A Review of Black Salve: Cancer Specificity, Cure, and Cosmesis

Abstract

Black salve is a topical escharotic used for the treatment of skin cancer. Although promoted as a safe and effective alternative to conventional management by its proponents, limited clinical research has been undertaken to assess its efficacy and potential toxicities. Patients are increasingly utilizing the Internet as a source of health information. As a minimally regulated space, the quality and accuracy of this information vary considerably. This review explores four health claims made by black salve vendors, investigating its natural therapy credentials, tumour specificity, and equivalence to orthodox medicine in relation to skin cancer cure rates and cosmesis. Based upon an analysis of in vitro constituent cytotoxicity, in vivo post black salve histology, and experience with Mohs paste, black salve is likely to possess normal tissue toxicity with some cancer cell lines being relatively resistant to its effects. This may explain the incongruous case study reports of excessive scarring, deformity, and treatment failure.

Black salve composition: An evaluation of the potential for normal tissue toxicity and treatment failure from black salve products

“…As some black salve constituents have concentration dependent normal cell cytotoxicity (Croaker et al, 2017a) and may possess genotoxic and carcinogenic potential (Das et al, 2005), a quantitative analysis of black salve constituents is of significant clinical relevance. For this reason, we conducted a HPLC-MS and ICP-MS analysis of a broad selection of black salve products with a particular focus on the alkaloids sanguinarine, chelerythrine, protopine and allocryptopine, as well as zinc chloride concentrations.…”

Assessing the risk of epidemic dropsy from black salve use

“…Having never been the subject of a clinical trial, its efficacy is currently unknown. A number of black salve toxicities have, however, been reported in case studies, including excessive scarring, disfigurement and disease recurrence resulting in death (Croaker, King, Pyne, Anoopkumar‐Dukie, & Liu, ).…”

Black salve in a nutshell

“…Among 25 lesions from published case reports, 13 cases (52%) noted scarring. 31 Complications included hypertrophic and keloid scarring requiring scar revision surgery, granulomatous plaque formation requiring topical steroid treatment, and abnormal pigmentation changes that required biopsy. Five cases (20%) of severe deformity occurred on the nose, secondary to extensive tissue destruction.…”