Photodynamic therapy and skin cancer: Technique effective in treating AK, SCC and BCC

August 1, 2008

There is increasing evidence demonstrating that photodynamic therapy is effective in the treatment of actinic keratosis, Bowen's Disease (squamous cell carcinoma in situ), as well as superficial and nodular basal cell carcinoma.

Key Points

Livilands, Stirling, Scotland - Photodynamic therapy (PDT) is proving itself to be a viable and competitive therapeutic option for cutaneous cancers and pre-cancerous lesion. PDT therapy can be optimized in the careful selection of lesions, as well as the patients to be treated, according to one expert.

"We have many therapies at our disposal for the effective treatment of cancerous and pre-cancerous skin lesions, from excision to cryotherapy to topical treatments, such as diclofenac, imiquimod and 5-fluorouracil.

"Photodynamic therapy is evolving as an effective therapy and sometimes the treatment of choice for various lesions, including actinic keratosis (AK), Bowen's Disease (BD) and basal cell carcinoma (BCC). Where other topical therapies fail, PDT can take over and prove to be very effective," says Colin Morton M.D., F.R.C.P., department of dermatology, Stirling Royal Infirmary, Livilands, Stirling, Scotland.

They are also effective in BD, achieving a good cosmesis, and are at least as effective as cryotherapy and topical 5-fluorouracil, while exhibiting fewer adverse events in the patients treated.

The same positive results with ALA-PDT can be seen in superficial BCC and with MAL-PDT in both superficial and nodular BCC less than 2 mm in depth.

PDT in the U.K.

In the U.K., topical PDT is readily used where there are a high number and confluent lesions, and in lesions where other therapies have failed.

Comparative studies of AKs with 1x ALA-PDT versus 5-fluorouracil, 2x ALA-PDT versus placebo and 2x ALA-PDT (blue or laser light) versus 5-fluorouracil have shown a 73 percent versus. 70 percent (at six months), 89 percent versus 13 percent (at three months) and 75 percent (blue light) and 42 percent (laser light) versus 75 percent (at one month) total clearance, respectively. Similar results were seen when the effectiveness of MAL-PDT was compared to cryotherapy.

"In our experience, PDT is a useful therapy in the short-term, especially for those patients who wish to avoid scarring; however, long-term follow-up has, to date, been limited," Dr. Morton says.

Previous studies comparing MAL-PDT and cryotherapy in superficial BCC and MAL-PDT and excisional surgery in nodular BCC have shown both approaches to be effective, with no recurrences occurring after three years following the treatment.

"Though the results of the therapeutic approaches are comparable, the major advantage with PDT is in the superior cosmetic outcomes, which is invariably an important issue for the patients," Dr. Morton says.