The people who are suffering from cancer, try and find every possible way using which they can be saved. Therefore, in addition to chemotherapy, the people these days also rely on radiation therapies which play a vital role in curing the patients who have already extracted a disease at a very advanced level. However, this therapy is not useful for patients who have developed negative lymph nodes. but ignoring the disadvantages, this therapy is extremely useful for the patients who have contracted positive lymph nodes and lymphovascular invasion.  Therefore, in order to validate such results, the scientist made an attempt to unravel the survival benefit of radiation therapy who already are diagnosed with gastric cancer. The method used for this process is Kaplan-Meier. The scientists were able to take a sample of 4000 people for conducting a survey. It was observed that all those patients who received chemotherapy alone had lesser chances of survival as compared to those patients who had been diagnosed with both chemotherapy and radiation therapy. Therefore, this shows that proper radiation therapy increases the chances of survival for patients diagnosed with gastric cancer.

Ref. link. https://www.clinicaloncologyonline.net/article/S0936-6555(19)30418-2/fulltext