Immune landscape and oncobiota in HPV-Associated Colorectal Cancer: an explorative study

Clin Exp Med. 2023 Dec;23(8):5101-5112. doi: 10.1007/s10238-023-01165-3. Epub 2023 Aug 23.


Worldwide more than 550,000 new patients suffering from malignant tumors are associated with human papillomaviruses (HPV) infection. However, only a small portion of patients infected progress to cancer, suggesting that other factors other than HPV may play a role. Some studies have investigated HPV infection in colorectal cancer (CRC) with discordant results; moreover, the role of HPV in CRC development is still unknown. We investigated HPV infection in 50 CRC from different regions, excluding the anal one, by immunohistochemistry (IHC), real-time PCR and RNA-seq. For each patient, we studied the tumor microenvironment in neoplastic and matched non-neoplastic samples, and we compared the tumor-infiltrating immune cell phenotypes among HPV-positive and negative samples. Finally, we compared the CRC-associated microbiota in HPV-positive and negative neoplastic samples by 16S rRNA sequencing. HPV infection was identified in 20% of CRC from the right side (caecum, ascending and transverse colon) and in 40% from the left side (descending colon and rectum). In all HPV-positive CRCs we found no expression of p53 and RB, thus suggesting HPV involvement in tumorigenesis. As far as the tumor microenvironment is concerned, in HPV-related cancers we observed a neoplastic environment with a reduced immune surveillance but an enhanced cytotoxic response by lymphocytes. HPV-positive and -negative CRC showed a different microbiota with lack of species normally found in CRC in the HPV-positive ones. Our results support the carcinogenic significance of HPV in CRC, suggesting a role of HPV in modulating the tumor immune microenvironment.

Keywords: Bacteroides; Colorectal cancer; Human Papillomavirus; Immune evasion; Immunity; Microbiota; Oncobiota.

MeSH terms

  • Colorectal Neoplasms* / genetics
  • Humans
  • Papillomavirus Infections* / complications
  • Papillomavirus Infections* / epidemiology
  • RNA, Ribosomal, 16S
  • Tumor Microenvironment


  • RNA, Ribosomal, 16S