Quantifying the genetic correlation between multiple cancer types.

Publication Type:

Journal Article

Source:

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (2017)

Abstract:

Many cancers share specific genetic risk factors including both rare high-penetrance mutations and common single nucleotide polymorphisms (SNPs) identified through genome-wide association studies (GWAS). However, little is known about the overall shared heritability across cancers. Quantifying the extent to which two distinct cancers share genetic origin will give insights to shared biological mechanisms underlying cancer and inform design for future genetic association studies. In this study, we estimated the pair-wise genetic correlation between six cancer types (breast, colorectal, lung, ovarian, pancreatic and prostate) using cancer-specific GWAS summary statistics data based on 66,958 case and 70,665 control subjects of European ancestry. We also estimated genetic correlations between cancers and 14 non-cancer diseases and traits. After adjusting for 15 pair-wise genetic correlation tests between cancers, we found significant (p<0.003) genetic correlations between pancreatic and colorectal cancer (rg=0.55, p=0.003), lung and colorectal cancer (rg=0.31, p=0.001). We also found suggestive genetic correlations between lung and breast cancer (rg=0.27, p=0.009), and colorectal and breast cancer (rg=0.22, p=0.01). In contrast, we found no evidence that prostate cancer shared an appreciable proportion of heritability with other cancers. After adjusting for 84 tests studying genetic correlations between cancer types and other traits (Bonferroni-corrected p-value: 0.0006), only the genetic correlation between lung cancer and smoking remained significant (rg=0.41, p=1.03x10-6). We also observed nominally significant genetic correlations between body mass index (BMI) and all cancers except ovarian cancer. Our results highlight novel genetic correlations and lend support to previous observational studies that have observed links between cancers and risk factors.