In view of the differences in biology of NSCLC and SCLC we examined the relationship between 15q25.1, 5p15.33 and 6p21.33 variants and tumor histology (Table 2). Variation at 15q25.1 defined by rs12914385, rs8042374 or rs9838682 was not associated with any difference in lung cancer histology. At 5p15.33 variation defined by rs4975616 (CLPM1L) was not associated with any difference in lung tumor type, however, variation defined by rs2736100 (TERT) was shown to influence lung cancer histology. Specifically, there was a significant difference in the allele frequency of rs2736100 between SCLC and NSCLC (P = 0.0011). This association was ascribable to a significantly increased frequency of the risk allele in cases with NSCLC-adenocarcinoma. Similarly for variation at 6p21.33 defined by rs3117582, whilst allele frequencies were not significantly different between SCLC and NSCLC cases (P = 0.15), a significant difference in allele frequency between adenocarcinoma and squamous disease was shown.
