Torque teno virus and cancers: current knowledge

Plain language summaryTorque teno virus (TTV) is detectable in up to > 90% of healthy people. It has been detected in various types of samples such as blood, serum, breast milk, cerebrospinal fluid and saliva, as well as in various types of tissue such as vagina and hepatocytes. TTV DNAemia is relatively stable in the healthy infected individuals, while TTV viral load is inversely correlated with the number and functions of T lymphocytes in the immunocompromised populations. The role of TTV in the pathogenesis of cancer and in the response to anticancer treatments is not well-known. The aim of this review is to assess the current knowledge about the relationship between TTV and cancer to define the potential key role of TTV in the oncological setting.Tweetable abstractTTV has proven its role of marker for functional immune competence in the setting of hematopoietic stem cell transplantation, but in the oncological field is yet to be defined.Aim: The aim of this systematic review is to assess the current knowledge about the relationship between Torque teno virus (TTV) and cancer in different settings. Methods: A systematic search was conducted in Medline via PubMed, Embase and Cochrane Library from the inception to the end of January 2023. Results: 34 articles were included in the qualitative synthesis of this review and 2145 patients with solid tumors have been analyzed. The most prevalent cancer types were hepatocellular carcinoma (HCC) and lung cancer. Conclusion: TTV has proven its role as a marker of functional immune competence in the setting of hematopoietic stem cell transplantation (HSCT), but in the oncological field is yet to be defined.