'An annual mammogram between the ages of 50 and 70 reduces mortality'

–How are cases of breast cancer normally detected?

–Nowadays breast cancer is diagnosed in two ways: through screening programmes, which account for nearly half of cases, - women who have no symptoms but have a mammogram which then shows something suspicious and a biopsy confirms that it is a tumour - and the other 50 per cent have symptoms.

–What are the most common symptoms?

–The most frequent symptom is a lump in the breast, but others include a retracted nipple, a general reddening of the breast, the appearance of a lymph gland in the armpit... but nowadays these are not so common because they are symptoms of a more advanced stage. So when a patient is diagnosed because of their symptoms, it is normally a lump in the breast.

–Speaking of the importance of screening, at what age should people start having check-ups?

–Science and politics have their own views on that. What science tells us is that a mammogram every year or two years clearly reduces the mortality rate between the ages of 50 and 70. It has been shown that this detects small tumours and those have the best prognosis and the best treatment. Under the age of 50 and after 70, things are not as clear. There is a tendency to reduce the age at which mammograms should begin and extend them beyond 70. Obviously, there is no robust scientific evidence for this, but from a social and political point of view they are moving towards earlier and later screening.

–And in addition to this screening process, is self-examination important?

–Self-examination has never been shown to be related with early diagnosis. For a woman to find a lump in the breast, in most cases, it has to be a centimetre and a half in size, at least. A tumour like that is considered to be relatively large. So although self-examination is recommended, it cannot be used as a substitute for screening through regular mammograms.

–In addition to these check-ups, how important is a healthy lifestyle in the appearance or otherwise of this type of illness?

–It is fundamental. Cancer is a genetic illness, in the sense that there is an alteration in the genome and it is external factors that often cause that alteration. That means that it is a preventable illness in half of all cases. A typical example is lung cancer: it would be rare for someone who doesn't smoke to get it. In breast cancer certain processes are very important, but they are difficult to change.

–Why?

–Because in breast cancer with positive receptors, the usual type, the most important factor is the gap between the date of the first menstruation and the date of the first pregnancy. The longer the gap, the greater the risk. The age of first menstruation is dropping nowadays because of the way children are fed. The chubbier a little girl is, the earlier she starts having periods, and women are increasingly delaying their first pregnancies. Modifying the date of that first pregnancy could almost be considered social engineering.

–And on the subject of social issues, is there still a stigma surrounding cancer?

–Thirty years ago, the stigma surrounding cancer was widespread. It is a serious illness. It is often trivialised, but it is still a serious illness and the treatments are very aggressive for the patients. It's an illness that makes people afraid and worried. But now, breast cancer has been socialised; it has become part of everyday life because it is very common, it affects one in every eight or nine women and, above all, it has a high rate of cure, between 85 and 90 per cent. There are many long-term survivors who speak out about the need for improved diagnosis and treatment.

–You often hear patients with cancer described as "battling" their illness. Is it good for them to think of what they are going through as a type of combat?

–I honestly don't think it is. Illness is not a fight. Introducing this concept is greatly related to a feeling of guilt. It makes it seem that if you are not cured, it's because you haven't fought hard enough. And that is not the way it is. Cancer is a biological process in which the cells don't know about your state of mind. It's a biological thing. It's like the theory of gravity. You can be a very positive person, but if you fall from the third floor of a building, you are going to have problems. That doesn't mean that you shouldn't face the illness with a positive attitude: you should, because that will improve the way you experience it in your everyday life.

–And with improvements in mind, what is the greatest challenge medicine is facing in terms of treating breast cancer nowadays?

–Nearly 90 per cent of women diagnosed with breast cancer are alive after five years. After ten years the figure is 80 per cent, and after that other causes of death come into it. Right now there are two challenges. One is to improve diagnosis and treatment, and the other is to do the same but with less aggressive treatments for the patient, less invasive surgery and the use of tests to avoid radiotherapy and chemotherapy for people we know can be treated safely without them.