Aetiology, genetics and prevention of secondary neoplasms in adult cancer survivors.

Second and higher-order malignancies now comprise about 18% of all incident cancers in the USA, superseding first primary cancers of the breast, lung, and prostate. The occurrence of second malignant neoplasms (SMN) is influenced by a myriad of factors, including the late effects of cancer therapy, shared aetiological factors with the primary cancer (such as tobacco use, excessive alcohol intake, and obesity), genetic predisposition, environmental determinants, host effects, and combinations of factors, including gene-environment interactions. The influence of these factors on SMN in survivors of adult-onset cancer is reviewed here. We also discuss how modifiable behavioural and lifestyle factors may contribute to SMN, and how these factors can be managed. Cancer survivorship provides an opportune time for oncologists and other health-care providers to counsel patients with regard to health promotion, not only to reduce SMN risk, but to minimize co-morbidities. In particular, the importance of smoking cessation, weight control, physical activity, and other factors consonant with adoption of a healthy lifestyle should be consistently emphasized to cancer survivors. Clinicians can also play a critical role by endorsing genetic counselling for selected patients and making referrals to dieticians, exercise trainers, and others to assist with lifestyle change interventions.