Suggest Diet For A Patient Suffering From Stage 4 Metastatic Disease

my uncle has stage 4 metastatic disease. at this point cancer is of unknown origin. he had a blockage at lower end of duodenum near entrance to small bowel. doctor placed a 12 cm. stent with endoscope this afternoon and took a couple of more biopsies, which were difficult to obtain because of very small workspace (?) he has spots in lungs, on liver, & bone biopsy was positive. I ve read some studies that show patients mean survival rate after stent placement is about 12 to 14 weeks because of the progression of the cancer. What is your opinion on that statistic? Also, what kind of diet would you recommend? Is there a chance diet-wise that he could eat soft bread or pizza?