Author: Gesche Tallen, MD, PhD, erstellt 2003/12/11, Editor: Dipl.-Biol. Maria Yiallouros, Reviewer: Prof. Dr. med. Dr. h. c. Günter Henze, English Translation: Hannah McRae, Last modification: 2011/11/05

It is difficult to diagnose cancer early in children and teenagers. Most of the early symptoms seem to be harmless since they are non-specific, such as bruises, headaches and fever. Nevertheless, parents should never hesitate to present their child to a paediatrician. In particular, if symptoms persist longer than a common cold, or if they progress, a paediatrician should see the child as soon as possible.
In general, patients with a malignant disease present both general and localised symptoms.

General symptoms

General symptoms occur as a result of the body's response to the increasing number of malignant cells. This response is a tough fight for the body, and requires great energy and strength, and is thus very exhausting for the patient.

General symptoms of a maligant disease are, for example:

• fever
• pallor
• frailty, lack of concentration, loss of interest in playing
• growth- and developmental delay
• loss of appetite, weight loss

It should be noted that having these symptoms does not automatically mean that a cancer is present. Nevertheless, it is important to seriously consider the possibility that the child could have cancer, which should be verified by a paediatrician, especially if the symptoms persist.

Local symptoms

Local symptoms develop from the space occupying effect, that the uninhibitedly dividing cancer cells produce on the organ or site of origin. Especially, when the cluster of cancer cells starts to invade the affected organ or pushes it aside, and thus impairs its normal function, local symptoms occur.

Examples of local symptoms are the following:

• local swelling, a lump and pain (for example: lymph node swelling can be a symptom of lymphoma, a distended tummy can be a sign of Wilms tumour, headaches can be a sign of a brain tumour, loss of vision can be a sign of retinoblastoma)
• reduced consciousness, palsies, seizures (can be signs of certain brain tumours)
• bone pain (can be caused by dividing leukaemia or other cancer cells while they are invading the bone marrow)

Some cancer cells can produce certain substances that can influence and impair various organ functions, and thus cause specific symptoms. For example, neuroblastomas can produce hormones, that can induce serious blood pressure dysregulations.

Some cancer cells produce tumour markers - substances, the levels of which can be elevated in the blood, urine or body tissues, and are indicative of a particular cancer. However, an elevated level of a tumour marker can also have causes other than cancer. In paediatric oncology, tumour markers are used to help detecting a certain cancer, also to monitor its response to treatment and to screen for recurrent disease. A tumour marker typical for some childhood cancers is, for example, alpha-1-fetoprotein (often elevated in the blood of patients with hepatoblastoma or germ cell tumours).

How is cancer diagnosed?

There are many different types of cancer in children and teenagers. Therefore and partially dependent on the patient's age and also on the symptoms, different tests are often necessary to obtain a diagnosis.

Children and teenagers with symptoms indicative of cancer should immediately be referred to a children's hospital with an oncology-unit. There, where different childhood cancer specialists, such as paediatric oncologists, surgeons, anaestesiologists, radiologists, pathologists, and many others specialised in and routinely dealing with young cancer patients, will team up to systematically approach the patient's situation. Following a thorough assessment of the patient's history and a detailed physical exam, blood tests and various diagnostic imaging are usually performed to get further information. However, in most cases, the definite diagnosis of cancer is made in the laboratory by microscopic and other specifically developed examinations of either a small piece of the tumour obtained by surgery or a sample of bone marrow obtained by a bone marrow-biopsy.

Screening tests for cancer like they are recommended for the adult population have not proven to be efficient for the early detection of cancers in the young. One of the reasons for this observation might be the usually rapid progression of childhood cancers.