Photodynamic therapy (PDT) involves the administration of a photosensitizing drug and its subsequent activation by light at wave-lengths matching the absorption spectrum of the photosensitizer. Because the skin is readily accessible to light-based therapies, PDT with systemic and particularly with topical agents has become important in treating cutaneous disorders. Topical PDT is indicated for treating actinic keratosis, superficial or thin non-melanoma skin cancer, including some cases of nodular basal cell carcinoma, and some cutaneous lymphomas. Advantages of aminolevulinic acid/methyl aminolevulinate PDT include the possibility of simultaneous treatment of multiple tumors and large surface areas, good cosmesis, and minimal morbidity, such as bleeding, scarring, or infection.
Sari M. Fien and Allan R. Oseroff
Stanley J. Miller, Murad Alam, James Andersen, Daniel Berg, Christopher K. Bichakjian, Glen Bowen, Richard T. Cheney, L. Frank Glass, Roy C. Grekin, Dennis E. Hallahan, Anne Kessinger, Nancy Y. Lee, Nanette Liegeois, Daniel D. Lydiatt, Jeff Michalski, William H. Morrison, Kishwer S. Nehal, Kelly C. Nelson, Paul Nghiem, Thomas Olencki, Allan R. Oseroff, Clifford S. Perlis, E. William Rosenberg, Ashok R. Shaha, Marshall M. Urist and Linda C. Wang
Merkel Cell Carcinoma Clinical Practice Guidelines in OncologyNCCN Categories of Evidence and ConsensusCategory 1: The recommendation is based on high-level evidence (e.g., randomized controlled trials) and there is uniform NCCN consensus.Category 2A: The recommendation is based on lower-level evidence and there is uniform NCCN consensus.Category 2B: The recommendation is based on lower-level evidence and there is nonuniform NCCN consensus (but no major disagreement).Category 3: The recommendation is based on any level of evidence but reflects major disagreement.All recommendations are category 2A unless otherwise noted.Clinical trials: The NCCN believes that the best management for any cancer patient is in a clinical trial. Participation in clinical trials is especially encouraged.OverviewMerkel cell carcinoma (MCC) is a rare, aggressive cutaneous tumor that combines the local recurrence rates of infiltrative non-melanoma skin cancer along with the regional and distant metastatic rates of thick melanoma.1–16 Several large reviews document the development of local recurrence in 25% to 30% of all cases of MCC, regional disease in 52% to 59%, and distant metastatic disease in 34% to 36%.1,16,17 MCC has a mortality rate that exceeds that of melanoma;18 overall 5-year survival rates range from 30% to 64%.3,19 A history of extensive sun exposure is a risk factor for MCC. Older white men (≥ 65 years) are at higher risk for MCC, which tends to occur on the areas of the skin that are exposed to sun.20The NCCN Non-Melanoma Skin Cancer Panel has developed guidelines outlining treatment of...