Pancreatic Cancer Screening Solely Based on Glycated Hemoglobin Level Not Effective

Based on findings published in JAMA Network Open, screening patients for pancreatic cancer based solely on elevation in glycated hemoglobin (HbA_1c) level is not likely to represent an effective approach.

Given this, researchers indicated that alternative approaches to risk stratification are still necessary for patients with pancreatic cancer to improve early detection.

“A major contributing factor to poor survival in pancreatic cancer is the late stage at diagnosis,” the authors wrote. “Based on the relatively low incidence, it is unlikely that widespread, population-based screening would prove beneficial. However, a targeted approach to screening patients at increased risk offers the potential for early detection, thereby improving survival.”

Using data collected from an integrated health system in California, researchers evaluated a total of 851,402 patients aged 50 to 84 years who had HbA1c measurements taken between 2010 and 2014 as a base cohort. Twelve contemporaneous cohorts were also created based on varying HbA_1c thresholds (i.e., 6.1%, 6.3%, 6.5%, and 6.7%) and prior diabetes status.

After excluding prior diabetes as well as confirmation of new-onset hyperglycemia based on an HbA_1c level of 6.5%, a total of 20,012 patients remained, with 74 of 1041 pancreatic ductal adenocarcinoma cases (7.1%) from the base cohort included. Overall, the rate of pancreatic cancer was 0.72 (95% CI, 0.32-1.42) per 1000 person-years among Asian patients, 0.83 (95% CI, 0.35-1.71) per 1000 person-years among non-Hispanic black patients, 0.84 (95% CI, 0.48-1.37) per 1000 person-years among Hispanic patients, and 2.37 (95% CI, 1.75-3.14) per 1000 person-years among non-Hispanic white patients.

Of the 74 pancreatic adenocarcinoma cases identified, 42 (56.8%) were diagnosed within 1 year of the index laboratory test. Moreover, of 1041 total cases, 708 (68.0%) had staging information available, of which 465 (65.7%) had stage III or IV disease at diagnosis. In the base cohort, the number needed to undergo evaluation to identify a single case of pancreatic ductal adenocarcinoma was 818 (95% CI, 770-869), with estimates ranging from 206 (95% CI, 160-264) to 600 (95% CI, 540-666) in the subcohorts.

“While previous attempts have focused on identifying a high-risk subgroup based on the identification of new-onset diabetes, the present study expands on previous research by providing estimates of pancreatic cancer incidence across a range of newly established hyperglycemia, including levels that would qualify as prediabetes,” the authors wrote.

“The present study also highlighted potential differences in the association of new-onset hyperglycemia and the risk of pancreatic cancer based on race/ethnicity that have not been reflected in recent attempts to develop risk-prediction models to further identify high-risk subgroups,” the authors continued. “Accounting for these differences in future approaches to risk stratification is an important step to avoid potentially exacerbating existing disparities in pancreatic cancer.”

Notably, the current study limited the analysis to evaluation of HbA_1c level; however, it is likely that cancer rates would have varied if other measures of hyperglycemia had been included. In addition, the researchers did not examine the role of antihyperglycemic medications, which could have played a role in determining glycemic status in the study cohorts that included patients with a history of diabetes.

“Ultimately, the number of patients needing to undergo testing based solely on elevation in HbA_1c level exceeded reasonable limits based on available testing strategies and resources,” the authors wrote. “Alternative approaches to risk stratification are still needed to improve early detection of pancreatic cancer.”

Reference:

Wu BU, Butler RK, Lustigova E, Lawrence JM, Chen W. Association of Glycated Hemoglobin Levels with Risk of Pancreatic Cancer. JAMA Network Open. doi: 10.1001/jamanetworkopen.2020.4945.