Comparison of gemcitabine plus oxaliplatin versus gemcitabine plus nab‐paclitaxel as first‐line chemotherapy for advanced pancreatic adenocarcinoma: A single‐center retrospective analysis

BACKGROUND: Pancreatic cancer is mostly diagnosed in an advanced stage and treated with systemic therapy with palliative intent. Nowadays, the doublet chemotherapy of Gemcitabine and nab‐paclitaxel (Gem‐Nab) is one of the most frequently used regimens worldwide, but is not ubiquitarily available or reimbursed. Therefore, we compared the clinical efficacy of Gem‐Nab to a historical control of patients treated with gemcitabine and oxaliplatin (Gem‐Ox) at our tertiary cancer center, which was the standard treatment prior to the introduction of FOLFIRINOX. METHODS: This single‐center retrospective real world study includes 121 patients diagnosed with locally advanced or primary metastatic pancreatic adenocarcinoma who were treated with chemotherapy doublet, with either Gem‐Nab or Gem‐Ox in palliative first‐line. Survival rates were analyzed using the Kaplan–Meier method, and comparisons were made with log‐rank tests. Gem‐Ox was considered as standard first line therapy at our institution for patients who were deemed fit for doublet chemotherapy between the years 2006 to 2012. These patients were compared to a cohort of patients treated with the new standard first‐line therapy of Gem‐Nab between 2013 and 2020. RESULTS: A total of 554 patients with pancreatic cancer of all stages were screened, and 73 patients treated with Gem‐Nab and 48 patients treated with Gem‐Ox in the palliative first‐line setting were identified and included in this analysis. Patients receiving Gem‐Ox had a statistically significantly better performance score (ECOG PS) when compared to the Gem‐Nab group (Odds ratio (OR) 0.28, 95% CI 0.12–0.65, p = 0.005), more often suffered from locally advanced than metastatic disease (OR 3.10, 95% CI 1.27–7.91, p = 0.019) and were younger in age (OR 0.95, 95% CI 0.91–0.99, p = 0.013). Median overall survival (OS) of the whole study cohort was 10.3 months (95% CI 8.5–11.6). No statistically significant difference in OS could be observed between the Gem‐Nab and the Gem‐Ox cohort (median OS: 8.9 months (95% CI 6.4–13.5) versus 10.9 months (95% CI 9.5–13.87, p = 0.794, HR 1.27, 95% CI 0.85–1.91)). Median progression‐free survival (PFS) was 6.8 months in the entire cohort (95% CI 4.9–8.4). No statistically significant difference in PFS could be observed between the Gem‐Nab and the Gem‐Ox cohort (median PFS: 5.8 months (95% CI 4.3–8.2) versus 7.9 months (95% CI 5.4–9.5) p = 0.536, HR 1.11, 95% CI 0.74–1.67). Zero‐truncated negative binomial regressions on OS and PFS adjusting for gender, age, performance status (ECOG PS), and CA19‐9 levels yielded no significant difference between Gem‐Nab or Gem‐Ox. CONCLUSION: From our analysis, we could evidence no difference in outcome parameters in this retrospective analysis despite the worse prognostic pattern for GemOX. Therefore, we suggest Gem‐Ox as potential first line treatment option for inoperable locally advanced or metastatic pancreatic cancer, especially if Gem‐Nab is not available.