The first step in diagnosing kidney cancer will be a scan to look for masses in your kidney. There are several different types of kidney tumours, and they can behave quite differently; some are aggressive, while others are not.
Most BHD kidney cancers are either oncocytoma, chromophobe, or a mixture of the two. Both of these tumour types grow more slowly and are less likely to spread than other types of kidney cancer, meaning that the prognosis for patients with these tumours is good.
A small number of patients develop clear cell or papillary kidney cancers, which are more aggressive and more likely to metastasise. However, with regular scans, these tumours will be found and removed early, reducing the likelihood of them spreading.
Staging and Grading of kidney cancer
The stage and grade of your tumours will also affect how successful your treatment is.
The TNM staging system (Tumour, lymph Nodes, Metastasis) is used to determine the stage of kidney tumours. These measures are then combined to give your tumour an overall stage from 1 to 4 (1).
Stage 1 – The tumour is localized to the kidney and is less than 7 cm.
Stage 2 – The tumour is localized to the kidney but is more than 7 cm.
Stage 3 – The cancer has grown into surrounding tissues or a nearby major vein. There may have been spread to lymph nodes
Stage 4 – The cancer has spread to another part of the body, and may have spread to tissues surrounding the kidney and may have spread to lymph nodes.
The tumour grade is a measure of how abnormal the cells look, again scored from 1 to 4. Cells in low grade tumours look more normal and are less likely to be aggressive. High grade tumours have more abnormal cells and are likely to be more aggressive.
Tumours take time to develop, meaning that if they are found earlier they will be smaller and less likely to have spread. This makes them easier to treat and less likely to be fatal. If you know you have BHD, it is important to have regular kidney scans so that you catch tumours early when they are at a lower stage and grade. Patients who have regular scans have a good prognosis.
Knowing what type of kidney cancer you have
To find out the type, stage and grade of your tumour, a sample will be sent to a pathology lab for testing. The sample can either be part of the tumour taken as a biopsy, or the whole tumour collected during surgery.
It is quite common for family members with BHD to have different types of tumour, or for the same person to have more than one type of tumour at a time.
If the results of the first pathology test are not clear, you may want to ask that a sample of your tumour is sent to a different lab for a second opinion. Discuss this with your doctor.
1. Number stages | Kidney cancer | Cancer Research UK [Internet]. [cited 2021 May 14]. Available from: https://www.cancerresearchuk.org/about-cancer/kidney-cancer/stages-types-grades/number-stages
Publication date: December 2014
Review date: May 2021