Women, Men and Melanomas

In the past, when I have performed a skin cancer screening on a patient, I have always told the patient that a melanoma in a woman is more likely to develop on the lower legs while a melanoma in a man is more likely to develop in a man on the trunk. Unbeknownst to me, my information was based on a study that was done in the over 40 years ago.

A new study (Clark LN, Shin DB, et al. Association Between the Anatomic Distribution of Melanoma and Sex. J Am Acad Dermatol 2007; 56 (May5):768-773) now shows that over 30 years later this difference in anatomic distribution for melanoma between men and women no longer holds true. This study suggests males are now as likely as females to develop melanomas on their lower legs and females were as likely as males to acquire melanoma on their upper backs. In fact, the only significant difference in site distribution was that men had a greater frequency of melanoma on the head and neck.

In this study done in 2004, for men 27% of their melanomas were on the head and neck, 43% on the trunk, 13% on the upper extremities, 17% on the lower extremities – for women 10% were on the head and neck, 51% on the trunk, 17% on the upper extremities and 22% on the lower extremities. The authors hypothesize that these changes could have come about by differences in clothing and lifestyle over the years.

So now when we do skin exams whether it is a man or a woman we should always do a head to toe inspection.

Botox Appointments Faster Than for Suspicious Moles

Patients seeking an appointment with a dermatologist to ask about a potentially cancerous mole have to wait substantially longer than those seeking Botox for wrinkles, a study published online yesterday by The Journal of the American Academy of Dermatology said. Researchers reported that dermatologists in 12 cities offered a typical wait of eight days for a cosmetic patient wanting Botox to smooth wrinkles, compared with a typical wait of 26 days for a patient requesting evaluation of a changing mole, a possible indicator of skin cancer.

“The difference in wait times between medical dermatology and cosmetic dermatology patients is clearly real,” said Dr. Jack S. Resneck Jr., the lead author of the study and an assistant professor of dermatology at the medical school of the University of California, San Francisco. “We need to look further and figure out what is leading to shorter wait times for cosmetic patients.” In Boston, the median Botox wait was 13 days, versus 68 days for a mole examination. In Seattle, the median Botox wait was seven and a half days, compared with 35 days for a changing mole.

The study, in which a researcher posing as a patient called every board-certified dermatologist in the 12 cities, including Miami, Cleveland and Lansing, Mich., did not examine the possible causes for the varying times. Dr. David M. Pariser, president-elect of the American Academy of Dermatology, said it seemed clear that cosmetic patients in the studied cities had faster access to dermatologists than did medical patients. “It doesn’t make me proud to say it, but it is true,” Dr. Pariser, a dermatologist in Norfolk, Va., said.

Can Coffee Prevent Skin Cancer?

America's most common cancer may be rarer among postmenopausal women who drink coffee. The researchers who report that news are talking about nonmelanoma skin cancer. The National Cancer Institute estimates that there will be more than a million new cases and fewer than 2,000 deaths from nonmelanoma skin cancer in the U.S. in 2007.

Wayne State University's Ernest Abel, PhD, and colleagues studied coffee consumption and nonmelanoma skin cancer in more than 77,000 white postmenopausal women in the U.S. The women participated in a long-term observational health study that began in the 1990s. When the women joined the study, they shared lots of information about themselves, including how much coffee (decaf or caffeinated) and tea they drank and whether they had ever been diagnosed with nonmelanoma skin cancer.

A total of 7,482 women reported ever having nonmelanoma skin cancer. The researchers considered factors including participants' smoking, drinking, age, BMI (body mass index, which relates height to weight), and whether the women lived in the sunny South or further north when the study started. After those adjustments, the researchers found that each daily cup of caffeinated coffee was associated with a 5% drop in the women's odds of reporting nonmelanoma skin cancer. Women who drank six cups of caffeinated coffee per day were 30% less likely than other women to report nonmelanoma skin cancer. Decaffeinated coffee and tea weren't linked to the women's odds of reporting nonmelanoma skin cancer.

Like other observational studies, this one doesn't prove cause and effect. That is, the researchers didn't test coffee to see if it prevents skin cancer. Abel and colleagues didn't have data on which women wore sunscreen or whether the women drank more or less coffee over the years. Also, the findings only show which women reported nonmelanoma skin cancer at the study's start. So it's not clear who developed nonmelanoma skin cancer later. Abel's team calls for long-term studies to track the relationship between coffee and nonmelanoma skin cancer over time.

Their findings appear in the European Journal of Cancer Research.

In July, other researchers reported that the combination of caffeine and exercise may help fight skin cancer. But Abel's team found that physical activity didn't cut skin cancer risk, perhaps due to sun exposure during outdoor activities.

Another Virus is Linked to the Skin Cancer Merkel Cell Carcinoma

A new way of searching for human viruses has helped scientists at the University of Pittsburgh Cancer Institute in the US find a previously unknown one that is linked to a deadly form of skin cancer called Merkel cell carcinoma (MCC). The discovery is published as a paper in this week's publication ahead of print issue of Science and is the result of work by a husband and wife team that had already discovered another virus linked to another incurable skin cancer, Kaposi's sarcoma. The University of Pittsburgh Cancer Institute (UPCI) researchers and authors of the paper, Drs Huichen Feng, Masahiro Shuda, and husband and wife, Drs Patrick Moore and Yuan Chang, describe their 10 year programme to perfect the sequencing technology for hunting the virus, which they have named the Merkel cell polyomavirus (MCV). Their work has not established a causal link between MCV and Merkel cell carcinoma (MCC), but if their results can be confirmed, then they are likely to lead to new treatment and prevention approaches.

The researchers analyzed nearly 400,000 sequences of messenger RNA taken from four tissue samples of MCC tumours using a technique called digital transcriptome subtraction (DTS). The team had developed the DTS method themselves. The DTS system allowed them to compare the tumour gene sequences to those already mapped by the Human Genome Project, so conducting a massive "subtraction" exercise, which left at the end of it, a group of genetic transcripts that were not present in the human genome and could therefore reasonably be assumed to have come from a foreign organism, like a virus. The researchers then mapped the left over genetic transcripts against known viruses and found there was one unknown but distinct sequence. Using this mystery pattern they showed it belonged to a new polyomavirus that was in 80 per cent of the Merkel cell tumours they tested, but only present in 8 per cent of control tissues from various body sites and 16 per cent of control tissues taken from skin.

Merkel cell carcinoma (MCC) is rare but extremely aggressive. It affects about 1.500 Americans a year, and the rate has tripled in the last 20 years. It is more prevalent among AIDS and transplant patients with immune system weakened by treatment with immunosuppressants. MCC starts in subcutaneous cells associated with the sense of touch. It occurs mostly in the face, head and neck and spreads rapidly into other tissues and organs. The life expectancy of a person with MCC is not long. About two thirds of MCC patients die within five years, and about half with the advanced form of the cancer live only nine months or less.

MCV can also be found in healthy people and not just in Merkel cell tumours. As already explained, it behaves like HPV in that it invades and integrates with the DNA of the host cell, and does this before the cell become cancerous. The UPCI team found that 6 of the 8 MCV-positive tumors had DNA patterns that showed viral DNA had integrated with the tumour genome in a way typical of MCV, a monoclonal pattern. This was taken as a strong sign that infection by MCV was the trigger for tumours to start. The researchers repeated these results with other specimens.

"Clonal Integration of a Polyomavirus in Human Merkel Cell Carcinoma."
Huichen Feng, Masahiro Shuda, Yuan Chang, and Patrick S. Moore.
Science, Published ahead of print, 17 January 2008.
DOI: 10.1126/science.1152586.

The Skin Cancer Epidemic

Here are some ominous facts about the skin cancer epidemic (particularly the last one from Australia):

1 in 2 Americans over 65 will develop a skin cancer.
1 in 5 Americans will develop skin cancer during their lifetime.
One in 34 Americans will have a lifetime risk of developing a melanoma.
Skin cancer rates have doubled in people under 40 in the U.S. in just the past 10 years.
Five or more sunburns double your risk of developing skin cancer.
Melanoma is one of the most common cancers in people younger than 30 years old.
One basal or squamous cell carcinoma gives you a 50% chance of having another skin cancer in 5 years.
In 2006, more than 1 million new cases of skin cancer will be diagnosed: that is more than prostate, breast, lung, colon, uterine, ovarian, and pancreatic cancer combined.
More than half of all new cancers diagnosed in the U.S. are skin cancer.
Ultraviolet light is the primary cause of skin cancer.
The closer to the equator you live, the higher the incidence of skin cancer.
Three major reasons for the skin cancer epidemic: increased intensity of ultraviolet light due to stratospheric ozone depletion, increased use of tanning booths (regular use triples the risk of skin cancer), and cigarette smoking (one pack per day over several years triples the risk of squamous cell carcinoma).
In the U.S., skin cancer is the fifth most expensive cancer diagnosis.
In Australia, skin cancer is the most expensive cancer diagnosis.

You can find more information from my article at:
http://www.marthajefferson.org/clinicalfront/website_fall_06/skin_cancer.php

The More Moles the Longer You Live...

Many of my patients are unhappy with their moles - now there is a study that suggests that the more moles you have the slower you age:

People with a lot of moles may age slower than those with few moles, say British scientists, who suggest this may mean fewer age-related illnesses such as heart disease or osteoporosis for "moley people." In a 10-year study of more than 1,800 twins, researchers at the University of London's King's College, found those with more than 100 moles had a biological age six to seven years younger than those with fewer than 25 moles. The study was published in the July edition of Cancer Epidemiology Biomarkers & Prevention.

The researchers estimated age using telomere length. Telomeres, which get shorter as we get older, are bundles of DNA found at the end of chromosomes in all cells and help protect, replicate and stabilize chromosome ends.
Scientists say telomeres are like the plastic tips on shoelaces, because they prevent chromosome ends from fraying and sticking to each other. While large numbers of moles are linked to an increased risk of melanoma, a rare form of skin cancer, doctors have long suspected that people with lots of moles may have some advantages because moles are common in the general population.

These results suggest those with higher numbers of moles may have a delayed aging as they have longer telomeres and appear to keep their moles for longer. In contrast, people with shorter telomeres have lower numbers of moles and appear to lose them quicker with age — which may be a marker of accelerated aging.
"We now plan to look in more detail at the genes which influence the numbers of moles and to see whether they may also slow down the aging process in general. We'll examine the rate of aging in the skin, muscles and bones in different groups according to their mole counts," said Tim Spector, study co-author.

Happy now about those moles?