How long can someone live with stage four lung cancer and penile cancer?

It varies: The prognosis for stage IV anything is poor, and this is especially true for both lung cancer and penile cancer, as by definition these diseases have spread to other distant parts of the body, which means that treatment may control but not cure the disease. Outcomes are variable, but there are occasional long term survivors. Overall ~10-15% of those with stage IV disease live more than 5 years.

Months: Stage 4 means advanced metastatic disease. Disease has spread beyound the primary site. Lung cancer being the more common and with worse prognosis between the two. Depending on the biology and the extent of disease involvement prognosis can be average of 6-12months. There are good chemotherapy drugs and palliative care and treatments that can help quality and length of life.