Smoking related cancers and loci at chromosomes 15q25, 5p15, 6p22.1 and 6p21.33 in the Polish population.

Genetic factors associated with the risk of smoking related cancers have until recently remained elusive. Since the publication of a genome-wide association study (GWAS) on lung cancer new genetic loci have been identified that appear to be associated with disease risk. In this replication study we genotyped 14 single nucleotide polymorphisms (SNPs) located at the 5p12.3-p15.33, 6p21.3-p22.1, 6q23-q27 and 15q25.1 loci in 874 lung, 450 bladder, 418 laryngeal cancer cases and cancer-free controls, matched by year of birth and sex to the cases. Our results revealed that loci in the chromosome region 15q25.1 (rs16969968[A], rs8034191[G]) and 5p15 (rs402710[T]) are associated with lung cancer risk in the Polish population (smoking status adjusted OR = 1.45, 1.35, 0.77; p ≤ 0.0001, 0.0005, 0.002; 95%CI 1.23-1.72, 1.14-1.59, 0.66-0.91 respectively). None of the other regions analyzed herein were implicated in the risk of lung, bladder or laryngeal cancer. This study supports previous findings on lung cancer but fails to show association of SNPs located in 15q25.1 and 5p15 region with other smoking related cancers like bladder and laryngeal cancer.

A range of cancers is associated with the rs6983267 marker on chromosome 8.

Several genome-wide searches for common cancers have lead to the identification of a small number of loci that harbor low-risk cancer susceptibility markers. One marker, rs6983267 on chromosome 8q24, has been linked to both colon and prostate cancer, and is therefore a good candidate for a multicancer susceptibility marker. To determine the range of cancer sites associated with rs6983267, we genotyped 7,665 cases of cancer, representing 11 common cancer sites, and 1,910 controls. A significant odds ratio (OR) was observed for prostate cancer for carriers of genotype GG [OR, 1.77; 95% confidence interval (CI), 1.47-2.13]. The homozygote OR was higher for tumors with Gleason score 8 to 10 (OR, 1.94; 95% CI, 1.18-3.20) than for tumors with Gleason score 7 and below (OR, 1.65; 95% CI, 1.31-2.08). Significantly elevated (homozygote) ORs were observed for 4 other cancer sites, including colon (OR, 1.36; 95% CI, 1.08-1.72), kidney (OR, 1.52; 95% CI, 1.12-2.05), thyroid (OR, 1.37; 95% CI, 1.02-1.82), and larynx (OR, 1.39; 95% CI, 1.02-1.90). Information was available on family histories of cancer for eight sites. For six of the eight sites (prostate, breast, bladder, larynx, lung, and kidney), the homozygote ORs were higher for cases with a positive family history (at least one first-degree with any cancer) than for cases with unaffected first-degree relatives. Our results suggest that the range of cancers associated with the rs6983267 marker might be larger than previously thought.

Lung cancer susceptibility locus at 5p15.33.

We carried out a genome-wide association study of lung cancer (3,259 cases and 4,159 controls), followed by replication in 2,899 cases and 5,573 controls. Two uncorrelated disease markers at 5p15.33, rs402710 and rs2736100 were detected by the genome-wide data (P = 2 x 10(-7) and P = 4 x 10(-6)) and replicated by the independent study series (P = 7 x 10(-5) and P = 0.016). The susceptibility region contains two genes, TERT and CLPTM1L, suggesting that one or both may have a role in lung cancer etiology.

Constitutional CHEK2 mutations are associated with a decreased risk of lung and laryngeal cancers.

Mutations in the CHEK2 gene have been associated with increased risks of breast, prostate and colon cancer. In contrast, a previous report suggests that individuals with the I157T missense variant of the CHEK2 gene might be at decreased risk of lung cancer and upper aero-digestive cancers. To confirm this hypothesis, we genotyped 895 cases of lung cancer, 430 cases of laryngeal cancer and 6391 controls from Poland for four founder alleles in the CHEK2 gene, each of which has been associated with an increased risk of cancer at several sites. The presence of a CHEK2 mutation was protective against both lung cancer [odds ratio (OR) = 0.3; 95% confidence interval (CI) 0.2-0.5; P = 3 x 10(-8)] and laryngeal cancer (OR = 0.6; 95% CI 0.3-0.99; P = 0.05). The basis of the protective effect is unknown, but may relate to the reduced viability of lung cancer cells with a CHEK2 mutation. Lung cancers frequently possess other defects in genes in the DNA damage response pathway (e.g. p53 mutations) and have a high level of genotoxic DNA damage induced by tobacco smoke. We speculate that lung cancer cells with impaired CHEK2 function undergo increased rates of cell death.

CDKN2A common variant and multi-organ cancer risk--a population-based study.

The population frequencies of the CDKN2A common variants remain undetermined. In Poland, there is a common variant of the CDKN2A: an alanine to threonine substitution (A148T), which has been detected in other populations. We have recently showed that it is significantly overrepresented among Polish melanoma patients when compared to general population. Herein, we ascertained the prevalence of the A148T variant in 3,583 unselected cancer cases and 3,000 random control subjects from the same Polish population. We evaluated eleven different malignancies, representing the majority of all common cancer sites. Positive association with A148T variant was observed for lung cancer (OR, 2.0; p = 0.0052). A similar trend, although nonsignificant after the Bonferroni correction, was observed for colorectal cancer (OR, 1.5; p = 0.5499). These results suggest that A148T variant may be associated with a multi-organ cancer risk in the Polish population.

Prevalence of the NOD2 3020insC mutation in aggregations of breast and lung cancer.

Both breast and lung cancers are common malignancies and within the context of known genetic predispositions to breast cancer, no association has been made in linking the two diseases together. This does not exclude the possibility that such associations may exist that lie outside the known high-risk breast cancer families. To examine the likelihood of common genetic factors that could influence the risk of disease, two sets of consecutively collected tumor groups were examined for the 3020insC mutation in the NOD2/CARD15 gene. A total of 4107 consecutively collected breast cancer patients were assessed for the prevalence of the 3020insC mutation and compared to a consecutively collected series of 389 lung cancer patients and 2068 control samples. The results revealed that a proportion of breast cancer patients who had a first or a second degree relative diagnosed with lung cancer were more likely to harbour a change in NOD2/CARD15 compared to patients who had no relatives affected by lung cancer. Furthermore, this difference appeared to be specific to the breast and lung cancer subgroup since there was no difference in the frequency of the 3020insC allele in the consecutively collected lung cancer patients. In conclusion, it appears that the 3020insC mutation of the NOD2/CARD15 gene may be a genetic predisposing factor for aggregations of breast and lung cancer.