Moreover, patients with locally advanced HNSCC showed significantly greater downregulation of Per1, Per2 and Per3 mRNA expression levels as compared to patients with early-stage cancer (<i>p</i> < .05).
Study distribution by tumor was as follows: breast cancer (n=15), prostate cancer (n=3), pancreatic cancer (n=2), non-Hodgkin's lymphoma (n=2), glioma (n=1), chronic lymphocytic leukemia (n=1), colorectal cancer (n=1), non-small cell lung cancer (n=1) and ovarian cancer (n=1).We identified 10 single nucleotide polymorphisms (SNPs) significantly associated with cancer risk: NPAS2 rs10165970 (mixed and breast cancer shiftworkers), rs895520 (mixed), rs17024869 (breast) and rs7581886 (breast); CLOCK rs3749474 (breast) and rs11943456 (breast); RORA rs7164773 (breast and breast cancer postmenopausal), rs10519097 (breast); RORB rs7867494 (breast cancer postmenopausal), PER3rs1012477 (breast cancer subgroups) and assessed the level of quality evidence to be intermediate.
For PER3 4/5-repeat variant, we found a moderate increase in risk of cancer among individuals with the 5-allele compared to individuals with the 4-allele, although this association was not statistically significant (homozygous model: odds ratio [OR] 1.17, 95% confidence interval [CI] 0.81-1.67; recessive model: OR 1.17, 95% CI 0.82-1.67).
The variable number tandem repeat (VNTR) polymorphism (rs57875989) in gene Period3 (Per3) is related to multiple phenotypic parameters, including diurnal preference, sleep homeostasis, infection and cancer.