Hey Dr. Berkoff, I’m curious what you think about the GRAIL Galleri test. I am particularly curious about your perspective on their comparison of their false positive rate to that of serial mammography. They claim that if we assume mammography has about a 10% false positive rate, then a biannual screening program for a woman from ages 50 to 60 exposes her to a cumulative false positive rate of 50% through that decade. They compare this to their lower false positive rate, which is a sort of pooled analysis for all types of breast cancer, at least for what is published so far. What do you think of evaluating false positive risk in aggregate?
While I share your sentiment about the importance of trust in the physician-patient relationship, I’m also curious about your clinician perspective on “worried well” patients generally. Is it sometimes rational for a physician to offer additional screening simply because the patient is concerned, is likely to be well, and also likely to be placated by additional screening? Is it sometimes rational for the clinician to sort of treat the worry, particularly from a presumption of wellness?
These are great questions. The main advantage of Galleri is that it can detect cancers that are not part of routine cancer screening. For example, there is not a routine population level screening test for pancreatic or kidney cancers but early cancers in those organs can be detected with Galleri.
I don't think the main risk associated with cancer screening is linked to the rate of false positives, either as an individual test or as an aggregate over time, but is a problem of patients using emotion rather than statistical reasoning to decide how they wish to proceed. This is less of an issue for cancers of the pancreas or kidney as they are rarely ever best left to surveillance, once detected, so the risk of over-treatment is low. But with cancers that are best left untreated most of the time, such as DCIS of the breast and AA of the prostate, successful screening is much more nuanced.
I do think that so-called 'worried well' patients need special care and that is where relationships of trust with their physicians come into play. For some such patients, increased frequency of screening or additional testing that yields negative results can help allay their fears. That is good for their health and happiness. But for others, it only strengthens their feeling that more testing is needed and might, should a test come back positive, drive them reflexively to pursue aggressive, unnecessary, risky treatments.
The argument I want to make is for a tailored approach to cancer screening that is as much a function of the (fading) art of medicine as it is part of medical science, and can only take place when doctors really get to know their patients and patients really come to trust their doctors. Sometimes a referral to talented mental health provider who can help 'worried well' patients better understand and manage their anxieties is a better initial strategy than more screening.
Hey Dr. Berkoff, I’m curious what you think about the GRAIL Galleri test. I am particularly curious about your perspective on their comparison of their false positive rate to that of serial mammography. They claim that if we assume mammography has about a 10% false positive rate, then a biannual screening program for a woman from ages 50 to 60 exposes her to a cumulative false positive rate of 50% through that decade. They compare this to their lower false positive rate, which is a sort of pooled analysis for all types of breast cancer, at least for what is published so far. What do you think of evaluating false positive risk in aggregate?
While I share your sentiment about the importance of trust in the physician-patient relationship, I’m also curious about your clinician perspective on “worried well” patients generally. Is it sometimes rational for a physician to offer additional screening simply because the patient is concerned, is likely to be well, and also likely to be placated by additional screening? Is it sometimes rational for the clinician to sort of treat the worry, particularly from a presumption of wellness?
Hi Alex,
These are great questions. The main advantage of Galleri is that it can detect cancers that are not part of routine cancer screening. For example, there is not a routine population level screening test for pancreatic or kidney cancers but early cancers in those organs can be detected with Galleri.
I don't think the main risk associated with cancer screening is linked to the rate of false positives, either as an individual test or as an aggregate over time, but is a problem of patients using emotion rather than statistical reasoning to decide how they wish to proceed. This is less of an issue for cancers of the pancreas or kidney as they are rarely ever best left to surveillance, once detected, so the risk of over-treatment is low. But with cancers that are best left untreated most of the time, such as DCIS of the breast and AA of the prostate, successful screening is much more nuanced.
I do think that so-called 'worried well' patients need special care and that is where relationships of trust with their physicians come into play. For some such patients, increased frequency of screening or additional testing that yields negative results can help allay their fears. That is good for their health and happiness. But for others, it only strengthens their feeling that more testing is needed and might, should a test come back positive, drive them reflexively to pursue aggressive, unnecessary, risky treatments.
The argument I want to make is for a tailored approach to cancer screening that is as much a function of the (fading) art of medicine as it is part of medical science, and can only take place when doctors really get to know their patients and patients really come to trust their doctors. Sometimes a referral to talented mental health provider who can help 'worried well' patients better understand and manage their anxieties is a better initial strategy than more screening.
Excellent article about the hazards of over testing for cancer.