M. Bontenbal

Phase II study of weekly gemcitabine in patients with metastatic breast cancer relapsing or failing both an anthracycline and a taxane

A phase II study was performed to investigate the efficacy and tolerability of gemcitabine as third-line chemotherapy for patients with metastatic breast cancer, previously treated with both an anthracycline - and taxane-containing regimen. Twenty-three patients were treated with gemcitabine 1200 mg/m2 in a 30-min infusion on day 1, 8 and 15 of a 28 day cycle. Seventy-four percent of the patients had visceral metastases. No complete or partial responses were observed. Six patients (26%) had stable disease with a median duration of 4.0 months. The median time to progression was 1.9 months and the median survival time was 7.8 months. Neutropenia grade 3 and 4 was observed in four patients (18%). Non-hematological toxicity grade 3 included nausea and vomiting in 14%, skin toxicity in 9% and elevation of transaminases in 23% of the patients. Gemcitabine is ineffective as third-line single agent therapy in patients failing anthracycline and taxane treatment for metastatic breast cancer.

Relationship of PS2 with response to tamoxifen therapy in patients with recurrent breast cancer.

PS2, an oestrogen-inducible protein, was measured in the cytosol of 230 primary tumours from patients who were subjected to first-line tamoxifen therapy for advanced disease without prior adjuvant therapy with tamoxifen. PS2 correlated positively with oestrogen receptor (ER, P < 0.01) and progesterone receptor content (PgR, P < 0.001), and with the length of progression-free survival (PFS, P = 0.05). Although not statistically significant, higher levels of PS2 (> or = 10 ng mg-1 protein) were also associated with increased probability of response to tamoxifen treatment and a longer total post-relapse survival (PRS). ER, PgR, menopausal status, site of disease and prior adjuvant chemotherapy were all associated with response to tamoxifen therapy and with PFS. In multivariate analysis for PFS, low levels of ER and PgR, visceral metastasis, a disease-free interval of less than 1 year and prior adjuvant chemotherapy were all significantly associated with an increased probability of a rapid disease progression after start of tamoxifen therapy. In the subset of 83 tumours with intermediate levels of ER and PgR (both > or = 10, but not both > or = 75 fmol mg-1 protein), PS2 was positively related with the length of PFS (P < 0.01) and PRS (P < 0.05). PS2 remained the strongest factor in multivariate analysis for PFS (P < 0.01) in this ER/PgR intermediate subgroup, but was not of predictive value in univariate or multivariate analysis for both PFS and PRS in tumours classified as ER/PgR low or high (> or = 75 fmol mg-1 protein). It is concluded that PS2 status may be used as a parameter, additional to ER and PgR, for better refinement of prediction of response to tamoxifen treatment in advanced breast cancer patients especially with intermediate ER/PgR levels in their primary tumour.

Cell biological factors associated with the response of breast cancer to systemic treatment

A large number of cell biological parameters are currently available to predict the prognosis of patients with breast cancer, but it is still difficulty accurately to predict the response to treatment. A valuable prognostic factor can be a poor predictive factor for response, and vice versa. High tumor levels of ER, PgR, AR and pS2 predict a relatively good response to endocrine therapy, while EGF-R positively, HER2/neu positivity, aneuploidy, high proliferation indices and possibly high uPA levels indicate a high chance of poor response to endocrine therapy in metastatic breast cancer. With respect to chemotherapy, a high proliferation rate and HER2/neu amplification predict a good response to therapy in metastatic disease, while MDR gene expression and possibly c-myc amplification are related to a worse response. In conclusion, the newer cell biological parameters can be used to select high and low-risk patients, type of systemic treatment, and as targets for new treatment modalities.

Randomized phase II study comparing efficacy and safety of combination-therapy trastuzumab and docetaxel vs. sequential therapy of trastuzumab followed by docetaxel alone at progression as first-line chemotherapy in patients with HER2+ metastatic breast cancer: HERTAX trial.

BACKGROUND Because chemotherapy for metastatic breast cancer (MBC) is associated with relevant toxicity, sequential monotherapy trastuzumab followed by cytotoxic therapy at disease progression might be an attractive approach. METHODS In a multicenter phase II trial, 101 patients with overexpression of human epidermal growth factor receptor 2 (HER2(+)) MBC were randomized between combination-therapy trastuzumab (Herceptin) plus docetaxel (H+D) and sequential therapy of single-agent trastuzumab followed at disease progression by docetaxel alone (H→D) as first-line chemotherapy for metastatic disease. The primary endpoint was progression-free survival (PFS) after completed sequential or combination therapy. RESULTS For the H+D group the median PFS was 9.4 vs. 9.9 months for the H→D group and 1-year PFS rates were 44% vs. 35%, respectively. However the overall response rates (ORRs) were 79% vs. 53%, respectively (P = .016), and overall survival was 30.5 vs. 19.7 months, respectively (P = .11). In the H→D group, response rates to monotherapy trastuzumab and subsequent docetaxel were 34% and 39%, respectively, with a median PFS during single-agent trastuzumab of 3.9 months. The incidence and severity of neuropathy were significantly higher in the H+D group. Retrospective analysis of trastuzumab treatment beyond progression (applied in 46% of patients in the H+D group and 37% in the H→D group) showed a correlation with longer overall survival in both treatment arms (36.0 vs. 18.0 months and 30.3 vs. 18.6 months, respectively). CONCLUSION First-line treatment in patients with MBC with H→D resulted in a similar PFS compared with H+D, but the response rate was lower and the overall survival nonsignificantly shorter.

Second-line chemotherapy with long-term low-dose oral etoposide in patients with advanced breast cancer

SummaryIn a phase II study, 27 patients with metastatic breast cancer were treated with oral etoposide as second-line chemotherapy at a dose of 50 mg/m2/day for 21 days, which courses were repeated every 4 weeks. Twenty-one patients were evaluable for response, and twenty-five for toxicity. In two (10%) patients a partial response was observed with a duration of 60 and 122 weeks respectively, and seven patients (33%) showed stable disease. Gastrointestinal toxicity was usually mild, though relatively frequent. Anemia grade II and III was observed in 20% of all courses (< 10% of all measurements), and leukopenia grade III and IV was observed in 22% of all courses (< 10% of all measurements). There was one toxic death.Reviewing the literature we calculated a response rate of intravenous etoposide treatment of 8% in 276 patients with metastatic breast cancer from 7 studies (response rates ranging between 0–14%), while (chronic) oral treatment caused a response rate of 19% in 145 patients from 8 different studies (response rates ranging between 0–35%).

Oestradiol enhances doxorubicin uptake and cytotoxicity in human breast cancer cells (MCF-7)

The cytotoxic effect of doxorubicin on human breast cancer cells (MCF-7) appeared to be correlated with drug concentration, exposure time and cellular uptake of doxorubicin. The effects of short-term stimulation of the growth of MCF-7 cells with 30 pM oestradiol was investigated with respect to the uptake of doxorubicin and cell kill. Culture of MCF-7 cells in steroid hormone-deprived medium resulted in an approx. 90% arrest of the cells in the G0G1-phase of the cell cycle. Growth stimulation with 30 pM oestradiol caused a 3-5-fold increase in the number of cells in S-G2M phase at between 18 and 24 h after administration of oestradiol to the medium. Incubation of oestradiol-stimulated cells with 0.37 microM doxorubicin during both 1 and 6 h resulted in an augmented inhibition of cell growth compared to unstimulated controls. An enhanced cellular uptake of doxorubicin after administration of oestradiol was observed only after an incubation period of 6 h and not of 1 h. These observations suggest that both an increased sensitivity to doxorubicin and an augmented cellular uptake of the drug may underlie the cytotoxic effects of doxorubicin after pretreatment with oestradiol.

Value of estrogenic recruitment before chemotherapy : First randomized trial in primary breast cancer

PURPOSE Several preclinical studies showed that short-term pretreatment of breast cancer cells with estrogens can increase the antitumor efficacy of different cytotoxic drugs. Some early clinical studies in patients with advanced breast cancer did seem to support these findings. Therefore, the efficacy of estrogenic recruitment followed by chemotherapy was compared with that of chemotherapy alone in a randomized phase III study in women with lymph node-positive primary breast cancer. PATIENTS AND METHODS Three hundred twenty-eight patients with stage II/IIIA breast cancer who were younger than 66 years of age were randomly allocated to chemotherapy with fluorouracil, doxorubicin, and cyclophosphamide (FAC) or FAC plus pretreatment with ethinyl estradiol (EE(2)). FAC (500, 50, and 500 mg/m(2), respectively) was administered intravenously once every 4 weeks for four cycles. EE(2) (0.5 mg) was administered orally, both 24 hours and immediately preceding FAC chemotherapy. RESULTS Patient and tumor characteristics and chemotherapy dosages were comparable in both treatment groups. Of 318 assessable patients, with a median follow-up of 6.8 years, 177 patients had a relapse and 127 died. No significant differences were observed between the two treatment groups with respect to relapse-free, local recurrence-free, and overall survival according to univariate and multivariate analyses adjusted for age, menopausal status, tumor size, grade, number of positive nodes, and steroid-receptor status. The power for the detection of an increase of 50% in the median relapse-free survival was 80%. CONCLUSION Estrogenic recruitment of breast cancer cells before FAC chemotherapy did not influence the efficacy of adjuvant chemotherapy in stage II/IIIA breast cancer patients after a follow-up of 6.8 years.

Weekly low-dose mitoxantrone plus doxorubicin as second-line chemotherapy for advanced breast cancer

SummaryWeekly low dose mitoxantrone (3 mg/m2) plus doxorubicin (8 mg/m2) was administered as second-line chemotherapy to 33 patients with advanced breast cancer. Four out of 28 evaluable patients (14%) obtained a partial response with a median duration of 34 weeks (range 18–67+ weeks), while 8 patients (29%) showed stable disease with a median duration of 28 weeks (range 11+–60 weeks). Gastrointestinal toxicity and alopecia were mild. Grade II and III leukopenia occurred in 63% of the courses without serious infectious disease. Four patients experienced an asymptomatic drop of 16–20% in the left ventricular ejection fraction (LVEF) after relatively low cumulative doses of each drug, and one patient with a history of pericarditis carcinomatosa and mediastinal irradiation developed a heart failure. In conclusion, this second-line combination treatment had moderate activity in breast cancer and caused only few subjective side effects, especially with respect to gastrointestinal symptoms.

Uptake and distribution of doxorubicin in hormone-manipulated human breast cancer cells in vitro

Background: Kinetic resistance to cytotoxic drugs may account for the moderate responsiveness of breast cancer to chemotherapy. In the present study the in vitro effects of estradiol-mediated DNA stimulation on the cellular uptake of the DNA intercalating drug doxorubicin (DOX) were examined in MCF-7 human breast cancer cells. Methods: Using the fluorescent properties of the drug, the cellular uptake was investigated by high performance liquid chromatography (HPLC), and by flow cytometry. Results: The uptake of DOX (0.01–2 μg/ml) by MCF-7 cells in suspension, incubated for 1 and 6 h, showed a strong correlation between the incubation concentration of DOX and the cellular uptake of the drug as measured by HPLC and flow cytometry. Simultaneous exposure of MCF-7 cells, in monolayer culture, to DOX (0.04–0.2 μg/ml) and estradiol (1 nM) for 1–24 h showed no significant difference in uptake of the drug compared to control cultures exposed to DOX in the absence of estradiol. Neither was there a significant difference in uptake of DOX when MCF-7 cells were pretreated with estradiol (1 nM) for 16–24 h followed by a 0.5, 1, 6, and 21/23 h incubation with DOX (0.01–2 μg/ml). Pretreatment with estradiol did not affect the retention of DOX as measured 24 h after a 0.5 h incubation with DOX (2 μg/ml). Furthermore, fluorescence microscopy revealed no difference in the cellular DOX distribution pattern of estradiol-stimulated MCF-7 cultures compared to unstimulated cultures. Conclusion: From this study we can conclude that, for the human MCF-7 breast cancer cells in vitro, the uptake, retention, and cellular distribution of DOX are not influenced by estrogenic manipulation.

Critical Review of Growth Factors as Clinical Tools in Primary and Metastatic Breast Cancer

Present research in the field of clinical breast cancer is focused on new diagnostic methods and on the development of new treatment modalities [25]. Adjuvant systemic therapy with chemotherapeutic drugs or endocrine treatment has been shown to result in a 25% reduction in annual odds of death, meaning an absolute decrease in death of 4% and 10% in nodenegative and node-positive patients, respectively [13] (reprinted in part in this volume). However, it must be concluded that the majority of patients with primary breast cancer will be overtreated in cases of adjuvant therapy. Both efficacy and cost effectiveness of adjuvant systemic therapy are presently important subjects of debate [20, 27]. Identification of high-risk and low-risk patients is therefore a major issue. For patients with breast cancer a large series of classical and modern prognostic factors (Table 1) have been reported [18, 23, 28, 29]. These factors concern patient characteristics and parameters determined in blood and tumor characteristics. Most of these factors have been evaluated with respect to relapse-free survival (RFS) and overall survival (OS), but very few with respect to response to hormonal or chemotherapy in primary or metastatic disease. However, also for patients with recurrent disease (macrometastases) prognostic factors and predictors for response to treatment are clinically important for reaching decisions concerning type of therapy.