Delays in the diagnosis of cancer: an issue on both sides of the Atlantic

By Monica Koo and Yoryos Lyratzopoulos

In recent years, there has been a lot of attention on the delays in the diagnosis of cancer in England. Evidence from the International Cancer Benchmarking Partnership (ICBP) has indicated that delays in diagnosis were contributing to poorer cancer survival in England compared to other countries. However, it would be wrong to assume that delays in diagnosis of cancer were unique to countries with a strong primary care system such as England.

We recently wrote an editorial in Cancer Epidemiology on this very topic, commenting on a new population-based study looking at delays in the diagnosis (and treatment) of lung cancer in elderly patients in the US. The study was based on linked routine healthcare data (SEER-Medicare to be specific) collected on nearly 50,000 US patients. There are a few key findings that we highlight in the editorial:

• The median diagnostic interval (the time between when a patient first presents with symptoms and diagnosis) was around 180 days (almost 6 months). This means that more than half of the patients in this study had a diagnostic interval of longer than 6 months, which is a pretty alarming finding. Similar findings have been published in England recently, showing how difficult it can be to detect and diagnose lung cancer.

• Older patients had longer median diagnostic intervals than younger patients, and women had longer diagnostic intervals than men. Again, similar patterns have been described before in the UK, but the inequalities found by this study were particularly large and clearly further research is needed in this area.

• There were also delays from diagnosis to treatment, which were much shorter than the diagnostic interval (27 and 18 days for patients with non-small cell and small cell lung cancer respectively). Patient characteristics didn’t have much effect on the length of the treatment interval, compared to the diagnostic interval. In other words, once a diagnosis of lung cancer was made, the patient’s age, sex, race, and comorbidity status (whether they had other health conditions) didn’t influence their time to treatment much.

Relatedly, specialist investigations are increasingly being used to inform treatment options, including PET-CT imaging and biomarker profiling. Unfortunately such advances in personalising cancer care also have the potential to delay the start of treatment. Although challenging, this may be seen as an opportunity to streamline and integrate cancer care pathways and services.

Overall, the findings of the US study add to the growing body of evidence on diagnostic delays in cancer from the UK and other countries, clearly indicating that this is a global problem that transcends countries and healthcare systems. Building on the shared learning generated by the ICBP, future international efforts in cancer outcomes research should aim to include US patients in order to bring further insights into the cause of such delays. By first asking “why” the delays occur, we can then turn to the “how” and “what” we can do about these universal problems.

Our editorial is open access (freely available online) and is available at: http://dx.doi.org/10.1016/j.canep.2015.08.008