As a doctor organising a scan is the path of least resistance, patients almost universally think that a scan = good care, and why would they not? More data is better surely as another commentator has noted.

So we do the scan and find an ovarian cyst, not to be unexpected, the prevalence of an ovarian cyst is widely quoted as anywhere between 8-15% [1]. You tell the patient that you found an ovarian cyst. Naturally she asks if it’s concerning. It’s a simple cyst, so if we use [1] to inform our figures we can tell her that in 1 years time there’s a 50% chance that the cyst will be gone, a 34% chance it will still be there, a 7.5% chance that there will be more than one cyst and a 5.5% chance that there will be a complex cyst. Simple cysts are not thought to be linked with an increased risk of ovarian cancer, but complex ones are.

Now on hearing that there’s a 5.5% chance of finding a complex cyst next year the patient opts for follow up scanning. They of course Google symptoms of ovarian cancer and see that bloating is a symptom. The patient worries, she has very bothersome bloating, she reads about doctors missing ovarian cancer and worries if her cyst has been misdiagnosed. Of course 31% of the population have bloating of significance [2], but how do we know in this case it isn’t ovarian cancer? So she gets an early ultrasound 3 months later. The cyst has now gone from the ovary, but the other ovary now has a cyst. She gets another scan in 3 months time and the cyst is still there, she’s finds herself more and more worried, why didn’t it go like the last cyst? She reads online about a blood test for ovarian cancer, the CA125. She reads survivors stories telling her the importance of having this blood test done early, so she goes to the doctor and asks to have it done. It comes back slightly elevated. Her fear is confirmed, she has cancer. Now a raised CA-125 has a positive prediction rate of about 10%, and with her imaging findings the likelihood is likely lower, but it is not zero. So we proceed to biopsy. A couple of weeks later the result is in, no cancer, in keeping with the most likely outcome in the scenario. The patient elated at the news thanks the doctor and all is well. Her journey has been 6 months all in all, she’s had multiple sleepless nights, her blood pressure has gone up and her stress levels have been higher, slightly invisibly nudging her up risk of a stroke or other cardiovascular disease in the future.

Now is this good medicine? I guess that’s up for debate, and like I said at the beginning patients like when we scan them, and appreciate when we tell them that their biopsy is negative. They like seeing things done. The doctor who told her not to the scan was clearly a hack as it showed the cyst. Despite the fact that if she’d listened to them she’d have saved herself months of worry and ultimately her health would have probably been slightly better through having avoided the stress and an invasive biopsy. We also know that screening for ovarian cancer does not change mortality for ovarian cancer, it leads to 1% of all women screened having some form or surgery who do not end up having cancer and 3-15% of these women end up with a major complication from this surgery. [6]

Another statistic that I keep in mind is that 11.5% of people under 40 have a thyroid cancer at autopsy and 13.4% of people over 80 [5]. These people lived a good chunk of their lives with this cancer which never caused them any issues or harm, it lay there growing slowly completely undetected and then they died of something else. Now would these people have been better off if they’d got a whole body scan, picked up the cancer and spent the last year of their life having their thyroid gland removed, taking new medication to replace their thyroid hormone, having regular bloods and follow up, all for something that ultimately never would have caused them issues, again I’m not convinced. The patient themselves however if we did go down that route will come in and thank me for saving their life, they’re often so grateful and happy that the cancer was picked up, sometimes they come in with a complication from the surgery, their voice horse from the vocal cord palsy, but they don’t mind as their cancer has been cured. The cancer that would never have caused them any harm.

[1]https://ascopubs.org/doi/abs/10.1200/jco.2008.26.15_suppl.55...
[2]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3264926/
[3]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6583394/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7592785/
[5] https://academic.oup.com/jcem/article-abstract/107/10/2945/6...
[6] https://pubmed.ncbi.nlm.nih.gov/29450530/