Prognostic Difference Between Eastern and Western Patients With Gastric Cancer: Quality of Care, Ethnicity, or Biology?

Predicting peritoneal recurrence after radical gastrectomy for gastric cancer: Validation of a prediction model (PERI-Gastric 1 and PERI-Gastric 2) on a Korean database

BACKGROUND

Peritoneal recurrence is a significant cause of treatment failure after radical gastrectomy for gastric cancer. The prediction of metachronous peritoneal recurrence would have a significantly impact risk stratification and tailored treatment planning. This study aimed to externally validate the previously established PERI-Gastric 1 and 2 models to assess their generalizability in an independent population.

METHODS

Retrospective external validation was conducted on a cohort of 8564 patients who underwent elective gastrectomy for stage Ib-IIIc gastric cancer between 1998 and 2018 at the Yonsei Cancer Center. Discrimination was tested using the area under the receiver operating characteristic curves (AUROC). Accuracy was tested by plotting observations against the predicted risk of peritoneal recurrence and analyzing the resulting calibration plots. Clinical usefulness was tested with a decision curve analysis.

RESULTS

In the validation cohort, PERI-Gastric 1 and PERI-Gastric 2 exhibited an AUROC of 0.766 (95 % C.I. 0.752-0.778) and 0.767 (95 % C.I. 0.755-0.780), a calibration-in-the-large of 0.935 and 0.700, a calibration belt with a 95 % C.I. over the bisector in the risk range of 24%-33 % and 35%-47 %. The decision curve analysis revealed a positive net benefit in the risk range of 10%-42 % and 15%-45 %, respectively.

CONCLUSIONS

This study presents the external validation of the PERI-Gastric 1 and 2 scores in an Eastern population. The models demonstrated fair discrimination and satisfactory calibration for predicting the risk of peritoneal recurrence after radical gastrectomy, even in Eastern patients. PERI-Gastric 1 and 2 scores could also be applied to predict the risk of metachronous peritoneal recurrence in Eastern populations.

Robotic versus laparoscopic gastrectomy for gastric cancer: A Western propensity score matched analysis

BACKGROUND

Robot-assisted gastrectomy (RG) has been shown to be safe and feasible in the treatment of gastric cancer (GC). However, it is unclear whether RG is equivalent to laparoscopic gastrectomy (LG), especially in the Western world. Our objective was to compare the outcomes of RG and LG in GC patients.

METHODS

We reviewed all gastric adenocarcinoma patients who underwent curative gastrectomy by minimally invasive approach in our institution from 2009 to 2022. Propensity score matching (PSM) analysis was conducted to reduce selection bias. DaVinci Si platform was used for RG.

RESULTS

A total of 156 patients were eligible for inclusion (48 RG and 108 LG). Total gastrectomy was performed in 21.3% and 25% of cases in LG and RG, respectively. The frequency of stage pTNM II/III was 48.1%, and 54.2% in the LG and RG groups (p = 0.488). After PSM, 48 patients were matched in each group. LG and RG had a similar number of dissected lymph nodes (p = 0.759), operative time (p = 0.421), and hospital stay (p = 0.353). Blood loss was lower in the RG group (p = 0.042). The major postoperative complications rate was 16.7% for LG and 6.2% for RG (p = 0.109). The 30-day mortality rate was 2.1% and 0% for LG and RG, respectively (p = 1.0). There was no significant difference between the LG and RG groups for disease-free survival (79.6% vs. 61.2%, respectively; p = 0.155) and overall survival (75.9% vs. 65.7%, respectively; p = 0.422).

CONCLUSION

RG had similar surgical and long-term outcomes compared to LG, with less blood loss observed in RG.

Application of the Khorana score for cancer-associated thrombosis prediction in patients of East Asian ethnicity undergoing ambulatory chemotherapy

BACKGROUND

The Khorana score (KS) has not been well studied in East Asian cancer patients, who have different genetic backgrounds for inherited thrombophilia, body metabolism, and cancer epidemiology.

METHODS

By using the Common Data Model, we retrospectively collected deidentified data from 11,714 consecutive newly diagnosed cancer patients who underwent first-line chemotherapy from December 2015 to December 2021 at a single institution in Korea, and we applied the KS for cancer-associated thrombosis (CAT) prediction. Age at diagnosis, sex, and use of highly thrombogenic chemotherapeutics were additionally investigated as potential risk factors for CAT development.

RESULTS

By 6 months after chemotherapy initiation, 207 patients (1.77%) experienced CAT. Only 0.4% had a body mass index (BMI) ≥ 35 kg/m² and changing the cutoff to 25 kg/m² improved the prediction of CAT. Age ≥ 65 years and the use of highly thrombogenic chemotherapeutics were independently associated with CAT development. KS values of 1 ~ 2 and ≥ 3 accounted for 52.3% and 7.6% of all patients, respectively, and the incidence of CAT in these groups was 2.16% and 4.16%, respectively, suggesting a lower incidence of CAT in the study population than in Westerners. The KS component regarding the site of cancer showed a good association with CAT development but needed some improvement.

CONCLUSION

The KS was partially validated to predict CAT in Korean cancer patients undergoing modern chemotherapy. Modifying the BMI cutoff, adding other risk variables, and refining the use of cancer-site data for CAT risk prediction may improve the performance of the KS for CAT prediction in East Asian patients.

Validation of two prognostic models for recurrence and survival after radical gastrectomy for gastric cancer

BACKGROUND

Prognostic models from Korea and Italy have been developed that predict overall survival and cancer recurrence respectively after radical gastrectomy for gastric cancer. The aim of this study was to validate the two models in independent patient cohorts, and to evaluate which factors may explain differences in prognosis between Korean and Italian patients with gastric cancer.

METHODS

Patients who underwent radical gastrectomy for gastric cancer between January 2000 and December 2004 at Seoul National University Hospital and at eight centres in Italy were included. Discrimination of the models was tested with receiver operating characteristic (ROC) curves and calculation of area under the curve (AUC). Calibration was evaluated by plotting actual survival probability against predicted survival probability for the Korean nomogram, and actual against predicted risk of recurrence for the Italian score.

RESULTS

Some 2867 and 940 patients from Korea and Italy respectively were included. The Korean nomogram achieved good discrimination in the Italian cohort (AUC 0·80, 95 per cent c.i. 0·77 to 0·83), and the Italian model performed well in the Korean cohort (AUC 0·87, 0·85 to 0·89). The Korean nomogram also achieved good calibration, but this was not seen for the Italian model. Multivariable analyses confirmed that Italian ethnicity was an independent risk factor for cancer recurrence (odds ratio (OR) 1·72, 1·31 to 2·25; P < 0·001), but not for overall survival (OR 1·20, 0·95 to 1·53; P = 0·130).

CONCLUSION

Both prognostic models performed fairly well in independent patient cohorts. Differences in recurrence rates of gastric cancer may be partially explained by ethnicity.

Lymphadenectomy: state of the art

The extent of lymphadenectomy in gastric cancer (GC) surgery has been for long time a matter of debate. Randomized trials performed in the West reported worse results of D2 dissection, in terms of postoperative complications and long-term survival benefit, than Eastern series and observational studies from specialized Western centers. However, long-term re-evaluation of such trials and in depth-analysis of other experiences demonstrated the potential benefit of D2 in reducing the probability of cancer-related death and the safety of this procedure when avoiding unnecessary spleno-pancreatectomy and in centers with ad adequate surgical volume. Nowadays, the D2 is considered the standard treatment in most guidelines all over the world. More limited procedures (D1, D1 plus) may be adequate in selected cases, and more extended dissections (D2 plus) could be indicated in advanced forms with high risk of metastases to distant nodes, but in specialized centers or in the setting of clinical studies. The integration with neoadjuvant therapies and multimodality approach could offer a chance of cure in groups of patients with poor results when approached with standard treatment.

External Validation of a Score Predictive of Recurrence after Radical Surgery for Non-Cardia Gastric Cancer: Results of a Follow-Up Study

BACKGROUND

A score predictive of tumor recurrence after radical surgery for non-cardia gastric cancer was previously developed in Italian centers. The aim of this study was to validate the score in a consecutive cohort with prospectively collected follow-up data.

STUDY DESIGN

Of 1,178 patients surgically treated between 1998 and 2006, six hundred and thirty-five patients who fulfilled the selection criteria and completed the follow-up program were available for analysis. The score value for each patient was calculated using the formula obtained from a logistic regression model. Discrimination and calibration of the score in the validation group were evaluated and compared with the data of 438 patients in the study group where the score was developed.

RESULTS

Most patients in both groups had very low or very high score values. In the validation group, the observed recurrence rates ranged from 5% to 92% in different score strata. The area under the receiver operating characteristic curve was 0.889 (95% CI, 0.864-0.914; p < 0.001), indicating a high discrimination value of the score for recurrence. A good calibration was observed by comparing the predicted risk with the actual risk of recurrence. With a score cut-off value of 50, sensitivity, specificity, and overall accuracy were 74%, 86%, and 81%, respectively. An inverse correlation between the time to recurrence and score level was also estimated (R(2) = 0.119; p < 0.001).

CONCLUSIONS

The high predictive value of the score was validated in a consecutive cohort. These results might allow the introduction of the score in clinical practice for Western patients.