Role of bacterial infections in pancreatic cancer.

Epidemiological data suggest that Helicobacter pylori may be a risk factor for pancreatic cancer, and more recently, data suggest that periodontal disease, and Porphyromonas gingivalis, a pathogen for periodontal disease, may also play a role in pancreaticcarcinogenesis. Individuals with periodontal disease have elevated markers of systemic inflammation, and oral bacteria can disseminate into the blood, stomach, heart and even reach the brain. These infections may contribute to the progression of pancreatic cancer by acting jointly with otherpancreatic cancer risk factors that impact the inflammation and immune response, such as smoking and obesity, and the ABO genetic variant, recently linked to pancreatic cancer through genome-wide association studies.   본문의 밑줄친 빨간색 문장을 보시면 잘 알려진 췌장암의 위험요소인 흡연, 만성췌장염, 비만, 당뇨 이외에도 “헬리코박터 파일로리와 잇몸병이 췌장암발생에 영향을 미칠 수도 있다” 라고 되어있습니다. 어디에도 확실하게 결론 내리는 말은 없네요. 그리고 이 연구 또한 환자들을 대상으로 한 연구도 아닌 리뷰형식의 연구입니다.  다른 문헌을 또 살펴보겠습니다. 유명한 Lancet지에 실린 연구입니다.  

Periodontal disease, tooth loss, and cancer risk in male health professionals: a prospective cohort study.

  FINDINGS: In the main analyses, 48 375 men with median follow-up of 17.7 years (1986 to Jan 31, 2004) were eligible after excluding participants diagnosed with cancer before 1986 (other than non-melanoma skin cancer, n=2076) and those with missing data on periodontal disease (n=1078). 5720 incident cancer cases were documented (excluding non-melanoma skin cancer and non-aggressive prostate cancer). The five most common cancers were colorectal (n=1043), melanoma of the skin (n=698), lung (n=678), bladder (n=543), and advanced prostate (n=541). After adjusting for known risk factors, including detailed smoking history and dietary factors, participants with a history of periodontal disease had an increased risk of total cancer (HR 1.14 [95% CI 1.07-1.22]) compared with those with no history of periodontal disease. By cancer site, significant associations for those with a history of periodontal disease were noted for lung (1.36 [1.15-1.60]), kidney (1.49 [1.12-1.97]), pancreas (1.54 [1.16-2.04]; findings previously published), and haematological cancers (1.30 [1.11-1.53]). Fewer teeth at baseline (0-16) was associated with an increase in risk of lungcancer (1.70 [1.37-2.11]) for those with 0-16 teeth versus those with 25-32 teeth. In never-smokers, periodontal disease was associated with significant increases in total (1.21 [1.06-1.39]) and haematological cancers (1.35 [1.01-1.81]). By contrast, no association was noted for lung cancer(0.96 [0.46-1.98]). INTERPRETATION: Periodontal disease was associated with a small, but significant, increase in overall cancer risk, which persisted in never-smokers. The associations recorded for lung cancer are probably because of residual confounding by smoking. The increased risks noted for haematological, kidney, and pancreatic cancers need confirmation, but suggest that periodontal disease might be a marker of a susceptible immune system or might directly affect cancer risk.  

Oral infections and orofacial pain in Alzheimer’s disease: a case-control study.