Toxicity and efficacy of salvage paclitaxel chemotherapy in Royal Marsden (RM) oesophagogastric adenocarcinoma (OGA) patients (pts).

Abstract

188 Background: Paclitaxel is a standard global salvage therapy for pts with advanced refractory OGA. Western pts may differ from Asian pts with respect to chemotherapy metabolism and cancer behaviour, and the benefits associated with paclitaxel in this setting have not been assessed outside of Asia. We examined the efficacy and toxicity associated with salvage paclitaxel for advanced OGA at RM over a 3 year period. Methods: This was a retrospective observational study. We identified all pts with OGA treated with salvage weekly paclitaxel from 01/06/2011 to 21/02/2014 from the electronic pt record at RM. The following data was collected: demographics, metastatic sites, resection status, response/duration of response to prior chemotherapy, ECOG PS, haemoglobin, albumin, alkaline phosphatase (ALP), neutrophil/lymphocyte ratio, CEA, CA19.9, RM prognostic score, CT response and date of progression, death or last follow up. Toxicity was collected as per NCI Common Toxicity Criteria (v4.0). Overall and progression free survival (OS/PFS) were estimated using the Kaplan-Meier method. Multivariate Cox regression analysis examined the association between clinical and laboratory variables with survival. Results: 57 pts were identified. Pts were 74% male; median age 64y; 66% PS 0-1; 91% 2nd line. Median number cycles 3 (range 1-8). Median follow up 13.6m. Response rate was 18.4% in evaluable pts. OS and PFS were 5.8m (95% CI: 4.8 – 6.8m) and 2.6m (95% CI: 1.9 – 3.2m). 2y and 3y survival from start of 1st line treatment were 26% and 13%. In multivariate analyses PS ≥2 [HR 2.28, p = 0.018], and ALP ≥100 U/L, [HR=2.01, p= 0.033] were independent negative prognostic factors for OS. ≥ Grade 3 nausea, diarrhea and neuropathy were uncommon (<2% each), rate of ≥ grade 3 fatigue was 11%. Grade 3-4 neutropenia, leucopenia and thrombocytopenia occurred in 12%, 11% and 2% pts. Conclusions: Advanced OGA pts treated at RM with salvage paclitaxel have an OS equivalent to pts in clinical trials with less hematological toxicity than seen in Asian patients. This may be due to regional pharmacogenetic profiles. As a significant proportion of pts now survive 2-3y with limited toxicity, therapeutic nihilism is unwarranted.