Plant Sap May Provide Cure For Skin Cancer Print

The British Journal of Dermatology will reveal  that a traditional medicine using the sap from a common weed is effective in treating non-melanoma skin cancers in a study due to be released this week.

 

The sap of Euphorbia peplus, a plant more commonly known as petty spurge in the UK, has been scientifically proven to be capable of 'killing' certain types of skin cancer cells when applied to the skin. The plant has been used for centuries as a traditional medicine to treat conditions such as warts, asthma and several types of cancer.

 

Following the anecdotal reports of the efficacy of the plant sap a team of scientists in Australia decided to conduct a clinical study of the sap involving 36 patients with a total of 48 non-melanoma skin cancer lesions. The lesions treated included 28 basal cell carcinomas (BCC), four squamous cell carcinomas (SCC) and 16 intraepidermal carcinomas (IEC). Intraepidermal carcinoma is a growth of cancerous cells confined to the outer layer of the skin, but occasionally they do progress into an invasive and more dangerous form of skin cancer.

 

The clinical study enrolled patients who had either previously failed to respond to other types of treatment including surgery, had refused surgical treatment, or were deemed unsuitable for surgery for reasons such as their age. The patients had their skin cancers treated once a day for three consecutive days by an oncologist using a cotton bud to apply enough of the E.peplus sap onto the skin to cover the surface of each lesion.

 

The initial results were impressive; after only one month 41 of the 48 cancers had shown a complete clinical response (CCR) to the E.peplus treatment, meaning that the tumour had completely gone and was not visible on clinical examination. Out of the test group, 15 of the 16 IEC tumours treated responded with a complete clinical response (94 per cent), followed by 23 of the 28 BCCs treated (82 per cent), and three of the four SCCs (75 per cent). Patients who experienced only a partial response to the first round of treatment were offered a second course one to three months later.

The lesions which responded positively to one or two courses of treatment were then followed up further for between two and 31 months. At their last follow-up appointment patients had their complete treatment response measured according to whether the tumour remained absent on clinical examination and/or histology results from punch biopsies. After an average of 15 months following treatment, two thirds (68.5 per cent, 30 of the 48) of the skin cancer lesions were still showing a complete response. Of the three types of skin cancer tested, the final outcome was a 75 per cent complete response for IEC lesions, 57 per cent for BCC and 50 per cent for SCC lesions.

 

By incorporating the additional findings of its effect on SCCs and IECs this study supports another work in the same field, which looked at the effect of using a purified compound from E.peplus in the treatment of BCCs*. The findings of both studies support the further development of the active ingredient ingenol mebutate in the treatment of non-melanoma and pre-cancers.

 

Non-melanoma skin cancer is very common accounting for at least 95 per cent of all skin cancers in the UK, and whilst not as deadly as melanoma skin cancer (which can rapidly spread to other parts of the body), it still represents a growing health problem. The results of this study show that active ingredient in E.peplus sap, ingenol mebutate, provides a viable non-surgical treatment for IEC, BCC and SCC skin cancers.

 

Kimberley Carter of the British Association of Dermatologists said: "This is a very small test group so it will be interesting to see what larger studies and the development of the active ingredient in E. peplus sap will reveal. Whilst it would not provide an alternative to surgery for the more invasive skin cancers or melanoma, in the future it might become a useful addition to the treatments available to patients for superficial, non-melanoma skin cancers. Any advances that could lead to new therapies for patients where surgery is not an option are definitely worth investigating.

 

"It is also very important to note that this is definitely not a treatment people should be trying out at home. Exposure of the sap to mucous producing surfaces, such as the eyes, results in extreme inflammation and can lead to hospitalisation. The concentration of the active ingredients in the sap also varies between different plants, with high doses able to cause very severe and excessive inflammatory responses."

 

A benefit of the treatment is the apparent lack of side-effects. In fact, 43 per cent of patients reported feeling no pain as a result of the treatment, 37 per cent reported mild pain, 14 per cent moderate, and only one patient encountered severe pain. When pain was experienced it was localised to the lesion site, and lasted between two hours and two days. In all cases of successful treatment the skin was left with a good cosmetic appearance.

 

Ingenol mebutate was identified as an active ingredient of E. Peplus sap, that when applied to the skin induces inflammation and primary necrosis (death) of the tumour cells. It also recruits white blood cells known as neutrophils that appear to reduce the risk of relapse by destroying any residual malignant cells that could allow the tumour to re-grow.

 

Non-melanoma skin cancers particularly affect people who have experienced too much exposure to ultra-violet light from the sun or from sun beds. Lesions usually appear on the areas that are most exposed to the sun, such as the head, neck, ears, and back of the hands.