Demographic trends and KRAS/BRAFV600E mutations in colorectal cancer patients of South China: A single-site report

Int J Cancer. 2019 May 1;144(9):2109-2117. doi: 10.1002/ijc.31973. Epub 2019 Feb 5.

Abstract

The incidence of colorectal cancer (CRC) is increasing in China. Here, we aimed to evaluate the latest demographic trends and KRAS/BRAF mutations status of Chinese CRC. Five thousand five hundred and forty-six CRC patients diagnosed from 2010 to 2017 were involved. KRAS exon 2 and BRAFV600E mutations were detected by Sanger sequencing and high-resolution melting analysis or allelic-specific probe method. Gene mutation profiles and clinicopathologic characteristics of 5495 patients were analyzed. The joinpoint regression model was used to predict the demographic data in 2018. We found KRAS exon 2 and BRAFV600E mutation rates were 37.7 and 2.8% in CRC patients. Tumors with KRAS exon 2 mutations were more likely to be present in female and patients aged older than 75 years, right colon and have well-differentiated histology. Tumors with BRAFV600E mutations were more likely to be present in the female, right colon and have poorly differentiated histology. From 2010 to 2017, the percentage of colon cancer and tubular adenocarcinoma in CRC increased substantially (from 39.3 to 51.8%, from 78.6 to 93.4%, respectively). The percentage of right colon cancer increased from 18.3 to 20.5%, which predictively may keep at 22.6% in 2018. The rise trends for patients with moderate differentiation tumor or KRAS exon 2 mutated tumor were apparent (from 50.3 to 78.6%, from 32.8 to 39.7%, respectively). In conclusion, in recent 8 years, there is a shift to the colon, especially right colon in the incidence of Chinese CRC. Moreover tubular adenocarcinoma is becoming the primary histology type.

Keywords: BRAF mutation; KRAS mutation; colorectal cancer; demographic trends; tubular adenocarcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / epidemiology*
  • Adenocarcinoma / genetics
  • Adenocarcinoma / pathology
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Base Sequence
  • China / epidemiology
  • Colorectal Neoplasms / epidemiology*
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / pathology
  • Demography
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Mutation / genetics
  • Proto-Oncogene Proteins B-raf / genetics*
  • Proto-Oncogene Proteins p21(ras) / genetics*
  • Sequence Analysis, DNA
  • Young Adult

Substances

  • KRAS protein, human
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • Proto-Oncogene Proteins p21(ras)