The interface of psychiatry and oncology

This special issue is dedicated to the field of psycho-oncology, an area of inter-disciplinary study at the interface of psychiatry and oncology. Psycho-oncology addresses the emotional dimensions of cancer care including the psychological responses of patients (and their families) to cancer, and elucidates the biological effects of cancer and its treatment on the brain, as well as the psychological, behavioural, and social consequences of cancer and its treatment in patients across the entire trajectory of cancer care. This field developed approximately 35 years ago in response to the broad spectrum of unmet psychological, physical and social needs of patients during all stages of cancer care including diagnosis, active treatment, survivorship and end-of-life care.

The complexity of cancer care requires inter- disciplinary collaborations across medical specialities in order to advance research and clinical care in both oncology and psycho-oncology. These collaborations have bolstered psycho-oncology research and led to numerous noteworthy contributions that profoundly impact cancer patient care. Notable key findings that have emerged from the field include identifying psychiatric and behavioural risk factors for incident cancer and disease progression, developing psychosocial interventions that enhance cancer patients’ quality of life and/or prolong survival, and elucidating the role of pro-inflammatory cytokines in the pathogenesis of depression. Other noteworthy clinical advances that have emerged from psycho-oncology research include the development of treatment strategies to manage the common and disabling effects of cancer and its treatment such as cancer-related fatigue and cancer-related cognitive impairment.

In a series of ten papers, this issue entitled ‘The interface of psychiatry and oncology’ highlights the broad spectrum of complex clinical issues and treatment advances within psycho-oncology. This special issue emphasizes advances in research that inform evidence-based clinical care of cancer patients across the life span and the trajectory of cancer care. Given the established role of psycho-oncology care in the routine care of breast cancer patients in the USA, a review of the most recent advances in and challenges to state-of-the-art treatment of breast cancer is presented to update clinicians. Lastly, a review of the emergence of the field and future goals for psycho-oncology at the international level are discussed. The contributing authors of this issue include a distinguished international cadre of scholars and leaders in psycho-oncology and/or oncology. As these experts hail from four different continents, their noteworthy contributions reflect an international perspective.

Breast cancer constitutes the most frequent cancer diagnosed in women. In the first paper, Libson and Lippman highlight recent treatment advances and challenges of surgical treatment, radiotherapy, and adjuvant therapy of breast cancer. The authors provide an outstanding, clinically relevant review of the epidemiology, pathology, prognostic factors and recent advances in state-of-the-art treatment modalities of breast cancer from early to metastatic disease, including dramatic changes in the standard of care for surgical management regarding breast conservation and sentinel lymph node biopsy. In addition, significant advances in systemic therapies including genetic profiling, therapy targeted to the oestrogen receptor, and biological therapy targeted to the herceptin-2 (HER2) receptor are reviewed. Lastly, Libson and Lippman postulate an intriguing immune mechanism by which depression may influence cancer recurrence and progression.

Depression has been the most extensively studied psychiatric disorder in cancer patients. The bidirectional relationship between depression and cancer has intrigued researchers and clinicians for decades. A recent review of studies investigating the relationship between major depression and cancer found chronic major depression to be an independent risk factor for incident cancer, disease progression, shortened survival time, and earlier mortality in cancer patients. (Currier & Nemeroff, 2014) In turn, several studies found psychotherapeutic interventions that reduce depression significantly prolonged survival time in patients with metastatic breast cancer. The next three papers highlight findings from the expansive landscape of depression and cancer research with an emphasis on clinical research advances pertaining to the prevalence, risk factors, pathophysiology, and treatment of depression in the context of cancer care. Moreover, the impact of depression and its treatment on cancer outcome and possible mechanisms which may account for this association are also reviewed. Sotelo, Musselman and Nemeroff review the burgeoning evidence that activation of the innate immune system, characterized by increased plasma levels of pro-inflammatory cytokines, plays a pivotal role in the pathogenesis of depression in patients with cancer. The authors highlight the evidence of cytokine-mediated depression, and discuss the mechanisms by which pro-inflammatory cytokines influence the neurobiological correlates implicated in depression. The authors postulate how the immune alterations associated with depression may contribute to the negative impact of depression on cancer outcome and future treatment strategies to target cytokine-mediated depression. The third paper by Barrera and Spiegel provides a thorough review on the benefit and efficacy of depression treatment utilizing psychotherapeutic interventions in depressed cancer patients across the trajectory of cancer care. The authors highlight studies that found effective psychotherapeutic treatment of depression prolonged survival in cancer patients. The paper presents additional immunological, genetic, cellular and molecular mechanisms by which depression may hasten cancer progression.

In the fourth paper, Grassi and colleagues provide a comprehensive review on the efficacy and safety of pharmacotherapy for psychiatric disorders and other conditions of cancer patients including fatigue, pain, hot flushes, nausea and vomiting, and pruritis. The authors systematically review literature regarding the clinical use of antidepressants, antipsychotics, psychostimulants, benzodiazepines, non-benzodiazepines, and anti-epileptic drugs in cancer patients. In addition, pharmacokinetic and pharmacodynamic interactions relevant to cancer treatment are discussed. A user-friendly table delineates clinically relevant information for quick perusal. This is a noteworthy contribution to the pharmacotherapeutic literature base of psycho-oncology.

The next set of papers focuses on recent advances in the management of complex clinical issues in three specific cancer patient populations including children with cancer, patients with haematological malignancies who are recipients of haematopoietic stem cell transplants, and terminally ill cancer patients in need of end-of-life palliative care. Mavrides and Pao provide an excellent review of the assessment guidelines and management of psychiatric disorders in children and adolescents with cancer. Discussion of the developmental issues from infancy to adolescence is especially helpful in understanding how children may react to cancer and its treatment. The authors describe the assessment of the complex psychosocial needs of the child and the family unit as an essential component of paediatric psycho-oncology. The paper concludes with a thorough review of the most recent advances in managing the unique challenges that children and adolescent cancer survivors experience. Rueda-Lara and Lopez-Patton highlight the prevalent psychosocial distress and psychiatric co-morbidities of cancer patients undergoing haematopoietic stem cell transplants, and the importance of conducting thorough pre- and post-transplant psychosocial assessments for early detection and treatment of these co-morbidities. Depression, post-traumatic stress disorder, delirium and cognitive disorders are common among transplant recipients and associated with poor medical outcome and shortened survival. Despite the potential life-saving nature of this treatment, considerable treatment-related morbidity is encountered including the physical and psychological consequences of graft-versus-host-disease, chronic fatigue, and cognitive impairment. The authors review the complex clinical psycho-oncology challenges and treatment considerations in the context of haematopoietic stem cell transplantation. In the seventh paper, Jaiswal, Alici and Breitbart provide a comprehensive review of the spectrum of palliative care needs in cancer patients, with an emphasis on the assessment and management of psychiatric disorders and despair in terminally ill cancer patients, and the challenging role of the psychiatrist in the end-of-life care of patients with cancer.

The eighth paper, by Janelsins and colleagues, eloquently highlights current clinical and pre-clinical research relevant to cancer-related cognitive impairment (CRCI) in cancer patients, with an emphasis on the breast cancer population. The authors review the high prevalence rate, variable course, and cognitive testing recommended for screening and assessment of this disabling condition. In addition, neurobiological mechanisms of CRCI are discussed including pro-inflammatory cytokines, neuroanatomical correlates, as well as genetic risk factors. Preliminary findings regarding use of cognitive rehabilitation training and pharmacotherapy for CRCI are reviewed.

In the ninth paper, Cassileth provides an excellent and thorough evidence-based review of the psychological and physical benefits of non-pharmacological integrative oncology therapies in cancer survivors. She specifically reviews the psychological and physical benefits derived from structured exercise, mind–body therapies such as tai chi, yoga, and mindfulness-based stress reduction, massage therapy, acupuncture, and music therapy in cancer survivors. By highlighting the day-to-day clinical operations of the Integrative Medicine Service at Memorial Sloan Kettering Cancer Center, the author provides tangible guidelines by which to develop similar programs at other cancer centres.

In the final paper, Watson, Dunn and Holland eloquently review the history and development of the field of psycho-oncology from a global perspective. The historical confluence of medical, psychological and societal factors that galvanized the emergence of psychosocial oncology care in developed countries is highlighted, as well as the future international directions for this field. The authors propose partnerships and strategies by which to advance the International Psycho-Oncology Society's (IPOS) priorities and goals, to develop psycho-oncology care standards and establish psychosocial oncology care as a routine aspect of cancer care around the world. It is with these goals in mind that I present this issue dedicated to the treatment advances of psychosocial oncology.

Declaration of interest: The author reports no conflicts of interest. The author alone is responsible for the content and writing of this paper.