Inter-institutional heterogeneity in outcomes of chemotherapy for metastatic gastric cancer: correlative study in the JCOG9912 phase III trial

Treatment selection for esophageal cancer: evaluation from a nationwide database

BACKGROUND

Most elderly patients poorly tolerate the standard treatment for esophageal cancer; however, little information is available regarding the appropriateness of non-standard esophageal cancer treatments for those patients. This study aims to analyze the treatment costs and completion rates of patients undergoing a real-world treatment for esophageal cancer to elucidate the treatment selection and its quality.

MATERIALS AND METHODS

We analyzed treatment costs and completion rates for patients with esophageal cancer and analyzed these data relative to patient age and center volumes. Patients with esophageal cancer [UICC, TMN, Clinical stage II/III (excluding T4)] who were diagnosed in 2013 were analyzed. Patients were classified into five groups defined as follows: surgical therapy, chemotherapy, concurrent chemoradiotherapy (CCRT), modified concurrent chemoradiotherapy (mCRT), and radiotherapy (RT).

RESULTS

Mean and median age of patients who received surgery and CCRT were comparable; however, patients who underwent mCRT and RT tended to be older. Medical costs associated with surgery were higher than costs associated with other non-surgical treatments. Cost and completion rate of chemoradiotherapy did not differ between CCRT and mCRT; however, both had higher completion rates compared to that of RT. Surgical expenses tended to be the highest in low-volume centers and the lowest in high-volume centers.

CONCLUSION

Treatment of esophageal cancer at high-volume centers seems well balanced compared with medium- to low-volume centers. mCRT was widely performed and comparable in medical cost to CCRT, although additional clinical impacts were unclear.

Are treatment outcomes in gastric cancer associated with either hospital volume or surgeon volume?

Surgical resection is the only curative treatment for gastric cancer. Postoperative outcomes may be affected by the average or total number of surgeries carried out at an institution (hospital volume) or by a surgeon (surgeon volume). Among seven large‐scale studies that each enrolled over 10 000 patients who underwent gastrectomy, six showed that higher hospital volume contributed to a lower mortality rate after gastrectomy. Surgeon volume was also reported by three of four studies that each included over 1000 patients to be a significant factor contributing to heterogeneity in mortality rates after gastrectomy. In contrast, most studies showed no relationship between hospital volume and postoperative morbidity. A significant long‐term relationship was demonstrated in four of nine studies that each included more than 1000 patients, but the other five studies showed negative results. A recent correlative study of randomized phase III trials for gastric cancer surgeries showed a significant relationship between hospital volume and postoperative morbidity in one trial but not in another trial. There was no correlation between overall survival and either hospital or surgeon volume. In addition, another correlative study of a phase III trial of randomized chemotherapy for unresectable or recurrent gastric cancer found that there was no correlation between hospital volume and overall survival, although there was a large degree of heterogeneity in median overall survival among participating institutions.

Institutional variation in short- and long-term outcomes after surgery for gastric or esophagogastric junction adenocarcinoma: correlative study of two randomized phase III trials (JCOG9501 and JCOG9502)

BACKGROUND

A critical issue in multicenter randomized trials focusing on surgical techniques is quality control, as the quality of the surgery usually varies widely if the procedure employed is complicated. Few studies have evaluated interinstitutional variation in randomized trials in order to check not only the generalizability of the results but also the reliability of the study group itself.

METHODS

Two randomized phase III trials (JCOG9501 and JCOG9502) were conducted that compared standard and experimental surgery for gastric and esophagogastric junction adenocarcinomas. Mixed effects models were used to examine short- and long-term outcome data for 521 patients from 23 hospitals in JCOG9501 and 157 patients from 21 hospitals in JCOG9502.

RESULTS

In both trials, some variation was observed in the number of dissected lymph nodes, the operative time, and the volume of blood lost. Estimated 5-year overall survival after standard surgery differed among hospitals (JCOG9501, 58.0-75.1 %; JCOG9502, 49.1-58.7 %), while there was little variation in the hazard ratio for overall survival (OS) for experimental versus standard surgery (JCOG9501, 1.05-1.48; JCOG9502, 1.44-1.48). Higher hospital gastrectomy volume was significantly correlated with a lower proportion of postoperative complications in JCOG9501 (ρ = -0.524, P = 0.010) and reduced blood loss in JCOG9502 (ρ = -0.442, P = 0.045). OS was not correlated with hospital or surgeon volume.

CONCLUSIONS

There was some degree of interinstitutional variation in outcomes after standard surgery, but there was little variation in the hazard ratio for OS for experimental surgery, indicating that the final conclusions of the two randomized phase III trials can be generalized to their respective target populations.