Metastatic esophagogastric adenocarcinoma: trends in first-line treatment and predictive factors for the implementation of HER2 testing in clinical practice during the first year after trastuzumab market approval.

PURPOSE: Little is known about the use of first-line chemotherapy in clinical practice in patients with advanced esophagogastric adenocarcinoma, and no data have been published regarding potential obstacles for the implementation of molecular testing for targeted agents in this patient group. Here, we sought to evaluate factors influencing treatment decisions with special focus on the implementation of HER2 testing during the first year after trastuzumab market approval in Germany. METHODS: A total of 754 patients undergoing treatment decisions for palliative first-line therapy in 2010 were documented using Therapiemonitor(®). Drug use and intensity of first-line treatment were analyzed. Data on HER2 testing and test algorithm are described, and variables influencing HER2 testing were selected using bivariate analysis. Significant factors were included in a multivariate logistic regression analysis. RESULTS: Compared with previous years, treatment intensity has further increased. The use of chemotherapy triplets rose from 10.1 % in 2006 to 60.3 % in 2010. In 2010, 49.1 % of patients were tested for HER2 and in 52.2 % of these patients the currently proposed test algorithm was used. Using multivariate logistic regression analysis age ≥67 years and "initiating institution: practice" were found to negatively impact the likelihood of HER2 testing, while treatment goal "prevention of progression", multiple metastases and a Karnofsky status >80 % showed positive correlation with HER2 testing. CONCLUSION: The tendency to use more intensive first-line chemotherapy regimens in patients with advanced esophagogastric adenocarcinoma continued in 2010. Only a minority of patients had an access to the appropriate molecular diagnostics and therefore to treatment with trastuzumab. The access was limited due to the preselection following individual, clinical and institutional factors.

Population-based patterns of care in the first-line treatment of patients with advanced esophagogastric adenocarcinoma in Germany.

BACKGROUND: Randomized studies proved the efficacy of new drugs for the systemic treatment of advanced gastric cancer in the past 5 years. However, little is known about the use of firstline chemotherapy in clinical practice in patients with advanced or metastatic adenocarcinoma of the esophagogastric junction (AEG) and the stomach. We investigated temporal trends in therapy and factors influencing treatment decisions for these patients during a 4-year period. PATIENTS AND METHODS: 1058 patients (median age 67 years) with advanced AEG or gastric cancers undergoing treatment decisions were documented with the Therapiemonitor® in 2006-2009. Therapiemonitor collects population-based data regarding treatment decisions and strategies. Time trends of drug use and intensity in the first-line treatment were analyzed in the entire patient group and according to age (cut-off 65 years) and Karnofsky performance status (KPS; cut-off 80%). RESULTS: Over time, the use of oxaliplatin and docetaxel as well as capecitabine increased while cisplatin and irinotecan use slightly declined. The use of chemotherapy triplets rose from 10.1% in 2006 to 47.0% in 2009. Treatment patterns significantly varied by age and KPS: Older patients were significantly less likely to receive chemotherapy triplets, cisplatin and docetaxel but tended to more often receive oxaliplatin. Likewise, triplets, cisplatin and docetaxel were less frequently used in patients with KPS < 80%, while capecitabine and irinotecan were significantly more often used in this patient group. CONCLUSIONS: A clear tendency towards the use of more intensive chemotherapy regimens in patients with AEG and gastric cancer was observed over time. Older or less fit patients were treated preferably with monotherapy or chemotherapy doublets during 2006-2009. Oxaliplatin and docetaxel use has substantially risen.