Lymph node ratio prognostic, can guide therapy in gastric cancer

Last Updated: 2017-06-15

By David Douglas

NEW YORK (Reuters Health) - A greater degree of lymphatic spread in patients with resected gastric cancer may be informative in choosing candidates for adjuvant chemoradiation therapy, according to a retrospective study.

As Dr. Timothy M. Pawlik explained in an email to Reuters Health, the study "emphasizes the importance of a ratio that incorporates both the number of nodes harvested (denominator) as well as the number of nodes with metastatic disease (numerator). The total number of nodes harvested at an operation can be an important metric of surgical quality."

"In addition," he pointed out, "our data would suggest that the ratio of 'positive' nodes to total number of nodes is a relevant factor in deciding which patients may benefit the most from additional post-operative adjuvant therapies to consolidate their cancer care."

The findings were published online May 31 in Surgery. Dr. Pawlik of the Wexler Medical Center at The Ohio State University, in Columbus, and colleagues analyzed data on 719 patients with gastric adenocarcinoma who underwent curative-intent resection between 2000 and 2013.

Most had total or subtotal gastrectomy with the remainder (18.4%) undergoing distal gastrectomy or wedge resection. In all, 45.2% had resection alone, 35.2% received 5-FU or capecitabine-based chemoradiation therapy, and the remaining 19.6% received chemotherapy. Median overall survival was 40.9 months, and five-year overall survival was 40.3%.

Five-year overall survival was 54.1% in patients with a lymph node ratio of zero. For 0.01 to 0.10, survival was 53.1%, and for greater than 0.10 to 0.25, it was 49.1%. However, in patients with a ratio greater than 0.25, survival fell to just 19.8% (hazard ratio, 2.3; p<0.05).

Other factors significantly associated with worse overall survival included involvement of the gastroesophageal junction (HR, 1.8) and lymphovascular invasion (HR, 1.4).

Versus resection alone, in a multivariable model, adjuvant chemoradiation was associated with significantly improved overall survival (HR, 0.40). Versus chemotherapy, the corresponding hazard ratio was 0.45. However, these benefits were seen only in patients with a lymph node ratio beyond 0.25.

The investigators stress that "there was no noted overall survival benefit of chemotherapy or chemoradiation therapy" among patients with a lower ratio.

Dr. Pawlik concluded, "providers should consider lymph node ratio as a prognostic factor, as well as a tool to decide which patients may derive therapeutic benefit from additional chemotherapy or radiation."

SOURCE: http://bit.ly/2t56YYn

Surgery 2017.