Merging therapies for ultimate cancer treatment

December 1, 2005

Atlanta — The ultimate approach to treating a skin cancer is to remove it in its entirety without leaving a scar, and while every therapy strives for this goal, none yet reach it.

"It is definitely advantageous to eradicate the skin cancer, but the problem with taking a surgical approach is the scarring, while a medical approach results in low cure rates," says Darrell S. Rigel, M.D., here at the American Society for Dermatologic Surgery - American College of Mohs Micrographic Surgery and Cutaneous Oncology combined annual meeting.

"The question is, can you find a way to combine the two therapies and optimize it in some way?"

Perhaps the most dramatic change in treating skin cancers in the last decade is the use of topical retinoids. Although surgery takes precedence in cure rates, results from laboratory and clinical trials suggest that retinoids offer chemo-protective effects in the disease, with oral retinoids showing great promise against numerous types of skin cancers.

Of note, the use of oral acitretin proved to inhibit the growth of new skin cancers in a cancer-prone patient (Lebwohl M., et al. J Dermatolog Treat. 2003;14 Suppl 2:3-6).

Topically, imiquimod 5 percent cream has been shown to be effective and well-tolerated for the treatment of primary superficial basal cell carcinoma (BCC). Recent preclinical research at the University of California, Los Angeles David Geffen School of Medicine also demonstrates that imiquimod can increase the effectiveness of the protective anti-tumor effects of a recombinant Listeria monocytogenes melanoma vaccine.

In addition to its cancer-deterring capabilities, research shows that imiquimod has proven to prevent the recurrence of surgically excised keloids (J Am Acad Dermatol. 2002;47:S209-211), and this could be the most important finding for the future of skin cancer treatment, Dr. Rigel tells Dermatology Times.

"Using topical medications in addition to surgery to improve cure rates for both non-melanoma skin cancers and possibly melanoma is en vogue," Dr. Rigel, clinical professor of dermatology, New York University, and past AAD president, says. "The combination is also proving to be effective in limiting scarring."

Combine and conquer

The most utilized combination therapy against skin cancers is electrodesiccation and curettage. The treatment offers a 92 percent to 93 percent cure rate for BCC, but the end result also includes scarring from the electrodesiccation. Interestingly, data from 20 years ago shows curettage alone results in an 80 percent cure rate, Dr. Rigel says.

Dr. Rigel is involved in a clinical trial with Abel Torres, M.D., and Haines Elv, M.D. They are studying the overall impact on BCC with curettage alone, followed by six weeks of imiquimod for healing.

"Our series of 19 patients (in the clinical trial) at one year out shows no recurrences (of the BCC)," Dr. Rigel says. "My colleagues who are also involved in the study are finding the same results at this point. In addition, the cosmetic results are dramatic - you can barely see the scar of those treated with curettage alone followed by Aldara (3M Pharmaceuticals)."

Final results showing the effectiveness of curettage and 5 percent imiquimod cream in the treatment of BCC, both clinical and cosmetic evaluation, will be presented at the upcoming 2006 American Academy of Dermatology meeting.

"The future of skin cancer treatments will not be all surgical or all medical; rather it will evolve to combine the two to optimize cure rate and cosmetic result," Dr. Rigel says.

Disclosures: 3M Pharmaceuticals funded Dr. Rigel's current study of curettage and 5 percent imiquimod cream in the treatment of basal cell carcinoma.