We were delighted to award Mindy Wang a travel grant to present her work at the ASCO GU Cancer Symposium earlier this year. Mindy shared her experience at the conference and explained her work in the blog below.

I am a researcher at the Michigan Center for Translational Research, University of Michigan. I study different types of kidney cancers with a team of doctors. Our goal is to make the diagnosis of kidney cancer more accurate and to develop better treatments for patients.

I was delighted to receive the travel grant from the Myrovlytis Trust (who run the BHD Foundation). With the generous funding support, I attended the ASCO GU Cancer Symposium in San Francisco in February 2023. This conference focuses on cancers in the urinary system, including kidney cancer. At the conference, healthcare providers and scientists share new findings on cancers. We discuss about the biology, diagnosis, and care of cancers.

I presented my research on Birt-Hogg-Dubé syndrome (BHD) associated Hybrid Oncocytic Tumour (HOT) of kidney. This type of tumour is challenging to diagnose. I found two protein markers that can help identify HOT and distinguish it from other types of kidney tumours. 

BHD is a condition that increases the chances of getting kidney cancer. The most common types of kidney cancer that people with BHD get are chromophobe renal cell carcinoma (chRCC), oncocytoma and HOT. chRCC is an aggressive type of kidney cancer. Oncocytoma and HOT are non-cancerous tumours. Doctors called pathologists identify what type of tumour someone has by looking at the cancer cells under a microscope. Under the microscope, chRCC tumour cells are large with clear cell borders, and they may look pink or clear. Renal oncocytoma cells are round and pink. HOT tumour cells look like they have features of both chRCC and renal oncocytoma. This mixture of different cells makes it difficult to diagnose HOT. It is also unclear if the overlapping features means these tumours share commonness at RNA and protein level.

To help doctors diagnose HOT, I compared the RNAs (genetic materials that help cells make proteins) of chRCC, oncocytoma, and HOT. I found two protein markers, one expressed in the chRCC-like tumour cells and one in the oncocytoma-like tumour cells, in HOT. Both markers have a specific pattern in HOT that is different form chRCC and oncocytoma. These markers can help doctors tell if someone has HOT or a different type of kidney tumour.

To learn more about HOT, we used these markers to separate the RNAs from the two different types of tumour cells found in HOT. We compared the RNAs from the two types of tumours in HOT. We also compared the RNAs to chRCC and oncocytoma. We discovered that the RNAs from the two types of tumours in HOT are different from each other, and also different from chRCC and oncocytoma, even though the tumour cells look similar. This study helps us find out which proteins are changed in HOT. This information can help create new treatments that focus on these important proteins.

We launched the BHD syndrome International Registry (BIRT) 1 year ago today! BIRT is a patient registry for Birt-Hogg-Dubé syndrome (BHD). We hope to use the data to reach consensus on the diagnosis and management of BHD and, ultimately, to help researchers develop treatments or a cure.

We are delighted to have 239 active participants in BIRT. We would like to say a massive thank you to each and every one of you for signing up to BIRT. Your participation in the registry will truly make a difference to BHD research in the future. As BHD is so rare, it is often difficult to get enough data to make solid conclusions to some of the common questions about BHD. This includes finding out if other types of cancer such as colon or thyroid cancer are associated with BHD. Taking part in studies such as BIRT will help researchers gather enough data to answers these questions and find new treatments.

On our 1 year anniversary we are sending out a call to action to the BHD community to join the registry, strengthen our community and drive forward research into BHD.

How do I get involved?

Getting involved is simple.

1. Visit https://birt.healthie.net and fill out the registration form.
2. You should then be sent an email to activate your account.
3. Sign the consent form.
4. Complete the surveys (this does not need to be completed in one go).

If you encounter any problems during the registration process, please email us.

I’m already taking part, what can I do?

If you’ve already signed up to BIRT, there are still things you can do to help us spread the word! You can help us by telling your family and healthcare professionals about the registry. We have a letter you can use to tell your family members, and there is a leaflet advertising the registry to doctors.

We also know there are lots of people who have signed up, but either haven’t completed their registration or filled out a survey. If everyone who has signed up fills out the surveys, we would have data from almost 400 people. Data from this many people would allow us to make the data from BIRT accessible to researchers. This would be done through a strictly controlled process. Researchers would have to apply to us for access. Their application would be assessed by the BIRT working group which consists of BHD expert doctors and people with BHD. All data will be deidentified to ensure your personal information is safe. This means removing all data that could be used to identify a specific person such as name or email address.

We recently published an FAQ to answer some of the common questions about BIRT. We are happy to answer any questions you have about the registry by email.

Over the next month we will be sharing highlights from the year across Facebook and Twitter. We would also like to say a massive thank you to our partners, Pulse Infoframe for hosting BIRT and their support over the last year. We look forward to working with them to develop BIRT in the future.

Birt-Hogg-Dubé syndrome (BHD) is characterised by skin bumps, lung cysts, collapsed lungs and an increased risk of kidney cancer. The condition is associated with faults (also called variants) in the folliculin (FLCN) gene. There is a lot of variation in the clinical features seen between individuals and families. There is no way of knowing which feature(s) you may get. For example, some family members will have lung collapse while others may only have skin bumps. The penetrance of the clinical signs of BHD is also not clear. Penetrance refers to the proportion of people with the genetic variant who exhibit the signs or symptoms of a genetic disorder.

A new study* has estimated the penetrance of different features of BHD syndrome. The authors of the study gathered all available data that was published between 2002 and 2016 that describes one or more features from one or more families. The authors of these papers were contacted and asked to provide additional information on families and/or additional cases. The final dataset included 552 families. However, 348 of these had to be excluded as there wasn’t enough data. This left a total of 204 families that were included in the study. However, not every family had data on every feature of BHD. This study also included data from family members who did not have a FLCN variant. The authors calculated the cumulative risk for each feature for men and women. This is the chance that by a certain age you will have a certain feature.

Skin Features

67 families (767 individuals) were used to inform the risk of skin involvement. Of these, 560 people had a FLCN variant and 356 (64%, almost two thirds of people) had skin features of BHD. Fibrofolliculomas were the most commonly reported feature, followed by trichodiscoma. However, the type of skin bump was not reported in a quarter of individuals. The cumulate risk for skin bumps by age 70 was 87% (almost 9 in 10 people) for men and 78% (almost 8 in 10 people) for women.

Lung Features

63 families (763 individuals) were used to inform the risk of lung involvement. This included lung cysts and/or collapsed lungs. 599 people had a FLCN variant. 519 out of 599 people (87%, almost 9 in 10 people) had lung cysts or a collapsed lung. Of these:

• About 1 in 4 people had lung cysts but had not had a collapsed lung.
• Around 1 in 3 people had lung cysts and a collapsed lung.
• Around 1 in 3 people had a collapsed lung but did not have lung cysts.
• However, not everyone had a scan of their lungs, and the type of lung involvement was not reported in a small number of people.

 From analysing the available data the cumulate risk for lung features by age 70 was 87% (almost 9 in 10 people) for men and 82% (just over 8 in 10 people) for women.

Kidney Cancer

88 families (1076 individuals) were used to inform the risk of kidney tumour involvement. Of these, 733 had a FLCN variant and 138 (19% or just under 1 in 5 people) had a kidney tumour. The average age at diagnosis was 50 years old. Different types of kidney cancer were reported:

• 15 in 100 people had clear cell kidney cancer.
• 15 in 100 people had chromophobe kidney cancer.
• 4 in 100 people had papillary kidney cancer.
• 9 in 100 people had an oncocytoma.
• 2 in 100 people had sarcomatoid kidney cancer
• 27 in 100 people had a mixed type kidney cancer.
• The type of cancer was not reported in 28 out of 100 people.

The cumulate risk for kidney tumours by age 70 was 19% (around 1 in 5 people) for men and 21% (around 1 in 5 people) for women.

Colon Polyps

29 families (221 individuals) were used to inform the risk of colon polyp involvement. Around 1 in 5 people reported having colon polyps. The cumulate risk for colon polyps by age 70 was 21% (around 1 in 5 people) for men and 32% (just over 3 in 10 people) for women. However, it is estimated that the prevalence of colon polyps in the general population over the age of 50 is between 25 and 38%. Therefore, people with BHD syndrome do not appear to be at an increased risk of colon polyps, based on this data. The authors were unable to look at the risk of colon cancer due to the lack of data in this study.

Summary

This study shows the variation of BHD presentation in a large dataset, including information from 99 new families. Skin and lung features were very common (had a high penetrance) and it is known that they tend to occur at an earlier age than kidney cancer. There didn’t appear to be a huge difference in the penetrance of features between men and women. Altogether, there is a need to raise awareness among doctors, particularly skin and lung doctors who are in a position to spot and diagnose BHD early. This allows kidney screening to occur earlier so any kidney cancer can be identified as early as possible.

However, more information is needed to answer questions about other features such as colon (or other) cancers. The BHD Foundation launched their patient registry to help answer some these questions and give people with BHD opportunity to take part in research. Find out more about the registry.

*Unfortunately this paper is not open access. Please contact us with any additional questions.

What is the BHD Syndrome International Registry (BIRT)?

The BHD syndrome international registry (BIRT) is a patient-reported database. A patient registry is a centralised database that collects information about people with a specific condition or set of conditions. This includes information on the diagnosis, symptoms and management of BHD syndrome. Find out more about the aims of BIRT.

Why are registries important?

One of the major problems that slows down rare disease research is the lack of consolidated data. A registry can help overcome this and be a source of data to drive forward research. The more information we have about BHD, the easier it is for researchers to answer some of questions about BHD that are currently unknown. It also gives people with BHD the opportunity to get involved with research. The data collected within this registry is high quality and organised to help researchers and healthcare professionals better understand BHD syndrome. This will help the development of new treatments or even a cure in the future.

What information is collected?

BIRT contains 4 surveys:

1. Medical History survey 

This survey asks questions concerning the diagnosis, symptoms, management and treatment of BHD syndrome.

2. Background survey

This survey collects your personal information such as your name and country. No information provided to the registry is viewable by other participants. This information collected through this survey provides important information for linking with health records in the future.

3. Demographics survey

The questions in this survey are optional. This data can help researchers and drug developers improve patient care.

4. Quality of life survey (SF-36 survey)

This survey asks questions to understand how having BHD syndrome impacts your daily life. This survey is also optional.

Why should I get involved?

This is your opportunity to get involved with research and be part of a large community of people with BHD syndrome working together to find new treatments and a cure for BHD. We need as many people to get involved as we really do have strength in numbers.

We would encourage you to tell your family members about the registry. To help, we have written a template letter explaining the BHD registry and inviting them to join. You can download and personalise the letter here.

How do I get involved?

Getting involved is simple.

1. Visit https://birt.healthie.net and fill out the registration form.

2. You should then be sent an email to activate your account.

3. Sign the consent form.

4. Complete the surveys.

If you encounter any problems during the registration process, please email us.

You can also download the BIRT user guide as a pdf or word document.

How long does it take to complete the surveys?

We estimate it will take between 30 minutes and 1 hour to complete all the surveys.

Do I have to complete the surveys all in one sitting?

No, the platform automatically saves your progress and you can return at any point.

Will anyone else know I am taking part in the registry?

No one else will know you are taking part in BIRT and your personal identity will never be revealed to researchers accessing the data.

Are researchers able to access the data?

We will be allowing researchers to access the data soon. Any researcher requesting access to the database will have to submit an application to us. This will be reviewed by the BIRT working group. All data will be deidentified. This means removing all data that could be used to identify a specific person such as name or email address.

Who owns my data?

You own your data at all times.  By taking part in BIRT you agree to share your data for the purposes outlined in a consent form that is digitally available and verified by DocuSign. Ultimately you have access to your own data and can consent to share the data with providers and other relevant parties. If you have any questions about the consent process please contact us.

Can I change my mind about participating in the Registry?

Participation in BIRT is completely voluntary. You can leave the registry at any time.

You can withdraw your consent on your profile. Sections 6.5b and 6.5c of the user guide explain this process. Download the user guide as a pdf or word document.  You can also email us with any queries about this process.

Is my data safe?

Privacy and data security is of extreme importance to us and our partners Pulse Infoframe. Security processes and technologies are integrated into all aspects of the BIRT platform.  Find out more about the security of the BIRT platform here: https://youtu.be/_LtM4gqCJoI

Is BIRT available in multiple languages?

BIRT is currently available in English. However, the registry will soon be available in French, Spanish and German. We hope to expand into other languages in the future.

Where can I see preliminary results?

We aim to provide regular updates about the data from the registry. Read our most recent update.

Who should I contact with additional questions or concerns?

Please email us with any additional questions or concerns. Please also contact us if you are having trouble registering.

At the BHD Foundation we are passionate about driving research into Birt-Hogg-Dubé syndrome (BHD). Through the Myrovlytis Trust, we have funded over £6 million of research into BHD since 2007. We are now pleased to announce the first 2 projects we funded in 2022.

Understanding how Kidney Cancer in BHD develops

We awarded funding to Professor Masaya Baba (Kumamoto University, Japan) for a PhD scholarship to investigate BHD kidney cancer. BHD is associated with changes in the gene folliculin (FLCN). Everyone has 2 copies of the FLCN gene, however changes in only one of them gives rise to many of the features seen in BHD. However, for kidney cancer to develop it is thought that changes in the second copy of FLCN are required (often known as a “second hit”). Masaya’s team will investigate what happens in cells lacking FLCN. They will identify pathways and specific proteins that are essential for cells lacking FLCN to survive and form tumours. In the longer term, these proteins could be targets for the development of new therapies to treat kidney cancer in BHD.

Watch Masaya describe his work in this short video or find out more. A transcript of the video is also available.

Natural Killer Cell Therapy for Kidney Cancer

Our second grant holder, Professor Mark Lowdell (University College London, UK) is interested in the interplay between the immune system and cancer. His group have a particular focus on a type of cell called natural killer (NK) cells. These can directly kill target cells, including cancer cells. However, many cancers develop strategies to avoid recognition by the immune system. Mark’s group have developed a drug to activate NK cells to make them better at killing cancer cells. We have awarded funding to Mark’s team for a 1-year project looking at whether people with kidney cancer have NK cells that can be enhanced with this drug. They hope to identify which patients will benefit most from this drug and use the data to design and support a clinical trial. Although this project isn’t looking at kidney cancer in people with BHD, we are still excited by the prospect of a new type of treatment for kidney cancer. Future work could be done to look at this type of treatment in BHD kidney cancer.

Watch Mark describe his work in this short video or find out more. A transcript of the video is also available.

At the BHD Foundation we are driven to find new treatments and eventually a cure for BHD. We have just launched our grant funding round for 2023. Find out more including what we fund and how to apply. We also welcome informal enquiries by email.

Birt-Hogg-Dubé syndrome (BHD) is characterised by skin lesions, lung cysts, collapsed lungs and an increased risk of kidney cancer. It is associated with changes in the gene folliculin (FLCN). Our genes are organised into thread-like structures called chromosomes. Humans have 23 pairs of chromosomes. The FLCN gene is found on chromosome 17, in a specific region called “17p11.2”. Another condition, called Smith-Magenis syndrome (SMS) is also associated with a deletion of this 17p11.2 region.

Unlike BHD, SMS is not normally inherited and occurs in every 1 in 15,000 – 25,000 people. Individuals with SMS often have a distinct facial appearance and varying degrees of developmental delay and intellectual disability. People with SMS also have distinct behaviours such as sleep disturbance and hyperactivity. However, this condition is distinct from BHD, as this 17p11.2 region also contains a gene called RAI1. Research has shown that a loss of RAI1 is responsible for most of the features seen in SMS. As such, people with BHD do not get the features seen in SMS. However, people with SMS may also be missing a FLCN gene and therefore may be at risk of the features seen in BHD. As the most serious complication of BHD is kidney cancer, people with BHD should get regular scans to monitor their kidneys. So far, cancer has only been occasionally reported in people with SMS and individuals do not have regular kidney scans.

To date, there have only been a few reports of people with SMS having features of BHD. A recent survey*, carried out by PRISMS (Parents and Researchers Interested in Smith-Magenis Syndrome) looked at the prevalence of BHD features in people with SMS. Of 117 respondents, 7 people reported at least one feature of BHD. 5 people had a collapsed lung, and 2 people had fibrofolliculomas. There were no cases of kidney cancer. However, most people in this survey were under 30 years of age. It is thought that the average age of onsent of kidney cancer in people with BHD is 50.

A recent paper* has summarised 4 cases of BHD in people with SMS and provides recommendations for cancer screening. All cases were confirmed to be lacking a copy of the FLCN gene. The first case decribed a patient (aged 50) who was found to have hybrid oncocytic tumours in both their kidneys and underwent surgery to remove these tumours. They did not have any skin lesions or lung cysts. The second patient was diagnosed with SMS aged 37. Aged 45, they were found to have diffuse B cell lymphoma. Scans also showed they had lesions on their kidney and further tests revealed this to be chromophobe kidney cancer. They had no skin or lung features of BHD. The third patient, aged 25, had lung cysts and skin lesions consistent with BHD. They had no kidney tumours. The last patient was aged 42 and had surgery to remove a 3.6 cm tumour that was confirmed to be chromophobe kidney cancer. They had no skin lesions or lung cysts.

In summary, this recent report identified 4 cases of people with SMS who also had features of BHD. 3 of these had kidney tumours. The authors of this study recommend screening for kidney cancer in adults with SMS in line with the current BHD guidelines, where kidney scans are recommended at least every 3 years starting from age 20.  Most of the studies in SMS so far have been done in children and adolescents and so it is still unclear how common features of BHD in SMS are, considering the features in BHD typically appear in adulthood. Further work, particularly long-term studies are required to fully characterise BHD in people with SMS.

*Unfortunately these papers are not open access. Please email us at contact@bhdsyndrome.org if you have any questions.

Birt-Hogg-Dubé syndrome (BHD) is a rare inherited condition associated with changes in the gene folliculin (FLCN). Most people are diagnosed through a genetic test to check for changes in the FLCN gene. However, a small proportion of people do not have a detectable change (or variant) in FLCN. This group of people can still be diagnosed with BHD based on the presence of clinical criteria. Features of BHD include skin lesions called fibrofolliculomas, lung cysts and collapsed lungs and an increased risk of kidney cancer.

A recent study described an individual who was initially diagnosed with BHD. They came to the clinic aged 33 with multiple skin lesions. These included fibrofolliculomas on the face and chest, skin tags, lesions in their mouth and multiple lipomas. They had no lung cysts but had one small kidney cyst. They were diagnosed with BHD based on the presence of fibrofolliculomas, but genetic testing did not find a FLCN variant. There was a family history of lipomas, other skin lesions and kidney cancer. By the age of 48, they had more than 50 lipomas surgically removed and many more still present. The patient then consented to whole exome sequencing to search for changes in other genes that might be responsible for these features. A variant in a gene called PRDM10 was found. The same change was also found in affected family members.

The authors of the study then looked at the function of PRDM10 in cells. They made cell lines (cells grown in a laboratory) that contained the PRDM10 variant. PRDM10 is proposed to function as a transcription factor. Transcription factors function to turn genes on and off to control which proteins are produced. The particular mutation in PRDM10 that this family was found to have is in a part of the protein important for turning on target genes. In a previous study in mice, it was shown that PRDM10 can turn on the FLCN gene. In this study, the authors found the same effect in human cells. This was confirmed in cells with the PRDM10 variant where the levels of FLCN were almost undetectable. They compared the cells with the PRDM10 variant to cells that were lacking FLCN and found many of the same changes. This included an increase in a protein called GPNMB which has been found in high levels in kidney tumours from people with BHD.

Linking their work in the lab back to the features found in the patient and their family, the authors suggested that the fibrofolliculomas and kidney cancer could be due to the reduction in FLCN. However, there were no lung cysts present which is a common feature of BHD. It was suggested that perhaps the levels of PRDM10 are lower in the lung than the skin and kidney. The levels of FLCN in cells may be under control of multiple different transcription factors. Lipomas were a very common feature in this patient and their family. It is yet to be discovered how the PRDM10 variant drives the formation of these. PRDM10 is likely to control other genes aside from FLCN. Although lipomas have been found in people with BHD, the authors thought that a loss of FLCN was unlikely to be responsible for this.

In summary, the authors of this study have identified a new syndrome with overlapping features of BHD. However, more work is needed to fully understand the role of PRDM10 in the development of this new condition. Identification of other families with the same variant in PRDM10 would also strengthen the data provided in this study. At the BHD Foundation, we found this study interesting as it increases our knowledge of BHD and similar conditions. We look forward to seeing future work on this, and potentially the identification of new BHD-like conditions.

As we put together a calendar of events for 2023, we reflect on our achievements from the last year. After the relaunch of the BHD Foundation in 2021, we were keen to drive the charity’s efforts to fund research and provide support for people with Birt-Hogg-Dubé syndrome (BHD) in 2022 and beyond. We are proud of what we achieved last year and would like to thank everyone who contributed to our work.

Here, we share our 2022 highlights.

Events

We kickstarted 2022 with a ‘Meet the Expert’ event hosted by the BHD Foundation team. We shared our achievements from 2021 and set out our plans for 2022. We then held 2 further ‘Meet the Expert’ events. In April, Dr Ed Cowen (NIH, USA) shared his work on BHD and the skin. We also held a panel discussion in July on BHD, genetics and pre-implantation genetic testing/IVF.

Join us for our next Meet the Expert with Professor Lisa Henske on February 1^st. Lisa will be talking about her work on BHD and lung cysts. Get your free ticket now.

Our biggest event of 2022 was the BHD Community Symposium. This symposium was the first deliberately designed to be accessible to all members of the community. We were thrilled to welcome people with BHD and their families alongside clinicians and researchers to further connect the community. We were delighted to have over 200 people registered from 22 countries across 5 continents for this virtual event. Read the research and patient-focused highlights.

Research and Conferences

One of our proudest achievements of 2022 was launching the BHD Syndrome International Registry (BIRT) at the end of March. We launched BIRT with the aim of driving forward research and giving people with BHD the opportunity to participate in research. We now have over 200 people registered and we look forward to this growing over the coming years. Read our 6 month registry update.

We took part in several conferences this year to raise awareness of BHD among researchers and clinicians. We developed a BHD awareness leaflet (a printable version is also available) that was shared on a virtual platform at the European Respiratory Society Congress and WONCA, the general practitioner conference. We were also delighted to be able to present our work on BIRT at the European Conference on Rare Diseases and the 4^th International Conference on Rare Diseases.

We were also delighted to announce our grant holders from 2021 in February. We also held another grant funding round in 2022 and will be announcing our new grant holders very soon. Research is an integral part of our work at the Myrovlytis Trust and BHD Foundation. Advancing research into BHD is important so that we can better understand it and develop new treatments

Raising Awareness and Social Media

2022 was also a busy year for getting involved in social media and raising awareness of BHD to the wider community. In January, we took part in Medics 4 Rare Diseases ‘Mystery Monday’ which educates future doctors about rare diseases. We also took part in Rare Disease Day and led the World Pneumothorax Day campaign. We got to share personal stories of BHD on these days including Lea’s story ‘From Lung Collapse to Ironman’ and Joanna’s story  ‘Married on a Mountain with a Collapsed Lung’. We look forward to taking part in these events in 2023 and sharing more of your inspiring stories.  

Read more about our work raising awareness of BHD in 2022.

Fundraising

We were thrilled to launch our fundraising programme this year. We held a Prize Draw this year and raised over £650 towards a new BHD Foundation website. There are several other ways you can get involved and we would love to hear your fundraising ideas!

We would like to say a huge heartfelt thanks to everyone who got involved with us in 2022 and can’t wait to continue building and supporting the BHD community in 2023 and beyond.

The Myrovlytis Trust and BHD Foundation would like to say a massive thank you to everyone who has got involved with our work this year! We are very grateful to each of you for sharing your story, taking part in World Pneumothorax Day, attending our Meet the Expert events and our first every community-focused symposium. We look forward to seeing as many of you as possible at our 2023 events to raise awareness and drive forward research into BHD together.

We are always keen to receive your feedback about what you would like to see from us in the future. We would greatly appreciate it if you could complete this short survey and let us know what is important to you. The survey will close on Tuesday 3^rd January. Take the survey now.

We also launched our fundraising programme this year and are extremely thankful to the community for helping us to raise money towards a new BHD website which we will be launching next year. We look forward to hearing your fundraising ideas in 2023.

Our offices will be closed from Friday 23^rd December 2022 and will reopen on Tuesday 3^rd January 2023. We will respond to any enquiries upon our return.

From all of us at the Myrovlytis Trust and BHD Foundation, we wish you a wonderful holiday season and a happy new year!

Kidney cancer occurs in up to 1 in 3 people with Birt-Hogg-Dubé syndrome (BHD). Normally, any kidney tumours are surgically removed if they reach 3 cm in size. Surgeons will aim to preserve as much of the kidney as possible.  This is because people with BHD may need multiple surgeries. However, surgery may not always be the best option. For example, the tumours may be in a part of the kidney that is difficult to operate on or in which surgery would lead to reduced kidney function. Therefore, alternative options to surgery for BHD kidney cancer are needed. A report was published looking at the outcomes of people with BHD who underwent percutaneous thermal ablation (PTA) to treat their kidney cancer.

What is percutaneous thermal ablation?
PTA is a non-surgical procedure that uses extreme heat or cold to destroy cancer cells. It is used to treat many different cancers. However, it is not routinely used in the treatment of BHD kidney cancer. There are many types of PTA. The most common are called radiofrequency, microwave and cryoablation. The type you get may depend on the experience of the person carrying out the procedure as well as the size and location of the tumour.

What did the researchers do?

This study looked at anyone with BHD who underwent PTA between 2007 and 2021 under the Reference Centre of the National Network for Rare Cancers in Adult PREDIR in France. In this timeframe, 6 people with BHD were identified. 4 people had previous surgery on the same kidney and one person had their other kidney completely removed. A total of 19 tumours were treated across 14 PTA sessions. Most of these tumours were treated using radiofrequency PTA. One was treated using microwave PTA and another tumour was treated using cryoablation.

All the tumours were treated successfully. This means that there was no evidence of the tumour remaining or spreading after treatment during the follow-up period (an average of 74 months). 5 of the people treated had chronic kidney disease. There was a slight reduction in kidney function after PTA in these people. However, none of the people treated developed kidney failure or required dialysis.

What did they learn?

In this study, PTA was found to be a successful way of treating kidney cancer in people with BHD. PTA has both benefits and limitations compared with surgery. PTA can be carried out without the need for general anaesthetic. General anaesthetic can increase the risk for having a collapsed lung in people with lung cysts due to BHD. It also appears that multiple rounds of PTA can be carried out successfully. However, it should be noted that surgery can be more challenging after ablation.

PTA could be particularly relevant for people in which surgery might not be suitable. This includes the elderly or people with reduced kidney function. However, the number of people in this study was very small. A larger study that could directly compare the effectiveness of PTA with surgery would be warranted.

Take part in research

As BHD is a rare condition, it is often difficult to get enough people to take part in a study to be able to draw conclusions. We launched the BHD Syndrome International Registry to capture as much information about BHD as possible. Sign up to the registry now to help us speed up and drive forward research.