Prevention is better than cure.
Screening can rarely prevent disease but can sometimes pick it up early and at a point where it is eminently treatable. There is little point in early detection of a disease that isn’t treatable to only create anxiety and stress in the patient who would then have to live the remainder of their life in the knowledge that they have a terminal illness without prospect of treatment or cure. However a diagnosis of conditions such as HIV in the early days was a ‘death sentence’ but diagnosis was helpful to modify behaviour and protect others – Covid-19 is similar and screening is now being used so that even those who are asymptomatic but infected can isolate and thus save others from illness and in the susceptible possible long term morbidity or even mortality. Detecting Huntington’s Disease/Chorea is possible in early life but currently there is no cure and a diagnosis will be hugely negatively life changing without much benefit – Of course a negative test would be very reassuring and the risk of passing on this horrible genetic disease mitigated. If a parent has the Huntington’s disease gene, there’s a 1 in 2 (50%) chance of each of their children developing the condition and affected children are also able to pass the gene to any children they have. The opposite is true of the spot tests offered to parents of new-borns. Here blood spot screening involves taking a blood sample to find out if the baby has 1 of 9 rare but serious health conditions. Of course most babies won’t have any of these conditions but, for the few who do, the benefits of screening are enormous and the test doesn’t carry any known risks for the baby. The conditions screened for are Sickle cell disease, Cystic fibrosis, Congenital hypothyroidism and 6 inherited metabolic diseases, PhenylKetonUria (PKU), Medium-Chain Acyl-CoA DehyDrogenase deficiency (MCADD), Maple Syrup Urine Disease (MSUD), IsoValeric Acidaemia (IVA), Glutaric Aciduria type 1 (GA1) and HomoCystinUria (pyridoxine unresponsive) (HCU) These can all be treated with a carefully managed diet and, in some cases, medicines as well and avoid the terrible consequences should these conditions remain undetected and untreated.
There is an Americanism that I like credited to Bert Lance who popularised the phrase:-
“If it ain’t broke, don’t fix it”
Unfortunately many physicians ignore this and will screen for everything easily measurable. Of course these ‘medicals’ do on occasion pick up some ‘abnormality’ but often these are only slightly out of range and once identified are difficult to ignore and thus further investigations causing not only angst and stress but significant cost to the patient/Health Service. These can include invasive procedures such as biopsy/surgery etc.
For example in women under 50 the risk of breast cancer is generally very low. Mammograms are more difficult to read in younger women because their breast tissue is denser. So the patterns on the mammogram don’t show up as well and some lesions that in an older woman might indicate a possible cancer may confuse the issue and thus the likelihood of unnecessary surgery is increased. Currently there is little evidence to show that regular mammograms for asymptomatic women below the screening age reduce deaths from breast cancer. However as techniques for detection improve the screening criteria will shift. (Ultrasound is a better tool for examining the younger breast. Also in those at increased risk of breast cancer, family history etc. the screening may well be of more benefit.)
I am reminded of an elderly patient who having attended a ‘Whole Body Scan’ requested 12 (Yes twelve!) referrals to separate specialists for ‘lesions’ that showed up, none of which were symptomatic and most were then impossible to confirm as being 100% benign, such as a deep seated brain cyst. This created enormous angst for this gentleman and nothing amiss was ever found and he developed no related conditions over the subsequent years apart from the anxiety related to carrying 12 different conditions of uncertain significance! (He died many, many years later of a completely unrelated condition.)
The caveat to the above is that screening deals with the health of a population, for the individual things may be perceived differently and thus if you are concerned about a particular issue, symptom or sign it’s worth having a conversation with your doctor.
In future blogs I’ll look at some of the most evidenced based of the screening tools that are in the main non-invasive and need only patient participation in the program and at worst a blood test or attendance for a scan.
Abdominal Aortic Aneurism