By Will Boggs, MD

NEW YORK (Reuters Health) – Median survival of patients with metastatic gastric cancer has not improved, despite increased use of chemotherapy, researchers from The Netherlands report.

“Despite the increased prescription of palliative chemotherapy and the presumed stage migration, the overall survival of patients with metastatic gastric cancer did not change over time (1990-2011),” Dr. Nienke Bernards told Reuters Health. “A subgroup of patients might benefit from palliative chemotherapy, but the marked hospital variation in administration suggests that more research is needed to identify them.”

Several studies have shown benefits of palliative chemotherapy in gastric cancer patients and it is recommended in national guidelines, note Dr. Bernards, from the Comprehensive Cancer Centre South in Eindhoven, and colleagues in their report, but daily practice data are scarce.

The team used data from the Eindhoven Cancer Registry to examine trends in the use of chemotherapy and overall survival in 4797 patients with metastatic gastric cancer diagnosed between 1990 and 2011 in the southern part of The Netherlands.

The researchers found that the incidence of gastric cancer in this region decreased from 27 per 100,000 in 1990 to 13 per 100,000 in 2010, but the proportion of patients presenting with metastatic disease increased from 24% in 1990 to 44% in 2011.

Five percent of patients with metastatic gastric cancer received palliative chemotherapy in 1990, compared with 36% of patients in 2011, according to the report in the Annals of Oncology online October 11th.

Older patients, patients with concomitant comorbidity, and those with multiple distant metastases or linitis plastica received chemotherapy less often, whereas patients under 60 years and patients with higher socioeconomic status received chemotherapy more often.

“Furthermore, a large interhospital variation was seen in the proportion of patients receiving chemotherapy, varying from 9% to 27%,” Dr. Bernards and colleagues report.

Despite the increased use of palliative chemotherapy, there was no improvement in overall survival, the authors report.

Median survival in the cohort remained 15 to 17 weeks over the 2 decades studied.  Median survival for untreated patients declined from 16 weeks to 9 weeks, whereas it remained stable at 32-37 weeks for patients treated with chemotherapy.

In multivariate analyses, chemotherapy was associated with improved survival, while male gender, poor or undifferentiated tumor, and the presence of liver or multiple metastases were associated with worse survival.

“The results are not an argument against palliative chemotherapy,” Dr. Bernards explained. “Patients receiving palliative chemotherapy still fared better than those who didn’t.  However, it is important to bear in mind that selection bias plays an important role.”

“Patients who are medically fit, those with a better overall survival beforehand, are more likely to be treated with palliative chemotherapy,” Dr. Bernards said. “Patients who are in terms of condition not eligible for treatment, those with a worse overall survival beforehand, are not treated with palliative chemotherapy.”

Dr. Florian Lordick from the University of Leipzig, Germany, who has published extensively on gastric cancer, told Reuters Health, “The goals of palliative chemotherapy are prolongation of life and – importantly! – symptom control and maintenance of quality of life. The latter has not even been looked at in this Dutch register study.”

“The results of the study are provocative,” Dr. Lordick said. “But we must not forget that prospective randomized controlled trials have proven that chemotherapy can prolong survival and maintain quality of life.”

“Do not base your individual treatment recommendations on observations derived from tumor registries!” Dr. Lordick concluded.

Dr. Ramon Andrade de Mello from the Portuguese Oncology Institute, Porto, Portugal told Reuters Health, “Environmental factors and patients’ previous exposure may have been different among the patients sampled throughout this 21 year study period. In addition, all patients in this study did not have the same chemotherapy opportunities due to the extensive heterogeneous population herein reported, and thus it could be dangerous take any conclusions concerning overall survival.”

“Chemotherapy is the backbone of metastatic gastric cancer treatment,” Dr. de Mello concluded. “Chemotherapy should be offered to a specific subgroup of patients who have good clinical condition to support the adverse side effects and who are keen to have a modest improvement in overall survival. However, do not forget that nowadays trastuzumab is indicated in addition to chemotherapy in those patients who are HER2 positive.”

SOURCE: No improvement in median survival for patients with metastatic gastric cancer despite increased use of chemotherapy
Ann Oncol 11 October 2013.