Basal Cell Carcinoma development after use of Metformin: Potential role of Nitrosamines as Enhancing Factors

Georgi Tchernev, Onkoderma-Clinic for Dermatology, Venereology and Dermatologic Surgery; Department of Dermatology and Venereology, Medical Institute of Ministry of Interior, Sofia, Bulgaria Simona Kordeva, Onkoderma-Clinic for Dermatology, Venereology and Dermatologic Surgery, Sofia, Bulgaria

The potential or actual contamination of widely distributed medications with nitrosamines is currently a serious problem. Medications, such as ranitidine, metformin, rifampicin, hydrochlorothiazide, angiotensin-converting enzyme (ACE) inhibitors, and sartans, used as monotherapy or in combination with other drug classes, practically contain ingredients potentiating tumor generation and tumor progression. The dilemma with the ˝increased availability˝ of nitrosamines concerns the subsequent development not only of single but also of multiple skin tumors, sometimes even in combination with other tumor types. The development, in particular, of keratinocyte tumors after administering drugs such as sartans, hydrochlorothiazide and ACE inhibitors has been described repeatedly over the past 7 years. Data on these types of tumors have been officially published not only in a number of large-scale european and american retrospective analyzes but also in the form of dozens of case studies with a retrospective/prospective nature. We describe the case of a patient who developed a basal cell carcinoma (BCC) of the chin, which enlarged significantly after taking potentially nitrosamine-contaminated metformin. The role of nitrosamines as a possible key factor in tumor development is discussed.

Palabras clave: Basal cell carcinoma. Drug-enhanced carcinogenesis. Metformin. Nitrosamines. Skin cancer. Valsartan.