Different impact of IL10 haplotype on prognosis in lung squamous cell carcinoma and adenocarcinoma

Background: Polymorphisms (1082A>G, - 819C>T, and -592G>A) in the interleukin-10 (IL10) promoter are associated with its transcriptional activity. IL10 induction by cigarette smoking plays a role in smokingrelated lung tumor progression. We therefore expected to find a difference in impact of IL10 haplotypes on overall survival (OS) and relapse-free survival (RFS) between squamous cell carcinomas (SCC) and adenocarcinomas (ADC) of lung. Materials and Methods: Normal lung tissues adjacent to resected tumors from 439 lung cancer patients were collected to determine IL10 haplotypes (ATA and non-ATA) by direct sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Kaplan-Meier and multivariate Cox regression models were used to assess the impact of IL10 haplotype on OS and RFS. Resluts: The non-ATA haplotype was more prevalent in patients with nodal metastatic tumors (N1 and N2) than in those with nonnodal metastatic tumors (N0). This observation was only made for patients with SCC and not ADC. Patients with SCC with the non-ATA haplotype had poorer OS and RFS when compared to those with the ATA haplotype, whereas IL10 haplotype was not associated with the clinical outcome of patients with ADC. Conclusion: The IL10 haplotype may independently predict survival and relapse in patients with surgically resected SCC, but not ADC.