Clinical biomarkers in adjuvant chemotherapy for gastric cancer after D2 dissection by a pooled analysis of individual patient data from large randomized controlled trials

Prognostic effect of excessive chemotherapy cycles for stage II and III gastric cancer patients after D2 + gastrectomy

BACKGROUND

According to relevant investigation and analysis, there are few research studies on the effect of excessive chemotherapy cycles after D2 gastrectomy on the survival of patients with gastric cancer.

AIM

To determine whether excessive chemotherapy cycles provide extra survival benefits, reduce recurrence rate, and improve survival rate in patients with stage II or III gastric cancer.

METHODS

We analyzed and summarized 412 patients with stage II gastric cancer and 902 patients with stage III gastric cancer who received D2 gastrectomy plus adjuvant chemotherapy or neoadjuvant chemotherapy. Analysis and comparison at a ratio of 1:1 is aimed at reducing realistic baseline differences (n = 97 in each group of stage II, n = 242 in each group of stage III). Progression-free survival, overall survival and recurrence were the main outcome indicators.

RESULTS

When the propensity score was matched, the baseline features of stage II and III gastric cancer patients were similar between the two groups. After a series of investigations, Kaplan-Meier found that the progression-free survival and overall survival of stage II and III gastric cancer patients were consistent between the two groups. The local metastasis rate (P = 0.002), total recurrence rate (P < 0.001) and distant metastasis rate (P = 0.001) in the ≥ 9 cycle group of stage III gastric cancer were statistically lower than those in the < 9 cycle group. The interaction analysis by Cox proportional hazard regression model showed that intestinal type, proximal gastrectomy, and ≥ 6 cm maximum diameter of tumor had a higher risk of total mortality in the < 9 cycles group.

CONCLUSION

Overall, ≥ 9 chemotherapy cycles is not recommended for patients with stage II and stage III gastric cancer because it has an insignificant role in the prognosis of gastric cancer. However, for patients with stage III gastric cancer, ≥ 9 cycles of chemotherapy was shown to significantly decrease recurrence.

Establishing a cancer driver gene signature-based risk model for predicting the prognoses of gastric cancer patients

Despite the high prevalence of gastric cancer (GC), molecular biomarkers that can reliably detect GC are yet to be discovered. The present study aimed to establish a robust gene signature based on cancer driver genes (CDGs) that can predict GC prognosis. Transcriptional profiles and clinical data from GC patients were analyzed using univariate Cox regression analysis and the least absolute shrinkage and selection (LASSO)-penalized Cox regression analysis to select optimal prognosis-related genes for modeling. Time-dependent receiver operating characteristic (ROC) and Kaplan-Meier analyses were done to assess the predictive power of this gene signature. A nomogram model for prediction of survival of GC patients was established using the CDG signature and clinical information, and a seven-CDG signature was identified. Risk scores were calculated using this signature, and patients were subsequently divided into high- and low-risk groups; high-risk patients in the training and validation datasets had poorer prognoses than low-risk patients. Cox regression analysis revealed that the CDG signature is an independent prognostic factor for GC. The signature and other clinical features were used to construct a nomogram for predicting overall GC patient survival. Calibration and decision curve analysis showed that the nomogram accurately predicted survival, highlighting its clinical utility. Thus, we established a novel CDG signature and nomogram for predicting GC prognosis, which may facilitate personalized treatment of GC.

Usefulness of an S-1 dosage formula: an exploratory analysis of randomized clinical trial (JCOG1001)

BACKGROUND

The blood concentration of S-1 and adverse events are affected by renal function. Herein, an S-1 dosage formula was developed based on renal function, indicating the dose for a target blood concentration. This study aimed to explore the usefulness of the formula in adjuvant chemotherapy for gastric cancer.

METHODS

In this ad hoc analysis of the JCOG1001 trial, which evaluated the role of bursectomy for resectable gastric cancer, the recommended dose of S-1 was calculated using the following formula: 1447.8 × (14.5 + 0.301 × CLcr + 8.23 × SEX [male = 1, female = 0]) × body surface area (BSA) (mg/day). Patients were divided into three groups by comparing the initial S-1 dose determined using BSA with the dose recommended by the formula: underdose (UD), equal dose (ED), and overdose (OD).

RESULTS

Among 686 eligible patients, 58, 304, and 324 patients were classified into the UD, ED, and OD groups. The patients' characteristics in the UD/ED/OD groups were median age (53.5/64.0/67.5 years), male sex (98.3%/75.3%/58.0%), and median BMI (24.8/22.8/22.3), respectively. The planned 1-year adjuvant S-1 therapy was completed in 74.1%/73.7%/68.5%, dose reduction was required in 8.6%/21.1%/30.6%, and treatment schedule was altered in 8.6%/17.1/19.8% in the UD/ED/OD groups, resulting in the 5-year overall survival rates of 77.3%/74.3%/77.0%, respectively. The incidences of grade > 3 anemia, thrombocytopenia, diarrhea, stomatitis, and anorexia were significantly higher in the OD group than in the ED and UD groups.

CONCLUSIONS

Dose optimization using an S-1 dosage formula can potentially reduce grade ≥ 3 adverse events for overdosed patients.