Sometimes your doctor may suggest an approach called active surveillance. This means watching your kidney tumour closely by doing imaging tests such as CT scans, MRIs or ultrasounds and waiting to start treatment until the tumour grows or starts to cause problems. This may be an option for some people with small, slow-growing renal masses (tumour is smaller than 4 cm), or if you are elderly and have other serious health problems. Some patients may not be healthy enough for surgery, or their kidney tumour may not pose a large risk to their health at the time, so treatment and the risks associated with it are delayed until it is really needed. Kidney tumours smaller than 4 cm rarely spread (metastasize). They can usually be removed by doing a partial nephrectomy or treated with ablative therapies, if they start to show aggressive features during surveillance.
The doctor may do a kidney, or renal biopsy, to find out if your kidney mass is cancer or not, what type of tumour it is, how fast it may grow and is likely to spread (tumour histology). This can help them determine if active surveillance is an appropriate option for you.
You may also wish to become part of an active surveillance clinical trial for kidney cancer, if one is available and you are a suitable and willing participant.
See active surveillance trials
Jewett Michael A.S., Rendon Ricardo, Lacombe Louis, et al. Canadian guideline for the management of small renal masses. Canadian Urological Association Journal. 2015; 9(5-6):160-3.