Warning,careful! Need/advisability of mastectomy in her2+breast cancer

[Lani]

ABSTRACT: Linking survival of HER2-positive breast carcinoma patients with surgical invasiveness [European Journal of Cancer]
The early peak of relapse in patients with breast carcinomas that overexpress HER2 oncoprotein and dissemination to the axillary lymph nodes might be related to proliferation of micrometastatic lesions induced by EGF family growth factors released at the time of surgery. If the levels of these growth factors have an impact on relapse, the survival of patients with positive nodes and HER2-positive tumours should be dependent on surgery wideness. To test this hypothesis, HER2 status of primary tumours from patients included in a randomized clinical trial addressing conservative quadrantectomy versus radical mastectomy was retrospectively analyzed. In HER2-negative patients, independently of node infiltration, and in HER2-positive patients without node infiltration, no differences in survival according to the type of surgery were observed. In patients with positive nodes and HER2-positive tumours the estimation of the time-dependent log-hazard ratios showed that radical mastectomy significantly increased early death rates (P = 0.037).

[R.B.]

VERY glad to see you are still around and posting. Your contributions are always considered and informative.

Thought provoking.

RB

[saleboat]

Hi Lani,

"In patients with positive nodes and HER2-positive tumours the estimation of the time-dependent log-hazard ratios showed that radical mastectomy significantly increased early death rates (P = 0.037)"

Am I reading this correctly? Does this mean that radical mastectomies were associated with early death rates? I guess I'm confused, but I'm not much of a statistician.

Thanks for any light you can shed.

Jen

[Lani]

I am still reading the original article, but the authors are making a lot of ASSUMPTIONS based on few facts and seeing if their statistics match their hypothesis, even if flawed.

In their experience those patients who had mastectomies had a shorter disease-related survival, however there may be other factors which caused the patients/their doctors to choose mastectomy which influenced survival, it may be that the inflammatory cascade set off by the surgery and not the micrometastases were at fault, there may be some substance (VEGF-C which is related to lymphatic-neogenesis ) which caused the lymph node metastasis which interacts with the physical or humoral results of surgery (perhaps the cortisol which is released due to the stress of surgery) resulting in more motility, more interaction with the stroma in bone, lung, brain or liver, etc.

I posted this even though it was based on too many assumptions for me to consider it in anyway definitive, as it is one of EXCEEDINGLY FEW studies which reported results for her2+ breast cancer's behavior ONLY.ie other articles discuss all breast cancers behavior or the behavior of ER+ or ER- breast cancers. IT is only by getting articles written about the natural history of her2+ breast cancer and how it responds to different treatment, whether SURGERY, Radiation therapy or chemo/immunotherapy that we will see whether previous attempts to fit all square pegs in a round hole ie, treat her2+breast cancer like other breast cancers has been appropriate or not.

Log hazard ratios have to do with how much more likely an even is to occur than one would expect and in this case the rate of early death was certainly "significantly increased" (not considering my caveats listed above)

Hope this helped!

Again, I was hesitant to post, but felt there might be someone perusing the site while deciding whether to have a mastectomy. I wouldn't let this article only sway someone, but as it involved her2+s only, it is certainly worth the read

[saleboat]

Thanks Lani. It makes sense now, in a counter-intuitive way.

Hopefully we'll see more Her2 specific info coming out of ASCO next month. (I never thought I'd be someone to look forward to such things...) We're all definetly on the cutting-edge of 'personalized medicine'-- i.e., being treated based on one's very specific disease profile, rather than catch-all buckets based on stage, lymph-node involvement, hormonal profile.

Thanks again,
Jen