Melkonian et al. Page 1604

The American Indian and Alaska Native (AI/AN) population bears a disproportionate burden of cancer incidence in the United States. To describe cancer incidence rates and trends in the AI/AN population compared with the non-Hispanic white population, Melkonian and colleagues used data from the central cancer registries linked with the Indian Health Service patient registration databases to identify cancers diagnosed between 2010 and 2015. The authors reported elevated rates of lung, colorectal, liver, kidney, and stomach cancer in the AI/AN population that varied by geographic region. This confirmed widening cancer disparities and highlighted missed opportunities for targeted interventions to reduce AI/AN cancer incidence.

Mahal et al. Page 1660

Over the last two decades, there has been a rise in head and neck cancers in the oropharynx, due to the human papillomavirus (HPV). These cancers require aggressive treatment with radiation, surgery, or chemotherapy. This study by Mahal and colleagues is the largest study to date on the incidence of HPV-positive oropharyngeal head and neck squamous cell carcinoma in the United States, finding that 75% of oropharynx cancers are related to HPV. The U.S. incidence of HPV-related throat cancer is 4.6 per 100,000 people, peaking amongst those ages 60 to 64, and highest in white men where it is the 6th most common incident nonskin cancer. The study shows that the favorable prognosis associated with Hp. is restricted to oropharynx cancer rather than other head and neck cancers and provides data to support education and prevention strategies, including vaccination.

Chang et al. Page 1694

Helicobacter pylori (H. pylori) eradication has been shown to decrease gastric adenocarcinoma risk. The epidemiology of gastric lymphoma, which is also associated with H. pylori, and other rare subtypes of gastric cancer is less clear. This study by Chang and colleagues comprehensively evaluated the incidence trend and the survival of gastric cancer in Taiwan by histologic subtype. The incidence trends of gastric cancer in Taiwan from 1996 to 2013 were evaluated using data from the Taiwan Cancer Registry. The incidence of all gastric cancers in Taiwan decreased. However, the incidence of adenocarcinoma and lymphoma, both of which are associated with H. pylori, showed diverging trends. The disparity in the incidence trends warrants the need to search for additional risk factors of gastric lymphoma.

Haznadar et al. Page 1704

The etiology of intrahepatic cholangiocarcinoma (ICC) is less well- known compared to hepatocellular carcinoma (HCC). As ICC has poor prognosis and response to conventional therapy, identifying diagnostic and prognostic biomarkers of this form of liver cancer is warranted. Liquid chromatography coupled to tandem mass spectrometry was used to measure non-invasively detected urinary metabolites in subjects from the U.S. (NCI-MD cohort) and Thailand (TIGER-LC cohort). Haznadar and colleagues found that metabolites were significantly increased in both, HCC and ICC in urine, but were significantly higher in ICC in urine and in tissue. Metabolite profile was robust at classifying ICC in combination with a clinically utilized marker, CA19-9, holding promise for diagnostic and prognostic evaluation of ICC.