Sample size The sample size is calculated as a study of non-inferiority. Assuming a sensitivity for cancer of 85% for the 25S needle and a difference of sensitivity of 15% as clinically significant, a sample size of 112 patients per group would be needed (α = 0.05 and β = 0.2). Since we perform approximately 400 EUS-FNA biopsies for solid lesions annually,. it is expected that this study could be completed within approximately 6 months.