<p>Tumor growth within physiological vessels often results in complex flow obstruction due to asymmetric constrictions formed along channel walls. The present work investigates the peristaltic transport in a microchannel containing two tumors of different sizes positioned at distinct axial positions on the upper and lower channel walls. This dual asymmetric tumor configuration enables a detailed examination of the combined influence of tumor size difference and relative position on flow dynamics. A mathematical model is developed under the assumptions of long wavelength and low Reynolds number, which are appropriate for physiological flow at micro scale. Peristalsis is imposed on the channel boundaries, while the tumors are represented as bumps with different sizes and relative positions. Analytical solutions are obtained for the velocity, pressure gradient, volumetric flow rate, shear stress and streamlines. The results demonstrate that tumor size and relative position strongly influence the flow resistance, pressure distribution, and flow characteristics. Higher tumor length and width raise the pressure drop, axial pressure gradients, and wall shear stress while reduce the volumetric flow rate and axial velocity through the constricted region. Also, symmetrically positioned tumors generate more pressure and shear stresses within the microchannel. The study further reveals that tumor size enhances the blockage near the tumor region, and substantially affects the bolus formation and trapping structures. These findings provide the new insights into the hemodynamic consequences of multiple asymmetric tumor-induced obstructions and contribute to a better understanding of physiological fluid flow, targeted drug delivery, and the design of tumor-mimicking microfluidic systems.</p>