Role of family history and genetic testing in diagnosis
Dr Marie Wood – University of Vermont, Burlington, USA
Can you tell me what it is you’ve been doing because it seems that family history and genetics has been a little bit overlooked? What are you doing?
Family history has been overlooked and certainly genetics is new and there’s a little bit of distrust about it. What we did is we tried to look at the family history taking practices of community oncologists. What we did was develop some test questions around breast cancer and colon cancer patients to look at the documented family history in the medical record and then to look at the number of patients who were actually referred for genetic counselling and testing.
And how effective was the testing that’s been going on already?
That was not a question that we asked but genetic testing has been very effective in identifying people who have a hereditary form of either breast or colorectal cancer.
How effective has the family history taking been up to now?
What we found was that patients or providers did a very good job of documenting the first degree family history, almost 80% of the charts of breast and colon cancer patients had a first degree family history. Only about two-thirds had a second degree family history and then when we looked at age at cancer diagnosis within that family history, a very important point that you need to understand for referral and consideration of genetic testing, that was documented less than 50% of the time. We found that the family histories were much more complete for the breast cancer patients than the colon cancer patients and there was a statistically significant difference in the family history taking around breast and colon cancer patients.
So do you think you’ve been able to make a step towards better quality control of family history taking?
I think we found that, with respect to first degree family history, there’s pretty good quality around that but we need to do a better job, mostly around education for community oncologists about the importance of the second degree family history and the importance of getting age at diagnosis. We also found that when we looked at who was referred for genetic counselling and genetic testing, about a little bit less than a quarter of all colon and breast cancer patients were referred but when we looked at those who met referral guidelines, we found the numbers dropped significantly. Less than half of the people who could have been referred were actually referred; much more common for breast cancer than colon cancer. So we need some education about those referral guidelines, who is appropriate and who could best benefit from considering genetic counselling and genetic testing.
So how would you list and sum up the practical things that the busy oncologist should be doing now?
I think it’s really important for the busy oncologist to make a way to take a first, second degree family history in the patients in their practice. It’s important when they do that to get the age at diagnosis; it’s important for ASCO to provide the tools, probably, to help those oncologists to do that. We need to make sure that oncologists are understanding who is best, who is the most appropriate person, for a referral for breast and colorectal cancer patients. And that’s more education again.
What sort of impact might this have on therapy for those patients?
Impact is high, we know that 16% of all cancers are second primary cancers. You can use the family history to identify which patients are at higher risk for a second primary cancer and you can intervene with additional screening and prevention options for those patients. So potentially we could reduce mortality - when you look at cancer survivors, second primary cancers are the biggest cause of mortality for that group while second cancers are caused not only by hereditary predisposition but therapy related. If we make an impact into identifying those patients who were at risk because of family history or genetic reasons, we can screen those patients better and offer them prevention options.