Link Between Skin Cancer And Reduced Alzheimer’s Disease Risk

A skin cancer diagnosis isn’t something you want from your dermatologist. However, researchers from the Albert Einstein College of Medicine in New York have recently found a correlation between non-melanoma skin cancer (NMSC) and a reduced risk of developing Alzheimer’s disease (AD).

According to Dr. Richard Lipton, the lead author, “The theoretical basis for thinking that there could be a relationship comes from the fact that Alzheimer’s and cancer are opposite kinds of disorders in terms of cell division,” as Alzheimer’s cells degrade whilst cancer cells abnormally replicate.

Lipton and his colleagues – Robert White, Charles Hall, and Joshua Steinerman – followed a cohort of 1,102 volunteers with an average age of 79 for approximately three to seven years.

To deduce a biological association between AD and NMSC, the team considered three outcomes groups: only AD (probable or possible AD as the sole diagnosis), any AD (probable AD or possible AD, as well as mixed AD/vascular dementia), and all-cause dementia.

While none of the participants had dementia at the study’s onset, 109 individuals reported they had been diagnosed with skin cancer in the past. During the course of the study, 32 more people developed skin cancer and 126 people developed dementia – 100 of those cases evolving into Alzheimer’s.

Of the 141 people with NMSC, only two developed AD – meaning skin cancer patients were 80 percent less likely to have this kind of cognitive impairment. However, cancer’s protective quality was only seen in regards to Alzheimer’s and not with other kinds of dementia such as vascular dementia (stroke related). The link also did not apply to melanoma, the least common but most aggressive form of skin cancer.

Clinicians are not entirely sure as to why these two conditions have an inverse relationship and additional research will be required.

Alzheimer’s disease is the most common type of dementia. Dementia is a loss of brain function that can occur with a comorbidity of diseases like Huntington’s, multiple sclerosis, and Parkinson’s or from a head injury where the cells of the brain are damaged. The risk of this disease increases as a person ages, but is rarely seen in individuals under the age of 60.

In most cases, dementia is considered a degenerative, persistent disease. Therefore, the condition worsens over time. Dementia originates in the cerebral cortex of the brain, which controls crucial sensory and cognitive functions. Memory, language, judgment, reasoning, planning, and behavior and personality are affected as vital sectors of the brain deteriorate.

How quickly dementia progresses depends on the cause and the area of the brain affected. Some types of dementia advance slowly over several years while others progress more rapidly.

Symptoms can manifest as mild cognitive impairments, which are casually disregarded as normal forgetfulness. These can include the inability to focus and perform more than one task, taking an inordinately prolonged amount of time to perform activities, forgetting recent events and conversations, misplacing items, and frequently getting lost on familiar routes.

Depending on the type of dementia, the person’s behavior may eventually become out of control. The person may become angry, agitated, and combative. They may also come off afraid, clingy, and childlike.

Skin is the largest organ of the integumentary system, and like any organ of the human body, it is vulnerable to cancer. Cancer is the uncontrolled growth of abnormal cells in the body. Its degree of perniciousness and cause can depend on multiple factors, and isn’t always isolated to one part of the body as it can metastasize (spread).

Tumors and lesions germinate from neoplastic cells, which can be malignant or benign. Malignant is cancerous, composed of cells that invade and destroy nearby tissue and spread to other parts of the body. Benign is non-cancerous. Benign tumors may grow akin to cancerous ones, but do not spread elsewhere.

Malignant melanoma is one of the two types of skin cancer; the other non-melanoma. Melanoma is a malignant tumor of melanocytes (cells). Melanin is a photochemical present in skin, hair, and eyes. It determines color and is produced by melanocytes found in the basal layer of the epidermis (outermost layer of the skin).

Melanoma can originate in any part of the body that contains melanocytes. When provoked by UVB rays, melanin – again, produced by melanocytes – reacts with a photo-protectant response, absorbing the ultraviolet light as heat. This process is meant to inhibit the damage to DNA. However, with prolonged exposure, the photochemical reaction creates freckling, tanning, and burning. The more often you burn, the higher the risk of damaging your DNA. When the integrity of DNA is compromised, a cancer-related mutation can result.

Melanoma is responsible for 75 percent of deaths related to skin cancer, particularly among Caucasians of northwestern European descent. However, that does not mean those with darker pigment are completely immune from developing skin cancer.

Most skin cancers, like basal cell carcinomas, are non-melanoma. Although it can cause damage to deeper tissue, it almost never spreads to other parts of the body the way melanoma does and can be excised from the affected area. These appear as warts or moles that change color, shape, and size, emerging on parts of the skin most exposed to the sun – head, neck, back, chest, and shoulders. The tops of the ears and along the nose are the most common places to develop skin cancer.

The research was published online in the journal Neurology.

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