THE discovery of the “incidentaloma” has long been dreaded by clinicians.
What to do about the unexpected nodule found on a scan conducted for another purpose? The patient has no symptoms and it’s probably nothing, but once you know something is there it’s hard to ignore it.
These kinds of incidental findings can set off a series of expensive, possibly risky, tests and procedures, causing untold anxiety to the patient.
But that’s nothing compared with the potential havoc from our ever-growing capacity to examine the human genome.
The likelihood of incidental genetic findings is increasing, as sequencing the entire genome becomes a more common and affordable option. A patient whose genome is sequenced for one clinically indicated purpose may face the prospect of findings related to other, unrelated genetic conditions.
In March, the American College of Genetics and Genomics released recommendations on such incidental genetic findings, including a “minimum” list of results it believes should be reported to patients as part of genetic sequencing conducted in adults or children.
The list covers 57 genes related to 24 disorders, including hereditary breast and ovarian cancer (BRCA1 and BRCA2 genes), Marfan syndrome and familial hypercholesterolaemia.
That didn’t stop the debate.
The college recommends the additional findings be reported without patients having consented to that happening, arguing the duty of clinicians and laboratories to prevent harm outweighs concerns about patient autonomy.
The recommendations also say allowing patients to decide which test results they wanted to receive would “become increasingly unwieldy as clinical sequencing becomes more common and more commonly ordered by clinicians with varying levels of ability and experience in genetic counselling”.
Patients who didn’t want to receive the additional findings would be able to decline to have the sequencing done in the first place, they suggest.
So, if you don’t want to receive a whole lot of results related to conditions you have no reason to suspect you are at risk of contracting, you should be denied sequencing that might provide an insight into the one condition that is clinically relevant to you?
This could seem like a new kind of genetic paternalism.
Of course, this kind of screening might deliver huge benefits to some patients, allowing early identification, and therefore treatment, of a condition that might otherwise have gone undetected.
But does that justify throwing out the principle of consent? Not to mention the unanswered question of how much the whole process might cost.
The recommendations acknowledge there is “insufficient evidence about benefits, risks and costs of disclosing incidental findings to make evidence-based recommendations”.
“Nonetheless, based upon available evidence and clinical consensus among its members, the working group determined that reporting some incidental findings would likely have medical benefit for the patients and families of patients undergoing clinical sequencing”, the recommendations state.
That doesn’t really cut it for me, but there’s no doubt we are going to have to keep grappling with these issues as investigations throw up ever more information.
As the college says in its clarifying statement: “The era of genomic medicine has begun, and we expect that it will continue to challenge long held models of medical practice.”
Jane McCredie is a Sydney-based science and medicine writer.
This article was revised by the author at 3 pm on 13 May after discussion with Associate Professor Judy Kirk, director of Familial Cancer Service at Westmead Hospital, Sydney.