My husband has stage 4 throat cancer. They have found a large mass in his lung, and a smaller one in his stomach. What are his survival chances?

Need further details. Patients with head and neck cancer have often concomitant new diagnosis of lung cancer; in certain clinical situations it may be important to differentiate if the lung lesions are new cancer vs. Spread of the throat cancer; discuss with your treating oncologist; in general if throat cancer has spread to multiple organs the treatments are palliative (not curative);.
Unknowable. Although the prognosis is grim (my sympathies), the question that should be asked is "how many joyful, meaninful days are left?" the answer lies in the love and support he derives from you, his family and friends. Fortunately, to a large extent, the question can be answered by you and others who love your husband.