There is an assumption that following up people with symptoms which are low risk but no risk of cancer will improve cancer pick up. But experts writing in The BMJ today say that we do not know whether this approach works. Nor, do we understand the best way to do it.
Patients visit their doctor every day about symptoms that could be cancer. Some will have easily recognised high risk symptoms such as difficulty swallowing (dysphagia) or coughing up blood (haemoptysis). But most will have vague or non-specific symptoms like cough, fatigue, or abdominal pain, where the likelihood of cancer is low.
Faced with this uncertainty, doctors have a responsibility to avoid causing unnecessary alarm and wasting scarce resources through over-investigation, which may result in harm to the patient. But this must be balanced with the potential harm of delaying a diagnosis of serious disease.
Safety netting is regarded as "best practice" for cancer diagnosis - allowing doctors to tease out serious disease by following up patients over time, for example by asking them to come back if the symptom hasn't resolved, or to watch out for new symptoms.
So Dr Brian Nicholson and colleagues at the University of Oxford searched for evidence on whether and how safety netting can be done effectively as part of a project funded by Cancer Research UK.
They found little evidence on whether it improves cancer detection. They found some evidence on how best to do it in patients with vague symptoms.
They discuss three main issues: the necessary components of safety netting, the roles of patient and doctor, and the problems arising from miscommunication or misinterpretation of initial test results.
Based on this evidence, the authors recommend ways that doctors and patients can work together to safety net more productively. Doctors should explain uncertainty about the cause of symptoms with patients, and ensure that they understand why, when and with who they should re-consult about which concerning symptoms.
Healthcare organisations should also have systems in place to ensure that test results are reviewed by somebody with knowledge of cancer guidelines, and that positive and negative results are communicated to the patient promptly.
Although the evidence base is uncertain, safety netting remains the best option, and is likely better than nothing," say the authors. "It is important that patients continue to visit their doctor until their symptoms are explained. We know that doctors are safety netting every day to keep their patients safe. By conducting research on safety netting we will be able to understand which safety netting messages and systems are effective."
Practice: Can safety netting improve cancer detection in patients with vague symptoms
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