Epidermal growth factor receptor and S-phase fraction as prognosticator combination in node negative primary breast cancer

A multicentre phase II study on gefitinib in taxane- and anthracycline-pretreated metastatic breast cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) is considered to be a viable drug target in a variety of solid tumors. The clinical benefit and safety of the EGFR tyrosine kinase inhibitor gefitinib ('Iressa')1 was evaluated in this Phase II, multicentre study of patients with taxane and anthracycline pretreated, metastatic breast cancer.

METHODS

Gefitinib (500 mg/day) was given to 58 patients until disease progression. Primary endpoint was the clinical response rate to the study treatment.

RESULTS

One patient (1.7%) had objective partial tumor response of her liver and pleural metastasis. Fifty-seven patients (98.3%) were non-responders with 52 patients (89.7%) having progressive disease and five patients (8.6%) were not evaluable. Two patients reported a significant improvement in pain at metastatic sites (1 liver, 1 bone). The median time to progression was 61 days (95% CI : 54-82 days) and the proportion of patients alive and progression free at 6 months at trial closure was 1.8% (95% CI : 0.0-5.2%). The median survival time was 357 days (95% CI : 257-441 days). Fifty-four patients (93.1%) discontinued study medication prematurely due to disease progression and three (5.2%) due to adverse events (diarrhea, pruritus, peripheral edema).

CONCLUSIONS

Gefitinib monotherapy at 500 mg daily did not appear to be efficacious in the treatment of heavily pretreated metastatic breast cancer patients. It was well tolerated and the side effect profile was as expected from current knowledge of the drug. There was no correlation between EGFR expression and response in this study.

Expression of endothelial and inducible nitric oxide synthase in benign and malignant lesions of the breast and measurement of nitric oxide using electron paramagnetic resonance spectroscopy

BACKGROUND

Nitric oxide (NO) is present in various human solid tumors and tumor cell lines, and it is believed that NO plays an important role in tumor growth. An increased NO concentration catalyzed by NO synthase (NOS) is cytotoxic and can promote apoptosis. The expression of endothelial NOS (e-NOS) and induced NOS (i-NOS) was examined in various breast tumors.

METHODS

Immunohistochemical staining with a monoclonal antibody (Ab) against e-NOS and a polyclonal Ab against i-NOS was performed on paraffin embedded tissues from 41 benign breast lesions, 9 in situ breast lesions, and 54 invasive breast lesions. Functionality was confirmed by detection of NO using spin-trapping electron paramagnetic resonance (EPR) spectroscopy.

RESULTS

e-NOS expression was found in 2 benign lesions (5%; 1 fibroadenoma and 1 proliferative mastopathy), in 5 in situ lesions (56%), and in 33 invasive lesions (61%). None of the benign lesions was positive for i-NOS, but 6 in situ lesions (67%) and 33 invasive lesions (61%) showed tumor cell staining. In particular, capillaries that were embedded in lymphocytic stroma showed a positive reaction for e-NOS. The functionality of NOS was demonstrated by direct NO formation using the EPR spin-trapping method. Tumors that were positive for e-NOS were observed more often in younger patients (P = 0.05). These tumors more frequently were highly differentiated or moderately differentiated and more often showed invasive ductal subtypes and a lower proliferation rate. Tumors that were positive for both e-NOS and i-NOS were more likely to be lymph node negative tumors. Both i-NOS-expressing lesions and e-NOS-expressing lesions showed strong coexpression (P = 0.00001).

CONCLUSIONS

NOS is detected predominantly in in situ lesions and invasive breast lesions but rarely in benign lesions. NOS is found more frequently in invasive carcinomas with low malignancy. Using the spin-trapping EPR method, this study demonstrates direct NO formation in human breast tumors for the first time.

CD44 variant exon epitopes in primary breast cancer and length of survival

CD44 designates a group of closely related cell-surface proteins generated by alternative splicing. We have previously shown that splice variants carrying sequences encoded by exon v6 are preferentially expressed in metastatic animal cancer cell lines and that they confer metastatic behaviour on non-metastatic animal tumour cell lines. In this study we set out to assess the expression of CD44 epitopes specific for variant exon sequences in human breast cancer and their potential for determining prognosis. We used affinity-purified polyclonal sera and four monoclonal antibodies raised against the human homologues of CD44 variant exon sequences to investigate the presence of CD44 on 100 primary invasive breast tumours, 12 local recurrences, 18 lymph node metastases, and normal tissue controls. Whereas normal mammary ductal epithelial cells and cells derived from hyperplastic lesions do not express CD44 variant exons, expression of v3, v5, and v6 epitopes was found in most tumour samples. The DIII (exon v6) epitope was present in 84% of the primary tumours and in 100% of axillary lymph node metastases and local recurrences. The presence of these CD44 epitopes is correlated with poor overall survival. 15 patients with exon-v6-negative tumours had good survival compared with 76 patients with exon-v6-positive tumours (p = 0.005; log rank test). Multivariate analysis showed that the CD44 epitope encoded by exon v6 was a good marker for prognosis independent of progesterone receptor, lymph node status, tumour size, and grade.