This study investigated a large number of patients to develop a predictive nomogram for survival and a web-based survival rate calculator that can dynamically predict the long-term survival of patients with primary gastric diffuse large B-cell lymphoma.

A total of 2647 patients diagnosed with primary gastric diffuse large B-cell lymphoma from 1998 to 2014 were extracted from the SEER database. We used the Lasso Cox regression model to identify independent risk factors for long-term survival and to develop a predictive nomogram for survival and a web-based survival rate calculator.

The median (mean) follow-up time was 30 months (52.8 months). Cancer-specific survival rates decreased with time, while the 5-year conditional survival increased with time. Cancer-specific deaths were not constant. Cancer-specific deaths of patients within the first 2 years were high, while the risk remained relatively constant after 2 years. The independent risk factors included surgery, chemotherapy, tumor stage and age, according to the Lasso Cox regression analysis. We developed a predictive nomogram and a web-based survival rate calculator (https://linjuli1991.shinyapps.io/dynnomapp/). The calibration plot suggested that the actual value exhibited good agreement with the predicted value.

We found that patients with primary gastric diffuse large B-cell lymphoma had a high risk of death during the first 2 years. Additional active follow-up strategies should be provided during this period. This is the first study to develop a predictive nomogram and a web-based survival rate calculator that can provide evidence for individual treatment and follow-up.