# Construction and validation of the prognostic nomogram model for patients with diffuse-type gastric cancer based on the SEER database

## TL;DR

This study builds and validates a nomogram model to predict survival in diffuse-type gastric cancer patients using data from the SEER database.

## Contribution

A novel nomogram model with higher accuracy than the TNM staging system for predicting survival in diffuse gastric cancer patients.

## Key findings

- The nomogram model achieved a c-index of 0.750, outperforming the TNM staging system.
- Age, T, N, M, TNM, surgical status, chemotherapy status, and seven markers were identified as independent predictors of survival.
- The calibration curve showed strong agreement between predicted and actual survival rates.

## Abstract

The prognostic factors of diffuse GC patients were screened the prognostic nomogram was constructed, and the prediction accuracy was verified.

From 2006 to 2018, there were 2877 individuals pathologically diagnosed with diffuse gastric cancer; the clinicopathological features of these patients were obtained from the SEER database & randomly divided into a training cohort (1439) & validation cohort (1438).To create prognostic nomograms & choose independent prognostic indicators to predict the overall survival (OS) of 1, 3, & 5 years, log-rank & multivariate COX analysis were utilized & discrimination ability of nomogram prediction using consistency index and calibration curve.

Age, T, N, M, TNM, surgical status, chemotherapy status, & all seven markers were independent predictors of OS (P < 0.05), & a nomogram of OS at 1, 3, & 5 years was created using these independent predictors. The nomogram's c-index was 0.750 (95% CI 0.734 ~ 0.766), greater than the TNM staging framework 0.658 (95%CI 0.639 ~ 0.677); the c-index was 0.753 (95% CI 0.737 ~ 0.769) as well as superior to the TNM staging mechanism 0.679 (95% CI 0.503–0.697). According to the calibration curve, the projected survival rate using the nomogram & the actual survival rate are in good agreement.

Prognostic nomograms are useful tools for physicians to assess every individual's individualised prognosis & create treatment strategies for those with diffuse gastric cancer. They can reliably predict the prognosis for individuals with diffuse gastrointestinal carcinoma.