C K Osborne

HER-2/neu in node-negative breast cancer: prognostic significance of overexpression influenced by the presence of in situ carcinoma.

PURPOSE Amplification and/or overexpression of the HER-2/neu oncogene have been shown to correlate with poor clinical outcome in patients with axillary node-positive breast cancer. In contrast, the prognostic significance of HER-2/neu in node-negative disease is controversial. This study was undertaken to evaluate further the relationship between HER-2/neu and clinical outcome in node-negative disease. PATIENTS AND METHODS Overexpression of HER-2/neu was evaluated by permanent-section immunohistochemistry in tumors from 613 patients with long-term clinical follow-up enrolled in the Intergroup Study 0011. Patients were stratified into low-risk (n = 307) and high-risk (n = 306) groups on the basis of tumor size and estrogen-receptor (ER) status. Low-risk patients were defined as having small (less than 3 cm), ER-positive tumors and were observed without additional treatment after initial surgery. High-risk patients had either ER-negative or large (greater than or equal to 3 cm), ER-positive tumors and were randomized to be observed (n = 146) or to receive adjuvant chemotherapy (n = 160) after surgery. RESULTS The rate of HER-2/neu overexpression was 14.3% in all tumors combined and was higher in invasive carcinomas with (21.5%) than without (11.2%) a significant noninvasive or in situ histologic component (P less than .0001). There was no relationship between overexpression and clinical outcome in the natural history setting of combined low-risk and high-risk patients not receiving adjuvant therapy (n = 453). Based on the reasoning that the influence of HER-2/neu may have been obscured by high-risk features and/or the presence of noninvasive carcinoma, we also analyzed the subset of patients with low-risk lesions not containing a significant in situ component (n = 179). Patients of this group with HER-2/neu-positive tumors showed only 40% disease-free survival (DFS) at 5 years, compared with over 80% in patients with HER-2/neu-negative tumors (P less than .0001). A similar inverse correlation was observed between overexpression and overall survival in the same group of patients (P = .0001). In a separate analysis involving patients receiving adjuvant chemotherapy, those with HER-2/neu-negative tumors showed significantly improved DFS in response to therapy compared with patients with HER-2/neu-positive tumors. CONCLUSION Overexpression of HER-2/neu is associated with poor clinical outcome in a subset of node-negative patients with small, ER-positive, predominantly invasive tumors and may play a role in resistance to adjuvant chemotherapy.

Survival from first recurrence: relative importance of prognostic factors in 1,015 breast cancer patients.

Univariate and multivariate analyses of potential prognostic factors for 1,015 women with recurrent breast cancer confirmed that the site of initial recurrence is an important determinant for predicting survival from the time of initial recurrence. However, both estrogen receptor (ER) status and axillary lymph node status at diagnosis, as well as the length of the disease-free interval, provide additional independent information for predicting patient survival after disease recurrence. Involved axillary lymph nodes at the time of initial diagnosis and/or lack of ERs may indicate a highly malignant tumor or a weak host defense, either of which might be related to short survival after relapse. Patients with ER-negative tumors recurred more often in visceral and soft-tissue sites, while patients with ER-positive tumors were more likely to recur in bony sites. However, for each metastatic site, receptor-positive patients had longer survival

Correlations between estrogen receptor, progesterone receptor, and patient characteristics in human breast cancer.

The relationships between estrogen receptor, progesterone receptor, and a variety of patient characteristics are described for 2,977 women with primary breast cancer. Older women were more likely to be estrogen-receptor positive than younger women. When patient age and menopausal status were analyzed together, age was found to be the primary determinant of increased estrogen-receptor concentrations. There appeared to be no relationship with progesterone receptor for either age or menopausal status when these variables were analyzed separately. But premenopausal women had higher progesterone receptor concentrations than postmenopausal women when patients of the same age were compared, perhaps reflecting greater estrogen-mediated synthesis of progesterone receptor. Tumor size was negatively related to steroid receptor concentrations, but no relationships were observed between steroid receptors and either the number of positive axillary lymph nodes or the location of the primary tumor.

Biologic Markers as Predictors of Clinical Outcome From Systemic Therapy for Primary Operable Breast Cancer

PURPOSE To determine whether pretreatment clinical features and molecular markers, together with changes in these factors, can predict treatment response and survival in patients with primary operable breast cancer who receive neoadjuvant therapy. PATIENTS AND METHODS Mitoxantrone, methotrexate (with or without mitomycin), and tamoxifen chemoendocrine therapy was administered to 158 patients before surgery. Clinical response was assessed after four cycles of treatment. Fine-needle aspiration cytology for estrogen receptor (ER), progesterone receptor (PgR), c-erbB-2, p53, bcl-2, Ki67, S-phase fraction (SPF), and ploidy were performed pretreatment and repeated on day 10 or day 21 after the first cycle of treatment. RESULTS Good clinical response (GCR, defined as complete response or minimal residual disease) was achieved in 31% of patients (49 of 158). Tumor size, nodal disease, response, ER, PgR, c-erbB-2, p53, bcl-2, Ki67, SPF, and ploidy were analyzed as predictors of survival. By univariate analysis, node-positive disease (P =.05), lack of ER (P <.05) and PgR (P <.05), and failure to attain GCR (P =.008) were associated with a significantly increased risk of relapse. A significantly increased risk of death was associated with node-positive disease (P =.02), lack of ER expression (P =.04), and failure to attain GCR. By multivariate analysis, GCR was an independent predictor for survival (P =.05). ER expression (P =.03), absence of c-erbB-2 (P =.03), and a decrease in Ki67 on day 10 or day 21 of the first cycle (P <.05) significantly predicted for subsequent GCR. CONCLUSION Molecular markers may be used to predict the likelihood of achieving GCR, which seems to be a valid surrogate marker for survival.

Measurement of steroid hormone receptors in breast cancer patients on tamoxifen

SummaryEstrogen (ER) and progesterone receptor (PgR) positive breast tumors often respond to tamoxifen, but ultimately progress as they become tamoxifen resistant. An accurate assessment of receptor status in specimens from tamoxifen-resistant patients could help to understand potential mechanisms of resistance and to predict response to second line hormonal therapies. However, since tamoxifen itself can affect ER and PgR determinations, assay results can be misleading. We measured ER and PgR by both ligand binding (LBA) and immunohistochemical (IHC) assays in 34 tumors from patients on tamoxifen, 30 of whom were displaying resistance to the drug. These tumors were classified into several receptor phenotypes. Eleven patients, 8 of whom were clearly progressing, expressed both receptors while on tamoxifen. ER was significantly less often negative when measured by IHC, suggesting that ER status by LBA was falsely negative in this group due to receptor occupancy by tamoxifen. Six patients had no detectable ER by LBA or IHC but still expressed PgR. The presence of PgR suggests that ER could still be functional, though undetectable, in these tumors, or that PgR is constitutively expressed by them. Finally, 12 patients were ER and PgR-negative by both assays, suggesting hormonal independence as the mechanism for resistance in this group. In a subset of patients with receptor assays both prior to tamoxifen and at the time of progression while taking the drug, we found that most ER-positive tumors converted to an apparent ER-negative status when assayed by LBA, while PgR status frequently remained unchanged. The continued expression of ER and/or PgR in many patients with tumor progression on tamoxifen indicates that mechanisms for resistance other than receptor loss are common in breast cancer.

bcl-2, p53, and response to tamoxifen in estrogen receptor-positive metastatic breast cancer: a Southwest Oncology Group study.

PURPOSE To test the hypothesis that high bcl-2 expression and accumulation of p53 protein, both of which should inhibit apoptosis, are associated with a poorer tamoxifen response and a more aggressive clinical course in estrogen receptor (ER)-positive metastatic breast cancer. METHODS A total of 205 paraffin-embedded tumor blocks were evaluated for nuclear p53 (a marker of p53 inactivation) and cytoplasmic bcl-2 by immunohistochemistry (IHC). All patients received tamoxifen as initial therapy for metastatic disease. The study began in 1982 and follow-up duration of the 24 patients last known alive is 8 years. RESULTS Response to tamoxifen and time to treatment failure (TTF) were not significantly associated with p53 status, although patients with higher p53 had a worse survival (P = .008; median, 36 v 20 months). Higher bcl-2 expression was associated with higher levels of ER (P = .02), better response to tamoxifen (62% v 49%; P = .07), longer TTF (median, 9 v 5 months; P = .002), and better survival (median, 40 months v 25 months; P = .009). In multivariate analyses, including ER, progesterone receptor (PgR), and p53, high bcl-2 remained significantly associated with a longer TTF (P = .007) and survival (P = .07). p53 status was a significant factor for shorter survival (P = .05), but not for TTF (P = .61). CONCLUSION p53 status, as determined by IHC is not significantly associated with response to tamoxifen, although tumors with altered p53 protein are inherently more aggressive. Contrary to expectation, high bcl-2 identifies a relatively indolent phenotype of ER-positive metastatic breast cancer, in which patients experience a better clinical response to tamoxifen and a longer survival.

Antagonism of Chemotherapy-Induced Cytotoxicity for Human Breast Cancer Cells by Antiestrogens

In a prior National Surgical Adjuvant Breast and Bowel Project (NSABP) adjuvant study, the addition of the antiestrogen tamoxifen to chemotherapy with melphalan and fluorouracil adversely affected survival in several patient subsets, suggesting an antagonistic drug interaction. To investigate this possibility, we studied the interaction of tamoxifen and other antiestrogens with several cytotoxic drugs in cultured human breast cancer cell lines. Clinically relevant concentrations of tamoxifen and melphalan reduced colony survival of estrogen receptor (ER)-positive breast cancer cells when used alone in a colony-forming assay. However, pretreatment of cells with tamoxifen followed by exposure to melphalan resulted in antagonism, with more colonies surviving treatment with the combination than with melphalan alone. Identical effects were seen using several other triphenylethelene antiestrogens. An antagonistic interaction was observed even with a brief preincubation with tamoxifen that had no effect on cell proliferation, indicating that antagonism was not due to tamoxifens known cell kinetic effects. Tamoxifen even antagonized melphalan cytotoxicity in ER-negative breast cancer cells and in cultured liver cells. An additive drug interaction occurred when melphalan was combined with pharmacologic concentrations of estradiol or medroxyprogesterone acetate, but antagonism was also observed with dexamethasone. Tamoxifen also antagonized the cytotoxicity of fluorouracil in these cells. However, an additive interaction occurred when the antiestrogen was combined with doxorubicin or 4-hydroxy-cyclophosphamide, an alkylating agent that is transported into the cell by a different carrier-mediated mechanism than melphalan. To avoid potential antagonism in the clinic, combinations of tamoxifen with melphalan and/or fluorouracil should be avoided.

Prognostic significance of S-phase fraction in good-risk, node-negative breast cancer patients.

PURPOSE Formalin-fixed, paraffin-embedded tissues from axillary node-negative breast cancer patients were analyzed by flow cytometry to determine the prognostic significance of DNA ploidy and S-phase fraction (SPF). PATIENTS AND METHODS All patients were registered on a good-risk control arm of an intergroup clinical trial. They had small- to intermediate-sized (less than 3 cm), estrogen receptor (ER)-positive tumors and received no adjuvant therapy after modified radical mastectomy or total mastectomy with low axillary-node sampling. The median follow-up was 4.8 years. RESULTS Assessable ploidy results were obtained from 92% of the 298 specimens studied (51% diploid, 49% aneuploid), and SPFs were assessable for 83% of the tumors. SPFs for diploid tumors ranged from 0.7% to 11.9% (median, 3.6%), compared with a range of 1.2% to 26.7% (median, 7.6%) for aneuploid tumors (P less than .0001). No significant differences in disease-free or overall survival were observed between patients with diploid and aneuploid tumors. Using different SPF cutoffs by ploidy status (4.4% for diploid, 7.0% for aneuploid), patients with low SPFs had significantly longer disease-free survival rates than patients with high SPFs (P = .0008). The actuarial 5-year relapse rates were 15% and 32% for patients with low (n = 142) and high SPFs (n = 105), respectively. Similar relationships between SPF and clinical outcome were observed for patients with diploid tumors (P = .053) and for patients with aneuploid tumors (P = .0012). CONCLUSION S-phase fraction provides additional prognostic information for predicting disease-free survival for axillary node-negative breast cancer patients with small, ER-positive tumors.

Adjuvant CMFVP versus tamoxifen versus concurrent CMFVP and tamoxifen for postmenopausal, node-positive, and estrogen receptor-positive breast cancer patients: a Southwest Oncology Group study.

PURPOSE To compare chemohormonal therapy, chemotherapy alone, and hormonal therapy alone in postmenopausal patients with estrogen receptor (ER)-positive operable breast cancer and positive axillary nodes with respect to survival and disease-free survival (DFS). PATIENTS AND METHODS Eight hundred ninety-two postmenopausal women with ER-positive, node-positive breast cancer were enrolled by the Southwest Oncology Group (SWOG) from July 1979 to March 1989 and 74 by the Eastern Cooperative Oncology Group (ECOG) between June 1987 and March 1989. Patients were stratified according to number of involved nodes and type of primary surgery and randomized to receive the following: (1) tamoxifen 10 mg twice daily by mouth for 1 year; (2) cyclophosphamide 60 mg/m2/d by mouth for 1 year, methotrexate 15 mg/m2 intravenously (IV) weekly for 1 year, fluorouracil (5-FU) 400 mg/m2 IV weekly for 1 year, vincristine .625 mg/m2 IV weekly for the first 10 weeks, and prednisone during weeks 1 to 10 with doses decreasing from 30 mg/m2 to 2.5 mg/m2 (CMFVP); or (3) the combination of tamoxifen and CMFVP. RESULTS The median follow-up duration is 6.5 years, with a maximum of 12.8 years. Treatment arms are not significantly different with respect to either survival or DFS (log-rank, 2 df, P = .82 and .23, respectively). The 5-year survival rate is 77% for the tamoxifen arm, 78% for CMFVP, and 75% for the combination. No significant differences were observed in node or receptor level subsets. Severe or worse toxicity was experienced by 56% of patients on CMFVP and 61% on CMFVP plus tamoxifen, compared with 5% on tamoxifen alone. CONCLUSION CMFVP chemotherapy, either alone or in combination with tamoxifen, has not been shown to be superior to tamoxifen alone in the treatment of postmenopausal women with node-positive, ER-positive, operable breast cancer.

Urokinase receptor in breast cancer tissue extracts. Enzyme-linked immunosorbent assay with a combination of mono- and polyclonal antibodies

SummaryUrokinase plasminogen activator (uPA) is a proteolytic enzyme involved in degradation of the extracellular matrix during cancer invasion. The levels of uPA and its inhibitor PAI-1 in tumor extracts have previously been demonstrated to be of prognostic value in breast cancer as well as other types of cancer. We have previously characterized a specific cell surface receptor for uPA (uPAR) which strongly enhances the catalytic activity of uPA and is expressed during mammary cancer invasion. In order to quantitate uPAR in breast cancer tissue, we have now developed a sensitive enzyme-linked immunosorbent assay (ELISA), with polyclonal catching antibodies and three monoclonal detecting antibodies. The detection limit of the assay is approximately 0.16 fmol of uPAR in a volume of 100 µl (1.6 pM). There is a linear relationship between signal and uPAR concentration up to at least 6.6 fmol per 100 µl (66 pM). Both free uPAR and uPAR in complex with uPA is detected. The recovery of an internal uPAR standard in breast cancer tissue extracts is above 87%. The intra-assay and inter-assay variation coefficients are 7% and 13%. In order to find a suitable buffer for extraction of various components of the uPA-system from breast cancer tissue, we tested buffers which previously have been used for optimal extraction of estrogen receptor (A), uPA (B), and uPAR (C). Buffer A and B extracted approximately 30% and 50%, respectively, of the amount of uPAR extracted with buffer C. Extracts of samples of breast cancer tissue from 94 patients all contained uPAR in amounts above the detection limit of the present assay, which appears suitable for studies of the potential prognostic value of uPAR in this disease. Significant correlations were found between uPAR, uPA and PAI-1 tumor levels.