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.     

Prognostic Significance of Tumor Cell Proliferation Analyzed in Fine Needle Aspirates from Primary Breast Cancer

The objective of this study was to analyze the role of proliferating fraction (PF) measured with Ki-67/MIB-1 antibody in a large series of preoperative fine-needle aspirate (FNA) biopsies as a prognosticator of disease recurrence. The study comprised 732 patients who all had a conclusive cytological diagnosis of breast cancer. The follow-up time ranged from 1.2 to 10.2 years with a median of 5.7 years. In multivariate analysis Ki-67/MIB-1 value was a strong (p<0.001) significant, prognosticator of disease recurrence free interval (DRFI) independent of lymph node status, progesterone receptor content, and tumor size. In the subgroup analysis of 430 node-negative patients the distant recurrence-free rate after 5 years was 94.4% in patients with Ki-67/MIB-1 value<15% compared to 88.7% in patients with Ki-67/MIB-1 value 15% (p=0.03). Test of the interaction between tumor size and the value of PF revealed a p-value of 0.06. If the patients, in addition, had a tumor size 20mm the distant recurrence-free rate after 5 years was 93.2% if Ki-67/MIB-1<15% compared to 80.7% in patients with Ki-67/MIB-1 value 15%. This difference was statistically significant (p<0.01). For patients with tumors <20mm Ki-67/MIB-1 value did not add any prognostic information. In the subgroup of 302 node-positive patients the distant recurrence-free rate after 5years was 86.0% in patients with Ki-67/MIB-1 value<15% compared to 70.6% in patients with Ki-67/MIB-1 value 15% (p<0.01). We conclude that PF assessed by Ki-67/MIB-1 antibodies in preoperative FNA biopsies has a significant prognostic value independent of lymph node status, PgR status and tumor size. To our knowledge, this is the first study demonstrating PF, which can contribute prognostic information when analyzed in preoperative smears.     

Phase II study of a 72-h concurrent continuous infusion of cisplatin and etoposide in advanced non-small-cell lung cancer

We conducted a phase II study to evaluate the antitumor activity and safety of concurrent continuous infusion of cisplatin and etoposide in advanced non-small-cell lung cancer (NSCLC). Cisplatin (30 mg/m² daily) and etoposide (80 mg/m² daily) were given as a 24-h continuous infusion for 72 h to 48 patients with previously untreated advanced NSCLC. Of the 46 evaluable patients, 9 achieved a partial response, for an overall response rate of 20% (95% confidence interval, 9.4%–33.9%). The median duration of response was 23 weeks. The median duration of survival for all patients was 34.4 weeks. The major toxicity was hematologic. Leukopenia (WHO grade 3) was observed in 22 patients (48%) and thrombocytopenia (WHO grade 3), in 13 patients (28%). In all, 20 patients (43%) experienced severe anemia (WHO grade 3). Nonhematologic toxicity mainly consisted of moderate to severe alopecia in 33 patients (72%) and moderate to severe nausea and vomiting in 25 patients (54%). No sigificant nephrotoxicity was seen. We conclude that a 72-h concurrent continuous infuson of cisplatin and etoposide does not appear to be active against advanced NSCLC.     

Weekly paclitaxel in women age 65 and above with metastatic breast cancer

We evaluated therapy with weekly paclitaxel 80mg/m² in metastatic breast cancer patients age 65. There was a low incidence of serious toxicities, with similar tolerability profiles in younger and older patients. Response rates and overall survival times were comparable in the two age groups (<65 and 65). Weekly paclitaxel therapy is a reasonable option for older patients with metastatic breast cancer.     

Static disease on anastrozole provides similar benefit as objective response in patients with advanced breast cancer

Background. This paper reports on the clinical relevance of durable static disease (SD) (24 weeks) in breast cancer patients treated with the aromatase inhibitor anastrozole.Patients and methods. All patients were part of two prospective, randomised, multicentre studies in postmenopausal women with advanced disease in which megestrol acetate was compared with anastrozole 1 mg. Survival from initiation of treatment was analysed by the response type, i.e., complete response (CR)/partial response (PR), static disease (SD) (24 weeks), or progressive disease (PD), achieved on therapy.Results. Median survival with anastrozole 1 mg was similar between patients who obtained CR/PR and SD (24 weeks). Similarly, no difference in survival was observed in patients treated with megestrol acetate who achieved CR/PR and SD. With both treatments patients with CR/PR and SD had improved survival over those patients with PD within 24 weeks. There was no difference between treatment arms for patients showing PD within 24 weeks.Conclusions. These data confirm that durable SD (24 weeks) is a clinically useful remission criterion in postmenopausal women with advanced breast cancer with predictive value for overall survival. It also confirms the value of this endpoint with anastrozole, a new generation aromatase inhibitor.     

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.     

Assessment of ventricular function by radionuclide angiography in patients receiving 4′-epidoxorubicin and mitoxantrone

Summary Serial assessment of ventricular function by means of radionuclide angiography was performed in 50 patients with malignant neoplasms who received either 4-epidoxorubicin or mitoxantrone for longer than 3 months.In 9 of 30 patients give 4-epidoxorubicin, a decrease of 10% in the left ventricular ejection fraction (LVEF) was documented at doses of 143–1200 mg/m². Two patients developed clinical signs of cardiotoxicity at a dose of >1000 mg/m².In 6 of 20 patients given mitoxantrone a decrease of 10% in the LVEF occurred at doses of 26–98 mg/m².This study was supported in part by a grant from the National Cancer Association of South Africa     

Hormone receptors and obesity in Japanese women with breast cancer

Summary An association between hormone receptors in primary breast cancer and obesity determined prior to mastectomy was investigated in 128 Japanese women. The following criteria for obesity were used: (1) weight 60 kg (132 lbs), (2) weight kg/height cm–105 1.3, (3) weight lbs/height in 2.30, (4) body surface area 1.56 m². In view of the 4 criteria, tumor estrogen receptor (ER) values 4 fmol/mg were observed in obese patients more often than in nonobese patients, though the difference was not statistically significant. The same tendency was observed in the postmenopausal subgroup, 62 patients, especially in the 36 patients more than 5 years beyond menopause. However, there was still no statistical difference between obese and nonobese patients because the number of subjects was small. The same tendency was observed in the case of progesterone receptor (PgR) (6 fmol/mg) as observed in the case of ER. Address for reprints: Dr. Keijiro Kuno, Department of Surgery, Cancer Institute Hospital, 1-37-1 Kami-Ikebukuro, Toshima-ku, Tokyo, Japan 170     

Combined Treatment Modality for Anaplastic Oligodendroglioma: A Phase II Study

Purpose: To investigate feasibility, toxicity and antitumor activity of combined surgery, postoperative radiation therapy (RT) and adjuvant chemotherapy (CHT) in adult patients with pure anaplastic oligodendroglioma (PAO) or mixed anaplastic oligoastrocytoma (MAO).Methods: Between January 1988, and June 1993, 23 patients entered into a phase II study. After surgery, post-operative RT was administered with 60Gy in 30 daily fractions in 30 treatment days in 6 weeks. Two weeks after RT, adjuvant modified PCV (mPCV) (Procarbazine, 60mg/m², days 1–14; CCNU, 100mg/m², day 1; and vincristine, 1.4mg/m² (max. 2mg), days 1 and 8) was administered every six weeks up to six cycles or until progression occurred.Results: Median survival time is not attained yet, while 1–5 year survival rates are 100%, 100%, 78%, 61%, and 52%, respectively. Median time to tumor progression is not attained yet, while 1–5 year progression-free survival rates are 100%, 100%, 70%, 52%, and 52%, respectively. On univariate analysis of potential prognostic factors, sex, tumor location (frontal versus other), and histology (pure versus mixed anaplastic oligodendroglioma) were not found to influence survival. Age of <50 years carried improved prognosis as well as Karnofsky performance status (KPS) 90–100 when compared to KPS of 70–80. Patients having tumors 4cm did better than those with tumors >4cm as well as those with total tumor resection when compared to those with subtotal tumor resection or biopsy only. Acute high-grade (3) CHT-related toxicity was mainly hematological with only 3 (13%) patients experiencing acute grade 4 toxicity.Conclusions: Combined treatment modality consisting of surgery, postoperative high-dose RT and mPCV chemotherapy for patients with anaplastic oligodendroglioma was effective with acceptable toxicity. Further studies are needed with more patients and longer follow-up to verify these results in this rare disease.     

Suppression of Cell Invasion on Human Malignant Glioma Cell Lines by a Novel Matrix-metalloproteinase Inhibitor SI-27: In Vitro Study

Matrix metalloproteinase (MMP) has come to be highlighted by its close relation to the cell invasion of gliomas. Suppression of MMP activity in malignant glioma cells would be meriting to local delivery of genes or chemotherapeutic agents. In this study, we employed a novel MMP inhibitor, SI-27 to investigate inhibition of cell invasiveness in human malignant glioma cell lines, U87MG, U251MG, and U373MG. We evaluated with zymogram, reverse zymogram, and cell invasion assay after exposure of SI-27 for 24h followed by preliminary MTT assay to find non-cytotoxic dose range, 51050100g/ml compared with non-treatment group as the control. Common to three glioma cell lines, zymogram disclosed that expressions of MMP-2 and -9 were suppressed in a dose-dependent fashion, meanwhile those of tissue inhibitor of MMP (TIMMP) in reverse zymogram were not. The numbers of invading cells through Boyden chamber were significantly reduced in a dose-dependent manner, while those with 5g/ml were not diminished common to those three lines. In conclusion, dose concentration ranging 10–100g/ml of SI-27 inhibited MMP-2 and -9 mediated cell invasiveness in malignant glioma cell lines. This is the first report for chemotherapeutic effect of SI-27 on glioma cells.     

Evaluation of Pre-radiotherapy Cyclophosphamide in Patients with Newly Diagnosed Glioblastoma Multiforme

Cyclophosphamide is an alkylating agent that has shown activity in the treatment of pediatric brain tumors, including high-grade gliomas. This study was designed to evaluate the response of patients with newly diagnosed glioblastoma multiforme to pre-radiotherapy cyclophosphamide. Fourteen patients with glioblastoma multiforme were treated with high-dose cyclophosphamide (2g/m²/day for 2 doses every 28 days) followed by either sargramostim or filgrastin. Sargramostim was given 250µg/m² subcutaneously twice a day continuing through the leukocyte nadir until the absolute neutrophil count was more than 1000 cells/µl for 2 consecutive days. The filgrastin dose was 10µg/kg given subcutaneously once daily until the post nadir absolute neutrophil count was 10,000cells/µl. A total of 46 courses was given. Four patients received a total of 3 courses, 7 patients completed 4 courses and 3 patients received 2 courses. Three patients demonstrated complete response; 3 stable disease; and 8 progressive disease. The most common toxicity was hematologic, requiring platelet and packed red blood cell transfusions, with 13 admissions for neutropenia with fever. There were no deaths related to infection or bleeding. These results suggest that high-dose cyclophosphamide has modest activity with acceptable toxicity against newly diagnosed glioblastoma multiforme.     

Growth Inhibition and Radiosensitization of Cultured Glioma Cells by Nitric Oxide Generating Agents

The authors examined the effect of nitric oxide (NO) generating agents on the growth and radiosensitivity of cultured glioma cells. Three glioma, rat C6, and human T98G and U87 cell lines were treated with the NO generating agents, S-nitroso-N-acetyl-penicillamine (SNAP) or sodium nitroprusside (SNP). These agents released NO in the cell culture media and inhibited the growth of the glioma cells. Growth-inhibition was attenuated by hemoglobin, a known inhibitor of NO, suggesting it is mediated by NO. When C6 and T98G cells were irradiated in the presence of SNAP or SNP at 100µM, radiosensitization was observed. SNAP at 100µM exhibited a sensitizer enhancement ratio (SER) of 1.4 for C6 cells and 1.8 for T98G cells. SNP at 100µM only radiosensitized T98G cells with a SER of 1.9. The effect of SNP on radiosensitization of C6 cells was unclear. We conclude that NO generating agents are potential growth inhibitors and radiosensitizers for malignant glioma cells. NO mediated radiosensitization of glioma cells by NO generating agents may offer a new therapeutic approach for malignant glioma.     

Differential effects of chemotherapeutic agents on the Bcl‐2/Bax apoptosis pathway in human breast cancer cell line MCF‐7

The present study explored the effects of three commonly used chemotherapeutic agents on the Bcl2/Bax apoptosis pathway and the interaction of these chemotherapeutic drugs with the estradiolmediated regulation of this pathway. Our results showed that: (1) Treatment of MCF7 cells with Adriamycin resulted in time and concentrationdependent decreases in Bcl2 and increases in Bax mRNA and protein levels. (2) Camptothecin elicited similar trends on Bcl2 and Bax as Adriamycin, while etoposide, at 50–100 fold (1–5M) the effective concentration of Adriamycin and camptothecin, only resulted in an increase in Bax mRNA levels. (3) Adriamycin and camptothecin, but not etoposide, were effective in suppressing estradiolstimulated increases in Bcl2 mRNA levels. Our study provides evidence that the Bcl2/Bax apoptosis pathway may be differentially regulated by chemotherapeutic agents. In addition, interaction between these agents and estradiol on the Bcl2/Bax apoptosis pathway may also exist.     

High complete pathological response in locally advanced breast cancer using paclitaxel and cisplatin

Background.In an earlier study, we have demonstrated a high response rate in metastatic breast cancer using paclitaxel (P) and cisplatin (C). A phase II study using the same regimen (PC) has been conducted in locally advanced breast cancer (LABC). Methods.A total of 72 consecutive patients with non-inflammatory LABC (T24cm, T3 or T4, N0–N2, M0). Patients were scheduled to receive 3–4 cycles of the neoadjuvant PC (paclitaxel 135mg/m² and cisplatin 75mg/m² on day 1) every 21 days. Patients were then subjected to surgery and subsequently received 6 cycles of FAC (5-fluorouracil 500mg/m², doxorubicin 50mg/m², and cyclophosphamide 500mg/m²) or 4 cycles of AC (doxorubicin 60mg/m², and cyclophosphamide 600mg/m²). Patients then received radiation therapy, and those with hormone receptor positive tumors were given adjuvant tamoxifen intended for 5 years. Results.The median age was 39 years (range, 24–78). Clinically, 7%, 58%, and 35% of patients had T24cm, T3, and T4, respectively. Disease stage at diagnosis was IIB (33%), IIIA (27%), and IIIB (40%). Complete and partial clinical response to PC was demonstrated in 13 (18%), and 52 (72%) patients, respectively. Of those patients with evaluable pathologic response (68 patients), complete pathologic response (pCR) was achieved in 15 (22%) patients. At a median follow-up of 22 (±3.5) months, 58 (81%) were alive with no recurrence, nine (12%) were alive with evidence of disease, and five (7%) were dead. None of the patients achieving pCR has developed any relapse. The median overall survival has not been reached for all 72 patients with a projected 3-year survival (±SE) of 90% (±4%). The median progression-free survival (PFS) was 42.1 (±4.8) months with a projected PFS of 74%±7% at 3-years (for 68 patients). Conclusions.PC regimen in LABC produced a high pCR. The contribution of the other added modalities to survival could not be assessed.     

Immune adjuvants for chemotherapy or radiotherapy in the 9L rat brain tumor model

Summary The therapeutic efficacy and toxicity of three biological response modifiers,Corynebacterium parvum (Cp), Chinese blister beetle extract (CBBE), recombinant human IL-1 (rhIL-1), used alone or in combination with chemotherapy or radiotherapy, were investigated in the intracerebral (ic) rat 9L brain tumor model. Used alone, Cp (2mg/rat, ip plus 70g/rat, ic), CBBE (5l of an ethanol extract, ic), or IL-1 (lg/rat, ic or 1g/rat × 3, q 3 d, ic), had no effect on animal survival compared to the untreated or saline treated controls. When combined with chemotherapy or radiotherapy, the three immunotherapeutic agents did not show any additive effects on survival compared to that observed with systemic BCNU (12mg/kg), local ic bleomycin (0.25 unit), or local radiotherapy (16 Gy). While ic IL-1 did not produce evident toxicity, there was fatal toxicity caused by ic Cp or CBBE treatment in a few animals. The combination of Cp and bleomycin produced severe neurotoxicity, resulting in the early death of animals. This study demonstrates a lack of efficacy of the nonspecific immune adjuvants IL-1, Cp or CBBE, used either alone or combined with cytotoxic chemotherapy or radiotherapy, in this rat brain tumor model.     

Neuroblastoma and parental occupation

Objectives: We evaluated parental occupation and the risk of neuroblastoma using data from a large case–control study conducted by the Children's Cancer Group and the Pediatric Oncology Group.Methods: We compared the distribution of 73 paternal and 57 maternal occupational groups among 504 newly diagnosed cases of neuroblastoma and individually matched controls obtained by telephone random digit dialing in the United States and Canada.Results: An increased risk of neuroblastoma was found for fathers employed as broadcast, telephone and dispatch operators (odds ratio [OR]=6.1; 95% confidence interval [CI]=0.7–50.9), electrical power installers and power plant operators (OR=2.7; CI=0.9–8.1), landscapers and groundskeepers (OR=2.3; CI=1.0–5.2), and painters (OR=2.1; CI=0.9–4.8). Elevated odds ratios were found for mothers employed as farmers and farm workers (OR=2.2; CI=0.6–8.8), florists and garden store workers (OR=2.4; CI=0.6–9.9), hairdressers and barbers (OR=2.8; CI=1.2–6.3), electric power installers and power plant operators, and sailors, fishers, and railroad workers. No increase in risk was found for other paternal occupations previously associated, including electricians, electrical equipment assemblers and repairers (OR=1.1; CI=0.6–2.0), or welders (OR=0.5; CI=0.1–1.6).Conclusion: The study reinforced some prior evidence of increased risks in electrical, farming and gardening, and painting occupations, but failed to confirm other previously reported associations. Further analyses of exposure to electromagnetic fields, metals, solvents, and pesticides are currently under way.     

Phase II study of carboplatin,cisplatin, and vindesine in advanced non-small-cell lung cancer

Cisplatin in combination with vindesine has been widely used for the treatment of advanced non-small-cell lung cancer (NSCLC), producing an overall response rate of 32%. We conducted a phase II study to examine whether the addition of carboplatin to the combination of cisplatin and vindesine would improve the antitumor activity of the two platinum agents in advanced NSCLC without increasing their toxicity. Carboplatin (240 mg/m²) and vindesine (3 mg/m²) were given intravenously on day 1 and cisplatin (60 mg/m²) and vindesine (3 mg/m²), on day 8. Of the 40 evaluable patients with advanced NSCLC, 12 showed a partial response, for an overall response rate of 30% (95% confidence interval, 17%–47%). The median duration of response was 12 weeks, and the median survival duration for all patients was 38 weeks. The major toxicity was hematologic: leukopenia (WHO grade3) was observed in 21 patients (53%) and anemia (WHO grade3), in 13 patients (33%). However, thrombocytopenia was mild and WHO grade 3 toxicity was observed in only 4 patients (10%). Nonhematologic toxicities consisted mainly of WHO grade2 nausea and vomiting in 16 patients (40%) and WHO grade2 alopecia in 11 patients (28%). No significant nephrotoxicity or neurotoxicity was seen. Our findings indicate that the addition of carboplatin to the combination of cisplatin and vindesine does not improve antitumor activity in patients with advanced NSCLC.     

Biomarkers for local recurrence after breast‐conservation — a nested case‐control study

Purpose: A previous cohort study of 759 women with invasive T1T2 breast cancer operated on with breastconserving surgery in Stockholm between 1976 and 1986 indicated that age <50 years, no postoperative irradiation, and nodal involvement were independent risk factors for ipsilateral breast tumor recurrences (IBTR). The aim of the current study was to analyse if selected biological markers assayed in tumor specimens from these patients could add prognostic information, thereby helping to identify groups of patients at high versus low risk of IBTR.Methods: The study was designed as a casecontrol study nested within the cohort. The cohort was stratified according to nodal status and the use of postoperative irradiation. In these four strata, the cases were those 80 women who developed IBTR between 1977 and 1994. In each stratum, women without IBTR were randomly selected as controls (n=159). Median time at risk was 12 (8–18) years. The following factors were analysed: histopathological tumor grade according to Elston–Ellis, DNA ploidy, immunohistochemical staining for apoptosis, angiogenesis, Ki67 (MIB1), cerbB2, p53, waf1, and bcl2. The prognostic role of each factor was assessed using linear logistic regression methods.Results: In univariate analyses only age <50 years was identified as a significant risk factor for IBTR, whereas none of the studied biomarkers yielded statistically significant information. However, in a multivariate model, age, MIB-1-index, and tumor grade significantly influenced the risk for IBTR: the odds-ratio (OR) for age 50 years was 0.4, 95% confidence interval (CI)=0.2–0.9; for medium or high grade tumors it was 0.4 (CI=09–0.9); and for MIB-1-index >30%, 2.1 (CI=1.0–4.4). In women 50 years, MIB-1-index >30% was associated with an OR of 3.5 (CI=1.4–8.8) compared to those who were younger. Patients 50 years with MIB-1-index 30% were thus identified as a low-risk group with an OR of 0.2 (CI=0.1–0.5). A possible high-risk group was patients <50 years with tumors showing a combination of c-erbB-2 and waf-1 immunoreactivity, with an OR of 6.7 (CI=1.3–34.7).Conclusion: Women 50 years with MIB-1-index 30% constituted a subgroup with a low risk of IBTR. This observation raises the issue whether this group of patients might be spared postoperative irradiation following breast-conserving surgery. However, due to the methodology of the study, including the large number of comparisions, the presented results warrant cautious interpretation and should be regarded as tentative.     

Evaluation of breast cancer incidence: is the increase due entirely to mammographic screening?

Objectives: To examine the trends in the incidence rates of breast cancer in a population with mammographic screening and in the unscreened women within that population.Methods: Data consisted of incident cases of breast cancer notified to the Victorian Cancer Registry in Victoria, Australia, between 1988 and 1996 and cases detected in the population-based BreastScreen Program. These data were grouped by age (25–39, 40–49, 50–59, 60–69 and 70 years of age) and size of tumor (10 mm, > 10–15 mm, and > 15mm). Poisson regression modeling was used to examine trends by age, tumor size, calendar year and availability of screening.Results: The incidence rate of breast cancer in the total population increased between 1988 and 1996. The greatest increase was seen after 1993 when population-based screening became available. In unscreened women, modeling demonstrated a statistically significant (p < 0.01) 1.5% annual increase in the incidence rate. The annual increase in this rate differed by size of tumor and was approximately 8% (p < 0.01) for small tumors ( 10 mm) but not significant for tumors > 10 mm. The greatest increase was in small tumors for women 50 years of age.Conclusion: The incidence of breast cancer has increased since population-based mammographic screening was introduced in 1994. The rate in unscreened women also showed a significant increase. This was greatest in small tumors for women 50 years of age. Whether this will translate into an increase in mortality is uncertain and long-term monitoring is required to determine if cohort and period effects impact on the underlying incidence of breast cancer in Victoria.     

Tissue inhibitor of metalloprotease (TIMP)‐1 and proliferative behaviour of clonal breast cancer cells

In the present paper, we have examined whether human tissue inhibitor of metalloprotease1 (hTIMP1) is able to exert a growth factorlike effect on two clonal cell lines (BC3A and BC61), isolated from a parental line of human breast carcinoma cells (8701BC), and endowed with different growth and invasive behaviour in vitro and in nude mouse. The data obtained indicate that only the more tumorigenic clonal cell line (BC61) is responsive to hTIMP1 treatment by increasing its proliferative rate in a dosedependent manner. It was also found that BC61 cells selectively express a transmembrane protein of about 80kDa able to bind hTIMP1 in vitro and in vivo with high affinity (K_d of 0.07 ± 0.004 nM), and that treatment of BC61 cells with a proliferationpromoting concentration of hTIMP1 is able to stimulate tyrosinetargeted phosphorylation. The cumulative results obtained strongly support the hypothesis that hTIMP1, classically regarded as a collagenase inhibitor, may be a crucial element of the extracellular signalling network during breast cancer development by controlling cell growth phenotype in autocrine and paracrine manner, and that intratumoural heterogeneity for the biological response to TIMP1 may exist within the composite cell population of the primary tumour site.