Malignant neoplasm should not be viewed as a 'psychogenic' nor as a 'primarily organic' disease but as an interaction of various forces, in which psychosocial factors may play an important role. To understand the increase in neoplastic disease, which has taken place in this century, requires a theoretical framework including social, psychosocial and behavioural dimensions, as well as the endocrine and immunologic mechanisms acting as pathogenic pathways. Recent theoretical developments in health psychology and allied disciplines on coping behaviour and social support should be integrated into biomedical models of the aetiology, pathogenesis and clinical course of malignant neoplasia. Environmental stressors, as well as mediating variables at the cognitive, affective, behavioural and physiological levels of adaptation, are suggested as major components of a model of multidimensional pathology. A growing body of research on the role of psychosocial factors in adjustment to cancer and its treatment has contributed new insights into possible variables and causal mechanisms which may be relevant in the aetiology of the disease. Closeness to parents in childhood and the ability to form close interpersonal relationships in later adult life very possibly influence the ability of the individual to cope effectively with environmental stressors prior to neoplastic disease and with the considerable stresses of being a cancer patient subsequent to diagnosis and treatment. Pathogenic pathways for future investigation include mental health variables, such as self-esteem and sense of control, at the psychological level and immunity surveillance at the biological. An integration and cross-fertilization of current work in the aetiology of and adjustment to cancer is suggested linking psychosomatic and somatopsychic models.