Novel marker may boost gastric cancer diagnosis

Last Updated: 2016-04-07

By David Douglas

NEW YORK (Reuters Health) - Presence of a fragment of the protein apolipoprotein CIII (apoC-III) detected via mass spectrometry in serum can help confirm gastric cancer, according to Chinese researchers.

"We found that the diagnostic ability of the apoC-III fragment . . . performed better than current standard gastric cancer diagnostic biomarkers," Dr. Jiaxiang Wang from The First Affiliated Hospital of Zhengzhou University told Reuters Health by email.

For their study, online March 22 in the British Journal of Cancer, Dr. Wang and colleagues examined 432 serum samples from 296 gastric adenocarcinoma patients.

The team used time-of-flight mass spectrometry and other techniques to screen for reliable protein biomarkers from matched serum samples (preoperative, postoperative and relapsed) as well as from healthy donors. These were then compared with the conventional markers CEA, CA19-9 and CA125.

They analyzed the relative intensities of the 6449 m/z (Da) peak of the apoC-III fragment, together with CEA, CA19-9 and CA125 data, in the testing set to determine diagnostic and prognostic values.

The sensitivity of combined CEA, CA19-9 and CA125 was 36.7% and the specificity was 48.1%. The combination along with 6449 Da gave 88.3% sensitivity and 84.6% specificity.

Notably, the researchers say, "the 6449 Da peak was elevated in 9 of 15 cases in which CEA, CA19-9 and CA125 were below cut-off levels."

This fragment, added Dr. Wang, showed superiority "both individually and in combination in distinguishing patients with gastric cancer from healthy individuals. Moreover, we found that this fragment represented a more robust potential prognostic factor for gastric cancer than the current conventional markers, a complement to the conventional biomarkers in detecting gastric cancer."

The researchers call for larger studies but conclude "that measurement of peak intensity positioned at 6449 Da in serum should improve estimation of postoperative survival chances for these gastric cancer patients."

SOURCE: http://bit.ly/1oF54Kf

Br J Cancer 2016.