RCC stage 4 - need your guidance

Hi,
My 70 year old dad had clear cell renal cell carcinoma on his left kidney in 2007. Had nephrons to remove his left kidney entirely . Now it has metastasized to his pancreas and half of his pancreas are removed . I wanted to check on Keytruda immunotherapy to prevent reoccurrence but the oncologist we went to says since the reoccurrence happened after almost 17 years we do not need to do immunotherapy . I wanted to know if anyone in similar boat and were you given immunotherapy ?

Note : his lymph nodes are clear . His rcc in pancreas was 4 cm and his spleen was removed to be safe.