When is cancer treatment optimal? Not too much, but not too little? That search takes place in a triangular relationship: between the doctor, the patient and the disease. And love triangles, as anyone who has ever dealt with them knows, are complicated, unclear and a source of conflict. Following a large article about less intensive cancer treatment in the Volkskrant, I wrote here last time about reasons why it can be difficult for the doctor to recommend such treatment for cancer.
Here is the part about the second point of the triangle: the disease. This is a bit technical, sorry about that.
When I studied medicine at the local university in Leiden, I was given a lecture about lung cancer. There were two types, I learned. Small cell (small cell lung cancer, SCLC) and – the logic is impeccable – non-small cell (non-small cell lung cancer, NSCLC). That difference could be seen under the microscope. The NSCLC group could be further subdivided into three types, again based on how the cells look under the microscope, but that was only fun for the pathologist, because this further subdivision did not matter for the treatment. (quiz question: what year was this class?)
Since then, things have remained a bit quiet around SCLC, but the science around NSCLC has skyrocketed. First of all, it became clear that this further subdivision is indeed relevant. The choice of chemotherapy depends on it. You must prescribe a different combination for one cell type than for another. Subsequently, tumor cells – especially those of the adenocarcinoma type – turned out to have special properties, so-called driver mutations.
‘A medicine with the right plug can enter the cell and kill it or at least slow it down’
There are now no longer two forms of lung cancer, but at least eight. This development has occurred in many forms of cancer: breast cancer, ovarian cancer, melanoma, various forms of leukemia. The choice of treatment is largely determined by the properties of the malignant cells.
I explained this to my patients this way: imagine that a cancer cell has different shaped sockets. That socket forms a path into the cell. A medicine with the right plug can then enter the cell and kill it or at least slow it down. This is called goal-oriented therapy. It follows that medicines with the wrong plug cannot work. And cancer cells without sockets do not care about targeted therapy anyway.
The discovery of that was for the patient driver mutations, followed by the development of specific drugs, both good and bad news. The good news was that for the first time, truly effective drugs against NSCLC were now available. The bad news was that these drugs could only work on tumor cells with the right properties. And only in a minority, about 20-25 percent of patients, the tumor consists of those types of cells. The majority remains dependent on ‘normal chemo’ with a low chance of effect.
But then you must of course determine whether those cells indeed possess those properties. And for this determination it is not enough to look at the cells under the microscope. The techniques required for this are complex.
‘Not once, but again and again, samples must be taken from the tumor when it appears that a drug no longer has the desired effect’
And here the practical problems begin. First, samples must be taken from the tumor. And not just once, but again and again when it turns out that a drug no longer has the desired effect. Sometimes the tests required to take a sample are quite burdensome. I must admit that I often dreaded having to perform a bronchoscopy (exploration of the airways) on the same patient for the sixth or seventh time. And then all I had to do was perform the examination, not undergo it. And secondly, laboratory tests are expensive. Partly because these are very complex studies, but partly because there is little centralization. Just like treatments, these tests also become cheaper if you do a lot of them in one place.
These two considerations mean that the correct diagnosis is not made for everyone. Cutting back on diagnostics is penny wise, pound foolish. Because it can cause the patient to either miss out on the best treatment, or only receive it by chance after a few other ineffective treatments have been tried first, or only receive treatments that do not (or cannot) work. This is extremely unpleasant for the patient, but also for society: because treatments that are unsuccessful are paid just as well. ‘Less, less, less’ of such treatments only seems a good thing to me.
And then it is the patient’s turn: is the treatment proposed after correct diagnosis appropriate?
More about patient considerations in part 3 of this mini-series.
 – Doctor and Auto){kind=link}