When the first childhood cancers were diagnosed in the 1950s, only 20% of children could hope to recover. Today, the proportion has been reversed: among those affected by cancer, 80 out of 100 children reach adulthood. This is a remarkable success, achieved thanks to the increase in the number of early diagnosis and improved access to treatment. However, childhood cancers remain, together with congenital malformations, the main cause of death among children and there is still much to be done to ensure that a culture of prevention takes root in all strata of the population. On the occasion of the International Day against Childhood Cancer, we are devoting our attention to deepening the problem so that awareness of the risks increases, but also the knowledge of how much progress has been made through research.
Not many people know that leukaemia, central nervous system cancer and lymphoma are the most common diseases. Even less is known about how to recognize these neoplasms and, above all, how to prevent them so that life expectancy grows even more.
WHAT ARE THE CAUSES AND RISK FACTORS?
While it has now been established that the appearance of carcinomas in adults is often linked to lifestyle, childhood cancers are related to causes that are not fully known. This means that it is more difficult to identify good habits that can help prevention. There are some rare forms of cancer such as retinoblastoma or Wilms’ kidney cancer that are caused by identified genetic mutations, but these are limited cases.
The Italian Association of Cancer Registers (Airtum), on the other hand, has collected a review of the main studies on the subject to identify what may be the main risk factors for children:
- Ionizing radiation. It has been shown that this is one of the causes of an increase in the incidence of leukaemia. The most obvious examples concern the period following the explosion of the atomic bomb on Hiroshima and Nagasaki and the Chernobyl accident. However, although there are conflicting studies, there are those who assume that there are some “daily” risks that explain a small part of the tumor incidence. According to the same Airtum report, in fact, for the majority of the population the problems could derive from radiographic examinations and radiotherapy.
- Tobacco smoke. The relationship between pediatric neoplasms and passive smoking has been extensively studied: a causal link emerges between the habit of using cigarettes by the parent and the incidence of neuroblastoma. The connection with other types of paediatric cancer remains uncertain.
- Chemical and dust pollution. Also in this case, we are facing a topic that is a source of wide debate in the scientific community. The results are not always consistent, but the IARC states that there is an association between non-Hodgkin’s lymphomas and exposure to solvents in parents. In addition, some studies suggest that there is a correlation between the use (including domestic) of pesticides and a higher incidence of central nervous system cancers and lymphomas.
- Infectious causes. The source of some pediatric neoplasms are to be found among viruses. In particular, the Epstein-Barr virus causes one third of non-Hodgkin’s lymphomas, the hepatitis B and C viruses cause many cases of cirrhosis and liver cancer, human immunodeficiency virus (HIV) affects the risk of developing tumors as a result of other infections.
- There are also other factors such as the high age of the mother (where recent studies give us encouraging signs), the intake of alcohol during pregnancy, the therapy with certain drugs, but the studies carried out so far have shown some limitations and it is not, therefore, possible to determine in a certain way, what is the real cause-and-effect relationship between these elements and childhood tumors. Moreover, these observations allow us to underline the importance of research: the only tool available to cure these diseases and ensure a longer and healthier life for the child.
WHAT ARE THE MOST COMMON CHILDHOOD CANCERS?
Although there are encouraging signs, the most common type of childhood cancer in Italy is still leukaemia. The disease develops from the child’s immature cells, which produce red blood cells, white blood cells and platelets in the bone marrow. From this tissue, the neoplasm then spreads to other organs such as the spleen or liver. Among the different types of leukemia, the most common is called “acute lymphoblastic”. It originates from a particular type of white blood cell, the lymphocytes, which “invade” the blood, bone marrow and other organs, weakening the body. Acute lymphoblastic leukemia, often abbreviated simply as LLA, mainly affects children between 2 and 5 years of age.
Symptoms appear early and coincide with the entry of diseased cells into the bloodstream where, progressively, they will replace healthy ones. The drop in red blood cells means that the child is often tired and weak. Other signs of a possible disease are infections, fever, bone or joint pain, easy bleeding, loss of appetite and weight, headaches, nausea and swelling of the spleen and lymph nodes.
The first thing to do is to talk to your paediatrician who, thanks to a full medical examination, will be able to guide the family, indicate any in-depth examinations to refine the diagnosis and, if necessary, propose a therapy.
TUMOURS OF THE CENTRAL NERVOUS SYSTEM
20% of pediatric neoplasms affect the central nervous system. The cells that develop the disease are generally astrocytomas, medulloblastomas/PNET, gliomas and ependymas, and are located in different areas of the brain. This type of tumor mainly affects children under 8 years of age or between 10 and 12 years of age. Survival today is estimated at between 60 and 65%.
The symptoms of childhood central nervous system tumours depend on the location of the carcinoma: in some cases, there are signs of hypertension accompanied by headache and vomiting, particular postures of the head; in others, instead, epileptic seizures, behavioural changes or neuropsychological disorders may appear.
Finally, spinal cancer, which is always part of the family of central nervous system neoplasms, is even more complex to identify: the only signal recognized is a gradual slimming of the child by the first birthday, linked to a decline in appetite.
HODGKIN’S LYMPHOMA AND NON HODGKIN’S LYMPHOMA
According to Airc, the third most common childhood cancer is lymphoma. We distinguish two main and different forms: Hodgkin’s Lymphoma and non-Hodgkin’s Lymphoma. The first type has a higher incidence among children and school-age children, but it is also widespread among adults between 20 and 30 years of age, and over 70 years of age. Neoplasm involves the lymphatic system, which is partly responsible for defending the body from external factors and for proper fluid circulation. Since lymphatic tissue is present throughout the body, the tumor can develop in different organs, but is more likely to take root first in the upper body: arms, chest and neck. The swelling of the lymph nodes may be a spy of the disease, but it is not the only symptom. In fact, it can be associated with fever, night sweats, weight loss and itching.
Non-Hodgkin’s lymphoma differs in that it has coughing, respiratory distress and abdominal swelling, even with considerable volume.
PAEDIATRIC TUMOURS IN FIGURES
Airtum monitored the impact, causes and effects of various types of paediatric cancer between 2003 and 2008, and collected data in the report “Cancers of children and adolescents”. Every year, 164 new cases are diagnosed per million children (0-14 years) and 264 per million adolescents (15-19 years).
Good news comes from the fight against acute lymphoblastic leukemia: diagnosis, in fact, drop by about 2% per year, consistently since 1995. On the contrary, cases of thyroid cancer are growing by 8% per year among adolescents. Overall, Airtum still reports, the trend of cancer incidence among both children and adolescents is stationary. As far as the future is concerned, it is estimated that between 2016 and 2020 7,000 new cases of cancer will be diagnosed by children and 4,000 by adolescents.
As mentioned above, the most reassuring fact is that it illustrates the survival of patients 5 years after diagnosis: in the period between 2003 and 2008 it grew to reach 82% among children and 86% among adolescents. The group of cancers for which a more significant improvement has been observed is that of leukaemia: not only do the diagnoses decrease, but the recoveries have increased by 15%.
GOOD NEWS FROM RESEARCH: MORE AND MORE CHILDREN’S CANCERS ARE HEALED
The attention and funding devoted to this area of research is growing steadily. In some cases, survival to leukaemia exceeds 90% of the diagnosis, a result of a well organized therapy. Another positive factor is the increase in bone marrow transplants, which has given good results.
The goal for the future is to further improve the life expectancy of children affected by all types of childhood cancer: efforts are now focused on cases of central nervous system neoplasms, through the use of tools such as proton radiotherapy and immunotherapy.
A second avenue for research is to avoid the onset of a new neoplasm in individuals cured of childhood cancer: the first research in this direction aims to develop an effective strategy to ensure a future free from the disease to children who have overcome leukemia.
Although the results are encouraging, the fight against childhood cancer is not nearing completion. Everyone can do their part: on the one hand, by supporting research, on the other hand, by learning to recognise worrying signs and by cultivating a culture of prevention. It is true that today 8 out of 10 children are cured, but there could be more if there were more early diagnosis and access to the best care was for all. Let us not be discouraged by long waiting times or high costs for examinations: from this point of view, support can come from supplementary health care, policies such as Family Protection for Children, promoted by UniSalute for children between 4 and 18 years of age, guarantees the constant support of a paediatrician who will be able to follow the development and growth of the child. Prevention and research are the best tools we have available, so why not use them?