At an academic function, a guest asks what I do and I say, “public hospital doctor”, which seems more benign than “oncologist”. When he asks me to elaborate, his eyes widen as he exclaims, predictably, “Wow, isn’t that depressing?” By now, I have form in explaining that being an oncologist is sobering but not depressing because, in the space between diagnosis and outcome, there is a lot of good one can do – not only through treating the disease but having empathy for the patient.

Next he asks if “they” will find a cure for cancer. Thinking of all the hard-working (and poorly paid) researchers, I say there is much to celebrate and much more to aspire to. He nods thoughtfully.

We spend the rest of the dinner in companionable conversation but my occupation has been on his mind. Before leaving, he leans towards me. “Can you suggest an ‘everything’ test for cancer?”

No such thing, I say, and he looks disappointed.

I thought of that conversation when reading about the failure of just the kind of blood test on which he had pinned his hopes.

The highest goal of cancer medicine is early detection, leading to the outcome with the greatest meaning to the patient: a cure. For oncologists like me, it would be a different world if we could accurately predict individual risk, detect cancer before it metastasised and reassure patients that early intervention saved lives.

To this end, the American company Grail (get it?) launched a blood test called Galleri to detect what it called........

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