Postgastrectomy pharmacokinetic changes of S-1 in patients with localized advanced gastric cancer

Phase I study of adjuvant chemotherapy with nab-paclitaxel and S-1 for stage III Lauren's diffuse-type gastric cancer after D2 resection (NORDICA study)

PURPOSE

The prognosis of diffuse-type gastric cancer (DGC) is poorer than that of intestinal type, but S-1 is a potential treatment option in DGC. This study explored the maximal tolerated dose (MTD) and the recommended dose for phase II study (RP2D) of nab-paclitaxel combined with S-1 (AS regimen) as adjuvant chemotherapy in stage III DGC.

METHODS

Patients with stage III DGC were recruited into this phase I dose-escalation study between July 2019 and June 2020 in Zhongshan Hospital. Nab-paclitaxel and S-1 (80-120 mg/day, d1-14, q3w) were administrated for 6 cycles, and then 8 cycles of S-1 monotherapy were applied. The patients received nab-paclitaxel at 180, 220, or 260 mg/m² according to the 3 + 3 design based on dose-limiting toxicity (DLT). The primary endpoint was RP2D. Secondary endpoints were the 1-year disease-free survival (DFS) rate and adverse events (AEs).

RESULTS

One case experienced DLT in 180-mg/m² dose group, subsequently three additional subjects were enrolled. DLT was not observed in the 220- and 260-mg/m² dose groups (both n = 3). Therefore, the MTD has not reached, and the RP2D of nab-paclitaxel would be 260 mg/m² . Five participants showed progressive disease, with three and two participants in the 180- and 220-mg/m² dose groups, respectively. The 6-, 12-, and 18-month DFS rates were 100%, 63.6%, and 50.9%, respectively. The most frequently observed AEs were neutropenia (83.3%) and leukopenia (66.7%).

CONCLUSION

The RP2D of nab-paclitaxel as adjuvant chemotherapy in DGC was 260 mg/m² . The AS regimen had a tolerable AE profile in stage III DGC.

The Effects of Bariatric Surgery and Gastrectomy on the Absorption of Drugs, Vitamins, and Mineral Elements

Bariatric surgery, which is an effective treatment for obesity, and gastrectomy, which is the primary treatment method for gastric cancer, alter the anatomy and physiology of the digestive system. Weight loss and changes in the gastrointestinal tract may affect the pharmacokinetic parameters of oral medications. Both bariatric and cancer patients use drugs chronically or temporarily. It is important to know how surgery affects their pharmacokinetics to ensure an effective and safe therapy. The Cochrane, PubMed, and Scopus databases were searched independently by two authors. The search strategy included controlled vocabulary and keywords. Studies show that bariatric surgery and gastrectomy most often reduce the time to maximum plasma concentration (t_max) and decrease the maximum plasma concentration (C_max) in comparison with the values of these parameters measured in healthy volunteers. Vitamin and mineral deficiencies are also observed. The effect depends on the type of surgery and the properties of the drug. It is recommended to use the drugs that have been tested on these groups of patients as it is possible to monitor them.

A Phase II Study Demonstrates No Feasibility of Adjuvant Treatment with Six Cycles of S-1 and Oxaliplatin in Resectable Esophageal Adenocarcinoma, with ERCC1 as Biomarker for Response to SOX

Simple Summary

Neoadjuvant chemoradiotherapy followed by surgery is currently standard of care in esophageal adenocarcinoma. However, prognosis remains dismal. The aim of our study was to assess the feasibility of administering six cycles of adjuvant S-1 and oxaliplatin following neoadjuvant chemoradiotherapy and esophagectomy. Although six cycles of adjuvant S-1 and oxaliplatin were not feasible in pretreated patients, mainly due to toxicity, efficacy results were promising compared to a propensity-score matched cohort. Exploratory biomarker analyses demonstrated potential benefit for patients with Excision repair cross-complementation group 1 (ERCC1) negative tumor expression. A proteomics biomarker model provided valuable information for prediction of survival and pharmacokinetics of 5-FU showed a correlation with treatment-related toxicity. Although it remains unclear if additional chemotherapy should be provided in the adjuvant setting, subgroups such as patients with ERCC1 negativity, could potentially benefit from this treatment option based on our exploratory biomarker research.

Abstract

We assessed the feasibility of adjuvant S-1 and oxaliplatin following neoadjuvant chemoradiotherapy (nCRT) and esophagectomy. Patients treated with nCRT (paclitaxel, carboplatin) and esophagectomy received six 21-day cycles with oxaliplatin (130 mg/m²) on day 1 and S-1 (25 mg/m² twice daily) on days 1–14. The primary endpoint was feasibility, defined as ≥50% completing treatment. We performed exploratory propensity-score matching to compare survival, ERCC1 and Thymidylate Synthase (TS) immunohistochemistry analyses, proteomics biomarker discovery and 5-FU pharmacokinetic analyses. Forty patients were enrolled and 48% completed all adjuvant cycles. Median dose intensity was 98% for S-1 and 62% for oxaliplatin. The main reason for early discontinuation was toxicity (67%). The median recurrence-free and overall survival were 28.3 months and 40.8 months, respectively (median follow-up 29.1 months). Survival was not significantly prolonged compared to a matched cohort (p = 0.09). Patients with ERCC1 negative tumor expression had significantly better survival compared to ERCC1 positivity (p = 0.01). Our protein signature model was predictive of survival [p = 0.04; Area under the curve (AUC) 0.80]. Moreover, 5-FU pharmacokinetics significantly correlated with treatment-related toxicity. To conclude, six cycles adjuvant S-1 and oxaliplatin were not feasible in pretreated esophageal adenocarcinoma. Although the question remains whether additional treatment with chemotherapy should be provided in the adjuvant setting, subgroups such as patients with ERCC1 negativity could potentially benefit from adjuvant SOX based on our exploratory biomarker research.