Cancer is one of the deadliest diseases leading to innumerable deaths worldwide. Early detection of lung cancer could increase the survival rate. To detect cancer various image processing techniques have been innovated and applied like median-wiener filter in the preprocessing stage. In the classification Back Propagation model, SVM (Support Vector Machines), Forward Neural Networks, Convolution Neural Networks are used to detect whether the nodule is cancerous or not. Although, there are many such techniques which are available these days but there is still need to further develop early detection to improve accuracy leading to better survival rate.