The second leading cause of cancer-related fatalities globally is lung cancer. A method for finding malignant nodules based on shadow detection is provided using 3D computer tomography (CT) images of the lung field. Cancer can be successfully diagnosed at an early stage using this method. The recommended method uses a 3D lung field created from a CT image as its input. The model is built using a three-dimensional convolutional neural network with a focus on shadow identification for cancer detection.