In English, there’s a saying “no pain, no gain”, meaning that we have to be prepared to suffer in order to achieve our goal. In oncology, however, it’s not necessarily so.
Indeed, anti-cancer treatment, including very aggressive chemotherapy with 2-3 drugs, sometimes causes few side-effects. Patients may even say that they had been told to expect to suffer pain, diarrhea, nausea, vomiting, hair loss, burning in the mouth, skin rashes, etc., while in reality none (or almost none) of this actually happened.
In other cases, by contrast, the doctor may have explained that the chosen therapy is usually well tolerated, but the patient has to go to the emergency department because of complications of the same side-effects described above, for instance in the event of an infection.
The toxicity of the therapy, just like the efficacy of the therapy, is variable. Each one of us is different and each tumor is different. The difference in toxicity depends on the bodily make-up of the individual person; some people may be less able to eliminate the chemotherapy drugs from their system, and so they will suffer more severe side-effects. This problem has no solution. We can tell patients that this or that drug usually causes this or that side-effect in 10-20….50% of cases, but we cannot say which specific patient will suffer which specific side-effect.
In short, there are no reliable tests that allow us to predict which individuals will suffer more or less severe side-effects, nor which individuals will respond best to a particular drug. Actually, some tests do exist, but their efficacy is very controversial and we have to be careful not to “get lost” in carrying out tests that have little reliability or importance. Whenever these tests are proposed, the patient should discuss the matter with the doctor and ask if they are absolutely necessary.
If a treatment proves to be very toxic, the patient may no longer be able to repeat the course of therapy. Such cases are covered by international guidelines; according to the gravity of the side-effect, these guidelines recommend postponing the course of therapy, reducing the drug dosage, or even discontinuing the drug altogether and changing the therapy. The most frequent side-effects of chemotherapy are shown in the table below. The side-effects of hormone therapy and biological therapies are generally rarer and less severe. In this website, we have devoted little space to the issue of side-effects, as this subject is adequately covered by many dedicated websites.
| Side-effect | Comment |
|---|---|
| Alopecia (hair loss) | This is always reversible; the hair “always” grows again. |
| Nausea and vomiting | This has greatly improved in the last 20 years, thanks to the development of a large number of new anti-vomiting drugs. |
| Diarrhea | The danger lies in the risk of dehydration if lost liquids are not adequately replaced (usually intravenously). |
| Inflammation of the oral mucosa | This causes painful burning in the mouth, which, in severe cases, may prevent the patient from eating. It may also be accompanied by fungal infection (thrush), requiring anti-fungal treatment. |
| fever | A very common reaction, it can generally be controlled by paracetamol alone |
| Neurotoxicity | Presenting as “pins and needles” in the feet and hands or numbness of parts of the body, this is usually a late, cumulative toxic effect: i.e. it occurs only after several weeks or months of therapy. As there is no treatment for this condition, we can only reduce or suspend chemotherapy and wait. |
| Muscle pain | Generally controlled by paracetamol; always reversible. |
The occurrence of side-effects has two very important practical consequences for both patients and their families: justifiable anxiety about not being able to undergo therapy “in the proper way”, and long hours spent in the day hospitals where treatment is carried out.
Postponing treatment courses or reducing the drug dosage because of side-effects is a source of worry for patients, who believe that the therapy may not work unless it is administered at exactly the prescribed doses and at the scheduled intervals. This belief is not correct; and it is important to rectify it, precisely because of the anxiety it causes. A patient who badly tolerates the recommended doses is evidently not an average patient; for her, the standard doses are too high. In this particular patient, reducing the dose leaves the same probability of efficacy as the normal dose will have in the average patient. Clearly, however, if the drugs already have to be discontinued after their first administration, on account of their excessive toxicity, no benefit can be expected and the therapy will have to be changed.
The second consequence of the side-effects of anti-cancer treatment is practical; in order to continue the courses of therapy in the day hospital, the doctors need to check that:
- the treatment is not affecting the patient’s vital organs. For this purpose, blood tests are carried out during each course of treatment (and sometimes also before). These tests measure, among other things, the levels of white blood cells and platelets, both of which are the preferential targets of the side-effects of chemotherapy. These levels may be very low, but the patient will not be aware of this. However, if the levels of white blood cells and platelets are too low, it is dangerous to administer the next course of chemotherapy. Indeed, low levels of white blood cells (below 1000) expose the patient to infections, while low levels of platelets (below 30,000) increase the risk of hemorrhage. In such cases, we should wait before continuing with the treatment. (In order to help to restore appropriate levels of white blood cells, “growth factors” can be injected subcutaneously; however, as this is not always effective, it is not always recommended).
- if the results of the blood tests are satisfactory and the patient’s vital organs are judged to be working properly, the doctor will talk to the patient in order to find out whether there are any other side-effects that would get worse if the therapy were not postponed or reduced. Indeed, some side-effects, such as inflammation of the oral mucosa (burning in the mouth) or diarrhea, can be very disturbing for the patient, even if his blood tests are perfectly normal.
This is why patients have to spend so long waiting in the oncology day hospital; however, all these tests and examinations are essential.