ASCO-GI 2020 – Decoding high incidence of colorectal cancer in young patients


  • Deepa Koli
  • Univadis
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Takeaway

  • Intratumoral bacterial profiling detected a greater percentage of Moraxella osloensis in older vs younger patients with colorectal cancer (CRC).
  • The rate of Fusobacterium nucleatum and the average number of species were higher in younger patients but not statistically significant.

Why this matters

  • Intratumoral microbiome profiling can potentially identify younger individuals at risk for CRC.

Study design

  • The study compared the intratumoral microbiome in 31 patients with CRC aged 65 years (n=13).
  • DNA was extracted from tumors and analyzed using 16S ribosomal gene sequencing.
  • Funding: Colorectal Cancer Alliance and others.

Key results

  • The median age of younger and older patients was 39.2 and 72.8 years, respectively.
  • A total of 478 unique bacterial and fungal species were detected. 
  • No significant difference observed in the rate of F nucleatum positive tumors of younger vs older patients (28% vs 23%).
  • The rate of M osloensis was significantly lower in younger patients (11% vs 46%; P=.043).
  • No significant difference observed in microbiome diversity in younger vs older patients (average species, 46 vs 42).

Limitations            

  • Small sample size.

Expert commentary

Study investigator Weinberg BA said, "If we can identify high risk stool microbiome — trying to look at the stool vs the tumor bacterial composition — it may help us identify someone at high risk of developing colorectal cancer."