Imiquimod, a topical cream, may help treat skin cancer

Apr 30 2009

In a case study of a type of melanoma skin cancer typically found on chronically sun-exposed skin, Saint Louis University researchers found that imiquimod, a topical cream, produced good results for patients when used together with surgery to treat the cancer, potentially helping doctors cut less.

The study, published in Dermatologic Surgery, looked at two cases of the most common type of melanoma of the head and neck, lentigo maligna (LM), a type of "melanoma-in- situ", the earliest stage of melanoma. This early form, known as LM, precedes the more invasive form, lentigo maligna melanoma (LMM), and the progression of LM to LMM typically occurs after 10 to 15 years. Though surgical removal of LM is most often used to treat the non-invasive form of the cancer, it can have high local recurrence rates.

In two patients who had both LM and LMM, investigators used imiquimod in conjunction with surgery. In both patients, surgery was first done to remove the area of known invasive disease, followed by the topical cream to the outer area of LM. This approach was chosen with patients who did not want extensive surgery due to the large size of the melanoma on their scalp and face. These cases, along with other recent studies, suggest that imiquimod may help to reduce the area needing surgery, manage the LM and hopefully minimize its recurrence.

"As we're seeing melanoma in younger and younger people, in their 30s and 40s, there is a longer window for the cancer to return and a greater desire to avoid disfiguring surgery," said Scott Fosko, M.D., chairman of the department of dermatology at Saint Louis University School of Medicine and lead study investigator.

Researchers hope that topical treatments like imiquimod may be used to lower the seriousness and the cost of treating the disease, as well as limit scars from surgery, and, most importantly, improve patient care.

"This subtype of melanoma is becoming more and more common, and can be one of the more challenging melanomas to manage," said Fosko, who is also director of the melanoma and cutaneous oncology section of the Saint Louis University Cancer Center.

"While more study is needed to understand how the drug works and which patients are likely to benefit from it, we are optimistic that the drug may prove to be a good option for some patients," said Fosko. "This may be an effective first line treatment."

Doctors stress that the best way to catch skin cancer early is through screenings.

Regular skin screenings are recommended for everyone, especially those over 40 years of age, and individuals at higher risk for skin cancer, those with a fair complexion, sunburn easily, have numerous moles, a personal or family history of skin cancer, and by occupation, recreation or use of tanning salons, get significant sun or ultraviolet rays exposure, regardless of age or race.

During a screening, a dermatologist will check moles, birth marks and other pigmentations for signs of cancer, which include abnormal size, color, shape or texture.

According to the American Cancer Society, more than 1 million new cases of skin cancer will be diagnosed in the United States this year. As many one in five Americans will develop skin cancer during their lifetime. Yet many people continue to tan both indoors and out.

Melanoma is the most deadly form of skin cancer and is the leading cancer in young adults, 25-29 years old. It is characterized by the uncontrolled growth of pigment-producing cells and may appear on the skin suddenly without warning or develop on an existing mole.

There are several warning signs of melanoma. Identifying these signs is as easy as ABCDE:

• Asymmetry - one half is unlike the other half
• Border - irregular, scalloped or poorly defined border
• Color - varied from one area to another; shades of tan and brown, black; sometimes white, red or blue
• Diameter - while melanomas are usually greater than 6 mm (the size of a pencil eraser) when diagnosed, they can be smaller
• Evolving - a mole or skin lesion that looks different from the rest or is changing in size, shape or color