Unsure , questions on what to do

I’m posting a little update we just got today after seeing a neuroendocrine oncologist . As mentioned before my husband had surgery to remove A well-differentiated, Grade 2 pancreatic neuroendocrine tumor (NET) with the following characteristics:
• Ki-67 of 4% (moderate growth rate)
• 3 out of 12 lymph nodes were positive
• Perineural and vascular invasion
• Tumor was fully removed surgically
• His CgA level is in the normal range (57.4)

This specialist is recommending for him to be part of a study for this type of NET tumors which basically it’s a chemo pill he will need to take for a period of 4 months , CapTem , we are afraid of spread to actual organs or recurrence but the doctor says it’s only about 5% chance . We’re not against treatment, we just want to make sure this is the best option for him, not just a cautious one and wonder if there’s anyone here that went or it’s going thru the same treatment and can give us just us any advice