TRUNCAL SITE AND DETOXIFYING ENZYME POLYMORPHISMS SIGNIFICANTLY REDUCE TIME TO PRESENTATION OF FURTHER PRIMARY CUTANEOUS BASAL-CELL CARCINOMA

Basal cell carcinoma (BCC) is the commonest cancer in Caucasians, Its incidence is rising and many patients develop multiple primary tumours at separate sites, Factors determining time between first primary tum our presentation and the next new primary lesion are unclear, We used Cox's proportional hazards model to study, in 856 Caucasians, the infl uence of tumour site, individual characteristics and polymorphism in g lutathione S-transferase (GSTM1, GSTT1) and cytochrome P450 (CYP2D6, C YP1A1) loci on time to next primary tumour presentation, More than one tumour at first presentation (P <0.0001, hazard ratio 2.72) and GSTT1 null (P = 0.028, hazard ratio 1.74) were associated with decreased ti me to next primary tumour presentation, Significant two-factor interac tions, corrected for number of tumours at presentation, were identifie d between a truncal tumour at first presentation and each of male gend er, GSTM1 null and CYP2D6 EM (P <0.003, hazard ratios 3.09-3.82). In e ach of these cases, all patients with the risk combination demonstrate d further separate tumours within 5 years of first presentation, Thus, patients with a truncal tumour at first presentation, especially male s and those presenting with more than one lesion have a significantly decreased time to presentation of further tumours and should receive m ore meticulous follow-up, Polymorphism in GSTM1 and CYP2D6 also influe nces the rate of new primary tumour accrual giving insights into the l ink between ultraviolet exposure and multiple tumour development.