CLINICAL Black salve in a nutshell Andrew Croaker, Alvin Lim, BLACK SALVE is an alternative topical and bloodroot,8 and it was reportedly Cliff Rosendahl therapy used to treat skin cancer. It is developed after observing horses produced in a variety of formulations; cure themselves of cancerous lesions most formulations contain two core by grazing on certain plants. Hoxsey Background ingredients: bloodroot (Sanguinaria opened 17 clinics across the US, treating Black salve is an alternative therapy canadensis) and zinc chloride.1 Black salve several thousand patients in a multi- increasingly chosen by patients to self- 9 manage their skin lesions. It is promoted causes skin tissue destruction, resulting million dollar enterprise. The American as an effective, safe and natural skin in the formation of an eschar of necrotic Medical Association branded Hoxsey cancer treatment, but such claims are tissue that eventually sloughs away. a charlatan, and the US Food and Drug not evidence-based, and serious Bloodroot, a North American member Administration (FDA) mounted warnings complications have been reported. The of the poppy family, has rhizomes about Hoxsey’s formulas in 46,000 US sale of black salve in Australia is illegal. containing a red sap rich in cytotoxic post offices.10 2 Objective alkaloids, sanguinarine being the Dr Frederick Mohs noted in the 1930s The aim of this article is to educate alkaloid with the highest concentration. that zinc chloride fixed and histologically general practitioners (GPs) about black Zinc chloride, a synthetic corrosive preserved skin in vivo. Mohs developed salve, enabling informed discussion with chemical, is usually the main black salve a paste that used stibnite and bloodroot patients considering using black salve. ingredient by weight,3 contradicting the to maintain zinc chloride in suspension, An overview of the scientific literature assertion by some vendors that black enabling it to act uniformly as a fixative.11 is presented. salve is a ‘natural’ therapy. Black salve By microscopically mapping entire Discussion may also contain several other botanical tumour margin involvement and excising Case reports have described significant extracts and synthetic compounds. until clear margins were obtained, Mohs morbidity and even mortality associated This lack of standardisation and the produced cure rates of 99.3% in 7257 with the use of black salve. Despite this, phytochemical variation inherent in cases of basal cell carcinoma (BCC) black salve is readily accessible to the its botanical constituents4 make black and 94.4% in 2551 cases of squamous public online; a simple internet search 12 yields multiple links to websites salve a heterogenous product group with cell carcinoma (SCC). However, these endorsing black salve as an effective unpredictable clinical effects. results were not due to Mohs’ paste natural skin cancer remedy. As GPs are Black salve or its ingredients can be constituents, as evidenced by similar cure often called on in the initial presentation easily ordered by patients through online rates with the subsequently developed of skin complaints, they are well vendors located in countries lacking fresh tissue technique where escharotics positioned to ask patients about their regulatory control. were not used. Mohs patented his paste to use of black salve and educate them prevent its improper use as a standalone about its risks. 13 The history of black salve topical therapy. In 1975, a Portuguese doctor, Almeida In the 1850s, American surgeon Jesse Goncalves, visited Mohs’ clinic and Fell learned of a plant used by Native observed how Mohs’ fixative paste Americans to treat cancer. He identified technique was performed. On returning this plant as bloodroot and subsequently to Portugal, Goncalves developed combined it with zinc chloride to a chemosurgical technique without formulate Fell’s Paste.5 On emigrating systematised microscopic control. His to London, Fell established a lucrative process used a paste similar to Mohs’, cancer practice using this paste6 but was but with galangal (Alpinia officinarum) ridiculed as a humbug by many in the instead of stibnite to facilitate zinc chloride medical establishment.7 suspension.14 The salve was applied for Harry Hoxsey, an Illinois insurance 24 hours to lesions as well as a 5–10 mm salesman, began selling cancer margin of clinically normal-appearing treatments, including an escharotic in tissue; biopsies were taken after treatment the 1920s. Hoxsey’s red paste contained to assess cancer clearance. Of 179 patients antimony trisulfide, zinc chloride with BCC and 33 patients with SCC, and 864 | REPRINTED FROM AJGP VOL. 47, NO. 12, DECEMBER 2018 © The Royal Australian College of General Practitioners 2018 BLACK SALVE IN A NUTSHELL CLINICAL with follow-up ranging from five to 10 Does black salve cure cancer? changes that required biopsy. Five cases years, Goncalves reported no recurrences. (20%) of severe deformity occurred on There was, however, a high failure rate There has never been a controlled clinical the nose, secondary to extensive tissue on initial application of 38% in BCC and trial conducted in black salve’s 160-year destruction. In two cases, this resulted in 21% in SCC, with multiple applications history of clinical use. Current data have complete loss of the nasal ala. Only two required by some patients. This suggests been derived from case reports that are lesions were reported as having ‘fair-to- that patients self-treating with salves are at by their nature prone to selection bias. good’ cosmetic results. considerable risk of residual cancer if they When used as a self-treatment by Black salve may also impair the do not have histological assessment after patients, prognostic outcomes are mixed. subsequent clinical and histological salve application. Some reports describe histological diagnosis of skin lesions. It is unknown In the 1990s, Greg Caton formed clearance of biopsy-confirmed SCC whether skin cancers persisting in black Alpha Omega Labs, the manufacturer and BCC.20 Follow-up times varied but salve scar tissue display dermatoscopic of a black salve formulation that was were generally only up to 12 months features present in diagnostic algorithms, previously marketed under the brand and therefore insufficient to determine and histological assessment after black name Cansema. With a traditional if long-term cure was achieved. Other salve therapy can be challenging.22 black salve base of bloodroot and zinc patients developed recurrent cancer at the Concerns exist as to whether chloride, Caton added chapparel (Larrea treatment site.21–23 One patient died as a sanguinarine, the main alkaloid ingredient mexicana), graviola (Annona muricata) result of metastasis from a nasal BCC that in black salves, may be a carcinogen. and oleander (Nerium oleander).15 Caton appeared to have resolved macroscopically Conflicting in vitro and in vivo results was convicted of mail fraud and the with black salve.24 Another presented have been reported; some suggest that introduction to interstate commerce with a fungating scalp SCC that had sanguinarine acts as a genotoxin, operates of unapproved new drugs, violating grown despite nine months of black salve as a cancer promoter in murine studies FDA regulations. After serving a prison treatment.25 Only two cases of primary and induces leukoplakia when used as a sentence, he relocated to Ecuador, where melanoma treated with black salve have mouthwash ingredient.32 Alpha Omega Labs operates outside US been reported in the literature; both 26,27 jurisdiction and sells black salve products developed metastatic disease. Why do patients use black salve? online to the world. By contrast, skin cancer excision has been evaluated in multiple trials with Despite regulatory efforts and bad publicity Are black salve ingredients highly reliable outcomes. The five-year in the media in recent years, black salve cancer-specific? recurrence-free rates after standard continues to be used and distributed in margin excision are 95.2% for primary Australia. The exact prevalence of use One in vitro study reported that BCC and 94.6% for SCC.28,29 Prognosis is unknown. Increasingly, individuals sanguinarine, the most prevalent alkaloid in melanoma is dependent on tumour have turned to the internet seeking self- in bloodroot, possessed cancer-specific thickness, with excision of primary treatment advice for their health problems cytotoxicity against the A431 SCC cell melanomas <1 mm thick resulting in a before consulting a health professional.33 line in a narrow 2–5 µM concentration 96% 20-year survival rate.30 There is People may find black salve appealing range.16 However, sanguinarine lost a lack of data regarding the long-term as it is described as safe, easy to use and cancer specificity at concentrations over efficacy of black salve and no evidence natural.20 It may also be recommended by 5 µM, being equally effective at killing to support claims that it is superior to friends or family members who reportedly normal human epidermal keratinocytes. conventional treatment for skin cancer. As sanguinarine concentrations show Box 1. Reported adverse outcomes a significant (up to 10-fold) variation Is black salve safe to use? between plants,17 it is unlikely that such of black salve use a narrow therapeutic window could be Black salve has been associated with a • Pain – ‘burning’ nature, may be targeted by currently produced black number of adverse outcomes (Box 1). intense25,38–40 salve formulations. Subsequent