Background Glutathione – S transferase genes GSTM1 have been reported to influence UV sensitivity and melanoma risk. There is increasing evidence identifying the role of dietary components in modulating the risk of melanoma. The aim of this study was to investigate GSTM1, GSTT1, coffee consumption and the risk of cutaneous melanoma.
Methods Within a case-control study aimed to study environmental and occupational risk factors for melanoma conducted in the inpatient wards of IDI-San Carlo Rome, individual patterns at two polymorphic genes (GSTM1 and GSTT1) belonging to Gluthathione S-Transferases family (GSTs) were investigated in 340 subjects (188 cases of melanoma and 152 controls). The genetic analysis were conducted by INAIL. Information on socio-demographic characteristics, diet, smoking history, sun exposure and pigmentary characteristics was collected for all subjects. The association between genetic polymorphyms, coffee consumption and cutaneous melanoma was assessed by logistic regression.
Results High frequency of coffee drinking (≥ once daily), compared with low frequency consumption of coffee (<7 times weekly) was associated with a protective effect for cutaneous melanoma (OR: 0.43; 95% CI: 0.25–0.73) after controlling for age, sex, education, number of nevi, pigmentary characteristics, tobacco smoking, sun exposure and polymorphic genes. After controlling for other food items simultaneously in the model the protective effect of coffee remained. After stratifying for GSTM1 and GSTT1 genotypes, the protective effect was more pronounced for GSTM1 null genotype (OR: 0.35; 95% 0.15–0.78) and GSTT1 null genotype (OR: 0.031; 95% CI: 0.006–0.30).
Conclusion Our results show that consumption of coffee is protective for melanoma and GSTM1 and GSTT1 null individuals may benefit more of this protection than GSTM1, GSTT1 positive individuals.