Constitutive activation of pp125fak in newly isolated human breast cancer cell lines

Our laboratory has developed twelve human breast cancer cell lines from primary and metastatic sites. In this report we demonstrate that eight of eight breast cancer cell lines examined exhibit constitutively tyrosine phosphorylated and enzymatically active endogenous pp125fak when grown in monolayer. The activation status of pp125fak in breast cancer cells in monolayer is significantly elevated over that exhibited by normal mammary epithelial cells cultured under the same conditions. Constitutive activation of pp125fak is the only characteristic so far studied that all of these breast cancer cell lines have in common. In contrast to HBC cells, tyrosine phosphorylation of pp125fak in HME cells was low or absent in monolayer culture but was induced to high levels by culturing the cells in Matrigel. Thus tyrosine phosphorylation and activation of pp125fak is a regulated process in normal mammary epithelial cells, but is constitutive in breast cancer cells. Finally, analysis of the ability of normal human mammary epithelial cells and breast cancer cell lines to grow under anchorageindependent conditions indicated that normal human mammary epithelial cells rapidly and uniformly lost viability when not substrateattached, whereas all of the breast cancer cell lines survived for a 3week culture period. Furthermore, a subset of the breast cancer cell lines grew to form large colonies under anchorageindependent conditions. Interestingly, pp125fak activation decreased dramatically in HBC cells cultured for two weeks in suspension, suggesting that activation of this kinase is not necessary for longterm growth under anchorageindependent conditions. These results suggest that constitutive activation of pp125fak results in preferential survival of human breast cancer cells under anchorageindependent conditions but that activation of pp125fak is not the sole mediator of anchorageindependent colony formation.     

Glycogen‐rich carcinomas of the breast display unique characteristics with respect to proliferation and the frequency of oligonucleosomal fragments

We determined the proliferation rate and apoptotic activity of glycogenrich carcinomas of the breast as opposed to nonclear cell tumors by means of MIB1 immunohistochemistry and in situ detection of oligonucleosomal fragments (TUNEL reaction). The retrospective biopsy series included six invasive clear cell carcinomas of the glycogenrich type as well as 15 randomly selected cases of invasive ductal carcinoma without evidence of glycogen storage. Three patients in the clear cell group and seven patients in the control cohort developed lymphnode metastasis. The MIB1 labeling index of glycogenrich carcinomas averaged 9.05%, while that of the controls was 30.03%. Apoptotic nuclei were present in a mean of 1.26% of glycogenrich carcinoma cells. The control tumors exhibited an average apoptotic frequency of 5.85%. Tumor size, hormone receptor status, and presence or absence of lymph node involvement were found not to correlate with either proliferation or apoptosis. We conclude that glycogenrich breast carcinomas are characterized by a peculiar low proliferationlow apoptosis cell kinetic profile. The aggressive clinical behavior of these neoplasms may possibly be accounted for by an ineffective apoptotic elimination of otherwise slowly proliferating tumor cells.     

Coexpression of c-kit and stem cell factor in breast cancer results in enhanced sensitivity to members of the EGF family of growth factors

Insulinlike growth factor (IGF)I protects many cell types from apoptosis. As a result, it is possible that IGFIresponsive cancer cells may be resistant to apoptosisinducing chemotherapies. Therefore, we examined the effects of IGFI on paclitaxel and doxorubicininduced apoptosis in the IGFIresponsive breast cancer cell line MCF7. Both drugs caused DNA laddering in a dosedependent fashion, and IGFI reduced the formation of ladders. We next examined the effects of IGFI and estradiol on cell survival following drug treatment in monolayer culture. IGFI, but not estradiol, increased survival of MCF7 cells in the presence of either drug. Cell cycle progression and counting of trypanblue stained cells showed that IGFI was inducing proliferation in paclitaxeltreated but not doxorubicintreated cells. However, IGFI decreased the fraction of apoptotic cells in doxorubicin but not paclitaxeltreated cells. Recent work has shown that mitogenactivated protein kinase (MAPK) and phosphotidylinositol3 (PI3) kinase are activated by IGFI in these cells. PI3 kinase activation has been linked to antiapoptotic functions while MAPK activation is associated with proliferation. We found that IGFI rescue of doxorubicininduced apoptosis required PI3 kinase but not MAPK function, suggesting that IGFI inhibited apoptosis. In contrast, IGFI rescue of paclitaxelinduced apoptosis required both PI3 kinase and MAPK, suggesting that IGFImediated protection was due to enhancement of proliferation. Therefore, IGFI attenuated the response of breast cancer cells to doxorubicin and paclitaxel by at least two mechanisms: induction of proliferation and inhibition of apoptosis. Thus, inhibition of IGFI action could be a useful adjuvant to cytotoxic chemotherapy in breast cancer.     

Tamoxifen and fenretinide in women with metastatic breast cancer

Background: Tamoxifen and fenretinide combination therapy has been shown to be an active treatment regimen in metastatic breast cancer patients. This pilot study sought to determine whether the addition of fenretinide to tamoxifen would be associated with antitumor activity in metastatic breast cancer patients who had been previously treated with tamoxifen or who had hormone receptor negative disease. The effect of this therapy on circulating plasma transforming growth factorbeta (TGF) levels and serum lipids was also examined.Patientsand Methods: Thirtyone patients were treated with tamoxifen (20mg po daily), and fenretinide (400mg po daily with a 3day drug holiday each month). Plasma TGF testing was performed using isoform specific sandwich ELISA.Results: Twenty four of the 31 patients were evaluable for an antitumor response including 14 estrogen receptor (ER) positive patients who had failed prior tamoxifen therapy, seven ERnegative patients, and three hormone therapy naive ERpositive patients. There were no objective antitumor responses; three patients had stable disease for 8, 8, and 24 months. Five patients (16%) discontinued therapy for toxicity (one for grade 3 skin rash and four for abnormal dark adaptation). There was a statistically significant decrease in total cholesterol (median change per patient of –13.5mg/dl; p=0.049, a 6.5% decrease), and an increase in HDL levels (median change per patient of +18mg/dl, p=0.0001, a 35% increase) with tamoxifen and fenretinide therapy.TGF-1 plasma levels were normal in 26 of 28 patients, and no changes in these levels post-treatment were demonstrated.Conclusions: Tamoxifen and fenretinide therapy is not an active combination in ER negative metastatic breast cancer or in patients whose disease has progressed on tamoxifen. This combination had a beneficial effect on total serum cholesterol and HDL levels with no associated rise in serum triglyceride levels. The 400mg dose of fenretinide was associated with symptomatic nyctalopia in one-third of patients making it an unsuitable dose for use in breast cancer prevention studies.     

p53 expression in breast and endometrium during estrogen and tamoxifen treatment of surgically postmenopausal cynomolgus macaques

Estrogens are important for both normal cell growth and malignant proliferation in the mammary gland as well as in the endometrium. Tamoxifen is a nonsteroidal antiestrogen widely used in breast cancer treatment. In recent years reports have been made of an increased risk of endometrial carcinoma during tamoxifen treatment. We used surgically menopausal cynomolgus macaques to study proliferation and p53 expression during hormonal replacement therapy (HRT) and tamoxifen treatment. Animals were treated continuously for 35 months with either conjugated equine estrogens (CEE; n = 20); medroxyprogesterone acetate (MPA; n =17); the combination of CEE + MPA (n = 13) or tamoxifen (n = 17) for 35 months. We found an increased expression of p53 in normal breast and endometrial tissue linked to CEE but not tamoxifen treatment. In the breast alveoli there was an association between proliferation measured by morphometry and p53 expression in all groups. However, in the endometrium CEE induced significantly more p53 positivity than tamoxifen, 9/20 vs. 3/17 in glands and 9/19 vs. 0/17 in stroma, respectively. If indeed longterm treatment with tamoxifen as in the present study could inactivate the tumorsuppressive function of p53, endometrial cells might thereby become more susceptible to genetic lesions associated with carcinogenesis.     

Cytokine‐regulated urokinase‐type‐plasminogen‐activator (uPA) production by human breast fibroblasts in vitro

It has been shown that, in breast stroma, urokinasetype plasminogen activator (uPA) mRNA is predominantly expressed by myofibroblasts located at the invasive areas of the tumor. To examine which factors present in a tumor environment are candidates responsible for the induction of these uPAproducing myofibroblasts, we studied in vitro the capacity of a paired panel of normal and tumorderived human breast fibroblasts to produce uPA protein and the myofibroblast marker smoothmuscleactin (SMA) in response to various cytokines implicated in the process of tissueremodeling during malignant transformation.We found that fibroblasts produced increased amounts of uPA protein after exposure to aFGF, bFGF, EGF, PDGFBB, and IFN, were unaffected in this respect by IL6, MCSF, GMCSF and Oncostatin M, and produced decreased amounts of uPA protein after exposure to IL1, TNF, IGFI, and IGFII. None of these cytokines were able to induce a striking increase in the fraction of SMApositive fibroblasts. On the other hand, 25pM TGF₁ increased the fraction of SMApositive fibroblasts 5fold in both normal and tumortissuederived fibroblasts. Nonetheless, the normalderived fibroblasts were unaffected in their uPAproducing capacity by TGF₁, and the tumorderived fibroblasts produced decreased amounts of uPA protein after exposure to this cytokine, implying that at least in vitro the myofibroblast phenotype is not a prerequisite for the production of uPA by human breast fibroblasts. In addition, we established that the basaluPAproduction of both normal and tumorderived fibroblasts was increased by autocrinely produced bFGFlike activity, and that the basaluPAproduction of at least the normalderived fibroblasts was decreased by autocrinely produced IGFlike activity.Altogether, our data suggest an active role for fibroblasts in the process of uPAdirected breast tumor proteolysis.     

Phase II of doxorubicin/taxol in metastatic breast cancer

Purpose. To assess the response rate, survival, and toxicity of Taxol®(paclitaxel) as 1h infusion plus doxorubicin as firstline treatment for patients with metastatic breast cancer (MBC).Patients and methods. Seventysix patients with untreated MBC were recruited. All of them had measurable disease and were evaluable for toxicity. Fiftyfive percent of the patients had visceral involvement. The dose of doxorubicin was fixed at 50mg/m² as a short intravenous infusion, followed by 200mg/m² of Taxol as a 1h intravenous infusion. Doxorubicin was administered during the first seven cycles, continuing with Taxol only up to a maximum of ten cycles.Results. Neutropenia was the most important toxicity: 30% grade 3 and 18% grade 4. Only 2 patients showed a decrease in the left ventricular ejection fraction (LVEF) which caused discontinuing the treatment. No clinical congestive heart failure (CHF) was observed. Seventyfour patients were eligible for response evaluation: 10 (14%) achieved complete response (CR) and 46 (62%) achieved partial response (PR). The mean duration of response was 13.47± 1.35 months (95% confidence interval (CI): 10.82; 16.12) and the mean survival was 21.50± 1.42 months (95% CI: 18.72; 24.29).Conclusion. The overall response (OR) rate was 76%. No CHF was assessed and 2 patients stopped treatment due to LVEF decrease. Although doxorubicin 50mg/m² followed by Taxol 200mg/m² in 1h intravenous infusion presents a toxicity profile which demands a close followup, it represents a convenient outpatient schedule with similar activity rate compared to longer Taxol infusions.     

Quantitative changes in cytological molecular markers during primary medical treatment of breast cancer: A pilot study

Aim: To quantify the changes in biological molecular markers during primary medical treatment in patients with operable breast cancer and to assess their possible relationship with response to treatment.Methods: The treatment group consisted of 31 patients with operable breast carcinomas, median age 57 years (range 41–67), treated with four 3weekly cycles of chemotherapy with Mitoxantrone, methotrexate (± mitomycin C), and tamoxifen before surgery. Fine needle aspiration (FNA) was used to obtain samples from patients prior to and at 10 or 21 days posttreatment. The following molecular markers were assessed: estrogen receptor (ER), progesterone receptor (PgR), p53, Bcl2, and Ki67 measured by immunocytochemistry, and ploidy and Sphase fraction (SPF) by flow cytometry. To evaluate the reproducibility of the technique, repeat FNA was performed in a separate nontreatment control group of 20 patients and the same molecular markers assessed, two weeks after the first sample with no intervening treatment.Results: The nontreatment control group showed a high reproducibility for the measurement of molecular markers from repeat FNA. In the treatment group there was a nonsignificant reduction in SPF and a significant reduction (p = 0.005) in Ki67. Patients who responded to neoadjuvant therapy were more likely to have a reduction in these two markers than those who failed to respond. Similarly, a reduction in ER scores was observed between the first and second samples (p = 0.04). For PgR, the change between the first and second samples was not significant although there was a significant difference between responders and nonresponders (p = 0.03). All nine patients with an increase in PgR were responders. No significant changes in p53 or Bcl2 were observed during treatment.Conclusion: Molecular markers can be adequately measured from FNA samples prior to and during neoadjuvant therapy. Changes in cellular proliferation and hormone receptors have been shown that may be related to tumour response. These relationships should be assessed in a larger cohort of patients.     

Induction of insulin‐like growth factor binding protein expression by ICI 182,780 in a tamoxifen‐resistant human breast cancer cell line

Earlier studies in our laboratory demonstrated that the steroidal antiestrogen ICI 182,780 is very effective in abolishing the tamoxifenresistant proliferation of MCF 7/523 cells [1]. In addition, preliminary binding studies showed that ICI 182,780 increased the binding of insulinlike growth factor (IGF)I to the MCF 7/523 cells, although this finding was not the result of an increase in the expression of the insulinlike growth factorI receptor (IGFIR). Hence, we reasoned that the inhibition of tamoxifenresistant cell growth by ICI 182,780 might have been due to increased expression of insulinlike growth factor binding proteins (IGFBPs).We observed the upregulation of noninsulinsuppressible IGFI binding in both the tamoxifensensitive MCF 7/521 cell line (1.5fold) and the tamoxifenresistant MCF 7/523 cell line (2.5fold) after 5 days of treatment with ICI 182,780 (10^–7 M) in serumfree medium, suggesting a role for cellassociated IGFBPs. Affinity crosslinking experiments confirmed the presence of an IGFI:IGFBP complex of approximately 38kDa in tamoxifen or ICI 182,780treated cells. Western ligand blots showed higher levels of a soluble 30kDa IGFBP in media conditioned by either of the subclones that had been treated with ICI 182,780, an effect consistently opposed by estrogen (E₂:10^–9 M). RTPCR showed higher levels of IGFBP5 mRNA than any of the other known IGFBPs, suggesting that this was the major IGFBP subtype. The protein was subsequently identified by Western immunoblotting as IGFBP5. In conclusion, we postulate that this may be a mechanism contributing to the greater potency of ICI 182,780 in the growth inhibition of the MCF 7/523, tamoxifenresistant cell line.     

Synergistic action of apoptosis induced by eicosapentaenoic acid and TNP‐470 on human breast cancer cells

The effects of eicosapentaenoic acid (EPA) and an angiogenesis inhibitor (TNP470) on the suppression of breast cancer cell growth were examined in five human breast cancer cell lines (MDAMB231, T47D, MCF7, KPL1, and MKLF). In all five cell lines, EPA and TNP470 alone both showed tumor growth inhibition in a time and dosedependent manner, and in combination, a synergistic effect was seen at high concentrations. EPA plus TNP470 treatment evoked apoptosis as confirmed by the appearance of sub G1 populations, by DNA fragmentation, and by cell morphology. With the combination, the expression of Bax and Bc1x_S, the apoptosisenhancing proteins, was more upregulated and that of Bcl2 and Bclx_L, the apoptosissuppressing proteins, was more downregulated compared to the use of EPA or TNP470 alone, suggesting that their synergistic effect was due to an acceleration of apoptosis.     

Involvement of nuclear steroid/thyroid/retinoid receptors and of protein kinases in the regulation of growth and of c‐erbB and retinoic acid receptor expression in MCF‐7 breast cancer cells

Nuclear steroid/thyroid/retinoid receptors and cerbB membrane receptor tyrosine kinases control epithelial growth and differentiation. Retinoid receptors can dimerize with the vitamin D receptor, the glucocorticoid receptor or the thyroid receptor. Furthermore, multiple cerbB receptor dimers have been identified. It has been shown that some of these receptor pathways communicate with each other via crossconnected regulatory networks. Molecular interactions between retinoid receptors or estrogen receptors (ER) and cerbB2, and between ER and retinoic acid receptor(RAR) have been reported. Here, we demonstrate the effects of steroids/thyroids/retinoids and of activators of protein kinase A (forskolin, Forsk) and C (12Otetradecanoylphorbol13acetate, TPA), on growth and expression of cerbB and RARs in MCF7 breast cancer cells, which contain high levels of RAR and , and which express significant amounts of cerbB2 and 3. All transretinoic acid (tRA), the antiestrogen ICI 182 780 (ICI), Forsk and TPA reduced, whereas triiodothyronine and 17estradiol (E₂) stimulated cell growth. Flow cytometry revealed that tRA and E₂ reduced cerbB2 and 3, whereas tamoxifen, Forsk and TPA upregulatedcerbB2. cerbB3 was coregulated with cerbB2. Northern analysis demonstrated that RAR was downregulated by dexamethasone, ICI, and TPA, whereas vitamin D₃ and E₂ upregulated RAR. RAR expression was less responsive to such treatment, being reduced only by ICI and Forsk. These data indicate that nuclear receptor and protein kinase signaling communicate with each other and control the expression of RARs and cerbB receptors. Efficient growth control requires the coordinated interplay of both receptor systems.     

Successful co‐treatment with LHRH‐agonist for ovarian over‐stimulation and cystic formation in premenopausal tamoxifen exposure

The present study evaluates the potential beneficial effect of cotreatment with LHRHagonist in resolving premenopausal tamoxifen's induced supraphysiological serum 17 estradiol levels and persistent ovarian cysts. Ultrasonographic and serum hormonal evaluations were performed before, during, and following three consecutive injections of long acting LHRHagonist administered to 14 premenopausal breast cancer patients treated with tamoxifen, who had supraphysiological serum 17 estradiol levels and simultaneous persistent ovarian cysts. Within 3 weeks of the first LHRHagonist injection, all patients had menopausal serum estradiol levels. Ovarian cysts completely disappeared within 2 months following the first injection. Following the discontinuation of LHRHagonist cotreatment, serum estradiol levels remained in physiological levels and the ovaries remained a normal size in 64.3% of the patients for 13.3 ± 11.5 months. 28.6% of the patients had a gradual reappearance of high serum estradiol levels and of ovarian cysts, and were, therefore, treated with a second course of LHRHagonist. Following the second course, serum estradiol levels remained in physiological levels and the ovaries remained a normal size for 8–15 months. It is concluded that short duration of cotreatment with long acting LHRHagonist administered to premenopausal breast cancer patients treated with tamoxifen, successfully resolved the tamoxifeninduced supraphysiological serum 17 estradiol levels and the ovarian cysts.affiliated with Sackler Faculty of Medicine, Tel Aviv University     

Phase I/II trial of high dose mitoxantrone in metastatic breast cancer: the M.D. Anderson Cancer Center experience

Anthracyclines are among the most active agents in metastatic breast cancer. Mitoxantrone demonstrated a different toxicity profile when compared to doxorubicin. We performed a phase I/II study of singleagent highdose mitoxantrone therapy for advanced breast cancer. Nineteen patients who had a diagnosis of metastatic breast cancer received treatment at the M.D. Anderson Cancer Center between June 1986 and December 1987. The patients received escalating doses of mitoxantrone until a maximum tolerated dose (MTD), defined as grade 3 or 4 nonhematologic toxicity or infection, was obtained. The starting dose of 25 mg/m², given by short intravenous infusion, was escalated by 25% in each fivepatient cohort if each patient in the previous cohort tolerated the initial course and 2 or fewer patients reached the MTD. The median cumulative dose of mitoxantrone was 93 mg/m² (range, 25–205) and the maximum single dose was 39mg/m². Myelosuppression was the dose limiting toxicity. The median duration of granulocyte count 250/l was 5–7 days. Four patients (22%) had infections that required hospitalization, 3 patients (17%) had cardiac toxicity. One patient (6%) achieved a complete response, and 3 (17%) had a partial response, with an overall response rate of 22.3%. No apparent doseresponse relationship was observed in our study. The mitoxantrone dosage recommended for phase II studies is 25mg/m² every 3–4 weeks. We conclude that highdose mitoxantrone therapy for metastatic breast cancer was relatively well tolerated but was not associated with a higher response rate than that of standard dose mitoxantrone.     

Mdm2 sensitizes MCF7 breast cancer cells to cisplatin or carboplatin

Overexpression of Mdm2 in cancer cells with otherwise wildtype p53 is believed to be an alternative mechanism for p53 inactivation during carcinogenesis. Because a number of genetic alterations that inactivate p53, including mutation, homozygous deletion, or viral oncoprotein expression (e.g. HPV16E6), inhibit DNA repair, we tested the hypothesis that Mdm2 would likewise inhibit DNA repair. Repair of cisplatininduced DNA damage was reduced in MCF7 cells overexpressing Mdm2, compared to MCF7 cells in which wildtype p53 function was intact. MCF7Mdm2 cells exhibited preferential sensitivity to cisplatin and carboplatin. MCF7Mdm2 cells showed a pronounced Sphase arrest after cisplatin treatment, similar to that observed in mutantp53 cells in the present and prior studies. MCF7 cells with intact wildtype p53, on the other hand, arrested primarily in G2/M phase after cisplatin treatment. These findings indicate that Mdm2 overexpression can recapitulate the effect of p53 mutations on DNA repair of cisplatin lesions.     

Invasion marker PAI‐1 remains a strong prognostic factor after long‐term follow‐up both for primary breast cancer and following first relapse

In 1991, our group was the first to report the prognostic strength of plasminogen activator inhibitor type 1 (PAI1) in primary breast cancer. The prognostic impact of invasion markers PAI1 and urokinasetype plasminogen activator (uPA) on diseasefree survival (DFS) and overall survival (OS) in breast cancer has since been independently confirmed. We now report on the prognostic impact of PAI1 and uPA after longterm median followup of 77 months for our cohort (n=316).Levels of uPA, PAI1, and cathepsin D were determined in tumor tissue extracts by immunoenzymatic methods. Sphase fraction (SPF) was measured flowcytometrically in paraffin sections. Using logrank statistics, optimized cutoffs were found for PAI1 (14ng/mg), uPA (3ng/mg), cathepsin D (41pmol/mg), and SPF (6%). In all patients, various factors (PAI1, uPA, nodal status, SPF, cathepsin D, grading, tumor size, hormone receptor status) showed significant univariate impact on DFS. In Cox analysis, only nodal status (p < 0.001, RR: 3.1) and PAI1 (p < 0.001, RR: 2.7) remained significant. In nodenegative patients (n = 147), PAI1, uPA, and SPF had significant univariate impact on DFS, whereas in Cox analysis, only PAI1 was significant. PAI1 was also significant for DFS within subgroups defined by established factors. In CART analysis, uPA enhanced the prognostic value of PAI1 and nodal status for determination of a verylowrisk subgroup. For OS, only lymph node status and PAI1 were significant in multivariate analysis. PAI1 levels in the primary tumor were also a significant prognostic marker for survival after first relapse in both univariate and multivariate analysis.     

Generation of reactive oxygen species by xanthine derivatives in MDA‐MB‐231 human breast cancer cells

Theophylline reduces cell number in MDAMB231 cells through mechanisms over and above phosphodiesterase inhibition. In the current study, we used an intracellular fluorescent dye to show that theophylline and, to a much greater extent, 3isobutyl1methylxanthine, evoke the generation of reactive oxygen species and also sensitize the cells to insult by other oxidants. Xanthine derivatives may therefore offer novel strategies for antitumor therapeutics.     

Phase II study of cisplatin and 5‐fluorouracil in previously treated metastatic breast cancer: an Eastern Cooperative Oncology Group study (PA 185)

Purpose: The present study was conducted to investigate the efficacy and toxicity of a cisplatin and 5fluorouracil (5FU) combination in previously treated advanced breast cancer.Methods: Thirtysix women with recurrent metastatic breast cancer were entered on a phase II study of 5FU 1000mg/m²/day given intravenously as a continuous infusion on days 1–3 and cisplatin 30mg/m²/day given intravenously over 1h on days 2–4, repeated every 21 days. All subjects had received one previous chemotherapy regimen for metastatic disease and either progressed during treatment or relapsed after responding to previous chemotherapy. Fourteen patients had also received previous adjuvant chemotherapy, 17 patients had previous radiation therapy, and 29 patients had previous hormonal therapy.Results: Among 32 responseevaluable patients, there were 10 partial remissions (31%) and 1 complete remission (3%), with an overall objective response rate of 34%. Median duration of response was 4 months. Median survival was 10.5 months for responders and 9.5 months for the entire group. Toxicity was mild to moderate in most patients. Overall twelve patients experienced grade 3 toxicity (10 hematologic, 1 mucositis, and 2 nausea). There were no grade 4 or 5 toxicities.Conclusion: Infusional cisplatin and 5FU is a well tolerated and active regimen in women with previously treated advanced breast cancer.     

Treatment of advanced breast cancer with gemcitabine and vinorelbine plus human granulocyte colony‐stimulating factor

Purpose. A phase II trial was performed to investigate the efficacy and tolerance of gemcitabine, vinorelbine, and recombinant human granulocyte colonystimulating factor (GCSF) in advanced breast cancer. Patients and methods. Between April 96 and August 97, 60 patients entered this trial. Fortyfive patients were previously untreated and 15 patients had failed previous palliative chemotherapy with (n = 10) or without anthracyclines (n = 5). Therapy consisted of gemcitabine 1000mg/m² on days 1 + 15 + 21 and vinorelbine 40mg/m² on days 1 + 21, both diluted in 250ml saline and infused over 30min. GCSF was administered at 5g/kg/day subcutaneously from days 2–6 and 22–26. Courses were repeated every 5 weeks. Treatment was continued in case of response or stable disease until a total of six courses. Results. The overall response rate was 55.5% for patients who had not received prior palliative chemotherapy (95% confidence interval, 40%–70.3%), including 5 CR (11.1%) and 20 PR (44.4%) 12 patients (27%) had stable disease (SD), and 8 (18%) progressed. Secondline treatment with this regimen resulted in 6/15 (40%) objective remissions, 5 had SD, and 4 PD. The median time to progression was 9.5 months (range, 1.5–28) in previously untreated patients, and 7.0 months (range, 2–23) in those who had failed prior chemotherapy. After a median followup time of 15 months, 44 patients (73%) are still alive with metastatic disease. Myelosuppression was commonly observed, though WHO 3 and 4 neutropenia occured in only 9 (l5%) and 2 patients (3%), and was never complicated by septicaemia; grade 3 anemia was noted in 2 patients. Severe (WHO grade 3) nonhematologic toxicity was rarely observed, and included nausea/emesis in 3 and constipation in 2 patients. Conclusions. Our data suggest that gemcitabine and vinorelbine plus GCSF is an effective and tolerable first as well as secondline combination regimen for treatment of advanced breast cancer.     

Staging efficacy of breast cancer with sentinel lymphadenectomy

Seventytwo patients underwent dyeguided or dye and gamma probeguided sentinel lymphadenectomy (SLND) followed by complete axillary lymph node dissection (ALND). The results of imprint cytology, frozen sections, and permanent sections of the sentinel lymph node (SLN) were compared to each other and to the histologic findings in the nonsentinel nodes. The SLN was identified in 62 (88%) of 72 patients. Evaluation of the SLN on the permanent sections yielded a diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100, although the reliability of SLN diagnosis using frozen sections or imprint cytology is limited. Therefore, it may be concluded that SLND with multiple sectioning and histopathologic examination of the SLNs can predict the presence or absence of axillarynode metastases in patients with breast cancer. However, further studies will be needed to investigate the value of SLND in respect to the longterm regional control and any possible detriment or benefit to survival, before it can replace routine ALND as the preferred staging operation for operable breast cancer.     

Incremental cost‐effectiveness of double‐reading mammograms

Background. Double reading is a widely used criterion standard in breast cancer screening despite a lack of evidence of the costeffectiveness of the second reading. This study evaluates the incremental costeffectiveness of such a strategy.Design. Costeffectiveness analysis: Nationwide populationbased semiannual screening program for women aged 50–59 in Finland. Participation rate was 91%. All mammograms (95,423) performed during 1990–1995 in three screening centers of the Finnish Cancer Society were read by two radiologists with gradings recorded. The effectiveness of the double reading was the difference in cancers detected in the double compared to that of the single reading. Incremental costs of the double reading for the health care and nonhealth care and the time costs were estimated. The main outcome measure was the incremental cost per additional cancer found as a result of the doublereading strategy.Results. The total number of cancers detected with the double and single reading were 290 and 261, respectively. A significantly higher ratio of carcinoma in situ was the causative pathology in cancers detected only by the second reader. The cost per cancer detected with a single reading was US$ 18,340. The incremental cost of any additional cancer found was US$ 25,523, that is, a 39% higher cost per additional cancer found by double reading.Conclusions. The additional cost per cancer detected by double reading is not drastically higher than with single reading. However, the additional cost per life year saved may be much higher.