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From the Townsend Letter Editorial
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Non-melanoma skin cancer is the most common form of cancer in the United States, with more than one million new cases diagnosed each year. Approximately 75% of non-melanoma skin cancers are basal cell carcinomas (BCC), and 25% are squamous cell carcinomas (SCC). The main risk factors for these cancers are excessive sun exposure (particularly a history of frequent sunburns) and the use of tanning beds. While non-melanoma skin cancers are usually not life-threatening, both types can extend to and damage adjacent tissue, and SCC can metastasize. Solar keratoses (also called actinic keratoses) are common precancerous lesions that progress in some cases to SCC.
The main treatment modalities for non-melanoma skin cancers are surgery and application of liquid nitrogen (cryotherapy). Radiation therapy is used in some cases, and chemotherapy may be administered in cases of metastatic SCC. Treatments for solar keratoses include topical application of 5-fluorouracil, liquid nitrogen, and electrocautery. While these treatments are usually effective in early cases, they can be costly ($600-$2,500), and the cosmetic result is not always optimal.
Solasodine glycosides, which are found in plants of the nightshade family, have also been shown to be effective as a topical treatment for non-melanoma skin cancers and solar keratoses. These compounds have been reported to kill cancer cells selectively, without harming normal cells. A cream containing a mixture of solasodine glycosides has been licensed in Australia since 1991 and is marketed under the name Curaderm. This product contains 0.005% solasodine glycosides, 10% salicylic acid, 5% urea, and 0.1% tea tree oil in a cream base. In an uncontrolled clinical trial, Curaderm treatment was successful in 100% of cases of BCC, SCC, and solar keratosis.
Eighty-six patients (aged 38-74 years) with a total of 138 histologically confirmed skin lesions (39 BCC, 29 SCC, and 56 keratoses), all of which were at least 5 mm in diameter, applied Curaderm to the lesions twice a day, after which the area was covered with a plastic dressing. Treatment was continued until clinical regression was seen (one to 13 weeks). In patients with BCC, the lesions rapidly became swollen, and erythema developed in the surrounding tissue. The lesions ulcerated after about two days, and this process continued until all cancerous cells were destroyed and healthy tissue grew in. SCC lesions also showed rapid regression, and solar keratoses responded similarly. All of the 138 lesions completely regressed (this was confirmed histologically) after mean treatment periods of 5.2 weeks for BCC, 5.6 weeks for SCC, and 2.9 weeks for solar keratoses.
The cosmetic result was generally good – in many cases, better than what might have been expected with surgery or liquid nitrogen. Curaderm treatment caused itching and burning around the lesions in most cases, but no other adverse effects occurred, and standard laboratory tests (hematology, chemistry, and urinalysis) remained normal. No recurrences were seen during follow-up periods of one to three years.1
These findings were confirmed recently in a double-blind trial that included patients with BCC. The product used in that study was Zycure, which is similar to Curaderm but is not commercially available. It contains 0.005% solasodine glycosides, 10% salicylic acid, 5% urea, and 5% propylene glycol. Ninety-four patients (mean age, 69 years) with histologically confirmed BCC were randomly assigned in a 2:1 ratio to receive, in double-blind fashion, Zycure cream (n = 62) or placebo (the vehicle without the solasodine glycosides; n=32). The cream was applied twice a day under an occlusive dressing for eight weeks. At the end of the treatment period, biopsies revealed complete resolution of the lesions in 66% of the patients in the active-treatment group and in 25% of those in the placebo group (p < 0.001). The positive responses in the placebo group were attributed to the presence of keratolytic agents in the vehicle (i.e., salicylic acid, urea, and propylene glycol). Ninety percent of the patients in the Zycure group who were successfully treated returned for follow-up at six months and one year. Of those who returned, 85% were free of recurrences after six months and 78% were free of recurrences after one year. Of the eight patients whose lesions resolved during placebo treatment, 63% were free of recurrences after six months and 50% were free of recurrences after one year. No serious adverse effects were reported.2
Proponents of the use of solasodine glycosides have suggested that the results in the study described above might have been even better if the treatment had been continued for an additional four weeks (i.e., a total of 12 weeks). That possibility is supported by the results of the earlier uncontrolled trial, in which the maximal response was not seen until week 13 in some cases.
The available evidence suggests that products containing solasodine glycosides are an effective alternative to conventional treatments for the most common malignant and precancerous skin lesions. Curaderm is available for purchase online at a cost of $129 for a 20-ml bottle. A typical course of treatment requires an average of three bottles. Instructions and precautions regarding the use of this product are available online. Because of the potentially serious nature of skin cancer, the treatment should be monitored by a physician.
Notes
1. Cham BE, et al. Topical treatment of malignant and premalignant skin lesions by very low concentrations of a standard mixture (BEC) of solasodine glycosides. Cancer Lett. 1991;59:183-192.
2. Punjabi S, et al. Solasodine glycoalkaloids: a novel topical therapy for basal cell carcinoma. A double-blind, randomized, placebo-controlled, parallel group, multicenter study. Int J Dermatol. 2008;47:78-82.
The main treatment modalities for non-melanoma skin cancers are surgery and application of liquid nitrogen (cryotherapy). Radiation therapy is used in some cases, and chemotherapy may be administered in cases of metastatic SCC. Treatments for solar keratoses include topical application of 5-fluorouracil, liquid nitrogen, and electrocautery. While these treatments are usually effective in early cases, they can be costly ($600-$2,500), and the cosmetic result is not always optimal.
Solasodine glycosides, which are found in plants of the nightshade family, have also been shown to be effective as a topical treatment for non-melanoma skin cancers and solar keratoses. These compounds have been reported to kill cancer cells selectively, without harming normal cells. A cream containing a mixture of solasodine glycosides has been licensed in Australia since 1991 and is marketed under the name Curaderm. This product contains 0.005% solasodine glycosides, 10% salicylic acid, 5% urea, and 0.1% tea tree oil in a cream base. In an uncontrolled clinical trial, Curaderm treatment was successful in 100% of cases of BCC, SCC, and solar keratosis.
Eighty-six patients (aged 38-74 years) with a total of 138 histologically confirmed skin lesions (39 BCC, 29 SCC, and 56 keratoses), all of which were at least 5 mm in diameter, applied Curaderm to the lesions twice a day, after which the area was covered with a plastic dressing. Treatment was continued until clinical regression was seen (one to 13 weeks). In patients with BCC, the lesions rapidly became swollen, and erythema developed in the surrounding tissue. The lesions ulcerated after about two days, and this process continued until all cancerous cells were destroyed and healthy tissue grew in. SCC lesions also showed rapid regression, and solar keratoses responded similarly. All of the 138 lesions completely regressed (this was confirmed histologically) after mean treatment periods of 5.2 weeks for BCC, 5.6 weeks for SCC, and 2.9 weeks for solar keratoses.
The cosmetic result was generally good – in many cases, better than what might have been expected with surgery or liquid nitrogen. Curaderm treatment caused itching and burning around the lesions in most cases, but no other adverse effects occurred, and standard laboratory tests (hematology, chemistry, and urinalysis) remained normal. No recurrences were seen during follow-up periods of one to three years.1
These findings were confirmed recently in a double-blind trial that included patients with BCC. The product used in that study was Zycure, which is similar to Curaderm but is not commercially available. It contains 0.005% solasodine glycosides, 10% salicylic acid, 5% urea, and 5% propylene glycol. Ninety-four patients (mean age, 69 years) with histologically confirmed BCC were randomly assigned in a 2:1 ratio to receive, in double-blind fashion, Zycure cream (n = 62) or placebo (the vehicle without the solasodine glycosides; n=32). The cream was applied twice a day under an occlusive dressing for eight weeks. At the end of the treatment period, biopsies revealed complete resolution of the lesions in 66% of the patients in the active-treatment group and in 25% of those in the placebo group (p < 0.001). The positive responses in the placebo group were attributed to the presence of keratolytic agents in the vehicle (i.e., salicylic acid, urea, and propylene glycol). Ninety percent of the patients in the Zycure group who were successfully treated returned for follow-up at six months and one year. Of those who returned, 85% were free of recurrences after six months and 78% were free of recurrences after one year. Of the eight patients whose lesions resolved during placebo treatment, 63% were free of recurrences after six months and 50% were free of recurrences after one year. No serious adverse effects were reported.2
Proponents of the use of solasodine glycosides have suggested that the results in the study described above might have been even better if the treatment had been continued for an additional four weeks (i.e., a total of 12 weeks). That possibility is supported by the results of the earlier uncontrolled trial, in which the maximal response was not seen until week 13 in some cases.
The available evidence suggests that products containing solasodine glycosides are an effective alternative to conventional treatments for the most common malignant and precancerous skin lesions. Curaderm is available for purchase online at a cost of $129 for a 20-ml bottle. A typical course of treatment requires an average of three bottles. Instructions and precautions regarding the use of this product are available online. Because of the potentially serious nature of skin cancer, the treatment should be monitored by a physician.
Notes
1. Cham BE, et al. Topical treatment of malignant and premalignant skin lesions by very low concentrations of a standard mixture (BEC) of solasodine glycosides. Cancer Lett. 1991;59:183-192.
2. Punjabi S, et al. Solasodine glycoalkaloids: a novel topical therapy for basal cell carcinoma. A double-blind, randomized, placebo-controlled, parallel group, multicenter study. Int J Dermatol. 2008;47:78-82.