ABSTRACT
Key points 269 Bibliography 269 Further reading 270
Improvements in cancer therapy, particularly advances in medical radiation physics and radiation biology, have resulted in prolonged survival times and increased survival rates for a variety of malignancies over the past two decades. Surviving cancer patients are, however, at an increased risk of developing secondary neoplasms (see Chapter 25). The most important reason for this is that patients cured of one cancer still retain more risk (e.g. molecular predisposition) to develop a (second) tumour than any other person of similar age, gender, lifestyle, etc., who had not previously experienced the disease. Second, the aetiological factors associated with the first tumour, such as smoking for lung and head and neck tumours, or alcohol consumption for tumours of the head and neck or the oesophagus, or exposure to other carcinogens, can continue and hence promote the manifestation of a second malignancy. Of 30 000 irradiated patients with a primary head and neck tumour, more than 20 per cent developed a second neoplasm (Hashibe et al., 2005), out of which 80 per cent were found in the head and neck region, the oesophagus and the lung. Third, the therapy itself, radiation exposure as well as chemotherapy, is
associated with an increased risk for second tumours. This is of particular importance for children and younger adults; childhood cancer survivors are at an up to 19-fold increased risk for developing another malignancy (Dickerman, 2007).
