How long can a particular person live with cancer?

Long life to you! With a diagnosis of cancer, don't give up! speak frankly with your doctors as to the extent & aggressiveness of your particular tumor. Treatment options are almost as varied as there are cancers to treat. Your medical team will help you choose the one right for your cancer type, age, resources, & comorbidities. No one will fault you, once fully informed, if you opt for a less aggressive approach.
Normal life spans. ...Are common with some cancers. Other cancers are quite devastating and might result in death in days. It really depends largely on the type of cancer and the treatment received (or not received).
It depends. Simple cancers such basal cell carcinoma of the skin can be around for many years.....But pancreatic cancer, for instance, the average time left from diagnosis of the cancer that already spread is about 6 months...