Microsatellite instability in human colonic cancer is not a useful clinical indicator of familial colorectal cancer

Gastroenterology. 1995 Dec;109(6):1765-71. doi: 10.1016/0016-5085(95)90742-4.


Background & aims: Microsatellite instability is a property of most tumors occurring in the context of hereditary nonpolyposis colon cancer. Instability also occurs in 10%-15% of apparently sporadic colorectal cancers, and it has been hypothesized that this instability may indicate a genetic predisposition to colonic cancer. This study evaluated whether there is a clinically useful association between colon cancer instability and a family history of cancer.

Methods: Colon cancer cases (n = 188) from a population-based study were evaluated for microsatellite instability with 10 polymerase chain reaction primer sets. Instability results were compared with family history and other clinical and biological characteristics.

Results: Microsatellite instability was found in 16.5% of tumors. It was predominantly a feature of right-sided tumors (P = 0.003) and was associated with the youngest and oldest ages at diagnosis (P = 0.01). Instability was not associated with family history of cancer, sex of the individual, or the glutathione-S-transferase mu 1 null genotype.

Conclusions: Although some very small, and as yet undefined, proportion of colon cancer may be caused by inherited mutations leading to microsatellite instability, tumoral instability by itself is not a marker for familiality and should not be considered as evidence for an inherited syndrome.

Publication types

  • Comment
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Base Sequence
  • Case-Control Studies
  • Chi-Square Distribution
  • Colonic Neoplasms / enzymology
  • Colonic Neoplasms / genetics*
  • Colorectal Neoplasms / diagnosis
  • Colorectal Neoplasms / enzymology
  • Colorectal Neoplasms / genetics*
  • Family Health
  • Female
  • Genotype
  • Glutathione Transferase / genetics
  • Humans
  • Male
  • Microsatellite Repeats / genetics*
  • Middle Aged
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • Predictive Value of Tests


  • Glutathione Transferase