DIAGNOSIS OF DIABETES AND PANCREATIC CANCER RISK

Members of minority populations who have recent-onset diabetes are at significantly greater risk of developing pancreatic cancer, especially within 3 years of being diagnosed with diabetes, an analysis of the Multiethnic Cohort Study (MEC) indicates.

The finding suggests that recent-onset diabetes in African American and Latino individuals may be an early manifestation of asymptomatic pancreatic cancer.

"Most previous studies have been done in Caucasians," Wendy Setiawan, PhD, Keck School of Medicine of the University of Southern California, Los Angeles, told Medscape Medical News in an email.

"This study is the first population-based prospective study with a large number of minorities — African Americans and Latinos," she added.

"Here we show the association between recent-onset diabetes and pancreatic cancer is evident in these understudied minorities, [although] African Americans and Latinos are also populations known to have high rate of diabetes as well," Setiawan indicated.

The study was published online June 18 in the Journal of the National Cancer Institute.

The MEC is a population-based, prospective cohort study involving more than 215,000 men and women from Hawaii and California who were from 45 to 75 years of age at study recruitment.

For the current analysis, the investigators included only MEC participants from California and focused on 48,995 African Americans and Latinos who had not been diagnosed with diabetes or cancer at the time of recruitment.

Almost one third of the cohort (32.3%) developed diabetes between the time of recruitment (1993 and 1996) and 2013, the investigators report.

At an average follow-up of 14 years, the investigators also identified 408 cases of pancreatic cancer. The median age at the time the cancer was diagnosed was 76.7 years.

In the overall cohort, a diagnosis of diabetes increased the risk for pancreatic cancer by more than twofold (hazard ratio [HR], 2.39), the researchers indicate.

However, among Latinos, the risk for pancreatic cancer among those whose diabetes had been diagnosed 3 years or less before their pancreatic cancer was detected was more than fourfold higher compared to those without diabetes (HR, 4.08).

Similarly, among African Americans, the risk for pancreatic cancer among those with recent-onset diabetes was more than threefold higher than it was for those without diabetes (HR, 3.38).

Among participants diagnosed with diabetes and pancreatic cancer, 52.3% developed diabetes in the 36 months preceding the diagnosis of pancreatic cancer.

The frequency of diabetes among participants who developed pancreatic cancer (31.4%) was significantly higher (P < .001) during follow-up than it was for participants who developed colorectal cancer (16.4%), breast cancer (14.5%), or prostate cancer (11.7%).

This was also true of recent-onset diabetes, the frequency of which was "strikingly higher" among participants who developed pancreatic cancer (16.4%) compared with those who developed colorectal cancer (6.7%), breast cancer (5.3%), or prostate cancer (5.5%).

"This striking relationship between recent-onset diabetes is unique to pancreatic cancer, and it is not seen in breast, prostate, and colorectal cancer in the cohort," Setiawan emphasized in a statement.

"Our findings strongly support the hypothesis that recent-onset diabetes is a consequence of pancreatic cancer and that long-standing diabetes is a risk factor for this cancer," she added.

Prediabetic or Diabetic

As previously reported by Medscape Medical News, up to 80% of patients with pancreatic cancer are either prediabetic or diabetic in the presymptomatic phase of the malignancy, suggesting a potential opportunity to identify the cancer early in this high-risk population with recent-onset diabetes.

"As part of a national consortium called the US Consortium on Chronic Pancreatitis, Diabetes and Pancreatic Cancer, we are working diligently to develop tests that can better identify patients with recent-onset diabetes who actually have pancreatic cancer at its earliest stage," Setiawan noted.

"Finding the cancer at an early stage and treating with surgical removal provides the best chance for cure of the disease," she said, adding, however, that these tests are not yet available.

The study was funded by the National Cancer Institute. Dr Setiawan has disclosed no relevant financial relationships.

J Natl Cancer Inst. Published online June 18, 2018. Abstract