Small cell lung cancer is, as you rightly say, aggressive very often. From your description it appears that it is of a limited stage. In that situation oncologists generally prescribe chemotherapy as you have listed. Often radiation is also required. The pancreatic abnormality is concerning although without more information it may be difficult to conclude on what it is. An endoscopic ultrasound guided biopsy or a CT guided biopsy is an option in some situations. If it does turn out to be another malignancy it will need to also be evaluated. Treating the lung cancer is important to prolong his survival but chemotherapy does have side effects unfortunately. Nutrition is important and if he is having swallowing difficulty he may need an artificial feeding tube inserted.This may mean that he needs treatment initially started in a hospital. Sometimes if his general medical condition is not adequate some oncologists will not give chemotherapy - that may however mean that the lung cancer will spread. The hoarseness may be from vocal cord paralysis from the cancer.