“Cancer” has been a frightening word for most people for many years. It refers to one of the diseases that still pose a great challenge to medicine. There are many types of tumors that can appear in our bodies, and they can be generated in any type of tissue and at any age.
One such type appears in neuroblasts, immature cells of the nervous system. We are talking about neuroblastoma, a rare cancer that generally appears in children, being one of the most common in infants and children under four years of age (in fact it is the most frequent before two years of age).
Neuroblastoma: Definition and Symptoms
The term neuroblastoma refers to a type of cancer that is rare, but nevertheless the most common cancer in childhood before the age of two. It is a type of embryonic tumour in which there is accelerated, uncontrolled and infiltrative growth of the precursor cells of neurons and glia: the neuroblasts.
These cells are formed during the gestation of the individual, appearing and forming part of the neural plate to later develop and differentiate during fetal development to form the cells of our nervous system (both neurons and neuroglia). In other words, are the precursors of our nerve cells .
While most neuroblasts are transformed into nerve cells during fetal development, occasionally some children may keep some of them immature even after birth. Usually they disappear over time, but sometimes for some reason they can grow uncontrollably and become a tumour .
They usually appear in the ganglia or nerve bundles of the autonomic nervous system, although this may mean that they can appear almost anywhere in the body. The areas where they most commonly appear are in the adrenal glands (being their most common point of origin), abdomen, medulla or thorax.
One of the difficulties of this disease is that the symptoms that can be awakened are initially very unspecific, making it easy to confuse it with other disorders or even go unnoticed. In fact, in many cases they are only observed when the tumour has already grown, so that it is relatively frequent that it is only detected once it has even metastasised .
Most often, alterations in appetite, fatigue and weakness appear. There is also usually fever, pain and gastric changes. Other symptoms will depend largely on the area where the tumor appears. For example headaches, dizziness or vision problems are common if there is brain involvement, bruising in the eyes or the existence of inequality between both pupils in terms of size. In addition, problems with urination, movement, balance, tachycardia, bone and/or abdominal pain or breathing problems are also common.
Stages of Neuroblastoma
As in other cancers, in neuroblastoma a series of phases and stages can be observed in which the tumor can be located according to its degree of malignancy, location and infiltration into other tissues. In this sense we can find:
- Stage 1: The tumor is localized and well-defined . Surgical removal can be simple
- Stage 2: The tumor is localized but nearby lymph nodes are found to have cancer cells. Removal is complicated .
- Stage 3: In this stage, the tumor is advanced and large, and cannot be resected or the resection would not kill all of the cancer cells
- Stage 4: Stage 4 indicates that the tumor has advanced and has infiltrated into different tissues, metastasizing . However, in some cases of children under 1 year of age (which we would call stage 4S) the subject may recover despite this metastasis.
What are its causes?
The causes of the appearance of a neuroblastoma are currently unknown, although it is proposed the existence of genetic problems that may generate the emergence of this problem. In fact, in some cases there is a family history, so that one could speak of a certain transmissibility in some cases (although this is not the majority).
Successfully treating neuroblastoma depends on certain variables, such as the location of the tumor, its stage and level of spread, the age of the child, and resistance to previous treatments.
In some cases, treatment may not be required, as it has been observed that sometimes the tumor disappears on its own or turns into a benign tumor. For the remaining cases, the removal of the tumour may be sufficient, but chemotherapy and/or radiotherapy may also be required (especially in those cases where there is some spread) to cure the disease or reduce its growth rate.
In cases where chemotherapy is carried out intensively, which stops cell growth, it is usual that prior to this the patient’s own stem cells are collected for their subsequent reintroduction into the body once the chemotherapy has been completed. A bone marrow transplant can also be made from the child himself (extracting it before the application of the treatment). On those occasions when the tumour is resected, immunotherapy can be carried out later by injecting antibodies that allow the patient’s own immune system to fight and destroy the remains of the tumour cells.
But regardless of how effective a treatment may or may not be, it must be taken into account that it is a type of tumour that especially affects young children , so it must be done taking into account what it may mean for a child to undergo certain treatments. Surgical interventions, relatively frequent visits to the doctor, check-ups, injections, the use of therapies such as radio or chemotherapy or possible hospital stays can be extremely aversive for the child and generate great fear and anxiety.
It is necessary to try to make the child’s experience as less traumatic and aversive as possible. For this purpose, different techniques can be applied, such as Lazarus’ technique of emotional staging, making the child visualize himself as a superhero with whom he identifies and who, through the treatment, is fighting the evil.
Psychoeducation of parents is also important , since it allows them to raise the issue, clear and express doubts and feelings, learn strategies to try to manage the situation and in turn contribute to the fact that the emotional reactions of the parents do not generate in turn negative expectations and a higher level of fear and distress in the child. It would also be useful to attend support groups or mutual help groups, in order to learn about other cases and share experiences with subjects who have suffered the same problem.
The prognosis of each case can vary greatly depending on several variables. For example, it is possible that in some cases the tumour may become benign or even disappear on its own, especially when it occurs in very young children.
However, in many other cases, if left untreated or detected late, metastasis may occur. In fact, in the vast majority of cases the diagnosis is made when this has already occurred.
The treatment is usually effective in non-spreading tumors, although when there are already metastases, the treatment is usually much more complex. One aspect to take into account is that the smaller the child is, the lower the probability that there may be recurrences in the future .
In terms of survival, generally in low-risk patients (stages 1 and 2) the prognosis is very positive after treatment, with a 95% survival rate. Those at intermediate or moderate risk (2-3) also have a very high survival rate (over 80%). Unfortunately, however, in high-risk patients (where there is spread, and the tumour is stage 4) the survival rate is reduced to 50%.
- Dome, J.S., Rodriguez-Galindo, C., Spunt, S.L., Santana, V.M. (2014). Pediatric solid tumors. In: Niederhuber, J.E., Armitage, J.O., Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, PA: Elsevier Churchill Livingstone; chap 95.
- Maris, J.M. (2010). Recent Advances in Neuroblastoma. N. Engl. J. Med., 362: 2202-2211.
- Modak, S, Cheung, N.K. (2010) Neuroblastoma: Therapeutic strategies for a clinical enigma. Cancer Treat Rev.,36(4):307-317.