These preliminary results showed that higher HRV predicts lower levels of a tumor marker, one year later, independent of confounders. This supports the hypothesized role of vagal activity in tumor modulation. Replication in larger samples is needed.

These biomarkers may mediate the relationships between certain psychosocial factors (e.g., hopelessness, social support) and cancer progression. Future studies should test the effects of altering such biomarkers on the prognosis of patients scoring high/low on their associated psychosocial factors. Clinical implications that need to be tested are provided.

The concept of rehabilitation of cancer patients is based on the relatively recent awareness of the strong interrelations existing between physical, psychological and social aspects of human life. Cancer potentially disrupts all of these primary components of quality of life. The aim of rehabilitation is to promote global physical and psychosocial adjustment by acting at all modifiable levels, namely strengthening individual coping resources through psychotherapy, improving quantity and quality of familial and social support, and restoring optimal physical functioning.

Our understanding of the cancer experience at the emotional and cognitive levels remains insufficient, leading to weakly positive results of psychosocial intervention models. The use of antidepressant medication has received substantial empiric and scientific support, but a risk of antidepressant-induced carcinogenesis has not been excluded, which should keep clinicians from overprescribing attitudes. Finally, improving the quality of doctor-patient communication and the psychologic impact of carrying a genetic marker of cancer risk should be the focus of further attention.

Cancer is a unique psychological experience. Its relapsing course and life-threatening nature constitute a potential source of severe and chronic stress, resulting in long-term psychological distress, poor quality of life and psychopathology. Biological consequences of cumulative stress include catecholamine hyperactivity and glucocorticoid dysregulation, and also affect the immune system. The understanding of those physiopathologic pathways needs further investigation, as the development of adequate screening tools does. In order to integrate all those challenges, multidisciplinary approaches are warranted.