Long-term consequences
Impairment of visionThe majority of children with unilateral retinoblastoma have the affected eye removed. However, as the vision is usually quite normal in the other eye, and young children learn to adapt very well to uniocular or monocular vision, they are not disabled in any way, and will be able to lead a normal life and go to a main-stream school. As retinoblastoma affects children when they are young they learn how to adapt very quickly. They will turn their head and body more so that they can see things in the peripheries of their vision. They will also position themselves, when in a group, so that people are sitting to their good side thus reducing the need to turn their bodies. This will become a subconscious thing. When they are older, some professionals recommend avoiding games like squash, badminton and some contact sports, others advise the use of special protective glasses. In addition, there are certain professions, for example, the armed forces, which they will not be allowed to enter, nor will they be allowed to work as a bus or train driver. For children with both eyes affected, the prospect for normal vision is less good, and there will often be some impairment. Although a few children will need to go to schools with a visual impairment support unit which have facilities for blind or partially-sighted children, many children will be able to go to a main-stream school, providing that they are given access to low vision aids and specialist support teachers as necessary. Children with impaired vision usually learn to compensate by making use of their other senses, particularly hearing and touch. They may have a greater need for the reassurance and comfort of the human voice than the child with normal vision. Remember to explain to the child what is going on around him/her, and describe everything in as much detail as possible. However, encourage the child to be as independent as possible and help him/her to look after him/herself. CataractsAfter whole eye radiotherapy, most children will develop a cataract. Fortunately, a new method of radiotherapy called lens sparing radiotherapy has been devised, which is suitable for many children requiring external beam radiotherapy, and cataracts do not occur with this technique. If a cataract does develop after whole eye radiotherapy, it can be removed by a simple operation, and the child will then be given special glasses to correct their vision. Unfortunately, following removal of the cataract, the eye is likely to be rather sensitive to bright light. Dry eyeWhole eye radiotherapy also results in a rather dry eye, caused by to damage of the lachrymal glands, which produce tears. A dry eye is more susceptible to infection, to damage from dust and air pollution, and to extremes of temperature. Therefore, children treated by whole eye radiotherapy will need to use artificial tears or eye drops to lubricate and keep the eye moist on a long-term basis. This problem is much less evident after "lens-sparing" radiotherapy. Facial asymmetryAnother late effect of radiotherapy is a reduction in the growth of the bones around the eye socket. If both eyes are irradiated, then the child will have a rather narrow forehead, and the eyes may seem a little close together. If the radiotherapy beam has exited through the jaw, dental problems may occur, and such children should be monitored regularly by an Orthodontist. Retinal detachmentVery rarely, the retina may become detached some months or possibly years after successful treatment for retinoblastoma. This tends to occur in eyes that were treated for large tumours and in certain eyes that received cryotherapy. People of all ages, who had retinoblastoma as a child have been advised by the professionals to refrain from diving until this issue has been discussed with their Ophthalmologist. Any sudden deterioration in vision should be taken seriously, and people are advised to make an urgent appointment to see the Ophthalmologist. Trilateral retinoblastomaVery occasionally, a new tumour can develop in the centre of the brain. This is known as trilateral or ectopic intracranial retinoblastoma. If it occurs, it usually does so between 2-6 years following the original diagnosis. It only seems to occur in children with the genetic form of retinoblastoma. The child may complain of headaches associated with vomiting and general ill-health. Sometimes the child may develop an excessive thirst and start passing large volumes of urine. If any of these symptoms occur and persist, parents are advised to contact the Ophthalmologist or Paediatric Oncologist who has been involved with the child's care, as the GP may not realise the significance of these symptoms. Fortunately, this problem seems to have become less frequent since the introduction of chemotherapy as primary treatment for children with bilateral retinoblastoma. Metastatic diseaseVery occasionally, retinoblastoma can spread to other parts of the body, such as the meninges (the membranes covering the brain), bones, bone marrow or to the lymph nodes in the neck. This problem is known as metastatic disease, but fortunately occurs very rarely. If metastases are going to develop, they almost always do so within two years of the initial diagnosis, and are extremely rare after this time. Treatment will be with intensive chemotherapy, and the child will be looked after by a Paediatric Oncologist. Orbital recurrenceUnfortunately, in a very small proportion of cases, the tumour can recur in the socket after the eye has been removed. Again, if this is going to happen, it nearly always does so during the first two years after diagnosis, and is unlikely to occur after this time. If the child's prosthesis becomes difficult to fit, or if the parents notice a swelling in the socket, the Ophthalmologist should be contacted and urgent arrangements made for an eye examination. If an orbital recurrence is diagnosed, the child will be treated with a combination of chemotherapy and radiotherapy, and with modern effective chemotherapy, this treatment is nearly always successful in eradicating the problem. Second tumoursThese are rare, but can occur in children with the genetic form of the disease. It is thought that radiotherapy given to babies under the age of a year increases the risk of a second malignancy developing. The most common types of second tumour are cancers of the bone (known as osteosarcoma), sarcomas of soft tissues such as rhabdomyosarcoma, fibrosarcoma and leiomyosarcoma, and a skin cancer known as malignant melanoma. Osteosarcoma can arise in any bone in the body, but most commonly in one of the leg bones or in the bones of the orbit around the eye. Soft tissue sarcomas can occur in the muscles of the face and scalp, or in the abdomen. Malignant melanoma tends to occur in the light exposed areas of the face and limbs. Rare cases of secondary leukaemia have been described in children receiving chemotherapy, usually within about five years of completing chemotherapy. The other types of second tumour, such as osteosarcoma, do not usually develop until later, most often between 5-15 years after the initial diagnosis of retinoblastoma, but if such a tumour occurs during childhood, it is best for the child to be referred back to the Paediatric Oncologist in the hospital the child attended for treatment of the retinoblastoma, as all the records of the previous treatment will be available there. The incidence of second tumours in children with the genetic form of retinoblastoma depends on various factors including the treatment given for the retinoblastoma. It is thought that the overall risk of a second tumour is in the region of I in 10 by 20 years from diagnosis. Adults with the genetic form of retinoblastoma may also develop adult type cancers such as breast, skin and lung cancer at an earlier age than normal. They are more susceptible to the known risk factors, and so should be strongly advised not to smoke and to avoid exposure to sun. A healthy diet with plenty of fruit and vegetables is also recommended. The following information can also be found in the genetics section of our website. The text is slightly more technical as it assumes you have read the whole article called 'About Genetics' which explains what a gene and a chromosome is and also the Rb Gene. If you want to read the article called 'About Genetics' please click here What are second primary tumours?People who have a damaged copy of the Rb gene in all cells of their body have a small chance of developing other tumours, away from the eye, later in life. This includes everyone with bilateral, multifocal or familial Rb, and a small proportion of people with unilateral Rb. The mechanism for the development of these other tumours is the same for Rb (i.e. the normal copy of the Rb gene must also become damaged). The tumours usually affect the bones, muscles or skin and usually show as unexplained lumps or pains or changes in moles. It is important for people who have had Rb to be aware of this potential and to seek medical advice for any worrying or persistent problems. There are no tests that can be done to screen for these second primary tumours. As melanomas can develop as a consequence of sun exposure it is important for everyone who has Rb to use sunscreen and avoid over exposure to the sun. People with visual impairment should make sure someone else looks at their skin regularly. People who have Rb should be monitored to detect and manage any long-term problems caused by the disease or treatment to ensure the best possible quality of life. It is especially important for those with the genetic form of Rb to be seen in an adult oncology follow-up clinic for the reasons mentioned above. If you are not currently seen in a follow-up clinic and would like to be, please contact our Support Worker, Juliette Carter, for more information. Email: juliette.carter@chect.org.uk Tel: 020 7377 5578 For general information for survivors of all childhood cancers visit www.aftercure.orgor call the Children's Cancer and Leukaemia Group (CCLG)and ask for the booklet called After Cure on Tel: + 44 (0) 116 249 4460. |
|
