AICR SCIENCE NOW
Volume 13
Summer 2005
Each year, more than one million new cases of nonmelanoma skin cancer are diagnosed in the U.S. This number is greater than the incidence of all other cancers combined. To prevent and treat this type of skin cancer, Huachen Wei, M.D., Ph.D., M.P.H., is looking at lycopene in an AICR-funded study.
There are two kinds of skin cancers:melanomas and nonmelanomas. Non- melanoma skin cancer is the more common one, and it includes basal and squamous cell carcinomas. Although nonmelanoma skin cancers are highly treatable, approximately $650 million is spent each year on treatment. This cost to the healthcare system, along with the 2,300 related deaths per year, calls for prevention.
Another reason for prevention is that the incidence of human skin cancers has increased significantly in the past 20 years and continues to increase at the alarming rate of four percent per year on average. Dr. Huachen Wei, Professor of Dermatology and Director of Dermatology Research Laboratories at Mount Sinai Medical Center, thinks that sunscreen lotions are partly at fault. "The early sunscreen applications of the 1980s did not always protect a person from UVA radiation, which can contribute to skin cancer," he says. "However, UVB radiation is the better known cause of skin cancer, especially in the presence of other factors, like benzopyrene, which is found in cigarette smoke." UVA and UVB rays are the two kinds of ultraviolet radiation that reach the earth's surface.
The Well-Known Antioxidant in Tomatoes
Lycopene, the phytochemical in tomatoes and their products, could possibly be used to prevent or treat skin cancer caused by UVB rays. "Although lycopene has shown an anticancer effect against other cancers like breast and prostate cancers, it has never been tested as a preventive agent against UVB-induced skin cancer," says Dr. Wei. "Epidemiological studies show, however, that those who consume more lycopene have less skin cancer."
In his AICR-funded laboratory study, Dr. Wei and his colleagues will feed lycopene to hairless mice in different amounts and then expose them to UVB rays to see how well lycopene inhibits carcinogenesis. After 50 percent of the mice have developed tumors, they will stop UVB exposure and continue to give one-half of the mice lycopene to see if it reduces the size of tumors.
Because other studies show that a high dose of lycopene can be given animals to delay or reduce the volume of tumors, it could possibly become part of a cancer treatment. "Lycopene has no obvious toxicity," says Dr. Wei.
The Next Step
If this study is successful and Dr. Wei confirms lycopene's effect against the initiation and progression of skin cancer by measuring biomarkers, a human trial will be started at Mount Sinai Hospital. A similar skin cancer study that Dr. Wei conducted with genistein, also funded by AICR, has already been translated into a clinical trial there.
"The clinical trial would see whether dietary lycopene can prevent skin cancer among people at high-risk for it, like patients with kidney transplants or psoriatic patients receiving PUVA (psoralen and ultraviolet A) treatments," according to Dr. Wei.
As a practicing dermatologist and cancer researcher, Dr. Wei always advises people to use a sunscreen that protects against both UVA and UVB rays and has an SPF factor in the range of 30 to 60 to help prevent skin cancer. "If you are active outdoors," he recommends, "reapply it every 3 hours." A long-sleeved shirt, pants and a hat - even an umbrella - offer good protection, too. However, you should try to avoid outdoor activity from 10 am to 3 pm when the rays are strongest.
Reference
Zsuzsanna Fazekas et al. Protective effects of lycopene against ultraviolet B-induced photodamage. Nutr. Cancer. 2003;47(2):181-7. All active news articles
Volume 13
Summer 2005
Lycopene: Another Defense Against the Most Common Cancer
Each year, more than one million new cases of nonmelanoma skin cancer are diagnosed in the U.S. This number is greater than the incidence of all other cancers combined. To prevent and treat this type of skin cancer, Huachen Wei, M.D., Ph.D., M.P.H., is looking at lycopene in an AICR-funded study.
There are two kinds of skin cancers:melanomas and nonmelanomas. Non- melanoma skin cancer is the more common one, and it includes basal and squamous cell carcinomas. Although nonmelanoma skin cancers are highly treatable, approximately $650 million is spent each year on treatment. This cost to the healthcare system, along with the 2,300 related deaths per year, calls for prevention.
Another reason for prevention is that the incidence of human skin cancers has increased significantly in the past 20 years and continues to increase at the alarming rate of four percent per year on average. Dr. Huachen Wei, Professor of Dermatology and Director of Dermatology Research Laboratories at Mount Sinai Medical Center, thinks that sunscreen lotions are partly at fault. "The early sunscreen applications of the 1980s did not always protect a person from UVA radiation, which can contribute to skin cancer," he says. "However, UVB radiation is the better known cause of skin cancer, especially in the presence of other factors, like benzopyrene, which is found in cigarette smoke." UVA and UVB rays are the two kinds of ultraviolet radiation that reach the earth's surface.
The Well-Known Antioxidant in Tomatoes
Lycopene, the phytochemical in tomatoes and their products, could possibly be used to prevent or treat skin cancer caused by UVB rays. "Although lycopene has shown an anticancer effect against other cancers like breast and prostate cancers, it has never been tested as a preventive agent against UVB-induced skin cancer," says Dr. Wei. "Epidemiological studies show, however, that those who consume more lycopene have less skin cancer."
In his AICR-funded laboratory study, Dr. Wei and his colleagues will feed lycopene to hairless mice in different amounts and then expose them to UVB rays to see how well lycopene inhibits carcinogenesis. After 50 percent of the mice have developed tumors, they will stop UVB exposure and continue to give one-half of the mice lycopene to see if it reduces the size of tumors.
Because other studies show that a high dose of lycopene can be given animals to delay or reduce the volume of tumors, it could possibly become part of a cancer treatment. "Lycopene has no obvious toxicity," says Dr. Wei.
The Next Step
If this study is successful and Dr. Wei confirms lycopene's effect against the initiation and progression of skin cancer by measuring biomarkers, a human trial will be started at Mount Sinai Hospital. A similar skin cancer study that Dr. Wei conducted with genistein, also funded by AICR, has already been translated into a clinical trial there.
"The clinical trial would see whether dietary lycopene can prevent skin cancer among people at high-risk for it, like patients with kidney transplants or psoriatic patients receiving PUVA (psoralen and ultraviolet A) treatments," according to Dr. Wei.
As a practicing dermatologist and cancer researcher, Dr. Wei always advises people to use a sunscreen that protects against both UVA and UVB rays and has an SPF factor in the range of 30 to 60 to help prevent skin cancer. "If you are active outdoors," he recommends, "reapply it every 3 hours." A long-sleeved shirt, pants and a hat - even an umbrella - offer good protection, too. However, you should try to avoid outdoor activity from 10 am to 3 pm when the rays are strongest.
Reference
Zsuzsanna Fazekas et al. Protective effects of lycopene against ultraviolet B-induced photodamage. Nutr. Cancer. 2003;47(2):181-7. All active news articles