Kidney symptoms related to Birt-Hogg-Dubé syndrome will often not be treated in the same manner as you would treat sporadic (non-hereditary) kidney tumours. The kidney tumours associated with BHD are of different histologies. See the Kidney Symptoms page for more details about these types and about the frequency of renal tumours occurring in BHD.
In general, removing the kidney tumours by surgery is recommended when they reach 3 cm in size (Menko et al., 2009). This applies both to the tumours that are found at first, and to those that develop after the original tumours have been treated or removed.
If you research kidney cancer, you may find references to treatments such as immunotherapy (IL-2), targeted therapies (multi-kinase inhibitors, Sutent, Nexavar, Temsirolimus), chemotherapy, radiation and nonmyeloablative allogeneic stem cell transplant. This page contains more detailed information about these topics.
The goal in treating kidneys of those affected by BHD is to preserve as much kidney tissue as possible, for as long as possible.
Even after the removal of kidney tumours associated with BHD, new tumours will grow. Clinical studies on kidney cancer have shown that therapeutics based on mTOR, such as the mTOR inhibitor Sirolimus, prevent further tumour growth only whilst the drug is being prescribed. Phase III clinical trials are ongoing with this drug in individuals with Tuberous Sclerosis; however there are no drugs currently available for BHD-specific kidney cancer. This makes early detection of kidney tumour growth and nephron sparing (kidney sparing) treatment a vital part of care for Birt-Hogg-Dubé syndrome. The earlier tumours are found, the more probable it is that they can be removed whilst still maintaining kidney function.
Research seems to indicate that BHD-associated renal tumours are slow growing (Linehan et al., 2009). For some people, this means that kidney tumours can be monitored for a longer period of time before surgery is necessary.
It is possible to live a normal life with just a part of one kidney if that tissue is functioning well. It is therefore important to maintain healthy kidney tissue for as long as possible. As a poor diet can cause damage to the remaining kidney tissue, you may want to talk to a dietitian or a nephrologist to see if they can research options for you and suggest an appropriate diet.