Prospective Assessment of nProfiler® 1 on Prognosis and Chemotherapy Response for Gastric Cancer

1. Background: According to Global Cancer Statistics of International Agency for Research on Cancer under World Health Organization, stomach cancer is the fifth most common cancer as there were over 1 million new cases in 2018 and the third leading cause of cancer death by 783,000 people are estimated to die of stomach cancer. In Korea, gastric cancer is the most frequent cancer in 13.3% of all cancer cases by the report of Korea Central Cancer Registry in 2018. Since 2010, adjuvant chemotherapy with advanced gastric cancer stage 2 and stage 3 patients following gastrectomy has become a standard treatment through clinical validation of increasing the patient's survival rate. However, even in the second and third stages of the same stomach cancer, the biological properties may be different. 2. Purpose:

The nProfiler® 1 Stomach Cancer Assay is a molecular diagnostic test to predict the prognosis for patients with stage Ⅱ-Ⅲ advanced gastric cancer. This study will evaluate the clinical utility of nProfiler® 1 Stomach Cancer Assay by recruiting subjects from multi centers and observing the 5-year survival rates of Low risk, Intermediate risk, High risk according to gastric cancer prognostic molecular diagnostic test. 3. Study Procedure:

* Obtaining of informed consent form * Review of provider's eligibility/ Sample preparation and delivery * Sample criteria evaluation * Subject enrollment * Gastric cancer prognostic prediction molecular diagnostic test * Prognostic group result report * 5-yr survival follow-up * Statistical analysis 4. Outcome Measures:

The following efficacy outcome measures will be assessed:

* Primary efficacy outcome measure

:High risk and low risk group's 5-yr Overall Survival(OS) rate * Secondary efficacy outcome measure

* High risk and Low risk group's 3-yr Disease Free Survival(DFS) rate * Intermediate risk group's 5-yr OS and 3-yr DFS rate * Subgroup analysis : Adjuvant chemotherapy benefit of Low risk (5-yr OS rate, 3 yr DFS rate)