NBN Mutation Found after Colon Cancer

kmlw

In my late 30s, after months of lethargy and fluctuating hemoglobin, I was told I had colon cancer. I went through with a hemicolectomy, and I also had genetic testing.  The results were that I had the NBN 657del5 mutation; thus, I was considered at higher risk for breast cancer.

There are so many conflicting reports out there regarding this mutation. As a matter of fact, many do not consider NBN a contributor to colon cancer cases though my oncologist tends to disagree.

My grandmother had breast cancer at 43 & uterine cancer at 53, and she passed away 15 years later from pancreatic cancer. 

Given her history, I am considering a prophylactic, skin-sparing mastectomy. Given that my grandmother's only daughter died at a young age (accident), I am one of only 2 female descendants of my grandmother. Therefore, family history doesn't help us a whole lot.

Has anyone in this forum faced a diagnosis of colon cancer and had an NBN mutation discovered? What were you advised to do?

Moderators

Hi Kmlw,

We want to send you a warm welcome to the community.

Hopefully others will be along soon to offer their insights on the NBN mutation.

In the meantime, you may find it useful to read our core content on this. It's not much but it may give you a little more info.

Abnormal Gene Testing

Best wishes,

The Mods.

vlnrph

Your situation certainly sounds unique! You might want to look at the FORCE website (mostly for those with BRCA mutations but could help with your decision making) and consider joining the PROMPT study.

I assume that a genetic counselor guided your testing and follow-up. Sometimes other family lines/cousins etc. will contribute valuable data if available. It can be a challenge going back generations when the true cause of death may have been obscured by fear & shame, termed 'female trouble' or was never diagnosed properly in years past.

Congratulations on the realization that these defects can be inherited through men. This fact seems to be a problem for many people to understand. More research is being done all the time so we do have hope for the future. Perhaps our children will have it easier because of the work underway at present...

Mominator

kmlw: welcome

Here are some links:

FORCE website (http://www.facingourrisk.org/index.php) FORCE is working towards a better future for people facing hereditary cancer. FORCE is dedicated to improving the lives of individuals and families affected by hereditary breast, ovarian, and related cancers. We believe no one should have to walk this journey alone.

PROMPT study (http://www.ambrygen.com/prompt) Ambry participates in PROMPT (Prospective Registry of MultiPlex Testing), a multi-site collaborative study that aims to better understand the clinical significance of mutations and variants of unknown significance (VUS) in hereditary cancer genes.

Myriad is a testing company. I had my testing with them. I am BRCA2 positive and I have STK-11 VUS.

Here is a chart my genetic counselor gave me with all the genes tested by Myriad. There are 25 genes associated with various hereditary cancers, 13 are associated with breast cancers. NBN is associated with breast, although colon is not listed at this time.

Which of your genes were tested? Your grandmother had breast cancer at 43, uterine cancer at 53, and then pancreatic cancer at 68. You had colon cancer in your late 30s. There may be one than one gene involved.

Best wishes,

Madelyn / Mominator

vlnrph

Good point about the possibility of multiple mutations mominator - another reason why a competent genetic counselor is so important, even in choosing which panel to order from a particular company.

Since Myriad does not include RAD 50 but Ambry does have it associated with HBOC, it's a concern of mine that some people will be tested and missed in error. We also need better definitions of the variations with unknown significance so adding our experiences to the PROMPT research will help those coming down this road after us.

I'll be 'looking forward' to my ten year colonoscopy this fall, hoping to find nothing significant...