Stomach cancer is responsible for 1.8 percent of cancer deaths in the U.S. According to the National Cancer Institute’s Surveillance, Epidemiology and End Results Program, 28,000 people were diagnosed with stomach cancer in 2017, and 10,960 individuals died as a result of their illness.
The study, published in the Journal of Periodontology, was performed in conjunction with the NYU School of Medicine and links the bacteria known to cause periodontal disease to precancerous lesions in the stomach.
The study further strengthens the connection between oral health and the prevalence of stomach cancer evidenced by earlier research.
Previous studies have found that the inflammation caused by the presence of the bacteria that cause periodontal disease contributes to the development of stomach cancer and several other types of cancers.
The study’s researchers examined 105 people who were scheduled for an upper endoscopy. Of the group, 35 people already had a diagnosis of precancerous lesions in the stomach.
The control group – the remaining 70 participants – did not have precancerous lesions.
The participants had full-mouth examinations in which researchers evaluated their oral health and collected saliva and dental plaque samples.
The researchers also examined the patients regarding oral microbial biodiversity to determine the ratio of good bacteria to gum disease-causing bacteria.
“When the mouth becomes overrun with the bacteria that cause periodontal disease, the good bacteria necessary for a balanced oral biome are pushed out and periodontal disease develops unchecked and often unnoticed,” said Dr. Stefania Caracioni, L.V.I.F.
Caracioni is a Topeka, Kansas, dentist who treats patients with varying stages of periodontal disease.
“The first stage is gingivitis and is reversible through good oral hygiene practices,” Caracioni said.
During the gingivitis phase, the gums become irritated, red and inflamed.
“If not treated, gingivitis then progresses to periodontitis, and in addition to inflammation and irritation, gums become painful and begin to pull away from the teeth,” Caracioni said.
Treatments for periodontitis include root planing and scaling, two procedures that remove the bacteria causing the infection from the roots of the teeth below the gum line, along with the placement of antibiotics below the gumline and antibacterial mouth rinses.
As the gums pull away from the teeth, a gap is created known as a gum pocket.
“Healthy gums have depths between 1 and 3 millimeters,” Caracioni said.
Gums over the 3-millimeter mark may be in the final stage of gum disease known as advanced periodontal disease. This level of gum disease could mean tooth loss, gum tissue loss and damage to the jaw.
Treatments for advanced periodontal disease include surgical removal of affected tissue, reshaping of the gum tissue, and in some extreme cases, the replacement of the gum tissue with cadaver gum tissue.
Among the group participating in the NYU study, P. gingivalis, T. denticola, T. forsythia and A. actinomycetemcomitans bacteria were present.
The 35 participants with precancerous lesions had a greater rate (31.5) of bleeding during periodontal probing than the control group without the lesions.
They also had more significant levels of the bacteria T. denticola and A. actinomycetemcomitans.
The findings, which took into account patients’ sociodemographic information and oral health behaviors like smoking, diet and oral hygiene practices and periodontal assessments, found that the presence of three bacteria – T. forsythia, T. denticola and A. actinomycetemcomitans – increased the chance of developing precancerous lesions.
The study concluded that the bacteria that cause periodontal disease and the lack of biodiversity in the mouth has the potential to raise the risk of the patient of developing stomach cancer.
“Studies like this connect the health of the mouth to the health of the rest of the body and are very beneficial for developing new treatments to prevent the development of more serious illnesses,” Caracioni said.
New York University. “Increased oral pathogens, decreased bacterial diversity predict precancerous stomach cancer lesions: Study points to controlling periodontal disease for possible cancer prevention.” ScienceDaily. ScienceDaily, 27 November 2017.
National Cancer Institute’s Surveillance, Epidemiology and End Results Program. Cancer of the Stomach. 2017.