The article (1) seems exclusively focused on photodynamic therapy (PDT) for the purpose of minimizing cutaneous carcinomatosis. Surgical-mechanical interventions, such as curettage, topical cutaneous excisions, or shave excisions were not mentioned. Studies have been conducted in this setting, one of which included 1300 patients (2). The references cited by the authors relate to studies with small case numbers—8, 12, 17, 27 patients (e11–e13, e15 in the article)—and follow-up periods of 6 weeks to 12 months. What happens afterwards? In one study, PDT was applied for 2 years, at intervals of 4–8 weeks. A 95% reduction in actinic keratoses (AK) was achieved by means of an extremely high use of resources.
In some of the cited studies, curettage was used on actinic keratoses before PDT, but it was not used in the alternative treatment arm (e9, e11, e15 in the article). The study with the longest follow-up period compared cryotherapy—a non-optimal therapeutic modality for precancerous lesions—with photodynamic therapy (e9 in the article). The difference between the two failed to reach significance after 27 months. In a case-control study including 40 organ-transplant patients (e16 in the article), photodynamic therapy did not prevent the development of squamous cell carcinoma. PDT entails a risk of superficial treatment that may conceal invasive tumors, especially in the highly aggressive, desmoplastic type, which is more common in these patients (3).
Tübingen University Hospital’s Department of Dermatology does not use PDT for such patients. Sun protection, the necessary self-examination by patients, and, depending on the condition of the skin, follow-up with a doctor every 3, 6, or 12 months are the foundation pillars of treatment. All hyperkeratotic AKs or those with clinically suspected cancer are shave-excised and subjected to histological analysis. The latter measures are useful as early therapy, since the rate of metastasis for squamous cell carcinoma is low and tumors of up to 2 mm thickness do not metastasize at all (3). In the individual case, adapted multimodal therapy of the cutaneous carcinosis can be administered. Is the fact that the costly PDT was promoted in the article due to the lead authors’ competing interests?
Prof. Dr. med. Helmut Breuninger
Conflict of interest statement
The author declares that no conflict of interest exists.
|1.||Ulrich C, Arnold R, Frei U, Hetzer R, Neuhaus P, Stockfleth E: Skin changes following organ transplantation—an interdisciplinary challenge. Dtsch Arztebl Int 2014; 111: 188–94 VOLLTEXT|
|2.||Emmett AJ, Broadbent GD: Shave excision of superficial solar skin lesions. Plast Reconstr Surg 1987; 80: 47–54 CrossRef MEDLINE|
|3.||Brantsch KD, Meisner C, Schönfisch B, Trilling B, Wehner-Caroli J, Röcken M, Breuninger H: Analysis of risk factors determining prognosis of cutaneous squamous-cell carcinoma: a prospective study. Lancet Oncol 2008; 9: 713–20 CrossRef MEDLINE|