The St. Gallen International Expert Consensus 2011 proposed a new classification system for breast cancer based on its division into five subgroups. The criteria to identify subtypes were further recently refined at the 2013 Conference, in that moderate of a strong expression of PR and Ki-67 level were both recognized as being important to the surrogate definition of a “Luminal A-like” disease. According to these criteria, the subtypes in question have been defined as: Luminal A – ER positive, HER2 negative, Ki-67 low, and PR high; Luminal B (HER2 negative) – ER positive, HER2 negative, and either Ki-67 high or PR low; Luminal B-like (HER2 positive) – ER positive, HER2 overexpressed or amplified, any Ki-67, and any PR; HER2 positive – HER2 over-expressed or amplified, ER and PR absent; and triple negative – ER and PR absent and HER2 negative.3 These exact criteria and their recognition of biology subtypes have been used here throughout the course of this study within the breast cancer spectrum.
Reasonof age 35..(gabriel)
Th e characteristics of tumors that arise in women under the age of 35 diff er from those that arise in premenopausal women who are older than 35. Women younger than 35 have a lower rate of ductal carcinoma in situ, likely due to detection bias (women in this age range do not typically have screening mammograms) . Tumors in women younger than 35 are more likely to be of a higher histological grade  and to be classifi ed as estrogen receptor (ER) and progesterone receptor negative [5,6]. In addition, young women are more likely to have local recurrences, to be diagnosed at a more advanced stage, and to have an inferior 5 year survival compared to their older premenopausal counterparts [4,6,7
according to american society of breast cancer young cancer are rom age of 20-39… but many the definition of breast cancer in young women is different .Many claims that age up to 40 is explained young women breat cancer . which is actually not true, according to premenopausal cancer ( REF GOLD AT EL) 51 is average age of menopause , and start from 45..
Results from cross-sectional studies have indicated that endocrine changes characteristic of the onset of the perimenopause begin at around age 45.48
Mean 45 to 51 is the most advocated years of menopause , ie it has started fron 45 and average age is 51. (R Trevoux, McKinlay SM, Magursky V)
In the existing body of literature definition of premenopausal cancer according to age group is ambiguous and most researched took ag e up to 40 when studing young women breast cancer or premenopausal breast cancer and perhaps true comparison of of pre and post menopausal cancer is not explicitly explain yet.
There is paucity of comparative data of breast cancer profile of two groups.
This will direct the future researchers to study breast cancer biology in to age groups among young women and that make clinician more equippedto direct the management.
Risk fators :
Delayed childbirth (fi rst child after age 30 years) is known to be a risk factor for breast cancer in women older than 35(Gabriel)
Carey at al SAYS there is difference between (40 vs 45)
Interestingly,further age-specific exploration of clinicopathologic features revealed a greater incidence of lymph node positivity among women age younger than 40 years compared with those age 40 to 45 years (Appendix Table A2, online only).
Age-specific differences in mRNA expression were evaluated solely within the subset of young women’s tumors ( 40 v 40 to 45 years). Women age younger than 40 years had lower mean mRNA expression of ER (6.6 v 7.8, respectively; P .03) and ER (5.3 v 5.9, respectively;P.01). However,mRNA expression of PR, HER-2, and EGFR was similar (Appendix Fig A1, online only).
As we begin to individualize treatment decisions based on the subclassification of breast cancer into its many clinical and molecular entities, we cannot overlook the cancer subtypes according to age .
Association of luminal A with axillary node involvement. In both age group.
Jahan er – ha data usko ethinifity sy expain karsakty hn?? Like carey at al
– BRCA1-related breast cancers are almost always basal-like/LUMINAL B (Foulkes et al. 2003).
Finally, young patients with Luminal B tumors may be
more likely to carry BRCA mutations,( Zhong X, Dong Z, Dong H, Li J, Peng Z, Deng L, Zhu X, Sun Y, Lu X, Shen F, Su
X, Zhang L, Gu Y, Zheng H. Prevalence and prognostic role of BRCA1/2 variants in
unselected chinese breast cancer patients. PloS one. 2016;11:e0156789)
the likelihood that a woman with breast cancer under the age of 35 had a detectable BRCA1/2 mutation was 9.4% (compared to a population prevalence of 0.2%) ;
Q4: Not every region “s young women have more triple negative, like us and add ore er wali studies
Literature indicates women with an early-onset BC with family history have a higher frequency of BRCA1 and BRCA2 compared to women without a family history [23,24]
23) Loman, N., O. Johannsson, U. Kristoffersson, H. Olsson, and A. Borg. 2001. Family history of breast and ovarian cancers and BRCA1 and BRCA2 mutations in a population-based
series of early-onset breast cancer. J. Natl Cancer Inst. 93:1215–2
.24) Malone, K. E., J. R. Daling, C. Neal, N. M. Suter, C. O’Brien, K. Cushing-Haugen, et al. 2000. Frequency of
BRCA1/BRCA2 mutations in a population-based sample of young breast carcinoma cases. Cancer 88:1393–402.
Outcomes of Estrogen Receptor Negative and Progesterone Receptor Positive Breast Cancer
• Melissa Chan, at al
Tumors expressing PgR, but not ER (ER-/PgR+) are uncommon, comprising 2–8% of breast cancers [5–7], with less known about their characteristics and responsiveness to therapy.
The clinical and biological significance of ER-/PgR+ breast cancers has been debated. Some authors hypothesize that this phenotype is a technical artifact. Several factors may alter the HR status of a breast cancer, resulting in a false-negative ER and/or false-positive PgR assay [8, 9]. These factors include improper tissue fixation, antibody selection for ER testing, different thresholds for reporting immunostaining, or less sensitive immunohistochemistry techniques [8–11]. It has been recommended by the American Society of Clinical Oncology/College of American Pathologists that ER-/PgR+ tumors should have testing repeated to rule out a false negative ER result 
Specifically, data support that ER-/PgR+ tumors occur more commonly in younger, premenopausal women and have been associated with more aggressive behaviour than ER+/PgR+ disease [5, 13]. Of interest, in the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) analysis, there was a non-significant association with reduced recurrences with adjuvant tamoxifen in the ER-/PgR+ phenotype despite this group being considered ER-negative .