The biological and clinical characteristics of breast carcinoma with mixed ductal and lobular morphology.
Although invasive ductal (IDC) and lobular (ILC) breast carcinomas are well characterised in the literature, the biological and clinical significance of mixed tumours with both ductal and lobular components has not been investigated. In the current study, we have examined a well-characterised series of breast carcinoma with a long term follow-up that comprised 140 mixed tumours, 2170 IDC and 380 pure ILC.


RESULTS
Mixed tumours constituted 3.6% of all cases. The majority (59%) of the mixed tumours were grade 2 compared to 33% in IDC and 88% in ILC. Positive lymph nodes (LN) were found in 41% and definite vascular invasion (VI) in 26% of the cases. DCIS was detected in 123 (89%) and LCIS in 43 (31%) (both DCIS and LCIS were found in 39 cases). The majority of tumours were predominantly (>50 of tumour area) of ductal type (57%). When compared to pure IDC, mixed tumours showed an association with lower grade, ER positivity and lower frequency of development of distant metastases. When compared to pure ILC, mixed tumours showed an association with higher grade, positive LN metastasis, VI and development of regional metastasis. After adjustment for grade most of these differences were no longer apparent. There was an association between histologic type of carcinoma in LN metastasis and the predominant histologic type of the primary tumour. Mixed tumours showed metastatic patterns similar to that of ILC with frequent metastasis to bone. No clinically meaningful differences in survival were found between these mixed carcinomas and pure IDC or ILC of the breast or between mixed tumours with predominantly ductal or lobular phenotype.
Rakha
Emad A
EA
Department of Histopathology, School of Molecular Medical Sciences, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK. emadrakha@yahoo.com
Gill
Muhammad S
MS
El-Sayed
Maysa E
ME
Khan
Marium M
MM
Hodi
Zsolt
Z
Blamey
Roger W
RW
Evans
Andrew J
AJ
Lee
Andrew H S
AH
Ellis
Ian O
IO
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000188:drug therapy / Q000473:pathology*; D018275:Carcinoma, Lobular / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000188:drug therapy; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate
D014408:Biomarkers, Tumor