How serious is pneumonia and brain tumors to a cancer patient?

Both are serious: To clarfy: you are asking whether in a patient with cancer (not of the brain), there is the subsequent finding of pneumonia and brain tumor-is this serious? Certainly, any time there is pneumonia that is serious. If there is finding of brain tumors, that is serious because that suggest metastasis. That is, cancer that had been confined to the primary site (ie breast, colon) has gone to the brain.