Ethanol Metabolism and Melanoma.

Malignant melanoma is the deadliest form of skin cancer. Despite significant efforts in sun protection education, melanoma incidence is still rising globally, drawing attention to other socioenvironmental risk factors for melanoma. Ethanol and acetaldehyde (AcAH) are ubiquitous in our diets, medicines, alcoholic beverages, and the environment. In the liver, ethanol is primarily oxidized to AcAH, a toxic intermediate capable of inducing tumors by forming adducts with proteins and DNA. Once in the blood, ethanol and AcAH can reach the skin. Although, like the liver, the skin has metabolic mechanisms to detoxify ethanol and AcAH, the risk of ethanol/AcAH-associated skin diseases increases when the metabolic enzymes become dysfunctional in the skin. This review highlights the evidence linking cutaneous ethanol metabolism and melanoma. We summarize various sources of skin ethanol and AcAH and describe how the reduced activity of each alcohol metabolizing enzyme affects the sensitivity threshold to ethanol/AcAH toxicity. Data from the Gene Expression Omnibus database also show that three ethanol metabolizing enzymes (alcohol dehydrogenase 1B, P450 2E1, and catalase) and an AcAH metabolizing enzyme (aldehyde dehydrogenase 2) are significantly reduced in melanoma tissues.

Alcohol as a Non-UV Social-Environmental Risk Factor for Melanoma.

Although cancer mortality has declined among the general population, the incidence of melanoma continues to rise. While identifying high-risk cohorts with genetic risk factors improves public health initiatives and clinical care management, recognizing modifiable risk factors such as social-environmental risk factors would also affect the methods of patient outreach and education. One major modifiable social-environmental risk factor associated with melanoma is ultraviolet (UV) radiation. However, not all forms of melanoma are correlated with sun exposure or occur in sun-exposed areas. Additionally, UV exposure is rarely associated with tumor progression. Another social-environmental factor, pregnancy, does not explain the sharply increased incidence of melanoma. Recent studies have demonstrated that alcohol consumption is positively linked with an increased risk of cancers, including melanoma. This perspective review paper summarizes epidemiological data correlating melanoma incidence with alcohol consumption, describes the biochemical mechanisms of ethanol metabolism, and discusses how ethanol and ethanol metabolites contribute to human cancer, including melanoma.

Giant Basal Cell Carcinomas Arising on the Bilateral Forearms of a Patient: A Case Report and Review of Nonsurgical Treatment Options.

Giant basal cell carcinomas (GBCCs) are large basal cell carcinomas (BCCs; <5 cm) with a greater propensity to invade and metastasize than standard BCCs. The presence of 2 GBCCs in a single individual is rare. We present the case of a 71-year-old Caucasian male with bilateral GBCCs on the dorsal forearms, measuring 130 cm2 and 24 cm2, respectively, that developed over a 21-year period. Over this period, the patient treated the tumors with herbal remedies. Histologic evaluation showed a conventional nodular BCC for both tumors. Computed tomography and magnetic resonance imaging revealed a T4N0M0 stage for the larger lesion. Surgical excision and grafting and reconstruction were offered, but he declined. This case highlights a shared belief in holistic treatments and rejection of Western medical interventions that are common among many patients with GBCC. Studies reporting nonsurgical treatments for GBCCs, including radiotherapy, vismodegib, topical imiquimod, and acitretin are reviewed.