Intraoperative consultation on surgical margins 98% accurate in gastric cancer

Last Updated: 2018-11-02

By Reuters Staff

NEW YORK (Reuters Health) - The false-negative rate of intraoperative consultation (IOC) on surgical margins during resection of gastric and gastroesophageal adenocarcinoma is less than 2% overall, according to a retrospective study at a specialty center.

IOC on surgical margins during curative-intent resection can contribute to conversion from an R1 resection to an R0 resection, which seems to be associated with a decreased rate of local recurrence, but it requires prolonged operative time and may be challenging for esophageal, gastroesophageal and gastric tumors.

Dr. John C. McAuliffe from Montefiore Medical Center, in the Bronx, New York, and colleagues reviewed 3,171 IOCs to ascertain the concordance between frozen-section and permanent-section margin status in order to define the prevalence of false-negative results and accuracy of IOC results.

The overall diagnostic accuracy for the IOC was 98.1%, with 1.7% false-negative results and 92.4% true-negative results, the team reports in JAMA Surgery, online October 24.

The prevalence of false-negative results was 1.2% for esophageal margins, 2.0% for gastric margins and 2.5% for duodenal margins, with overall accuracy rates of 98.7%, 97.8% and 96.8%, respectively.

The accuracy of IOC results was somewhat higher for non-signet ring disease (98.6%) than for signet ring disease (96.7%), and higher for nondiffuse disease (98.4%) than for diffuse disease (96.9%).

Neoadjuvant chemotherapy did not appear to affect IOC results, whereas neoadjuvant radiotherapy was associated with a slightly decreased risk of a false-negative IOC result.

The median disease-specific survival was 34.0 months among patients with a false-negative IOC result, compared with 26.9 months among those with a true-positive IOC result (P=0.72).

"The findings of our study suggest that the uncommon false-negative IOC result should be interpreted in the context of the stage of disease, patient risk factors, and the understanding that there are few data that support survival benefit of additional local therapy," the researchers conclude. "The results of this study may help to provide surgeons, pathologists, and patients with expectations for the role of IOC at the time of resection of gastroesophageal junction and gastric adenocarcinoma."

"Gastric cancer is highly prevalent worldwide, and in the United States, as population dynamics evolve in the coming decades, it is likely that esophageal and gastric cancers will be of increasing importance internationally, including in the United States," write Dr. Teviah E. Sachs and Dr. Jennifer F. Tseng from Boston University School of Medicine in a linked editorial. "It is, therefore, increasingly important that studies such as that of McAuliffe et al. focus on best practices and multidisciplinary evaluation of these potentially lethal diseases for which surgical resection remains the mainstay of potentially curative treatment."

Dr. McAuliffe did not respond to a request for comments.

SOURCE: https://bit.ly/2PzxuHb and https://bit.ly/2Ono90y

JAMA Surg 2018.