Histological grade provides significant prognostic information in addition to breast cancer subtypes defined according to St Gallen 2013
2017 (English)In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 56, no 1, 68-74 p.Article in journal (Refereed) Published
Background: The St Gallen surrogate definition of the intrinsic subtypes of breast cancer consist of five subgroups based on estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor type 2 (HER2), and Ki-67. PgR and Ki-67 are used for discriminating between the Luminal A-like and Luminal B-like (HER2-negative) subtypes. Histological grade (G) has prognostic value in breast cancer; however, its relationship to the St Gallen subtypes is not clear. Based on a previous pilot study, we hypothesized that G could be a primary discriminator for ER-positive/HER2-negative breast cancers that were G1 or G3, whereas Ki-67 and PgR could provide additional prognostic information specifically for patients with G2 tumors. To test this hypothesis, a larger patient cohort was examined. Patients and methods: Six hundred seventy-one patients (amp;gt;= 35 years of age, pT1-2, pN0-1) with ER-positive/HER2-negative breast cancer and complete data for PgR, Ki-67, G, lymph node status, tumor size, age, and distant disease-free survival (DDFS; median follow-up 9.2 years) were included. Results: Luminal A-like tumors were mostly G1 or G2 (90%) whereas Luminal B-like tumors were mostly G2 or G3 (87%) and corresponded with good and poor DDFS, respectively. In Luminal B-like tumors that were G1 (n = 23), no metastasis occurred, whereas 14 of 40 Luminal A-like tumors that were G3 metastasized. In the G2 subgroup, low PgR and high Ki-67 were associated with an increased risk of distant metastases, hazard ratio (HR) and 95% confidence interval (CI) 1.8 (0.95-3.4) and 1.5 (0.80-2.8), respectively. Conclusions: Patients with ER-positive/HER2-negative/G1 breast cancer have a good prognosis, similar to that of Luminal A-like, while those with ER-positive/HER2-negative/G3 breast cancer have a worse prognosis, similar to that of Luminal B-like, when assessed independently of PgR and Ki-67. Therapy decisions based on Ki-67 and PgR might thus be restricted to the subgroup G2.
Place, publisher, year, edition, pages
TAYLOR & FRANCIS LTD , 2017. Vol. 56, no 1, 68-74 p.
Cancer and Oncology
IdentifiersURN: urn:nbn:se:liu:diva-134987DOI: 10.1080/0284186X.2016.1237778ISI: 000392819600011PubMedID: 27762648OAI: oai:DiVA.org:liu-134987DiVA: diva2:1078816
Funding Agencies|Swedish Cancer Society; Gunnar Nilsson Cancer Foundation; Mrs. Berta Kamprad Foundation; Anna and Edwin Bergers Foundation; Swedish Breast Cancer Association (BRO); Swedish Cancer and Allergy Foundation; Scientific Committee of Blekinge County Council; Skane County Councils Research and Development Foundation; Governmental Funding of Clinical Research within the National Health Service2017-03-062017-03-062017-03-06