Poster Presentation Joint Scientific Meeting of the Australian & NZ Head & Neck Cancer Society & NZ Association of Plastic Surgeons

The perils of Cansema (1351)

Caitlin O'Hare 1 , Darryl Dunn 1
  1. Plastic and Reconstructive Surgery, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia


To highlight the dangers associated with the use of a “natural” remedy for non-melanoma skin cancers



3 patients have presented to clinic with locally advanced disease. Patients used a topical escharotic (Cansema or black salve) resulting in more locally advanced disease (and regionally advanced disease in 1 of these cases) leading to larger resection and reconstruction and therefore greater morbidity.



Black salve is derived from the plant Sanguinaria canadensis, known colloquially as “blood root”1. It is a strong escharotic paste which causes profound inflammation and eschar to tissues1,2. Given its lack of evidence as well as varied strengths as there is no regulated formula, this treatment is unpredictable and potentially dangerous. There are multiple case reports of cancer spread and death due to delayed diagnosis and inadequate treatment due to Cansema, and significant tissue damage leading to a poor cosmetic outcome (pictures 1 and 2) 1,2.


The Therapeutic Goods Administration of Australia has banned sales of this product in Australia, however is available for purchase online2. In our institution, it appears that patients have easy access to this medication resulting in a larger treatment burden of the head and neck requiring more extensive surgery. In one of these cases, prior treatment with Cansema resulted “islands” of tumour which makes resection more difficult. Pathological opinion so far has identified dermal scar and extensive ulceration with suppurative inflammation and tissue necrosis.


Given this, it is concerning that patients still continue to use alternate therapies such as Cansema and there is a role for increased education for our patients.



  1. Rosendahl, C. Science or Snake oil: what is black salve? Faculty of medicine, University of Queensland (2018). Accessed at
  2. New Zealand Medicines and Medical Devices Safety Authority. Trans-Tasman Early Warning System – Alert Communication. Medsafe (2013). Accessed at,also%20cause%20a%20disfiguring%20injury
Download Presentation