Basal-like breast carcinomas: clinical outcome and response to chemotherapy.
BACKGROUND
Grade-III invasive ductal carcinomas of no special type (IDCs-NST) constitute a heterogeneous group of tumours with different clinical behaviour and response to chemotherapy. As many as 25% of all grade-III IDCs-NST are known to harbour a basal-like phenotype, as defined by gene expression profiling or immunohistochemistry for basal cytokeratins. Patients with basal-like breast carcinomas (BLBC) are reported to have a shorter disease-free and overall survival.


METHODS
A retrospective analysis of 49 patients with BLBC (as defined by basal cytokeratin expression) and 49 controls matched for age, nodal status and grade was carried out. Histological features, immunohistochemical findings for oestrogen receptor (ER), progesterone receptor (PgR) and HER2, and clinical outcome and survival after adjuvant chemotherapy were compared between the two groups.


RESULTS
It was more likely for patients with BLBCs to be found negative for ER (p<0.0001), PgR (p<0.0001) and HER2 (p<0.01) than controls. Patients with BLBCs were found to have a significantly higher recurrence rate (p<0.05) and were associated with significantly shorter disease-free and overall survival (both p<0.05). In the group of patients who received anthracycline-based adjuvant chemotherapy (BLBC group, n = 47; controls, n = 49), both disease-free and overall survival were found to be significantly shorter in the BLBC group (p<0.05).


CONCLUSIONS
BLBCs are a distinct clinical and pathological entity, characterised by high nuclear grade, lack of hormone receptors and HER2 expression and a more aggressive clinical course. Standard adjuvant chemotherapy seems to be less effective in these tumours and new therapeutic approaches are indicated.
Banerjee
S
S
Breast Unit, Royal Marsden Hospital, London, UK.
Reis-Filho
J S
JS
Ashley
S
S
Steele
D
D
Ashworth
A
A
Lakhani
S R
SR
Smith
I E
IE
D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology* / Q000556:secondary; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
D007633:Keratins; D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone