Hereditary cancer: myth or threat?

From studies conducted worldwide it can be inferred that on average every second or third of the planet’s inhabitants will be diagnosed with a malignant tumour during their lifetime. People’s attitude towards the possibility of developing a cancer is very different. Some maintain a healthy lifestyle in order to minimise risks. Others in their turn blame genes for everything and consider that if they are doomed to cancer, they will fall ill in spite of anything. There are, of course, those who do not think about it at all, as well as those whose fear of cancer is comparable to a phobia.

To date research has shown that inherited genes cause cancer in about 15 % of cases. The remaining part is caused by gene mutations developed over a lifetime, the development of which is often reinforced by bad habits, environmental conditions, lifestyle and other factors. In addition, one of the most important factors is age – the older the person is the more mutations have been accumulated over the lifetime.

Although inheritance is attributable to a relatively small part of tumours, however, it is a significant group of patients – because it is possible to predict the risk and take appropriate action to detect the disease as early as possible. Several cases of cancer in first and second degree relatives, especially if the cancer has developed in people younger than 50 years of age, may indicate the possibility of genetically inherited cancer. People with such family medical history can contact their general practitioner who will evaluate the need for referral to a hereditary cancer specialist. The patient has to collect as much information as possible about cases of malignant tumours in the family so that the doctor can assess the situation.

One of the tools in the hands of a doctor who helps to assess the risk of hereditary cancer is to perform genetic testing. Professor Edvīns Miklaševičs, Director of Rīga Stradiņš University (RSU) Institute of Oncology says: “At present, most often genetic testing helps to identify genetic mutations that cause breast and ovarian and bowel cancer. For example, in the case of breast-ovarian cancer BRCA1 and BRCA2 tests are usually done – these two mutations are blamed for about 80% of cases detected in Latvia. The total range of potential genetic tests is quite wide, but as the detection of separate rare gene mutations is very expensive, rationality of their use is limited. Often there are cases when all signs indicate that there is hereditary cancer in the family, but no tests show any of the currently known mutations. There are still many types of genetic disorder causing cancer that have not been studied and recognised.”

Based on all the information available, the doctor evaluates the risk of hereditary cancer and gives the patient recommendations on the preventive measures to be taken. Dr Andris Gardovskis, assistant professor and leading researcher of RSU Department of Surgery who has specialised in hereditary cancer issues, acknowledges that patients often expect from the doctor more than the modern medicine is able to provide: “There is no miracle cure that could be given to the patient and spare him from malignant tumours. What we can do is to recommend regular checks in order to detect the potential tumour at an early stage. Timely commencement of treatment gives better results, is more considerate as well as has less impact on the quality of life and requires fewer resources. The doctor may also advise the patient of a variety of preventive measures related to diet and lifestyle in order to reduce the likelihood of cancer. If a patient is found to have a high hereditary cancer risk, other family members are also recommended to undergo tests.”

In some cases, when the risk of cancer is up to 70 %, the doctor may also recommend preventive surgery, such as breast or ovary removal. A real storm of debate was recently triggered by Hollywood actress Angelina Jolie, who underwent both of the operations mentioned above. Many supported this step, but just as many were deniers who considered the actress’s action as exaggerated. Such operations, of course, have an impact on the quality of life, but they protect from the possibility of cancer. The doctor may recommend preventive surgery, informing about the risks and the opportunities, but the woman herself has to take the difficult decision weighing up all “fors” and “againsts”. Professionals have noticed differences between various countries in the attitude towards surgery to prevent breast cancer. For example, women in Latvia are afraid of losing their breasts, because they believe that with it they will lose their partner, but Scandinavian women opt for this operation more readily because in their society there is a different attitude towards the woman and her body.

Familial adenomatous polyposis patients, who have hundreds of polyps formed in the colon, any of which can develop into malignancy, have the least options. If the mutation characteristic of this hereditary disease is found in the tests, there is almost a hundred percent chance that the malignant tumour will develop by 40 years of age. In such cases the only solution is the removal of the colon, which means spending the rest of life with a colostomy bag as the intestinal contents are expelled through an opening in the abdomen, but the benefit is the timely saving of the patient’s life.

Although inheritance is an important factor in early cancer diagnosis, however, we must not forget that the majority of cancer-causing genetic changes develop during a lifetime. From the moment the ovum is fertilised and the cell division starts, it continues throughout a person’s life. Mutations in the genetic information of cells sometimes occur in each of the innumerable divisions. Most of the mutations are harmless but some of them can cause an oncological disease. Therefore the cancer risk correlation is largely related to the life expectancy of the society. We ourselves often reinforce mutations by acquiring harmful habits. Smoking is in the leading position in this respect – tobacco smoke contains numerous substances that promote gene mutation incidence, so smoking is to be blamed for 30 percent of cancer cases. In addition, it promotes not only lung cancer but also other cancer risks.

Professor Miklaševičs says that he has come across rather paradoxical situations: “Smoking patients, who are concerned about a hereditary cancer risk, come and even are ready to have preventive surgeries, but they are not ready to give up smoking! If people gave up smoking, the incidence of cancer would possibly decrease by at least one third. Instead, many choose to worry about the letter “E” on the food labels or other less important factors.”

Dr Gardovskis also refers to the light-hearted attitude of patients towards their health: “Of course, there quite frequently are queues to do examinations which delay commencement of the treatment process, but just as often you have to listen to a wide range of patients’ excuses why immediate treatment should be postponed. Patients excuses include: they feel well, have a lack of time, gardening, holidays, Midsummer, Christmas and everything possible to postpone the treatment, not realising that only early intervention can provide the best results and thus they lose valuable time. We often hear people saying that health in our country is not a priority. Unfortunately, it must be admitted that for many patients their health is not placed highest on the scale of importance.”

Professionals admit that they have to face another extreme: cancerophobic people who are haunted by a strong fear of developing cancer. They are frequent guests of hereditary cancer specialists, arriving without a valid reason, when there are no factors indicating a hereditary disease in the family. Doctors usually have difficulty convincing these people that there is no reason for concern.

The happy medium should certainly include being familiar with one's own family medical history, getting to know and observing inherited oncological risks, but, in particular, working with those risk factors which we can influence ourselves because their role in the incidence of cancer is much greater. It is important also to keep track of our own health and to consult a doctor in a timely manner if there are noticeable changes. In addition, one should definitely use preventive breast, cervical and bowel cancer examinations which are regularly offered free of charge by the government to inhabitants of a certain age. Even if the disease cannot be prevented, early diagnosis of cancer can provide the opportunity to fully recover and continue a full life.

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