The treatment may be unlikely to help
A treatment is useful only if it has a reasonable chance of achieving something that matters: cure, a lower risk of recurrence, cancer control, longer life or symptom improvement.
Some cancers do not respond to a particular treatment. In other situations, the cancer may have already grown through several treatments, making another response less likely. A drug can be technically available without being clinically worthwhile in that setting.
Side effects and treatment burden may outweigh the likely benefit
Anti-cancer treatment can cause infection, bleeding, organ injury, fatigue, nausea, hospital admission and other complications. Radiotherapy and surgery have their own site-specific risks.
If the chance or expected duration of benefit is small, even a familiar treatment may do more harm than good. Time spent attending hospital and recovering also matters, especially when the aim is to protect day-to-day quality of life.
Performance status and other health problems matter
Performance status records how illness is affecting activity and self-care. A reduced performance status can increase treatment risk and reduce the chance of benefit, although the reason for the reduced function is important.
Kidney, liver, heart, lung or bone-marrow function may limit particular treatments. Frailty, infection and other medical conditions can also change the balance. Age alone should not decide the issue.
Sometimes a reversible problem can be treated and the decision reconsidered. In other situations, waiting would not make treatment safer or more effective.
The cancer's behaviour and extent affect the options
A local treatment such as surgery or radiotherapy can only help if it can address the relevant disease safely. When cancer is widespread, a local treatment may still relieve a symptom, but it may not control the illness as a whole.
The exact cancer type, stage, grade and biomarkers also determine which drug treatments have evidence of benefit. This is one reason people with apparently similar cancers can receive different recommendations.
Previous treatment can narrow the choices
Cancer may become resistant to drugs it has already encountered. Previous surgery or radiotherapy can make further local treatment more difficult. Some side effects accumulate, and organ function may not recover enough for another course.
The team should still consider alternatives, including relevant clinical trials, but a trial is appropriate only if the person meets its criteria and the uncertainty is acceptable to them.
Supportive or palliative care is active care
When anti-cancer treatment is unlikely to provide enough benefit, care can focus on symptoms, function, emotional support and practical needs. Specialist palliative care may add expertise without replacing the oncology team.
This recommendation is not abandonment. Palliative and supportive care can involve medicines, procedures, radiotherapy for symptoms, rehabilitation and coordinated support at home or in hospital.
Patient priorities remain part of the decision
People place different value on a small chance of benefit, particular side effects, time at home, independence and important future events. A clinician should explain the realistic options and listen to those priorities.
A patient can ask for clarification or a second opinion. A second opinion may confirm the same recommendation, but it can still help someone understand that the relevant options have been considered.
Questions to ask
- What outcome would treatment be intended to achieve?
- How likely is that benefit, and how long might it last?
- Which risks make treatment unsuitable for me?
- Is any problem reversible enough for the decision to be reviewed?
- Are there other treatments or relevant clinical trials?
- What care will be provided if anti-cancer treatment is not given?
This article cannot decide whether treatment should be offered to a particular person. That requires the clinical details, an honest discussion of benefit and harm, and the person's informed preferences.