How long does chemotherapy take to work for stomach cancer?

The medicine may begin affecting cancer cells during the first cycles, but a visible change is not always immediate. Your oncology team may compare scans, physical findings, appetite, pain, swallowing or digestive symptoms, blood tests and weight over time. A symptom change alone cannot confirm whether the tumour is shrinking. The aim may be to shrink disease before surgery, control cancer that cannot be removed, or reduce the chance of return after an operation.

Attend each planned review and tell the team about vomiting, difficulty eating, diarrhoea, constipation, pain or new weakness. Keep a simple record of food and fluid intake and treatment-day symptoms. Do not stop or delay a dose because you do not yet feel a change; the team may adjust timing or medicines if side effects affect your health. Ask how response will be checked and whether nutrition support is appropriate.

Contact your cancer team promptly for fever, chills, repeated vomiting, inability to keep fluids down, black or bloody stools, severe abdominal pain, confusion or breathlessness. These problems can need assessment even when treatment appears to be helping. Use the urgent contact instructions given by your clinic rather than waiting for the next appointment.

Ask which changes will show that treatment is working, when your first response review is planned, and what happens if the scan shows stable disease or growth. You can also ask how the plan relates to surgery, how side effects will be managed, and whom to call outside clinic hours.