Basal cell and squamous cell carcinomas, developed on skin overexposed to the ultraviolet light of the sun, are the two most common and highly treatable of three types of skin cancers. Approximately one million Americans are diagnosed each year with these non-melanoma skin cancers, according to Memorial Sloan-Kettering Cancer Center. Malignant melanoma occurs less often, but is much more aggressive. While practitioners of herbal medicine claim that aloe juice plays a part in an overall medical plan for skin cancers, the need exists for further scientific studies to confirm its effectiveness. In any case, bring all suspicious growths to the attention of your physician.

Indigenous to Africa and grown as a house plant around the world, aloe, or aloe vera, reaches heights of 2 feet and features prickly, succulent leaves. Its leaves yield two distinct types of medicinal sources -- clear gel commonly used for skin conditions and a bitter liquid known as aloe bitters used for internal conditions. To collect the gel and bitters, herbalists cut and drain the leaves. Commercial manufacturers distill aloe juice from the gel.

An article by researchers at Texas Tech University Health Sciences Center and published in the June 2006 issue of "Journal of Drugs in Dermatology" noted that various clinical studies and animal models suggest that the immune system plays a vital part in preventing skin cancer. According to Phyllis A. Balch, certified nutritional consultant and author of the book "Prescription for Herbal Healing," aloe contains an active complex sugar that helps stimulate and regulate the immune system. Balch says that aloe halts the development of inflammation required for skin tumors to gain new blood supplies and grow. Balch goes so far as to claim that aloe gel and vitamin E have even produced remission in some people.

The American Cancer Society reports that scientific evidence does not substantiate the safety and efficacy of aloe as a treatment for any type of cancer. In fact, a 2010 study published in "National Toxicology Program Series Report" found that aloe products actually enhanced skin cancer caused by ultraviolet radiation in female mice. At any rate, clinical trials have focused on aloe gel, not aloe juice.

Occasionally, topical application of aloe juice causes allergic reactions, including rashes or hives. Ingesting aloe juice, can reduce blood sugar levels and cause diarrhea, nausea, vomiting, abdominal pain and electrolyte imbalance, particularly a loss of potassium. Children, pregnant and nursing women and people with liver disorders or kidney disease should avoid aloe juice.