Expression of SFTPA2 mRNA and total SP-A protein was significantly lower in cancer tissue when compared to adjacent NC tissue (p < 0.001), and correlated with the hypermethylated status of an SFTPA2 CpG site in AC samples.
We found (a) no significant marker associations with SCLC, (b) rare SP-A2 (1A9) and SP-A1 (6A11) alleles associate with NSCLC risk when compared with population control, (c) the same alleles (1A9, 6A11) associate with risk for AC when compared with population (6A11) or clinical control (1A9), and (d) the SP-A1-6A4 allele (found in approximately 10% of the population) associates with SCC, when compared with population or clinical control.