Thursday, October 20, 2011

TNBC: The Statistics of Survival


The people whose discussions fill the Breastcancer.org forums are savvy folks. They are highly informed about the details of breast cancer—they read the research and discuss it like pros. So, when they came across an essay in The New York Times that presented some frightening statistics, they questioned it.
The piece, “Finding Little Comfort in the Statistics of Survival,”was written by Ellen D. Feld, M.D., an internist and teacher at Drexel University. Feld was diagnosed with a 2.2-centimeter tumor with no affected lymph nodes, making hers a stage IIA cancer. Her chances of survival, she writes, referring to an unnamed book, are at 70 percent for five years and 50 percent at ten years.
The writers on the BCO discussion boards, though, wanted to know where Feld got those numbers, as they are odds with their own research. Clarify and verify, they said.
“I notice the author doesn't quote a source for the numbers,” wrote Michelleo13.
“There is something we don't understand about those statistics,” wrote Mitymuffin.
This discussion thread was for women with triple-negative breast cancer and many of the writers also noted that Feld’s numbers don’t necessarily match the stats for TNBC. And nowhere in the article does she say what type of breast cancer she had—an omission that makes significant difference, as the statistics can vary a great deal from cancer to cancer, and TNBC women have much better long-term survival rates once they hit three years past diagnosis.
I appreciate Feld’s position of constantly worrying. We do that. In fact, I have written about it myself.
But why make others worry more? This is the unintentional result of Feld’s piece, which is otherwise well written. Wouldn’t it be better to advance the dialogue of hope rather than of terror?
So, let’s clarify and verify survival rates for TNBC.
In a study at the M.D. Anderson Cancer Center and published in the Journal of the National Cancer Institute (2008) of 2,838 women treated between 1985 and 2001:
• 93 percent of women with hormone-negative breast cancer had no recurrences within 5 years
• 89 percent had no recurrences after 10 years.
• They did not break other figures down by hormone receptor status, so these figures apply for all breast cancers: Within five years, those with stage I cancer had a 7 percent risk of recurrence; stage II faced an 11 percent risk; and stage III faced a 13 percent risk. Nowhere is there a 50 percent risk.
And in research on 1,601 patients with breast cancer diagnosed between 1987 and 1997 and published in Clinical Cancer Research (2007) at Women’s College Hospital in Toronto:
• The death rate for those ten years after diagnosis was zero. Nothing. Nada. No deaths.
• Most deaths were within one to three years of diagnosis.
I do not know where Feld’s numbers come from, but using these numbers as our guide, we can say estimate that, if her stage IIa tumor were triple-negative, she would face an 11 percent risk of recurrence within five years, a 0-11 percent risk within 10 years.
Remember that these are averages and are a bit like weather reports. When the forecaster says we face a 10 percent chance of rain on any given day, that means that, because of the specific weather conditions, there is a 1 in 10 chance it will rain. It seldom rains on those days. And we all can remember instances when the forecast told us a huge storm was coming and we ended up with sunny skies.

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SOURCES:
Brewster, A. M. , Hortobagyi, G. N. , Broglio, K. R. ,Shu-Wan Kau, Santa-Maria, C.A. . Arun, B., Buzdar, A.U., Booser, D.J., Valero,V., Bondy, M., Esteva, F.J., “Residual Risk of Breast Cancer Recurrence 5 Years After Adjuvant Therapy.” Journal of the National Cancer Institute, 100(16):1179-1183. 2008.
Dent, Rebecca, Trudeau, Maureen, Pritchard, Kathleen I., Hanna, Wedad M., Kahn, Harriet K., Sawka, Carol A., Lickley, Lavina A., Rawlinson, Ellen, Sun, Ping Narod, Steven A., “Triple-Negative Breast Cancer: Clinical Features and Patterns of Recurrence”, Clinical Cancer Research, vol. 13, no. 15, 4429-4434 (2007).

9 comments:

Sue in Italia/In the Land Of Cancer said...

Perhaps she received her dismal numbers from the commercial for- doctor's-eyes-only site Adjuvant. I was a Stage 2A TNBC patient with no nodal involvement with a 3 cm tumor. The site said (my doctor showed me it) that I had a 70% chance of being alive in 10 years assuming I had the standard chemo and only 50% chance without it. Not very good numbers. However these numbers were by definition more than 10 years old. They lumped the her2 positives with the negatives and early stage her2 positives did not get Herceptin in those days so their even worse odds skew the results. Also no dose dense treatment 10 years ago without Neulasta.

It is also possible she got her data from a small set of patients. Even though about 20,000 to 30,000 receive this diagnosis in the US every year, rarely do studies include very many of us.

Thank you so much Pat for keeping an eye on all this data and the articles you post.

Patricia Prijatel said...

As always, Sue, thanks for your perspective. You are correct that TNBC patients were underrepresented in older studies, which is why newer research focusing only on us is the most reliable. And statistics are generalizations, but patients are people. Still, I would have translated those 50-50 chances to mean that I would be in the healthy 50 percent. And, even if I were wrong, I would still have been happier longer.

Anonymous said...

This was a very encouraging article. We needed some positive information!
A friend of mine has a TNBC blog, and she has a post stating that once recurrence happens, 3/4 of those women die, and the average survival time is 9 months. That was very scary to read. Also read that if there is alot of vascular involvement (which my mother had), it ups the risk of recurrence.
Again, I can't thank you enough for giving us all hope. You are the best!
Lisa

pattihatescancer said...

From reading her article, she is obviously a "glass half empty" sort of person. I, like you, can handle 50-50 odds by assuming I will be in the 50 percent who survive! Knowing that much, plus the studies showing how diet and exercise improve our odds, gives me great hope and a feeling that I...not some study, , statistic, or other entity, can make a difference in my own life, outlook, and survival.

Anonymous said...

I am confused. It says 2A tnbc has an 11% the first five years, then 0-11% through year 10 and then 20%up to year 20. I thought after 5 years triple negative has a very low recurrence rate and does not increase with time. Why a 20% after year 10 to year 20? am I misunderstanding?

Anonymous said...

sorry, I meant 20% for 15 years not 20.

Patricia Prijatel said...

Anon: Thanks for being my fact-checker. I appreciate when readers ask these kinds of questions, because they make me double-check the research. In this case, I found, in rereading the article, that the 15-year figure was not accurate. I should have focused instead on the encouraging five year rates in that study--92 percent overall survival. Survival does, interestingly, go down to 89 percent in ten years--still an excellent number. And both rates are better than for hormone-positive cancers. And researchers did not have access to Her2 data, so these are not necessarily TNBC cases. This just shows that we need to focus on our own case--that statistics can vary significantly. I have edited the article to reflect these changes. Thanks again.

Anonymous said...

I am a 9 year TNBC survivor - ladies there is hope! I was diagnosed at the age of 46, I decided to have a mastectomy - although chemo was recommended I couldn't go through with it....I took this as a "wakeup call" and changed my diet and lifestyle and 9years later I am able to share this story with you. Hope and blessings to all!

Anonymous said...

That is awesome. I was also diagnosed a year ago at age 48. Had a mastectomy, without chemo. I am living life daily.