What is stage 5 small cell lung cancer?

There is not: Small cell lung cancer is divided into limited and extensive stage. The usual stage i-iv cancer staging system is not used. Limited stage means that all sites of cancer can be focused in a radiation treatment field. If this is not the case, it is extensive stage. http://www.cancer.org/cancer/lungcancer-smallcell/detailedguide/small-cell-lung-cancer-staging.

None: There is no stage called 5. It is only limited or extensive stage.

?: Small cell lung cancer usually goes by limited or extensive disease, depending on whether it has spread from one lung to elsewhere. Non-small cell lung cancer is classified in stages 1 through 4 but I am not aware of stage 5 in any lung cancer. Could it be that the doctor was flippant and meant the cancer is totally untreatable? Sorry and good luck!