The association between oral health, related bacteria and gastrointestinal cancer risk and progression

  • Haydee Wilma Tavares Jordao

Student thesis: Doctoral ThesisDoctor of Philosophy


Cancer is a worldwide public health burden, with an overall annual incidence of 18.1 million new cancer cases and 9.6 million deaths each year reported in 2018. Approximately one-third of these cases were attributable to cancers of the gastrointestinal (GI) tract. Cancer incidence and mortality rates have rapidly increased in the 21st century, due to several factors including the global adoption of the western lifestyle and longer life expectancies.

Previous research has highlighted that poor oral health and/or periodontal disease may be implicated in the aetiology or progression of some GI cancers. However, the associations reported have been inconsistent and the underlying biological mechanisms remain unclear. A better understanding of the association between poor oral health and GI cancers may help health policymakers to develop services which improve cancer surveillance, prevention and cancer outcomes.

This thesis describes a series of studies addressing current knowledge gaps and collectively aims to better identify and understand the association between poor oral health, related bacteria and GI cancer risk and progression. Following an introduction to GI cancer epidemiology and oral health in Chapter 1, four novel epidemiological analyses were undertaken as described deeply in Chapters 2-5, culminating in the discussion Chapter 6 which provides an overview of the thesis findings, it’s implications for public health recommendations and future research directions.
Date of AwardDec 2020
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsAngolan scholarship
SupervisorHelen Coleman (Supervisor), Gerry McKenna (Supervisor) & Andrew Kunzmann (Supervisor)


  • Digestive cancer
  • Epidemiology
  • Oral health

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