with each separate cancer, and to know which factors are important in each disease in predicting its behaviour and the chance it will spread. So maybe the comparison with infections is fair after all. We know that a cold won’t last six months, but we can’t predict whether it will be gone in five days or ten days.
Having established that all two hundred (or more) cancers do share a common process, let’s start by taking a look at that process itself.
The cancer process
Cancer is what happens when a group of normal cells start to grow in a disorderly and uncontrollable way and may spread into neighbouring areas or to distant parts of the body. In fact, the cancer process consists of three stages.
First, a particular group of cells, for example in a duct in a breast, starts growing in a way that we can see under the microscope is disorderly and uncontrollable. The cells don’t line up in the normal way, their nuclei look peculiar, and their whole appearance—to the expert pathologist—suggests that the cells have escaped from the normal mechanisms that regulate and control cell growth.
Second, the growing cells invade into neighbouring areas. In normal tissues, the boundaries between one type of tissue and the neighbouring areas are strictly demarcated and the tissues on each side of the border, as it were, stay in their allotted territory. In cancers, the cancer cells do not respect the normal boundaries and wander across the border.
Now, if every single cancer did only these two things—grow uncontrollably and invade locally—cancers would probably pose a very small risk to health and life, and there would be a fairly small number of deaths from the cancers every year. In most types of cancer, the primary tumour is not the major problem.
The problem with most of the common cancers is that they may also display a third kind of behaviour. They may spread to distant areas of the body. That process is called metastasising. When a cancer does that, the secondary cancers that it creates in distant areas of the body—for example, the liver or the lungs—are called metastases, or secondaries. It is the metastases that are most often the real problem and that usually pose a more serious threat to health and life. (There are a relatively small number of situations in which the primary cancer in itself can cause serious illness or death. It can happen, but it’s rare.)
So, the process of metastasising is extremely important and has been the focus of major research efforts over the last fifty years. We now believe that some cancer cells have a high tendency to metastasise, while others do not. We now know a few of the characteristics of highly metastatic cells—the hallmarks, as it were, of aggressive and spreading tendencies.
In many cancers, the pathologist can tell us, to some extent, whether the chance of its spreading to distant areas is high or low or average. At the moment, however, we cannot predict whether an individual cancer in a specific person will or will not spread. We can say, for example, that some breast cancers have a high chance of metastasising. But we cannot tell Mrs Brown if hers will metastasise or not.
And that’s a very important point. Because if we knew for certain that Mrs Brown’s breast cancer was not going to spread, then we would not need to recommend any treatment after surgery in her case. And, if we knew for certain that Mr Smith’s cancer of the bowel was going to spread, then we would recommend further treatment after surgery. And if, over the course of a few years, Mr Smith did not develop metastases then we could say for certain that our treatment had worked.
Sadly, we are not there yet. At present we can confidently predict only the range of probability of metastasising, and then recommend treatment options to decrease the risk.
Take breast cancer as an example. If a woman has a small breast cancer (say a centimeter or so) and if it has spread to, let’s say, only one of the lymph nodes in the armpit, and if tests on the cancer show that it is likely to respond to hormone treatment, then we can make some pretty good predictions about its behaviour and the size of the risk to the patient.
In this case, we can say that for an average type of cancer with these characteristics, the chance of it spreading to distant areas of the body is not high. In fact, the chance of dying of a breast cancer like that over the next ten years, if the patient doesn’t take any treatment after the surgery, is about 15 per cent. But if the patient does takes hormone tablets for five years after the surgery, that chance is reduced by about one-third, to about 10 per cent or so. Of course even a 10 per cent chance of the cancer coming back is not trivial—but compared to the general perception of the situation with breast cancer, it is (to most people) surprisingly low.
This is relatively easy to understand. What’s difficult to realise, often, is that nobody knows what will happen in any individual case. We know the general risks, but not the specific outcome.
Nobody can say whether or not an individual cancer will spread. And therefore nobody can say—in any individual case—whether the treatment is preventing recurrence or whether the cancer would not have recurred anyway.
Presently, then, in the majority of cases where we recommend treatment after surgery (as we shall discuss further in Step Three, page 39) we can only talk about the likelihood of the cancer spreading and the likelihood of the recommended treatment preventing that spread. It’s not a very good basis on which to make recommendations, but for the moment it’s the best we have.
In the future, we may be able to ‘fingerprint’ the cancer cells much more accurately and perhaps distinguish with certainty those cancers that will not spread from those that will. When we reach that stage, the whole basis on which we recommend treatment will be much more rational and intelligible. And we may see that stage, for some cancers, in the next five or ten years.
So, it’s this third step of the cancer process—by which the cancer can spread to distant parts of the body—that represents most of the threat to health and life.
To put it simply then, the cancers are a group of diseases that all share the characteristics of growing in a disorderly and uncontrollable way and potentially spreading to other areas of the body. If you can keep this fundamental principle in mind, then much of the next section, in which we discuss the six steps in coping with a cancer diagnosis, will make a lot of sense.
STEP ONE
‘Are you really sure it’s cancer, Doctor?’
The diagnosis
The actual diagnosis is always a shock. Furthermore, it quite often happens that the initial diagnosis may be preliminary and may not be definitive or absolutely certain. In those situations, the uncertainty almost always makes things more difficult for you, as well as for the people around you who want to know what’s going on and what’s going to be done for you. It’s almost always harder for everyone to cope when nobody knows exactly what needs to be coped with.
So this section explains what the diagnosis depends on: when it is likely to be definitive and when it isn’t, and what types of further tests may be important.
There are basically only three main ways in which a cancer can be detected and diagnosed. Naturally, this is going to be a considerable oversimplification, but it’s helpful to discuss the process of diagnosis under these three broad headings because it will make it easier for you to understand what is going on in your own particular case. It is one of those situations where a map of the forest is useful before you go through the field guide to the trees.
The ways in which a first diagnosis is made
Although there are literally hundreds of symptoms and tests that may eventually lead to a diagnosis of a cancer, for practical purposes we can divide the situations into three broad categories. This way of thinking about the process of diagnosis may actually make it easier for you to keep track of where you are at the moment, and what your future options are, as you move along what may feel like a very convoluted and slippery path.
In broad