Pancreatic adenocarcinoma patients aged 79 were significantly more likely to receive chemotherapy (50.3%) than those aged 80 (45.1%, OR 0.79), demonstrating age-based left-digit bias.
Does age-based left-digit bias (being age 79 vs 80) affect treatment decisions and overall survival in patients with pancreatic adenocarcinoma?
Left-digit bias influences treatment decisions in pancreatic adenocarcinoma, with 79-year-olds significantly more likely to receive chemotherapy than 80-year-olds, despite no difference in overall survival.
Abstract Purpose: Left digit bias, where the left-most digit disproportionately influences decision-making, can impact treatment decisions and patient outcomes. This study examines how such bias may affect treatment decisions for patients with pancreatic adenocarcinoma (PDAC), focusing on differences between patients aged 79 and 80. Method: A retrospective cohort study using the National Cancer Database (2004-2020) analyzed patients with PDAC aged 79 and 80. The primary exposure was age-based left-digit bias. The main outcomes measured included differences in treatment received and overall survival. Statistical analyses included chi-square tests, multivariate analysis, Kaplan-Meier survival curves, and Cox proportional hazards models. Results: Among 5,304 patients (2,718 aged 79, 2,586 aged 80), chemotherapy use was higher in 79-year-olds (50.3%) than 80-year-olds (45.1%) (OR 0.79, 95% CI 0.70-0.89, p0.01). No significant differences were found in surgery or radiation. Chemotherapy was associated with lower mortality risk (HR 0.85, 95% CI 0.79-0.92, p0.01). Adjusted overall survival was similar between groups (HR 1.00, 95% CI 0.93-1.07, p=0.91). Conclusion: Left digit bias was observed in the treatment of PDAC, with a tendency to favor chemotherapy for patients aged 79 over 80. This highlights the need for age-neutral decision-making in treatment planning to avoid biases that could impact patient care and outcomes. Citation Format: Qianyun Luo, Bethel Ozed-Williams, David Brauer, Bryan Trottier, Todd Tuttle, Jane Hui, Eric H. Jensen, Jacob Ankeny, Christopher J. LaRocca, Schelomo Marmor. Age-based left-digit bias in the treatment of pancreatic adenocarcinoma abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 896.
Luo et al. (2026) studied this question. Pancreatic adenocarcinoma patients aged 79 were significantly more likely to receive chemotherapy (50.3%) than those aged 80 (45.1%, OR 0.79), demonstrating age-based left-digit bias.