Reporting patient characteristics and stratification factors in randomized trials of systemic chemotherapy for advanced gastric cancer

BACKGROUND

There is no consensus on which patient characteristics are the most suitable to report or to be used as stratification factors in clinical trials for advanced gastric cancer (AGC), to our knowledge.

METHODS

We conducted a comprehensive review of published randomized trials for AGC to examine the patient characteristics that were reported.

RESULTS

Among the 67 analyzed trials, age, gender, performance status, proportion of patients with measurable disease, and previous gastrectomy were frequently reported (>69%). Histology, number of disease sites, and adjuvant treatment were reported in less than 50% of trials. Although the reporting of second-line chemotherapy has increased in recent trials, it remains at less than 50%. Notably, recent trials have tended to include patients with better performance status and less locally advanced disease, with Asian trials more frequently including patients with more diffuse histology and less locally advanced disease or liver metastasis than non-Asian trials. Stratification was conducted in approximately 60% of the trials, using quite variable stratifying factors.

CONCLUSION

Inconsistency exists in the reporting of patient characteristics, the characteristics themselves, and the use of stratification factors in clinical trials for AGC. A consensus set of important patient characteristics and strata may be necessary to conduct and interpret quality randomized studies.

Phase II study of bolus 5-fluorouracil and leucovorin combined with weekly paclitaxel as first-line therapy for advanced gastric cancer

OBJECTIVE

We evaluated the efficacy and safety of bolus 5-fluorouracil (5-FU) and leucovorin combined with weekly paclitaxel (FLTAX) in advanced gastric cancer (GC) patients.

METHODS

Patients with untreated stage IV GC received paclitaxel 80 mg/m(2) as a 1-hour infusion, followed by 5-FU 600 mg/m(2) as a bolus infusion and L-leucovorin 250 mg/m(2) as a 2-hour infusion on days 1, 8 and 15. Treatment cycles were repeated every 28 days. The primary endpoint was response rate.

RESULTS

Thirty-five patients were enrolled. The median age was 62 years (range 34-75). Twenty-one patients (60%) had diffuse-type cancer and 11 had peritoneal metastasis. The confirmed response rate was 43% (95% CI 26-61) with 15 partial responses. Stable disease was observed in 16 (46%) patients. Median progression-free survival and overall survival were 6.8 months (95% CI 5.8-7.4) and 16.2 months (95% CI 10.0-22.8), respectively. Grade 3-4 adverse events were: neutropenia (54%), febrile neutropenia (3%), diarrhea (6%) and sensory neuropathy (11%).

CONCLUSION

FLTAX showed a desirable safety profile, and the efficacy against advanced GC was encouraging. FLTAX may be a good option for GC patients with deteriorated general condition, and a randomized clinical trial in such patients is currently underway.

Second-line chemotherapy for gastric cancer: a new issue lies ahead in global trials

Chemotherapy for gastric cancer has been advancing fairly well. It has been indicated that not only advances in first-line chemotherapy but also those in second-line chemotherapy have contributed to the prolongation of overall survival. The Arbeitsgemeinschaft Internistische Onkologie (AIO) study supports the idea that second-line chemotherapy is appropriate in patients with a good general condition. Also, the Japan Clinical Oncology Group (JCOG) integral analysis suggests that advances have been made in second-line chemotherapy. However, most recently reported studies of second-line chemotherapy have been conducted as small-scale phase II or retrospective trials. No randomized control trial to establish standard treatment has been reported. Which regimen is the most appropriate as second-line therapy must be investigated in the future. Currently, molecularly targeted agents for gastric cancer are being developed and tested in global trials. As a new issue in global trials, second-line chemotherapy has been emphasized. In recent global trials, subset analysis showed regional differences in overall survival. This was possibly associated with the regional differences in second-line chemotherapy. When developing new molecularly targeted agents for first-line chemotherapy, we cannot ignore the result that the proportion of patients in whom treatment was switched to second-line chemotherapy was high in Asia. In planning a global trial, this new issue should be sufficiently discussed.

Association of fluoropyrimidines, platinum agents, taxanes, and irinotecan in any line of chemotherapy with survival in patients with advanced gastric cancer

BACKGROUND

Although fluoropyrimidines, platinum agents, taxanes, and irinotecan are used in the treatment of advanced gastric cancer (AGC), it remains unclear whether these agents in any line of chemotherapy are associated with overall survival (OS) in these patients.

METHODS

We retrospectively analyzed 704 patients with AGC. To avoid possible lead-time bias, we applied time-varying covariate analysis for chemotherapy with four agents in any line.

RESULTS

Median OS was 12.3 months. The frequency of exposure to each agent class during all lines of treatment was 92.6% for FU (5-fluorouracil or oral fluoropyrimidine), 48.2% for platinum agents, 65.1% for taxanes, and 39.1% for irinotecan. According to a multivariate Cox model with exposure to each agent class as a time-varying covariate, the hazard ratios (HRs) of death were 0.41 (95% confidence interval [CI], 0.27-0.57; p < 0.001) for FU, 0.71 (95% CI, 0.58-0.84; p < 0.001) for platinum agents, 0.51 (95% CI, 0.41-0.63; p < 0.001) for taxanes, and 0.53 (95% CI, 0.43-0.65; p < 0.001) for irinotecan. Although other agents were used in 18.6% of the patients, they did not affect survival.

CONCLUSIONS

Each of the four agent classes (FU, platinum agents, taxanes, and irinotecan) appears to be independently associated with improved OS in patients with AGC regardless of timing. This result suggests the importance of developing strategies which make these active agents available to all patients with AGC to prolong OS.

Progression-free survival and time to progression as surrogate markers of overall survival in patients with advanced gastric cancer: analysis of 36 randomized trials

Progression-free survival (PFS) and time to progression (TTP) have been reported to correlate with overall survival (OS) in several types of cancers. To our knowledge, however, their use in the evaluation of new agents for AGC has not been investigated. We evaluated the potential of PFS and TTP to act as surrogates of OS in clinical trial settings. Randomized trials of systemic chemotherapy for advanced gastric cancer were identified by comprehensive electronic and manual search. Correlations between PFS/TTP and OS were evaluated. Thirty-six trials with a total of 83 treatment arms and 10,484 patients were selected for analysis. The nonparametric Spearman rank correlation coefficient (ρ) between median PFS/TTP and OS was 0.70 (95% CI, 0.59 to 0.82) and the correlation coefficient between hazard ratios in PFS/TTP and OS was 0.80 (95% CI, 0.68 to 0.92). Correlation tended to be higher in trials reporting PFS (ρ = 0.85; 0.72-0.97) than in those reporting TTP (ρ = 0.60; 0.24-0.97), trials in Non-Asian countries (ρ = 0.80; 0.61-0.99) than Asia (ρ = 0.67; 0.39-0.94), trials in patients with measurable lesions only (ρ = 0.91; 0.77-1.00) than in those including non-measurable lesions (ρ = 0.71; 0.50-0.93), albeit that none of these differences was significant. Our results indicate that improvements in PFS/TTP in advanced gastric cancer strongly correlate with improvements in OS. Further research is needed to clarify the surrogacy of PFS/TTP for OS or the role of PFS as the true end point in future randomized clinical trials of chemotherapy for AGC.