statistics for efficacy of adding herceptin to chemo for small, node-negative her2+bc

[Lani]

ABSTRACT: Adjuvant trastuzumab with chemotherapy is effective in women with small, node-negative, HER2-positive breast cancer
[Cancer]

Background: Several large, randomized trials established the benefits of adjuvant trastuzumab with chemotherapy. However, the benefit for women with small, node-negative HER2-positive (HER2+) disease is unknown, as these patients were largely excluded from these trials. Therefore, a retrospective, single-institution, sequential cohort study of women with small, node-negative, HER2+ breast cancer who did or did not receive adjuvant trastuzumab was conducted.

Methods: Women with ≤2 cm, node-negative, HER2+ (immunohistochemistry 3+ or fluorescence in situ hybridization ≥2) breast cancer were identified through an institutional database. A "no-trastuzumab" cohort of 106 trastuzumab-untreated women diagnosed between January 1, 2002 and May 14, 2004 and a "trastuzumab" cohort of 155 trastuzumab-treated women diagnosed between May 16, 2005 and December 31, 2008 were described. Survival and recurrence outcomes were estimated by Kaplan-Meier methods.

Results: The cohorts were similar in age, median tumor size, histology, hormone receptor status, hormone therapy, and locoregional therapy. Chemotherapy was administered in 66% and 100% of the "no trastuzumab" and "trastuzumab" cohorts, respectively. The median recurrence-free and survival follow-up was: 6.5 years (0.7-8.5) and 6.8 years (0.7-8.5), respectively, for the "no trastuzumab" cohort and 3.0 years (0.5-5.2) and 3.0 years (0.6-5.2), respectively, for the "trastuzumab" cohort. The 3-year locoregional invasive recurrence-free, distant recurrence-free, invasive disease-free, and overall survival were 92% versus 98% (P = .0137), 95% versus 100% (P = .0072), 82% versus 97% (P < .0001), and 97% versus 99% (P = .18) for the "no trastuzumab" and "trastuzumab" cohorts, respectively.

Conclusions: Women with small, node-negative, HER2+ primary breast cancers likely derive significant benefit from adjuvant trastuzumab with chemotherapy.

[Laurel]

Love this!!!!!

[AlaskaAngel]

.....but not yet proof whether (or when) adding the chemo to the Herceptin is effective....

[Lien]

Exactly. I'd like to know whether giving just Herceptin without chemo would be beneficial for this group. And the differences are there, but small.

Here in the Netherlands, usually chemo was not suggested for tumors smaller than 1 cm. So is there a benefit for that group? I'm not sure I'd want to take chemo and Herceptin with their side effects if my long term benefit would be just a few percent.

So more research would be good.

Jacqueline

[suzan w]

smiling :-)

[Lani]

the following is a great article on how many/few would have in all l likelihood achieved a PCR if their tumor had been big enough when found to do neoadjuvant treatment, depending on how ER+ it was... it assumes the behavior of her2+ breast cancer is the same once it has become invasive whether it is found at T1 stage or T2 and greater stage (you may or may not want to make this assumption, but it certainly fits better for her2 than for quite a few other types of bc):

Modern Pathology advance online publication 19 November 2010; doi: 10.1038/modpathol.2010.209
Semiquantitative hormone receptor level influences response to
trastuzumab-containing neoadjuvant chemotherapy in HER2-
positive breast cancer
Rohit Bhargava1, David J Dabbs1, Sushil Beriwal2, Isil A Yildiz1, Preeti Badve1, Atilla Soran3,
Ronald R Johnson3, Adam M Brufsky4, Barry C Lembersky4, Kandace P McGuire3 and Gretchen
M Ahrendt3


It discusses treatment with chemo with and without herceptin.
Adjuvant studies where they give herceptin first, rebiopsy, then addd chemo might also give an idea of how much difference the chemo makes, but they have not usually been graded as well as this one as to HOW ER+ the tumor was.

[AlaskaAngel]

I wonder how effective the treatment would be without chemotherapy but with non-chemo ovarian ablation, so that we at least know the answer to that question when choosing to undergo therapies, with the many support drugs and side effects and added risks of those therapies.

A.A.