5-FU cream proves promising for superficial BCC

Key Points

San Diego - A recent study finds that 5 percent 5-fluorouracil (5-FU) is highly effective in treating superficial basal cell carcinoma (BCC), offering a generally good cosmetic outcome and high levels of patient satisfaction.

According to one expert, 5-FU is underutilized and can provide a viable option in treating precancerous and cancerous skin lesions.

The results showed a 90 percent cure rate (28/31 lesions cured).

The mean time to clinical cure was 10.5 weeks, and patients showed a good tolerability to the treatment, a good cosmetic outcome and a high level of satisfaction to the therapy.

"This was an interesting study, because when 5-FU originally came out, one of the indications for it was superficial BCC, yet in my own practice, I've never really used it for that, and I do not believe most physicians do," Dr. Gross says.

He says that other therapies for superficial basal cell carcinoma include desiccation and curettage, cryotherapy and excision, but, more recently, imiquimod is being used. Geisse et al (J Am Acad Dermatol. Sept. 2002) showed that imiquimod used twice a day for 12 weeks can have close to a 100 percent cure rate for superficial BCC. Current recommendation is imiquimod therapy based on combining high efficacy with an attempt to limit adverse events is once daily, achieving a cure rate of approximately 90 percent, very similar to that of 5-FU.

Interpreting findings

According to Dr. Gross, the usual adverse events of 5-FU or imiquimod therapy include inflammation, crusting and scale, as well as texture and color changes that may persist.

In this study, Dr. Gross notes that the majority of patients had no pain or scarring and only mild erythema.

"One of the differences between these two therapies is that with imiquimod, it is easier to clinically ascertain whether a lesion was cured or not at the end of treatment. This clinical judgment cannot be made as easily with 5-FU. I found it harder to judge clinically whether the lesion was cured or not. However, I think that for the treatment of superficial basal cell cancers, they are comparable in their efficacy," he says.

Concern about imiquimod

According to Dr. Gross, imiquimod is highly effective when used properly.

Dr. Gross expresses concern with some current uses of imiquimod, as some physicians use the medication for the treatment of invasive squamous cell carcinoma (SCC), or as a primary treatment for lentigo maligna (LM). Dr. Gross says that he often uses imiquimod as an adjuvant therapy for SCC and LM, starting about 25 days after Mohs surgery.

"I believe the profile for imiquimod and 5-FU are close. In my experience, those patients that do not respond to imiquimod may respond to 5-FU. This gives you another option of treatment, as there are a percentage of patients that will not respond to imiquimod and even a percentage that cannot afford to purchase it," Dr. Gross says.

Drug comparisons

Imiquimod is an immunomodulator and requires toll-like receptor 7 to be present and active.

Its action depends on the body recognizing abnormal cells. On the other hand, 5-FU is chemotherapy and works on dividing cells, and it does not require an intact immune system. Dr. Gross says there is a possibility that these two drugs may be synergistic and complementary, and not only for superficial BCC but potentially for other types of lesions. Furthermore, the effects of both of these medications are increased by the use of topical retinoids.

"This study provides more data that we do have another valuable tool to treat certain cancerous and pre-cancerous lesions. In my opinion, 5-FU and imiquimod are equally effective for superficial BCC, as well as actinic keratosis. In the end, the more options we have, the better therapists we are," Dr. Gross says.