Archive for August, 2012
This comment is from:http://thedermblog.com/2010/12/10/skin-cancer-where-the-sun-dont-shine/
The most interesting point (which is not referenced) and I would think does not apply to Australia is the bit about half of all deaths from skin cancer other than melanoma being due to skin cancer of genitalia.
I have never heard such a statement, even from the USA……
Not all skin cancers are from sun exposure. Viruses such as human papilloma virus(HPV), the virus that causes genital warts, also cause skin cancer. Skin cancer from HPV develops on genital skin in both men and women. It is rarely talked about, but it’s important and can be deadly.
Did you know that half of all deaths from skin cancer other than melanoma are from genital skin cancer? You probably also didn’t know that women are more likely to die from genital skin cancer as they are from skin cancer that developed from sun exposure (again, excluding melanoma).
We dermatologists are inexhaustible when it comes to warning people about the dangers of sun exposure, but we should also be warning people about the dangers of genital warts. HPV protection, which includes HPV vaccines, is as important as sun protection in preventing death from non-melanoma skin cancer.
Genital warts can lead to deadly skin cancer. If your dermatologist has not checked your genital skin, then be sure your primary care physician or gynecologist does. This is especially important, because unlike other STDs which often have symptoms, HPV or genital warts often don’t. It may be embarrassing, but it could save your life
The below study does not really add anything new to what we know but reaffirms that the most important thing for patients to know is that if you have had a basal cell carcinoma, you have a 44 percent chance of getting another.
There are also some other interesting findings eg ACE inhibitors increasing risk
A new study affirms that basal cell carcinoma, the most common form of skin cancer, should be viewed as a chronic disease.
That’s because once most people have a single occurrence, they are at risk of getting another.
“Basal cell carcinoma has generally been viewed as something that comes up, is treated and cured,” said Dr. Martin Weinstock, a study co-author and professor of dermatology at the Warren Alpert Medical School at Brown University in Providence, R.I. “For someone with an isolated lesion, that’s a reasonable way of looking at it. But most people are constantly at risk of this and will be getting more.”
The study confirmed what was commonly understood about the disease: a prior history of basal cell carcinoma is the greatest risk for another lesion. But the research found that eczema may also predict a recurrence among those at high risk for the disease. Those with a family history of eczema had a 1.54 times greater risk than those without.
Older age, sun sensitivity, intense sun exposure before age 30, and use of certain blood pressure-lowering medications (angiotensin-converting enzyme inhibitors or angiotensin receptor blockers) were also associated with increased risk.
Why would eczema, a chronic skin disorder that involves scaly and itchy rashes, be associated with basal cell carcinoma? Weinstock said it’s unclear. “There may be some differences in these people’s immune systems compared to people without eczema,” he said, noting that other investigators need to confirm the findings.
Having other types of skin cancer or actinic keratoses (scaly or crusty growths caused by sun damage) did not appear to raise the chances for basal cell carcinoma.
The study was published online July 19 in the Journal of Investigative Dermatology and funded by the U.S. Department of Veterans Affairs. It involved more than 1,100 people, nearly all men, all veterans, with a median age of 72.
On average, each participant had more than three instances of basal cell cancer or squamous cell cancer (another type of skin cancer) before participating in the research. During the study period, 44 percent developed new basal cell cancers, and those with the most basal cell cancers in the five years before the study had the most recurrences.
Study participants with more than five prior basal cell cancers were nearly four times as likely to develop a new one as those with one or no prior skin cancers. And their risk was twice as high as those with three previous skin cancers, the study found.
Now the most common cancer in the United States, basal cell carcinoma begins in the outer layer of the skin, often as a small white or flesh-colored bump that grows slowly and sometimes bleeds. While these cancers rarely spread, they must be removed or treated, usually in a physician’s office with local anesthetic.
Weinstock said researchers are eager to find a preventive medication to guard against the recurrence of basal cell carcinoma. Last year a team he led concluded that topical tretinoin did not prevent new basal cell cancers in high-risk patients. Now he is involved in a study looking at whether 5-Fluorouracil, a compound used to treat actinic keratoses, may prevent basal cell cancer when given intravenously.
Dr. Jean Tang, an assistant professor in the department of dermatology at Stanford University School of Medicine who is familiar with the study, said the most important thing for patients to know is that if you have had a basal cell carcinoma, you have a 44 percent chance of getting another.
“This study doesn’t change any clinical guidelines or recommendations,” she added. Current advice still stands: “Get an annual skin assessment by your dermatologist,” she said.
A little out of left field but this was on NineMSN this morning. May be useful to model to study:
Australia’s sunny climate has been linked to high rates of skin cancer in humans but it now seems fish could also be susceptible.
Melanomas have been detected in wild fish populations for the first time in species on the world heritage-listed Great Barrier Reef.
The most likely culprit is ultra-violet radiation, says lead researcher Michael Sweet from the UK’s Newcastle University.
The university and the Australian Institute of Marine Science examined 136 coral trout caught at Heron Island and One Tree Island, in the southern area of the Great Barrier Reef Marine Park, between August 2010 and February 2012.
About 15 per cent of the fish captured had dark lesions on the surface of the skin but were otherwise healthy.
The lesions were characteristic of melanomas created in laboratories on the fish species Xiphophorus, the research found.
The study, published in the journal PLoS One, said the sampled fish were caught in a protected marine park area with no evidence of pollution, and therefore the likelihood the cancers were caused by carcinogenic pollutants was low.
“Further work needs to be carried out to establish the exact cause of the cancer but having eliminated other likely factors such as microbial pathogens and marine pollution, UV radiation appears to be the most likely cause,” Dr Sweet said.
Previous studies have shown UV radiation can have detrimental effects on marine and freshwater organisms and can penetrate at deep as 60 metres, the researchers said.
The coral trout in this study were all captured in less than 20 metres of water.
However, the high levels of melanoma in the population could also be linked to a genetic defect, said Australian Institute of Marine Science research fellow, Michelle Huepel.
She said it could be a combination of UV radiation, genetics, and the southern Great Barrier Reef location where coral trout live at their temperature limit, which could compromise their immune systems.
Dr Huepel said commercial fishermen had observed the dark lesions on coral trout for many years, so the phenomenon was not a new one.
However, it was Dr Huepel who raised the alarm and sent samples to Dr Sweet for analysis.
She said coral trout can vary in colour and therefore the brown and black spots may not have sparked curiosity before.
The study did not find any fish with advanced cancer. The authors suggesting those fish would be less active and feeding less, and therefore would not have been caught.
More work would need to be done to examine how the disease spreads and whether it is benign or malignant.
Coral trout are an iconic and commercially important species, supporting a high-value fishing industry on the reef.
Dr Huepel said understanding the causes of the disease was important to the conservation and management of reefs.