Significance of glutathione S-transferases M1, T1 and P1 polymorphisms in Swedish melanoma patients

Polymorphisms of GSTM1, GSTT1 and GSTP1 were examined in melanoma patients and tumor-free individuals. Relationships between the polymorphisms and tumor characteristics and pigment phenotypes of the patients were analyzed. There was no significant difference in GSTM1 null and GSTT1 null genotypes nor GSTP1 GG genotype between melanoma patients and controls. In melanoma patients, these polymorphisms were not correlated with early or later onset of melanomas or gender of the patients. Frequency of GSTM1 null genotype was higher in patients with melanoma >2.5 mm than in those with tumors <1.0 mm, and higher frequency was found in nodular melanoma than in the other tumor types. GSTP1 GG genotype was more often found in the patients with brown and mixed eye color or brown and black hair than those with blue and green eyes or blond hair. It is unlikely that polymorphisms of GSTM1, GSTT1 and GSTP1 are general risk factors for melanoma in the Swedish population. GSTM1 null genotype was correlated with Breslow thickness and tumor type, which might serve as an additional biomarker for a rapid tumor progression. GSTP1 GG increases risk for melanoma in the subgroup of individuals with dark eyes or hair.