Basal-cell carcinoma
Basal-cell cancer is a very common skin cancer. It is much more common in fair-skinned individuals with a family history of basal-cell cancer and increases in incidence closer to the equator or at higher altitude. There are approximately 800,000 new cases yearly in the United States alone. Up to 30% of Caucasians develop basal-cell carcinomas in their lifetime. In Canada, the most common skin cancer is basal-cell carcinoma (as much as one third of all cancer diagnoses), affecting 1 in 7 individuals over a lifetime.
Basal-cell carcinoma
Some superficial cancers respond to local therapy with 5-fluorouracil, a chemotherapy agent. Topical treatment with 5% Imiquimod cream, with five applications per week for six weeks has a reported 70–90% success rate at reducing, even removing, the BCC [basal-cell carcinoma]. Both Imiquimod and 5-fluorouracil have received FDA approval, and topical IMQ is approved by the European Medicines Agency for treatment of small superficial basal-cell carcinoma. Off label use of imiquimod on invasive basal-cell carcinoma has been reported. Imiquimod may be used prior to surgery in order to reduce the size of the carcinoma. One can expect a great deal of inflammation with this treatment. Chemotherapy often follows Mohs surgery to eliminate the residual superficial basal-cell carcinoma after the invasive portion is removed. Some advocate the use of imiquimod prior to Mohs surgery to remove the superficial component of the cancer. Removing the residual superficial tumor with surgery alone can result in large and difficult to repair surgical defects. One often waits a month or more after surgery before starting the Imiquimod or 5-fluorouracil to make sure the surgical wound has adequately healed. Some people advocate the use of curettage (see EDC below) first, followed by chemotherapy. These experimental procedures are not standard care. The 2008 study reported that topical IMQ appears effective in the treatment of primary small superficial BCCs but only "may possibly" have a role in the treatment of primary nodular BCC.