Monday, June 16, 2008

Follow up to a question on breast cancer

I got a question about some of the ideas I was talking about in my last post on how I think about breast cancer. A breast cancer patient wrote me and asked about the difference in how her oncologist explains things
"They quote an 80% recurrence free 10 year survival rate for stage IIA and 75% for stage IIB. I'm stage IIA and my onc says I am probably cured (after surgery, chemo, etc.).

Do you really think all node positive younger women are destined to recur?

Another question: how do you compare positive nodes with lympho vascular invasion? My onc says that there is no data that LVI is as negative an indicator as nodes."


I think it's important to understand that not all breast cancers of stage "x" are created equal, and the biologic "aggressiveness" of a tumor can really skew your personal risks. I talked about 3 of the more important factors (node status, estrogen receptor status, and tumor size), but you've also got histologic characteristics (like tumor grade) and other genetic markers (like HER2/neu) in the mix. Some % of these patients also identified or unidentified inherited genes or mutations which increase their risk substantially for breast and other cancers.

There were two competing worldviews of breast cancer in the classic "Halsted Model" (breast cancer progresses from local->regional->systemic disease) and the "Systemic Model" (breast cancer is already systemic at the time of most diagnosis). I found a nice summary of these ideas on this old newsgroup post for those interested. Personally, I split the difference in my head in that I think that if you're node negative with favorable histology the Halsted model is still true, and that a true absence of residual cancer is possible. If you have nodes involved I'm inclined to believe the Systemic Model in that you have already likely have had some cancer burden establish elsewhere. This is supported by the fact that metastatic breast cancers still show up decades after mastectomy on occasion with no local or regional recurrence of the original cancer preceding it.

Younger breast cancer patients are particularly worrisome in that you have some many decades left of potential exposure for recurrence or new primary breast cancers. It makes absolutely no sense to me to push breast conservation (lumpectomy and radiation) for all but the most favorable invasive cancers in women in their 20's or early 30's. I think maximum risk reduction should be advised for many of these women with bilateral prophylactic mastectomy.

For stage II/III breast cancers (those without systemic mets) the data's a pretty slippery slope where 10 year survival curves run from 70-78% in the more favorable patients to 20-40% depending on grade, size, and # of nodes. This data is laid out nicely at this British Cancer site. Keep in mind that all 3 of those factors are subject to sampling error, and that some of the stage II patients are actually stage III.


There's a great article in the Atlantic magazine "Good News and Bad News About Breast Cancer" from a decade ago which is much more eloquent then I am trying to be reluctant about telling people they're "cured" from breast cancer. It features some of the work by one of my professors, the late Dr. John Spratt from the University of Louisville, who was really visionary in describing tumor's behavior and growth clinically

Breast cancer, unfortunately, is not among this select group (of tumors we can eradicate). As far as we know, a woman found to have invasive breast cancer is always at higher risk of dying prematurely than women without breast cancer. Even thirty years after her diagnosis she is up to sixteen times as likely to die of the disease as a woman in the general population. That is why responsible researchers in this field avoid the word "cure." Even as they report advances, they must acknowledge the reality: Postsurgical chemotherapy and antihormonal therapy do buy time—an important advance. The slowed progress of the disease can give a woman additional years of life and even allow her to die of other, less traumatic, causes. But breast cancer is every bit as incurable as it was in Halsted's day.


Rob

4 comments:

Snafu Suz said...

But breast cancer is every bit as incurable as it was in Halsted's day.

Well as a breast cancer survivor I have to say this particular blog entry is quite depressing. ;)

What's interesting is that the general public seems to see breast cancer as totally curable. While no one has said this to me personally, I know of women who - upon sharing their diagnosis - actually had someone say, "At least you got the good kind of cancer!"

Obviously there is no such thing as "the good kind of cancer" but I think people want to believe that there is. Cancer scares the hell out of people and it's easier to believe that medical science has come so far that it's not a big deal anymore. Unfortunately the surge of breast cancer awareness seems to be accompanied by a fair amount of misconception and misinformation.

When people find out I had cancer they get this horrible look on their face that says, please tell me you're in remission. I refuse to say I'm in remission - or heaven forbid, cured - because there's really no way to know if that's true. Cancer very well could be lurking in my body somewhere but as yet is too microscopic to be detected. So I usually say something along the lines of, "Don't worry, I kicked cancer's butt!" I guess I am guilty in perpetuating some of those breast cancer misconceptions but I can’t stand that awful look of pity and awkwardness on their faces. And in all honesty, I don’t think in that moment they really want a dissertation on why “remission” and “cured” really have no place in breast cancer vocabulary.

So did I kick cancer’s butt? Probably, since I was stage 1 node-negative and chose aggressive treatment. However, I was also HER2+, ER-, PR-, and my cancer was high grade. The reality is that there’s no way to know for sure. The rest of the world can choose to live in denial, but that’s an uncertainty I’ll have to live with for the rest of my life.

Thanks for bringing some accurate awareness to the subject.

Anonymous said...

Wow, thanks for the extremely informative (and fast) post!

I'm the woman who asked the original question. Not that it matters, but my tumor was grade III (9/9 BM), her2 neg, ER/PR positive. Multifocal disease, with a 3cm and 2cm tumor plus other "areas of infiltration." But, no nodes. So, it's been really hard for me to understand where I fall on the scale, as all the oncs seem to look at is the nodes.

Thanks again!

Anonymous said...

OK, I looked at the British site you posted, and I'm not even in there! There's no stats at all given for a cancer above 2cm, high grade, with no cancer in the lymph nodes. Grrr.

Tom Fiala, MD said...

Rob:

What's your stance on the controversy surrounding prophylactic contralateral mastectomies? High risk patients only - or are you recommending them to some younger pts.?

Tom