ratio (BTR); number of benign naevi excised per melanoma (number needed to treat [NNT]). Results: Of 69780 billed activities, 34 622 (49.6%) were consultations, 19 358 (27.7%) biopsies, 8055 (11.5%) surgical excisions, 2804 (4.0%) additional surgical repairs, 1613 (2.3%) non-surgical treatments of cancers and 3328 (4.8%) treatments of premalignant or non-malignant lesions. A total of 6438 cancers were treated (116 melanomas by excision, 4709 non-melanoma skin cancers [NMSCs] by excision, and 1613 NMSCs non-surgically); 5251 (65.2%) surgical wounds were repaired by direct suture, 2651 (32.9%) by a flap (of which 44.8% were simple flaps), 42 (0.5%) by wedge excision and 111 (1.4%) by grafts. The CBR was 1.79, the BTR was 3.1 and the NNT was 28.6. Conclusions: In this network of Australian skin cancer clinics, one in three biopsies identified a skin cancer (BTR, 3.1), and about 29 benign lesions were excised per melanoma (NNT, 28.6). The estimated NNT was similar to that reported previously in general practice. More data are needed on health outcomes, including effectiveness of treatment and surgical repair.
Resumo:
Clinical trials have shown temozolomide to be an effective agent for treatment of malignant melanoma. In order to investigate its suitability for delivery via the skin, a series of temozolomide esters was synthesized as prodrugs. In vitro assays demonstrated temozolomide, temozolomide acid and the hexyl ester equi-effective against selected cancer cell lines. The susceptibility of the esters to enzyme hydrolysis and their effectiveness for application to the skin were investigated. The esters effectively diffuse through rat skin and the hexyl ester demonstrated profound potency for penetrating through skin. Topical application of 5% (w/v) hexyl ester in DMSO solution on a mouse model demonstrated a significant inhibition of tumor growth. These results suggest that temozolomide esters could be an effective alternative to temozolomide in the treatment of skin cancer. © 2005 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Skin cancer is the most common form of cancer in the United States. Melanoma is a particular type of skin cancer, which arises from the malignant transformation of melanocytes and generally exhibits a high propensity to metastasize. Melanoma progression is dependent on angiogenesis to deliver the oxygen and nutrients required to maintain the altered metabolism of rapidly proliferating tumorigenic cells. Recent studies have implicated the growth factor Endothelin 3 (Edn3) in melanoma progression and metastasis. The aim of this study was to examine the role that Edn3 plays in the angiogenesis of melanocytic lesions. For this purpose, Dct-Grm1 transgenic mice, which spontaneously acquire melanocytic lesions through the aberrant expression of the metabotropic glutamate receptor 1 (mGluR1), were crossed with K5-Edn3 transgenic mice that overexpress Edn3. Tumors in the Dct-Grm1/K5-Edn3 experimental population were examined and compared to the control Dct-Grm1 population using immuno-fluorescent staining targeted against the vascular endothelial cell marker CD31. Proteomic arrays were also used and identified changes in the expression of specific angiogenic factors. CD31 antibody staining results revealed an increased vascular density in Dct-Grm1/K5-Edn3 tumors compared with tumors from the Dct-Grm1 controls. Analysis of the relative expression of angiogenic proteins showed an upregulation of various vascular factors in tumors from the Dct-Grm1/K5-Edn3 population, including VEGF-B, MMP-8, MMP-9, and Angiogenin. These results suggest that endothelin signaling promotes angiogenesis in melanocytic lesions. Targeting the factors upregulated by Edn3 signaling may prove effective in hindering melanoma progression.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação Nanociência e Nanobiotecnologia, 2016.
Resumo:
Cryosurgery is an efficient therapeutic technique used to treat benign and malignant cutaneous diseases. The primary active mechanism of cryosurgery is related to vascular effects on treated tissue. After a cryosurgical procedure, exuberant granulation tissue is formed at the injection site, probably as a result of angiogenic stimulation of the cryogen and inflammatory response, particularly in endothelial cells. To evaluate the angiogenic effects of freezing, as part of the phenomenon of healing rat skin subjected to previous injury. Two incisions were made in each of the twenty rats, which were divided randomly into two groups of ten. After 3 days, cryosurgery with liquid nitrogen was performed in one of incisions. The rats' samples were then collected, cut and stained to conduct histopathological examination, to assess the local angiogenesis in differing moments and situations. It was possible to demonstrate that cryosurgery, in spite of promoting cell death and accentuated local inflammation soon after its application, induces quicker cell proliferation in the affected tissue and maintenance of this rate in a second phase, than in tissue healing without this procedure. These findings, together with the knowledge that there is a direct relationship between mononuclear cells and neovascularization (the development of a rich system of new vessels in injury caused by cold), suggest that cryosurgery possesses angiogenic stimulus, even though complete healing takes longer to occur. The significance level for statistical tests was 5% (p<0,05).