I know your posts were quite a while ago, but I wanted to respond anyway. I am so sorry to hear about what your families are going through. For some people participating in research helps them feel like they are doing something to help fight the disease. There are studies looking for genes involved in pancreatic cancer.
There is definitely a genetic link in some families. Two people in a family can get PC from environmental factors, like smoking, or just by chance. When there are 3 or more, it is more likely that there may be a genetic influence. There are known genes that can cause PC, such as families with BRCA mutations, HNPCC, P16 and familial pancreatitis. There is/are also 1 or more genes that have not yet been found that cause pancreatic cancer. There are studies looking for these genes, and families with 2 or more cases of PC, for which your family may be ligible. You can search for "familial pancreatic cancer genetic study" or follow this link for more info:
http://www.karmanos.org/cancer.asp?cid=19&id=927
You can also search for "CAPS 3" for a reasearch study on screening for PC in families with multiple cases.
I wish you the best with your quest.