and the end of life. Medlock Holmes enters The House of Cancer, expecting to investigate a disease of abnormal cells. But he quickly discovers that cancer never occupies only one room. In the laboratory, cells divide uncontrollably. In the adjoining rooms, entirely different processes are unfolding: a newly diagnosed patient sits stunned after hearing the word cancer; another cannot sleep before a surveillance scan; another is depressed during chemotherapy; a survivor is terrified that every new pain means recurrence; a parent tries to explain illness to a child; and, in the final room, a patient with advanced disease asks not simply how long they have left, but what their remaining life means. Holmes realises that oncology treats the tumour, but psycho-oncology examines the human being who has the tumour. Psycho-oncology sits at the intersection of oncology, psychiatry, psychology, palliative care and the wider multidisciplinary team. Its concern stretches across the entire cancer trajectory: PREVENTION → DIAGNOSIS → TREATMENT → REMISSION → SURVIVORSHIP → RECURRENCE → ADVANCED DISEASE → END OF LIFE At every stage, the psychological task changes. A diagnosis may produce shock, disbelief, fear and uncertainty. Treatment introduces pain, fatigue, nausea, altered appearance, sexual difficulties and loss of independence. Remission may bring relief but also fear of recurrence. Advanced disease raises questions of mortality, meaning, dignity and hope. Importantly, distress is not synonymous with psychiatric disorder. Fear after a cancer diagnosis may be entirely understandable. Sadness in someone confronting loss does not automatically constitute major depression. The psychiatrist must therefore distinguish an adaptive human response from adjustment disorder, anxiety disorder, major depression, delirium or another psychiatric syndrome. This becomes particularly difficult because cancer and its treatment can reproduce many of the somatic symptoms ordinarily used to diagnose depression: FATIGUE • POOR SLEEP • APPETITE CHANGE • WEIGHT CHANGE • REDUCED ENERGY • IMPAIRED CONCENTRATION Holmes therefore looks beyond symptoms alone. He examines persistent low mood, anhedonia, hopelessness, guilt, worthlessness, withdrawal, suicidal thinking and the patient’s psychological relationship with their illness. Anxiety is equally complex. Patients may fear treatment, procedures, pain, disfigurement, disability, recurrence or death. Some develop panic symptoms. Others experience anticipatory nausea or intense anxiety associated with chemotherapy. Cancer can also be experienced as traumatic, although fear and intrusive memories do not automatically mean PTSD. Then Holmes encounters one of psycho-oncology’s most important diagnostic traps: delirium. In a patient with cancer, sudden confusion or behavioural change demands a medical investigation. Infection, metabolic disturbance, organ failure, brain involvement, medications, opioids, corticosteroids and other treatment-related factors may all contribute. The rule is simple: A NEW PSYCHIATRIC PRESENTATION IN CANCER MAY HAVE A MEDICAL CAUSE UNTIL PROVEN OTHERWISE. Cancer treatments themselves can affect mental state. Corticosteroids may produce insomnia, mood disturbance, mania, psychosis or delirium. Other medications can interact with psychotropics, and organ impairment can alter drug metabolism. Psycho-oncology therefore requires genuine consultation-liaison thinking: psychiatric treatment cannot be separated from the oncology treatment plan. But Holmes finds another chart on the wall labelled DISTRESS. Distress exists on a continuum. At one end are understandable vulnerability, sadness and fear. Further along are disabling anxiety, depression, social disruption, spiritual crisis and psychiatric illness. This is why psychosocial distress should be recognised rather than waiting for patients to volunteer it. Yet the investigation cannot stop with the patient. Cancer enters relationships. Partners may become carers. Children may become frightened. Sexual relationships may change. Employment and finances may deteriorate. Roles within families may reverse. Carers themselves can develop substantial psychological distress. The true unit of care may therefore become: PATIENT ↔ FAMILY ↔ CLINICAL TEAM Body image and sexuality form another major part of the case. Surgery, hair loss, weight change, scars, stomas, mastectomy, altered fertility and treatment-related sexual dysfunction may change how people experience their bodies and identities. These issues should not be dismissed as secondary simply because survival is the immediate medical priority. Then Holmes reaches The Survivorship Wing. The patient has finished treatment. Everyone expects life to return to normal. But the patient no longer knows what normal means. Survivors may experience persistent fatigue, cognitive complaints, sexual difficulties, altered relationships, occupational disruption and fear of recurrence. Follow-up appointments and surveillance scans can themselves become recurring psychological stressors. Survival therefore does not necessarily mean the psychological story has ended. In advanced cancer, the questions change again. The aim is not simply to eliminate distress. Some distress is inseparable from confronting mortality. The task becomes helping patients retain connection, dignity, purpose and meaning while treating remediable depression, anxiety, delirium and suffering. This distinction becomes crucial when a patient expresses a wish to die. Such statements require careful exploration rather than immediate assumptions. They may represent uncontrolled symptoms, depression, hopelessness, fear of dependency, demoralisation, loss of dignity, existential suffering or a sustained desire for hastened death. The psychiatrist asks: What does the wish mean? The answer may reveal something treatable. Psychotherapy therefore occupies a central place in psycho-oncology. Supportive therapy, cognitive-behavioural approaches, group interventions, family work and existential or meaning-centred approaches can help patients manage fear, uncertainty, loss and mortality. Psychopharmacology can also be important, but treatment must account for physical illness, drug interactions, organ function, prognosis, adverse effects and the patient’s goals of care. For children with cancer, Holmes finds another principle written above the paediatric ward: CHILDREN OFTEN KNOW MORE THAN ADULTS THINK THEY KNOW. Repeated hospital visits, procedures, chemotherapy, hair loss and conversations around them make secrecy difficult. Communication should therefore be truthful while remaining developmentally appropriate. Avoidance intended to protect the child can sometimes increase anxiety, while age-appropriate explanation can reduce uncertainty. The psychiatrist also cares indirectly for parents and siblings, because childhood cancer affects the entire family system. Finally, Holmes notices that the clinical staff themselves are represented on the hospital map. Cancer clinicians repeatedly encounter suffering, uncertainty, deterioration and death. Psycho-oncology therefore extends beyond the patient to communication within teams, professional boundaries, grief and the emotional burden carried by healthcare workers. Holmes closes the casebook. The fundamental mistake was believing that cancer could be understood only by studying the tumour. The complete equation is larger: CANCER ↔ BODY ↔ BRAIN ↔ EMOTION ↔ IDENTITY ↔ RELATIONSHIPS ↔ MEANING And the central principle of psycho-oncology becomes: Treat the cancer - but care for the person living through it. Key Takeaways * Psycho-oncology is the psychiatric and psychological study and treatment of people affected by cancer. * It forms an important part of consultation-liaison psychiatry. * Its scope extends from cancer prevention and diagnosis through treatment, survivorship, recurrence, advanced disease and end-of-life care. * Psycho-oncology is inherently multidisciplinary. * Oncology, psychiatry, psychology, nursing, social work, palliative care and spiritual care may all contribute. * Cancer affects psychological health as well as physical health. * Psychological and behavioural factors can also influence cancer prevention, detection, treatment engagement and adaptation. * The psychological meaning of cancer varies enormously between individuals. * A person’s response depends partly upon cancer type, stage, prognosis and treatment. * It also depends upon personality, previous psychiatric history, coping style, relationships, culture, socioeconomic circumstances and previous experiences of illness. * There is therefore no single psychological response to cancer. * Cancer commonly produces distress. * Distress exists on a continuum rather than representing a single diagnosis. * Mild distress may represent an understandable response to illness. * Severe distress can substantially impair functioning and quality of life. * Distress does not automatically indicate psychiatric disorder. * Conversely, understandable distress should not prevent clinicians recognising treatable psychiatric illness. * Screening for psychological distress has become an important component of comprehensive cancer care. * The psychological impact of cancer changes across the illness trajectory. * Diagnosis commonly produces shock, fear, disbelief and uncertainty. * Patients may initially experience difficulty processing complex information. * Emotional responses can change considerably once treatment begins. * Treatment introduces additional psychological burdens. * These can include pain, fatigue, nausea, weakness and sleep disturbance. * Changes in physical appearance can substantially affect psychological wellbeing. * Hair loss, scars, mastectomy, stomas and weight changes may alter body image. * Cancer can affect sexual functioning and sexual identity. * Fertility concerns may b