A Nomogram Based on Clinicopathologic Features and Preoperative Hematology Parameters to Predict Occult Peritoneal Metastasis of Gastric Cancer: A Single-Center Retrospective Study

Abstract

Background. In patients with gastric cancer (GC), peritoneal metastasis is an indication of the end stage and often indicates a poor outcome. The diagnosis of peritoneal metastasis, especially occult peritoneal metastasis (OPM), remains a challenge for surgeons. This study was designed to explore the relationship between OPM and clinicopathological characteristics and preoperative hematological parameters in patients with GC and to develop a nomogram to predict the probability of OPM before surgery. Methods. A total of 672 patients with GC from our center were included, including 583 OPM-negative and 89 OPM-positive patients. These patients were divided into training and validation groups based on when they received treatment. OPM was diagnosed during surgery in patients without any signs of metastasis through imaging examination. Predictive factors were screened by least absolute shrinkage and selection operator logistic regression of all 18 characteristics. The nomogram of OPM was constructed based on these filtered variables. The discriminative and calibration performance of the model were simultaneously evaluated. Results. A total of six variables, including tumor size, degree of differentiation, depth of invasion, Glasgow prognosis score, and plasma levels of CA125 and fibrinogen, were selected for integration into the final predictive nomogram. The area under curve (AUC) of the nomogram with six factors was 0.906 (95% confidence interval (CI): 0.872-0.941) and 0.889 (95% CI: 0.795-0.984) in the training and validation groups, respectively. Calibration plots of the nomogram in the two sets revealed a good consistency between predicted and actual probabilities. Decision curve analysis showed that the nomogram had a positive net benefit among all threshold probabilities between 0% and 82%. This nomogram was superior to models incorporating only clinicopathologic or hematologic features. Conclusion. Both clinicopathological and preoperative hematological parameters are significantly associated with OPM. The nomogram constructed with six factors could be used to calculate the probability of OPM and identify the high-risk population in GC. This may be helpful for early detection of OPM in patients with GC.

The Burden of Peritoneal Metastases from Gastric Cancer: A Systematic Review on the Incidence, Risk Factors and Survival

“…After title and abstract screening, 38 studies were considered potentially eligible. After full text screening, seventeen studies were included [ 12 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. The study flowchart and reasons for exclusion are shown in Figure 1 and Appendix B .…”

“…The study flowchart and reasons for exclusion are shown in Figure 1 and Appendix B . In sixteen studies, information on incidence numbers of synchronous gastric peritoneal metastases was provided [ 12 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Risk factors for gastric peritoneal metastases were reported in four studies [ 15 , 16 , 17 , 18 ].…”

“…Of all included studies, five studies were population-based studies [ 12 , 15 , 16 , 17 , 18 ], six studies were observational cohort studies [ 19 , 20 , 21 , 22 , 23 , 24 ] and six studies reported surgical cohorts of patients who underwent a staging laparoscopy [ 25 , 26 , 27 , 28 , 29 , 30 ]. Study characteristics and outcome measures of all studies are presented in Table 1 A,B and Table 2 .…”

“…The six observational cohort studies were published between 2003 and 2015 and the number of included patients ranged from 1108 to 4559 ( Table 1 B) [ 19 , 20 , 21 , 22 , 23 , 24 ]. The six studies that reported the incidence of gastric peritoneal metastases of patients who underwent staging laparoscopy were published between 2013 and 2020, and the number of included patients ranged from 89 to 867 ( Table 2 ) [ 25 , 26 , 27 , 28 , 29 , 30 ].…”

“…Six studies reported the incidence of synchronous gastric peritoneal metastases of patients who underwent a staging laparoscopy. Patient in these studies were eligible for curative intent surgery and no systemic metastases after radiological staging [ 25 , 26 , 27 , 28 , 29 , 30 ]. The studies in this subgroup were conducted in the United States [ 25 ], China [ 26 , 27 ], Pakistan [ 28 ] and the United Kingdom [ 29 , 30 ].…”