Add-Aspirin: A Trial Assessing the Effects of Aspirin on Disease Recurrence and Survival After Primary Therapy in Common Non Metastatic Solid Tumours

This study is for adults aged 16 and over a certain type of cancer that hasn't spread. You would have already finished your main cancer treatment, such as surgery, and any other standard treatments like chemotherapy or radiotherapy, for breast, bowel (colorectal), stomach/gullet (gastro-oesophageal), or prostate cancer. Crucially, your doctors must confirm that there's no sign of the cancer remaining or having spread after your treatment.

To be considered, you'll need to be in reasonably good health overall, able to manage normal daily activities. Women should not be pregnant or breastfeeding, and should not plan to be during the study. Before officially joining, you'll also be asked to take a low dose of aspirin for about eight weeks. This helps check if your body tolerates aspirin well and if you can stick to taking the medication consistently. This 'run-in' period helps make sure the study is safe and effective for everyone involved.

There are also specific criteria for each cancer type, which your doctor will go through with you. For example, for breast cancer, the study looks at certain features of the cancer, like whether lymph nodes were involved or what type of tumour it was, to make sure you're a good fit for the research.

If you decide to take part, you'll first have an eight-week 'run-in' period where you'll take a low dose (100mg) aspirin every day. This helps make sure aspirin is suitable for you. After this, you'll be randomly assigned to one of three groups, like drawing lots: one group will take a 100mg aspirin every day, another will take a 300mg aspirin every day, and the third group will take a dummy pill (placebo).

Neither you nor your study doctor will know which group you are in – this helps keep the study fair. All pills will have a special coating to help protect your stomach, and you'll take them daily for at least five years. Regularly throughout the study, you'll have appointments to check on how you're feeling, if there are any side effects, and to make sure you're taking your medication as prescribed. Researchers will also keep track of whether your cancer comes back and your overall health. The total time you'd be involved in the study would be at least five years, or potentially longer, to carefully monitor the effects over time.