Invasive lobular carcinoma classic type: response to primary chemotherapy and survival outcomes.
OBJECTIVE
To investigate the impact of histologic type invasive lobular carcinoma (ILC) versus invasive ductal carcinoma (IDC) on response to primary chemotherapy (PC) and long-term outcome.


METHODS
The study included 1,034 patients with stage II and III breast cancer who participated in six clinical trials of PC at our institution between 1985 and 2002. One hundred twenty-two patients (12%) had ILC and 912 (88%) had IDC. All patients received anthracycline-based PC, and 346 patients (33.5%) also received a taxane as part of PC. Pathologic complete response (pCR) was defined as no evidence of invasive disease in the breast and axillary lymph nodes.


RESULTS
The median patient age was 48 years (range, 18 to 79 years). Patients with ILC tended to be older (median age, 53 years v 47 years for patients with IDC) and have more hormone-receptor-positive tumors (92% v 62%; P < .001), lower nuclear grade (nuclear grade 3, 16% v 56%; P < .001), and higher stage at diagnosis (10% v 0% with stage IIIB or IIIC disease; P < .001). Patients with ILC were less likely to have a pCR (3% v 15%; P < .001) and had a larger number of involved axillary lymph nodes (41% v 26% had > 3 involved nodes; P = .001). At a median follow-up time of 70 months, ILC patients tended to have longer recurrence-free survival (P = .004) and overall survival (P = .001).


CONCLUSIONS
ILC is characterized by lower rates of pathologic response to PC but better long-term outcomes compared to IDC. pCR might not be a prognostic indicator for this group of patients.
Cristofanilli
Massimo
M
Department of Breast Medical Oncology, Unit 424, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030-4009, USA. mcristof@mdanderson.org
Gonzalez-Angulo
Ana
A
Sneige
Nour
N
Kau
Shu-Wan
SW
Broglio
Kristine
K
Theriault
Richard L
RL
Valero
Vicente
V
Buzdar
Aman U
AU
Kuerer
Henry
H
Buchholz
Thomas A
TA
Buccholz
Thomas A
TA
Hortobagyi
Gabriel N
GN
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology; D001952:Bridged-Ring Compounds / Q000627:therapeutic use; D044584:Carcinoma, Ductal / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D018275:Carcinoma, Lobular / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology; D018572:Disease-Free Survival; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy / Q000401:mortality; D043823:Taxoids / Q000627:therapeutic use; D016896:Treatment Outcome
D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane