Positive Health Online

Abstract

WEINZWEIG and others, Department of Plastic Surgery, Brown University School of Medicine, Rhode Island Hospital, Providence 02905, USA, scalpels@aol.com, have investigated the role of vitamin A supplements in the growth and metastasis of malignant melanoma in mice.

Background

Vitamin A is known to promote the growth of collagen fibres, a component of skin and connective tissue. It has been shown that it can result in the formation of a fibrous capsule around certain breast and lung tumours, thus preventing them from forming metastases. The present study aimed at investigating whether a similar process would happen in malignant melanoma, a form of skin cancer, in mice.

Methodology

Sixty mice were inoculated with melanoma cells and divided into three groups, a control group, a pre-vitamin A group, and a post-vitamin A group. The control group were fed a normal but not vitamin A deficient diet. The mice in the pre-vitamin A group were fed an additional 150,000 IU of vitamin A per kg of diet for 10 days before inoculation and during the remainder of the study. The post-vitamin A mice were fed the vitamin A supplemented diet beginning on the day of inoculation. 60 days after inoculation, tumour growth was assessed and histological assessment of invasiveness of tumours was carried out.

Results

60 days after inoculation, 60% of mice survived in the control group compared to 100% in both vitamin A groups. The supplemented animals had significantly smaller tumours (5.7 mm as compared to 26.1 mm in the control group). All of the control animals had tumours, and one had distant metastases. In the pre-vitamin A group, none of the animals had tumours, and in the post-vitamin A group, 40% had tumours.

Conclusion

This animal study indicates a potential prophylactic and therapeutic effect of vitamin A in the treatment of malignant melanoma.

References

Weinzweig J, Tattini C, Lynch S, Zienowicz R, Weinzweig N, Spangenberger A, Edstrom L. Investigation of the growth and metastasis of malignant melanoma in a murine model: the role of supplemental vitamin A. Plastic and Reconstructive Surgery 112 (1): 152-158, Jul 2003.