Tyrer-Cuzick IBCIS risk assessment questions

Lea7777

This Sept 2018 study states Tyrer-Cuzick is accurate out to 19 years. Maybe the model has been revised. Mid-Sept I was counseled at a cancer research center and they used the Tyrer-Cuzick model. The numbers were the same as what previous models had produced.

https://jamanetwork.com/journals/jamaoncology/fullarticle/2677301

SassyMutt

Late to the game here.... but I was diagnosed with LCIS in Nov 2014. At the time, my surgeon estimated my lifetime risk of invasive breast cancer at 67%. As others have noted, that's the Angelina Jolie range. I'm not sure which model she used but it was a sobering (and scary!) statistic to hear. I've been on Tamoxifen for almost 4 years and am grateful that I haven't had any further issues to date. But, it's always top of mind. What stopped me from pursuing the PBMX route was my surgeon stressing that advancements are continuously happening and that, given my age (40 at diagnosis), things would look quite different in 10-20 years. She stressed that my risk at age 40 was just about 12% but wold increase by about 1% per year. So, if we could reduce my risk and buy time, the future for women with LCIS could look very different a decade from now. So, I have trusted in that and continue to do 6 month alternating MRIs and mammograms along with Tamoxifen. {{{crossing fingers}}}

leaf

Interesting Lea

Note in the study you cited, https://jamanetwork.com/journals/jamaoncology/full...,

women with a lobular carcinoma in situ diagnosis before or at baseline were excluded.

(To restrict to a cohort with negative screening findings, we excluded women diagnosed with in situ or invasive breast cancer within 6 months of their initial screening mammogram. All women aged 40 to 73 years at entry who attended at least 1 screening visit (baseline) with BI-RADS density recorded and did not have a prior diagnosis of invasive breast cancer or ductal carcinoma in situ were included;)

Still, its important for other (non-LCIS, non-invasive, non-DCIS) women to have an idea how much information this model provides.

Elisabeth_W

There is a doctor at Mercy/Oklahoma City who is a specialist in early breast cancer detection and maintains a blog he posts to a once a month. While I found his site after I'd done my research and made my decision, I found several of his posts very supportive of the decision I ended up making, specifically what he says in the post below about LCIS and the moniker of "risk factor" vs "non obligate precursor.

Evidence continues to accumulate that the ipsilateral side is more likely to develop invasive cancer than the contralateral side, and that there is a disproportionate number of invasive lobular cancers, sometimes occurring at the old LCIS site. This is not "tissue risk" behavior, but is "non-obligated precursor" behavior, much like low grade DCIS. (From personal experience, once you perform a wide excision for LCIS, then 10 years later, you're back in the O.R. again, operating on invasive lobular carcinoma originating at the exact site where you previously did the biopsy, you quit using the phrase, "LCIS is only a risk factor.")

https://alanhollingsworth.wordpress.com/2017/06/

In my case, I had a 12 mm ILC, that was removed via lumpectomy, but had LCIS remaining in 3 margins after the surgery. I was trying to understand my rate of risk in each breast to make a decision about pursuing radiation vs. mastectomy.

I read through Dr. Hollingsworth's entire blog, and he has a lot to say about the data models out there, including Tyrer-Cuzick, and some of the issues with looking at lifetime risk vs. remaining lifetime risk, etc. He also talks about density being the key risk factor as mammography is not particularly effective for detecting BC in women with dense breasts and lobular neoplasia (ALH, LCIS, and ILC). My ILC, for example, was completely occult on 3D mammogram.

LCIS and ILC are diagnoses where we have to look at the long (10+ years) game. Even with tamoxifen/AI and radiation, the occurrence of a first or additional breast cancer after diagnosis/treatment goes up after the 10 year mark, and continues to increase. Depending on your age that can be a big deal or not.

Considering that we with lobular are in the vast minority (and not studied nearly as much as our ductal sisters), I think the reality is: they just don't know enough to make truly definitive predictions. They are SWAGs at best. Dr. Hollingsworth has some interesting things to say about the difference between mathematical risk models and predicting for an individual patient.

Some studies say risk factors like density, age at menarche, family history, etc., don't have an impact, others do. What I take away from that is: they just don't know yet. Particularly for lobular. Given lobulars "indolent" nature, I stopped even looking at studies with less than 10 years of follow-up. Even this discussion thread proves the "they don't know" point: some studies say Tyrer-Cuzick is pretty accurate, others don't.

I also started looking at doctors differently. I'm 49. When a doctor says to me, "in my experience" I take that with a huge grain of salt if that doctor is younger than me. Most oncology related doctors really start practicing in their specialty in their early 30s. And in oncology, only 10-15% of their patients have lobular. So a doctor younger than me has a pretty short data set of experience they're working from, with a minority of their patients. I also realized that an oncologists idea of success is different than mine: they want to ensure that if I DO have another cancer, it is caught early and can be removed with it is still "curable" in the breast. My idea of success is to NOT HAVE another cancer.

In the end, the best we can hope for is a range of risk for each breast and make our individual decisions from there.

Lea7777

Let's hope for some big advancements, SassyMutt. Soon.

I have read Dr. Hollingsworth's comments and his reference to Pluto and LCIS both being re-categorized. Thanks for his and your insights, Elisabeth. You mention, "some studies say Tyrer-Cuzick is pretty accurate, others don't." I'll just add that every single professional in the field that I have talked with (I am up to at least 8 now) says Tyrer-Cuzick is inaccurate or invalid, at least for LCIS. Most have actually advised me to just ignore the results.

You make a very good point on how we define success:

I also realized that an oncologists idea of success is different than mine: they want to ensure that if I DO have another cancer, it is caught early and can be removed with it is still "curable" in the breast. My idea of success is to NOT HAVE another cancer.

Great find, Leaf, that the study omits LCIS. Odd because Tyrer-Cuzick is the only model those with LCIS can use.

"The main aim of this study was to evaluate the Tyrer-Cuzick model to 19 years after risk assessment or 75 years of age..."

IF the Tyrer-Cuzick model is the only one to incorporate LCIS AND this study is designed with the main aim to evaluate the accuracy of Tyrer-Cuzick, BUT those with LCIS were omitted, THEN those with LCIS are back to having no reliable stats.