Author: Dr David Shaw, a skin and cosmetic GP at Kingscliff Health medical and allied health centre in Kingscliff, NSW.
Black Salve (BS), aka Cancema is a blanket term for any topical paste typically consisting of zinc chloride (largest ingredient), bloodroot and sometimes other botanicals. The recipe is not standardised so it’s difficult to compare products and you can’t really be sure what you are actually getting in that mail order. The zinc and toxic alkaloids from the botanicals cause tissue destruction. So yes, if the tissue destruction coincides with the borders of your skin cancer then it will ‘cure’ the cancer. But this is where things get complicated.
It is regularly claimed by proponents (i.e. product manufacturers and sellers) that BS can actively seek out and selectively destroy cancer cells much like a chemotherapy drug. However laboratory studies have demonstrated that it is at least as toxic the normal skin and tissue cells. It is also claimed that it won’t ‘react’ on the skin (i.e. destroy tissue) unless it is applied to a cancer. There is no evidence to suggest this is the case. Moreover, I have personally seen many instances of BS ‘reacting’ when applied to scar tissue, normal skin and other benign skin lesions. So again, the properties of BS appear to be, shall we say, overstated.
Also of great relevance is the considerable variation in the biology of individual skin cancers. Some low-grade skin cancers may completely resolve if most of the cells are destroyed. However, higher grade skin cancers will recur and may aggressively spread locally or even to other parts of the body if even a few cells remain after treatment. Recurrence is often in the deeper layers of the skin where the BS couldn’t penetrate down to and thus will not be detected until it has grown to a large size. So you may get lucky and ‘cure’ your skin cancer with BS. However, there is no way to determine if you have done so and you are running a significant risk of recurrence which may require extensive surgery or even be inoperable and life threatening. There are many documented cases where this has occurred. In addition I have seen major scarring and ulceration after BS application.
What do I advise clients who wish to use BS? Firstly, I don’t think BS conveys any advantage over treatment modalities that a good skin doctor can perform other than the ability to DIY. I recognize that this is important to some people. So if you must use BS, please be safe! It is imperative that you get your spots properly diagnosed and assessed for suitability for BS. Once BS has been applied, there is no way to determine the nature of the original lesion.
So in summary, skin cancers can be very serious. BS is not a ‘natural’ product (zinc chloride is the main ingredient) and it is not safe to use without the assistance of an experienced skin doctor.
Dr David Shaw is a highly experienced skin and cosmetic GP with areas of interest in dermatology, skin cancer checks, skin cancer surgery, and cosmetic injectables. Book an appointment online with Dr David Shaw or call us on 02 6670 1400.
* The information provided in this article is for educational purposes only and not intended to be a substitute for professional advice. You must consult your doctor before acting on the information in this article, especially if you have concerns regarding health related issues for yourself and your family.