title: Breast cancer subtypes identified by the ER, PR and HER-2 status in Thai women.
abstract: Expression of estrogen-receptor (ER), progesterone-receptor (PR) and HER-2 has recently been linked with various breast cancer subtypes identified by gene microarray. This study aimed to document breast cancer subtypes based on ER, PR and HER-2 status in Thai women, where expression of these subtypes may not be similar to those evident in Western women. During 2009 to 2010, histological findings from 324 invasive ductal carcinomas (IDC) at Siriraj Hospital were studied. Various subtypes of IDC were identified according to expression of ER, PR and HER-2: luminal-A (ER+;PR+/-;HER-2-), luminal-B (ER+;PR+/-;HER-2+), HER-2 (ER-;PR- ;HER-2+) and basal-like (ER-;PR-;HER-2-). As well, associations of tumor size, tumor grade, nodal status, angiolymphatic invasion (ALI), multicentricity and multifocality with different breast cancer subtypes were studied. Of 324 IDCs, 143 (44.1%), 147 (45.4%), 15 (4.6%) and 12 (3.7%) were T1, T2, T3 and T4, respectively. Most tumors were grade 2 (54.9%) and had no nodal involvement (53.4%). According to ER, PR and HER-2 status, 192 (59.3%), 40 (12.3%), 43 (13.3%) and 49 (15.1%) tumors were luminal-A, luminal-B, HER-2 and basal-like subtypes. HER-2 subtype presented with large tumor (p=0.04, ANOVA). Luminal-A IDC was associated with single foci (p<0.01, χ2). HER-2 and basal-like subtypes were likely to have high tumor grade (p<0.01, χ2). In addition, HER-2 subtype had higher number of nodal involvement (p=0.048, χ2). In conclusion, the luminal-A subtype accounted for the majority of IDCs in Thai women. Percentages of HER-2 and basal-like IDCs were high, compared with a recent study from the USA. The HER-2 subtype was related with high nodal invasion. The findings may highlight biological differences between IDCs occurring in Asian and Western women.
authors.affiliation: Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. sisuebwong@mahidol.ac.th
authors.forename: Suebwong
authors.initials: S
authors.lastname: Chuthapisith
authors.forename: Watthanasak
authors.initials: W
authors.lastname: Permsapaya
authors.forename: Malee
authors.initials: M
authors.lastname: Warnnissorn
authors.forename: Charuwan
authors.initials: C
authors.lastname: Akewanlop
authors.forename: Vorapan
authors.initials: V
authors.lastname: Sirivatanauksorn
authors.forename: Poramaporn
authors.initials: P
authors.lastname: Prasarttong Osoth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000145:classification* / Q000378:metabolism / Q000473:pathology; D002280:Basal Cell Carcinoma / Q000145:classification* / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000145:classification* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D013785:Thailand
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone