Tuesday, April 18, 2006

Skin cancer epidemic

More bad news from CNN.

There is an unrecognized epidemic of skin cancer under way in the United States, the American Academy of Dermatology warns.

One in five Americans will develop skin cancer, and a person's risk of the disease doubles if he or she has had five or more sunburns, according to a report in the April issue of the Mayo Clinic Health Letter.

Basal and squamous cell carcinomas, the most common and treatable types of skin cancers, had long been considered a problem only for people over 50, according to the report.

But Mayo Clinic researchers found that the percentage of women under 40 with the more common type, basal cell, tripled between 1976 and 2003, while the rate of squamous cell cancers increased four-fold.

In the same study, the researchers found that just 60 percent of the cancers they identified occurred on skin frequently exposed to the sun, such as the head and neck, rather than the normal 90 percent.

Most of the remaining cancers were seen on the torso. The researchers suspect this may be due to more widespread use of tanning beds.

Melanoma recurrance more common than thought

Well, this isn't good.

From HealthDayNews:

Recurrent melanoma is more common than previously thought, with nearly 15 percent of people diagnosed with the potentially fatal skin cancer at risk of a second diagnosis within two years, a new study found.

About 6 percent of patients will develop a second melanoma within one year of the initial diagnosis, while 8 percent will be diagnosed with a second malignancy within two years, according to the researchers from Dartmouth Medical School in Hanover, N.H.

This rate is more frequent than previously thought and points to the importance of surveillance and skin screenings, according to the study in the April issue of Archives of Dermatology.
According to the new study, previous studies have put melanoma recurrence at less than 4 percent within one year.

The current study included 354 New Hampshire residents who'd had a previous diagnosis of melanoma. All participants answered questions about their medical history, sun exposure history, hair and eye color, and whether their skin tanned, burned or freckled in the sun. Then they underwent a skin examination by a physician.

Six percent of the participants developed an additional melanoma within one year of the first diagnosis, while 8 percent developed an additional melanoma within two years.

Roughly two-thirds of those who developed additional malignancies and 37 percent of those who did not had at least one atypical mole, which is a risk factor for additional melanomas. Someone with three or more atypical moles had four times the risk of developing an additional tumor. Atypical moles have at least three of the following features -- a diameter larger than 5 millimeters; redness; an irregular or ill-defined border; a variety of colors or a portion that is flat, the researchers said.

In one-third of the patients who developed another melanoma within two years, the subsequent melanoma was deeper than the first.

Thursday, April 06, 2006

Shock Treatment

Interesting new treatment being tried out for melanoma. When used with gene therapy, shocking the tumours has had good results in clinical trials. Other than the discomfort of a 6-second electric shock, there are no known major side-effects.

From ABC 7 in Chicago:

Researchers are now focusing on gene therapy for melanoma patients. The challenge has been getting the gene into the tumor. The overall goal is for the gene to stimulate the immune system to fight the cancer. For the first time, researchers are using electroporation on humans to deliver gene therapy in melanoma patients.

Electroporation involves the use of a handheld device with a number of prongs on the end of it. The device is put into the tumor on the skin and delivers electricity. Researchers say this stimulation opens up pores in the tumor cell membrane, allowing small molecules called DNA plasmids to get inside the tumor before the tumor membrane pores close again. These plasmids contain the gene for interleukin-12. Adil Daud, M.D., an oncologist at Moffitt Cancer Center in Tampa says, "It will be like a flag that says danger or warning to the immune system and cause the immune system to destroy that tumor."
The first clinical trials began in 2005. So far, seven patients with stage four melanoma have been treated with electroporation. Dr. Daud says the purpose of this study is to see if it is safe for the patient. However, they are encouraged by the findings thus far.
There are no major side effects associated with this treatment; however, one downside is discomfort for the patient. The treatment involves shocking the patient's tumor for six seconds for each treatment.

New way to diagnose melanoma

From the Pittsburgh Post-Gazette:

Melanoma researchers have identified protein markers that help predict whether an abnormal mole could become cancerous, which could lead to strategies to prevent the deadly disease.

The same molecular signalling systems that are turned on in melanomas are also switched on in atypical moles, explained principal investigator Dr. John Kirkwood, director of the University of Pittsburgh Cancer Institute's melanoma center.

His colleague Dr. Wenjun Wang presented the findings yesterday in Washington, D.C., at the annual meeting of the American Association for Cancer Research.