basal-like AND HER2+?

[Debbie L.]

Basal-HER2 phenotype shows poorer survival than basal-like phenotype in hormone receptor-negative invasive breast cancers
Résumé / Abstract

Previous studies have shown conflicting results on prognostic significance of basal-like breast tumors, but hormone receptor is a confusing factor in most of the prognostic evaluations. We aimed to characterize the prognostic features ofbasal-like tumors without the influence of hormone receptor status in a series of hormone receptor-negative breast tumors.

Using tissue microarray and immunohistochemistry methods, according to the expression of HER2 and basal markers (CK5/6, CK14, EGFR), we categorized 713 consecutive hormone receptor-negative invasive breast cancers into 3 subtypes: HER2 (HER2+), basal-like (HER2-, any basal marker+), and null (HER2-, all basal markers-). The HER2 phenotype was subdivided into pure-HER2 (HER2+, all basal markers-) and basal-HER2 (HER2+, any basal marker+) subgroups. Expression of p53, p63, vimentin, and BRCA1 was assessed immunochemically.

Basal-like tumors showed significantly higher grade, more frequent recurrence, and higher expression of vimentin and p63 than HER2 and null phenotypes. Basal-HER2 phenotype had significantly younger mean age and expressed a higher level of p53 and vimentin like basal-like and/or HER2 phenotypes. However, unlike all the other hormone receptor-negative phenotypes, they highly expressed BRCA1. No significant difference was found in 5-year survival among basal-like and the other hormone receptor-negative phenotypes, except for basal-HER2, which showed poorer 5-year overall survival than basal-like tumors.

In conclusion, although basal-like breast tumors have distinct clinicopathologic and immunohistochemical features, they have similar 5-year survival compared with the other hormone receptor-negative tumors including HER2 and null phenotypes. However, there exists a small group of hormone receptor-negative tumors expressing HER2 and basal markers simultaneously. This small group of tumors showed significantly poorer 5-year overall survival than basal-like breast tumors and might require different treatment strategy.

Auteur(s) / Author(s)

HUI LIU ⁽¹⁾ ; QINHE FAN ⁽²⁾ ; ZHIHONG ZHANG ⁽²⁾ ; XIAO LI ⁽²⁾ ; HUIPING YU ⁽³⁾ ; FANQING MENG ⁽⁴⁾ ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Pathology, Nanjing Medical University, Nanjing 210029, CHINE
⁽²⁾ Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, CHINE
⁽³⁾ School of Basic Medical Science, Southeast University, Nanjin 210009, CHINE
⁽⁴⁾ Department of Pathology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University, Nanjing 210008, CHINE
Revue / Journal Title

Human pathology ISSN 0046-8177 CODEN HPCQA4 Source / Source

2008, vol. 39, n^o2, pp. 167-174 [8 page(s) (article)] (22 ref.)Langue / Language

Anglais
Editeur / Publisher

Elsevier, New York, NY, ETATS-UNIS (1970) (Revue)

[Becky]

I have always contemplated this as well as several other factors.

First - does a basal type Her2+ cancer respond to Herceptin therapy (might not respond as well) and does it behave more like Her2+ or (triple negative).

Second - I was always under the assumption that basal like is more determined by the "supposed" location of the tumor (or where the first cell to go "bad" was located). If you think about a duct, it is like a hose. If you look down the hose, you have the cells lining the inside, you have cells lining the outside and then you have the middle (the cells that are sandwiched into the inner and outer linings). I was once led to believe that Luminal A (Her 2 neg, high ER/PR) came from cells in the inner lining, Luminal B (Her 2 + and low to moderate ER/PR - and maybe those that are just Her2+)came from the middle and all triple negative from the outside lining (hence the terminology "basal"). I never believed that this was truly the way things worked 100% of the time but it makes sense that different affected cells would evolve into different types of pathology with different prognosis. However, I am sure differing types of bc could arise from anywhere in the duct (or lobe) and we all know there is a difference between ductal and lobular cancer and how they behave.

Anyway - nice article. I learned something today.

[Hopeful]

Becky,

Thanks for your explanation - I learned something today.

Hopeful