Prognostic and predictive importance of the estrogen receptor coactivator AIB1 in a randomized trial comparing adjuvant letrozole and tamoxifen therapy in postmenopausal breast cancer: the Danish cohort of BIG 1-98.

PURPOSE: To evaluate the estrogen receptor coactivator amplified in breast cancer 1 (AIB1) as a prognostic marker, as well as a predictive marker for response to adjuvant tamoxifen and/or aromatase inhibitors, in early estrogen receptor-positive breast cancer. METHOD: AIB1 was analyzed with immunohistochemistry in tissue microarrays of the Danish subcohort (N = 1396) of the International Breast Cancer Study Group's trial BIG 1-98 (randomization between adjuvant tamoxifen versus letrozole versus the sequence of the two drugs). RESULTS: Forty-six percent of the tumors had a high AIB1 expression. In line with previous studies, AIB1 correlated to a more aggressive tumor-phenotype (HER2 amplification and a high malignancy grade). High AIB1 also correlated to higher estrogen receptor expression (80-100 vs. 1-79%), and ductal histological type. High AIB1 expression was associated with a poor disease-free survival (univariable: hazard ratio 1.35, 95% confidence interval 1.12-1.63. Multivariable: hazard ratio 1.29, 95% confidence interval 1.06-1.58) and overall survival (univariable: hazard ratio 1.34, 95% confidence interval 1.07-1.68. Multivariable: hazard ratio 1.25, 95% confidence interval 0.99-1.60). HER2 did not seem to modify the prognostic effect of AIB1. No difference in treatment effect between tamoxifen and letrozole in relation to AIB1 was found. CONCLUSIONS: In a subset of the large international randomized trial BIG 1-98, we confirm AIB1 to be a strong prognostic factor in early breast cancer. Hence, although tumor AIB1 expression does not seem to be useful for the choice of tamoxifen versus an aromatase inhibitor in postmenopausal endocrine-responsive breast cancer, AIB1 is an interesting target for new anti-cancer therapies and further investigations of this biomarker is warranted.

Prognostic and predictive role of ESR1 status for postmenopausal patients with endocrine-responsive early breast cancer in the Danish cohort of the BIG 1-98 trial.

BACKGROUND: Estrogen Receptor 1 (ESR1) aberrations may be associated with expression of estrogen receptor (ER) or progesterone receptor (PgR), human epidermal growth factor receptor-2 (HER2) or Ki-67 labeling index and prognosis. PATIENTS AND METHODS: ESR1 was assessed in 1129 (81%) of 1396 postmenopausal Danish women with early breast cancer randomly assigned to receive 5 years of letrozole, tamoxifen or a sequence of these agents in the Breast International Group 1-98 trial and who had ER ≥ 1% after central review. RESULTS: By FISH, 13.6% of patients had an ESR1-to-Centromere-6 (CEN-6) ratio ≥ 2 (amplified), and 4.2% had ESR1-to-CEN-6 ratio <0.8 (deleted). Deletion of ESR1 was associated with significantly lower levels of ER (P < 0.0001) and PgR (P = 0.02) and more frequent HER2 amplification. ESR1 deletion or amplification was associated with higher-Ki-67 than ESR1-normal tumors. Overall, there was no evidence of heterogeneity of disease-free survival (DFS) or in treatment effect according to ESR1 status. However, significant differences in DFS were observed for subsets based on a combination of ESR1 and HER2 status (P = 0.02). CONCLUSIONS: ESR1 aberrations were associated with HER2 status, Ki-67 labeling index and ER and PgR levels. When combined with HER2, ESR1 may be prognostic but should not be used for endocrine treatment selection in postmenopausal women with endocrine-responsive early breast cancer.

Which patients benefit most from adjuvant aromatase inhibitors? Results using a composite measure of prognostic risk in the BIG 1-98 randomized trial.

BACKGROUND: On average, aromatase inhibitors are better than tamoxifen when used as initial or sequential therapy for postmenopausal women with endocrine-responsive early breast cancer. Because there may be contraindications to their use based on side-effects or cost, we investigated subgroups in which aromatase inhibitors may be more or less important. PATIENTS AND METHODS: Breast International Group 1-98 trial randomized 6182 women among four groups comparing letrozole and tamoxifen with sequences of each agent; 5177 (84%) had centrally confirmed estrogen receptor (ER) positivity. We assessed whether centrally determined ER, progesterone receptor (PgR), human epidermal growth factor receptor 2, and Ki-67 labeling index, alone or in combination with other prognostic features, predicted the magnitude of letrozole effectiveness compared with either sequence or tamoxifen monotherapy. RESULTS: Individually, none of the markers significantly predicted differential treatment effects. Subpopulation treatment effect pattern plot analysis of a composite measure of prognostic risk revealed three patterns. Estimated 5-year disease-free survival for letrozole monotherapy, letrozole→tamoxifen, tamoxifen→letrozole, and tamoxifen monotherapy were 96%, 94%, 93%, and 94%, respectively, for patients at lowest risk; 90%, 91%, 93%, and 86%, respectively, for patients at intermediate risk; and 80%, 76%, 74%, and 69%, respectively, for patients at highest risk. CONCLUSION: A composite measure of risk informs treatment selection better than individual biomarkers and supports the choice of 5 years of letrozole for patients at highest risk for recurrence.

Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial.

BACKGROUND: To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial. METHODS: We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment. RESULTS: The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy. CONCLUSIONS: Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients.

WITHDRAWN: Combined epirubicin and vinorelbine as first-line therapy in metastatic breast cancer: a pilot study performed by the Danish Breast Cancer Cooperative Group.

The publisher regrets that this is an accidental duplication of an article that has already been published in The Breast, 12 (2003) 42-50, doi:10.1016/S0960-9776(02)00180-7. The duplicate article has therefore been withdrawn.

Predictors of early relapse in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial.

BACKGROUND: Aromatase inhibitors are considered standard adjuvant endocrine treatment of postmenopausal women with hormone receptor-positive breast cancer, but it remains uncertain whether aromatase inhibitors should be given upfront or sequentially with tamoxifen. Awaiting results from ongoing randomized trials, we examined prognostic factors of an early relapse among patients in the BIG 1-98 trial to aid in treatment choices. PATIENTS AND METHODS: Analyses included all 7707 eligible patients treated on BIG 1-98. The median follow-up was 2 years, and the primary end point was breast cancer relapse. Cox proportional hazards regression was used to identify prognostic factors. RESULTS: Two hundred and eighty-five patients (3.7%) had an early relapse (3.1% on letrozole, 4.4% on tamoxifen). Predictive factors for early relapse were node positivity (P < 0.001), absence of both receptors being positive (P < 0.001), high tumor grade (P < 0.001), HER-2 overexpression/amplification (P < 0.001), large tumor size (P = 0.001), treatment with tamoxifen (P = 0.002), and vascular invasion (P = 0.02). There were no significant interactions between treatment and the covariates, though letrozole appeared to provide a greater than average reduction in the risk of early relapse in patients with many involved lymph nodes, large tumors, and vascular invasion present. CONCLUSION: Upfront letrozole resulted in significantly fewer early relapses than tamoxifen, even after adjusting for significant prognostic factors.

Axillary staging during surgery for breast cancer.

BACKGROUND: Axillary lymph node status remains the single most important prognostic parameter in patients with breast cancer. In approximately half of operations sentinel lymph node biopsy cannot be employed and axillary dissection is indicated. Retrieval of ten nodes has hitherto been considered sufficient, but it remains questionable whether the removal of more lymph nodes might improve staging. METHODS: Data from 31 679 breast cancer operations in Denmark were analysed. RESULTS: The number of axillary lymph nodes retrieved was an independent and strong predictor of node positivity. The more lymph nodes retrieved, the better the staging of the disease; this was evident for all sizes of tumour. Dissection of 20 or more nodes rather than ten to 14 increased the probability of node positivity from 14.2 to 25.9 per cent for 1-5-mm tumours, from 38.6 to 47.9 per cent for 11-20-mm tumours, and from 80.6 to 90.0 per cent for tumours with diameter greater than 50 mm. CONCLUSION: The number of metastatic lymph nodes increased as more nodes were retrieved. These findings underline the need for high-quality specialist surgical and pathological services in breast cancer treatment.

Treatment of anthracycline extravasation with Savene (dexrazoxane): results from two prospective clinical multicentre studies.

BACKGROUND: The purpose of this study was to assess the efficacy and tolerability of i.v. dexrazoxane [Savene (EU), Totect (US)] as acute antidote in biopsy-verified anthracycline extravasation. PATIENTS AND METHODS: Two prospective, open-label, single-arm, multicentre studies in patients with anthracycline extravasation were carried out. Patients with fluorescence-positive tissue biopsies were treated with a 3-day schedule of i.v. dexrazoxane (1000, 1000, and 500 mg/m(2)) starting no later than 6 h after the incident. Patients were assessed for efficacy (the possible need for surgical resection) and toxicity during the treatment period and regularly for the next 3 months. RESULTS: In 53 of 54 (98.2%) patients assessable for efficacy, the treatment prevented surgery-requiring necrosis. One patient (1.8%) required surgical debridement. Thirty-eight patients (71%) were able to continue their scheduled chemotherapy without postponement. Twenty-two patients (41%) experienced hospitalisation due to the extravasation. Mild pain (10 patients; 19%) and mild sensory disturbances (nine patients; 17%) were the most frequent sequelae. Haematologic toxicity was common as expected from the fact that the extravasation occurred during a chemotherapy course. Other toxic effects were transient elevation of alanine aminotransferases, nausea, and local pain at the dexrazoxane injection site. CONCLUSION: Dexrazoxane proved to be an effective and well-tolerated acute treatment with only one out of 54 assessable patients requiring surgical resection (1.8%).

Continuous versus intermittent tamoxifen versus intermittent/alternated tamoxifen and medroxyprogesterone acetate as first line endocrine treatment in advanced breast cancer: an EORTC phase III study (10863).

BACKGROUND: Continuous ligand depletion of endocrine responsive tumours may enhance resistance to therapy. Intermittent treatment with tamoxifen (T) was considered to mimic (incomplete) ligand depletion and reintroduction. Furthermore it was postulated that alternating tamoxifen with a non-cross resistant endocrine modality could (further) postpone hormone resistance. PATIENTS AND METHODS: Postmenopausal patients with advanced breast cancer who did not progress after 4 months of first line T therapy were randomised to continue T (40 mg daily) or to 2 monthly intermittent T or intermittent/alternated T and medroxyprogesterone acetate (MPA, 300 mg daily). At progression during break or during MPA, T should be reintroduced. Endpoints of the study were progression free survival (PFS), time to resistance to tamoxifen and overall survival (OS). RESULTS: Of 593 registered patients, 276 were randomised. After 8 years follow-up the median PFS for continuous T, intermittent T and intermittent/alternated T and MPA was 11.0 (8.1-15.2), 8.0 (6.2-12.4) and 10.8 (7.1-16.7) months, respectively (NS). Resistance to tamoxifen was established only in 84%, 70% and 55% of patients in the three treatment arms, respectively. The median times from randomisation to resistance to tamoxifen were 12.5 (9.1-21.1), 13.2 (8.8-19.8) and 24.0 (16.9-60.9) months, respectively (p<0.001), without translation in differences in survival times. CONCLUSION: Intermittent T or intermittent/alternated T and MPA had no impact on PFS or OS as compared with classical continuous T in patients with advanced breast cancer. Intermittent/alternated T and MPA resulted in prolonged time to resistance to T, but this might partly be due to bias by omittance of the proof of tamoxifen resistance in a high proportion of the patients in this treatment arm.

Reduced mortality for women with mammography-detected breast cancer in east Denmark and south Sweden.

The 5-year relative survival from breast cancer in Denmark is 10 percentage points lower than in Sweden. This difference has been demonstrated previously as being caused partly by more involved lymph nodes and larger tumours in Denmark. Sweden has had nationwide mammography-screening coverage since 1991, whereas this is still in its infancy in Denmark. In the search for an explanation for the remaining survival difference, patient delay was a likely candidate. This study compared patient delay and mammography-detection between two national regions. Data on patient delay and mammography were obtained from hospital records from 1989 and 1994, and analysed using Cox proportional hazard analysis of death within the first 5 years, with the factors age, country, delay/mammography detection and established patho-anatomic variables. A comparison of patient delay and mammography detection in 1989 and 1994 showed more mammography-detected tumours in south Sweden and more women with long delay in east Denmark. Mammography detection, but not long patient delay, had a significant effect on the death hazard when adjusting for patho-anatomic risk factors. The hazard ratio was not eliminated in 1989, but in 1994, the hazard ratio between east Denmark and south Sweden was reduced from 1.3 to 1.1. In conclusion, patient delay did not appear to have any effect on 5-year survival when adjusting for patho-anatomic factors, but tumour detection by mammography affected survival favourably and partly explained the survival difference between east Denmark and south Sweden.

Quality-adjusted survival in a crossover trial of letrozole versus tamoxifen in postmenopausal women with advanced breast cancer.

BACKGROUND: Results from a phase III study of postmenopausal women with advanced breast cancer demonstrated longer time to disease progression for patients taking letrozole versus tamoxifen. This analysis compares the trade-offs between progression-free survival and toxicity. DESIGN: Quality-adjusted survival was calculated using Q-TWiST (quality-adjusted time without symptoms or toxicity). Survival curves were partitioned into three health states: toxicity (TOX), disease progression (PROG) and periods without toxicity or disease progression (TWiST). The utility-weighted sum of the health state durations was derived and compared. RESULTS: There was not a significant difference in mean duration of serious adverse events prior to progression between the letrozole (n=453) and tamoxifen (n=454) groups (2.2 and 2 months, respectively). For TWiST, the mean duration for letrozole was 11.5 months, versus 8.5 months for tamoxifen (P <0.001). The mean duration of PROG was 11.5 months for letrozole and 12.7 months for tamoxifen (P=0.047). Using utility weights of 0.5 for TOX and PROG resulted in a 2.5-month difference in quality-adjusted survival favoring letrozole (P <0.0001). CONCLUSIONS: The longer time to disease progression with letrozole versus tamoxifen was achieved without increased time with adverse events and resulted in more quality-adjusted survival for patients on letrozole.

Tissue inhibitor of metalloproteinases-1 in breast cancer.

Whether patients diagnosed with primary breast cancer are offered adjuvant systemic therapy following surgical removal of the tumor is based on prognosis. Prognosis is estimated in every patient using established prognostic variables. Unfortunately, when using the currently available prognostic parameters a significant proportion of patients are over-treated. Thus, in order to improve stratification of breast cancer patients, additional prognostic factors need to be identified. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is one of the promising candidates for new prognostic markers in breast cancer, as a number of studies have demonstrated an association between high tumor-tissue levels of TIMP-1 mRNA as well as TIMP-1 protein and a poor prognosis of breast cancer patients. TIMP-1 is a member of the TIMP family, currently comprising four members (TIMP-1-4), and its main function is inhibition of the activity of various matrix metalloproteinases (MMPs). The association between high levels of protease inhibitor and poor prognosis may be somewhat surprising, as proteolytic activity plays a pivotal role in cancer cell invasion and metastasis. However, the recent discovery of other biological functions of TIMP-1 such as growth-stimulating functions, as well as anti-apoptotic and pro-angiogenetic effects, may in part explain this paradox. The purpose of this review is to give an update on the current status of TIMP-1 in breast cancer, emphasizing the prognostic utility of the inhibitor. In addition, the suggested tumor-stimulatory roles of TIMP-1 will be outlined.

Superiority of letrozole to tamoxifen in the first-line treatment of advanced breast cancer: evidence from metastatic subgroups and a test of functional ability.

PURPOSE: The letrozole study 025 is a large (n = 907), international, double-blind, randomized, phase III trial in postmenopausal women with advanced breast cancer. This subanalysis compares the efficacies of letrozole and tamoxifen as first-line therapy in postmenopausual women with advanced breast cancer according to site of metastatic lesions and Karnofsky Performance Status (KPS). MATERIALS AND METHODS: Nine hundred seven patients with advanced breast cancer were randomly assigned to once-daily oral letrozole (2.5 mg; Femara; Novartis Pharma AG; Basel, Switzerland) or tamoxifen (20 mg; Tamofen; Leiras OY; Turku, Finland). Time to progression (TTP) was estimated using the Kaplan-Meier product-limit method. Treatments were compared by Cox proportional hazards regression models. RESULTS: Letrozole treatment significantly prolonged TTP in all subsets of patients: those with nonvisceral metastases, those with visceral metastases without liver involvement, and those with liver metastases. The reduction in risk of progression ranged from 25%, for patients with nonvisceral metastases, to 36%, for patients with liver metastases. The distributions of baseline KPS scores for both treatment groups were similar (57% had KPS scores >/=90). Time to worsening of 20 points or more in KPS score was significantly longer with letrozole than with tamoxifen, but modest numbers of patients experienced such deterioration (letrozole, 20%, tamoxifen, 22%, in patients without visceral metastases; 23%-24% in patients with liver metastases; and letrozole, 14%, tamoxifen, 30%, in patients with visceral metastases without liver involvement). CONCLUSION: These data demonstrate the consistent superiority of letrozole over tamoxifen and support the use of letrozole as a new standard of endocrine therapy in postmenopausal women with advanced breast cancer.

Efficacy of first-line letrozole versus tamoxifen as a function of age in postmenopausal women with advanced breast cancer.

PURPOSE: To compare the efficacy, in regard to time to progression (TTP) and objective response rate (ORR), of letrozole (Femara; Novartis Pharma AG; Basel Switzerland), an oral aromatase inhibitor, with that of tamoxifen (Tamofen; Leiras OY; Turku, Finland) as first-line therapy in younger (<70 years) and older (>/=70 years) postmenopausal women with advanced breast cancer. MATERIALS AND METHODS: Nine hundred seven patients with advanced breast cancer were randomly assigned to receive 2.5 mg letrozole (n = 453) or 20 mg tamoxifen (n = 454) once daily in a double-blind, multicenter, international trial. Among the prospectively planned analyses were analyses of TTP and ORR by age (<70 and >/=70 years). The results of these prospectively planned analyses are reported here. RESULTS: Letrozole was as effective in older postmenopausal women (>/=70 years of age) as it was in younger postmenopausal women (<70 years of age). The overall ORR in the older subgroup was significantly higher in patients treated with letrozole (38%) than in patients treated with tamoxifen (18%). In the younger subgroup of postmenopausal patients, the ORRs were not significantly different (letrozole, 26%; tamoxifen, 22%). TTP was significantly longer for letrozole than for tamoxifen in both age groups (younger: letrozole median TTP, 8.8 months; tamoxifen, 6.0 months; older: letrozole median TTP, 12.2 months; tamoxifen, 5.8 months). Although age was independently prognostic of TTP, there was no significant effect of age on ORR in the presence of other factors. CONCLUSION: The data show that letrozole, 2.5 mg once daily, is as effective in older, postmenopausal women as it is in younger postmenopausal women with advanced breast cancer. In addition, letrozole was more effective than tamoxifen in both younger and older patients.

Can the survival difference between breast cancer patients in Denmark and Sweden 1989 and 1994 be explained by patho-anatomical variables?--a population-based study.

Analyses of data from cancer registries have shown a 10% unit difference in 5-year relative survival between Danish and Swedish patients with breast cancer. This study investigates the effect of age and patho-anatomic variables on this survival difference. Hospital records were collected for women over 40 years of age diagnosed in 1989 or 1994 in east Denmark and south Sweden; patho-anatomical variables and survival were compared between 2289 Danish and 1715 Swedish women. Tumours were smaller, node-negative axillae more frequent and well-differentiated tumours almost 10% more frequent in Sweden. A superior 5-year relative survival in Sweden was found in the 50- to 79-year age group. The adjusted hazard rate ratio between countries was 1.7 in 1989 and 1.3 in 1994. Conditional survival after surviving the first 5 years was similar for the two countries. Adjusting for patho-anatomical variables reduced but did not eliminate the higher risk of death among the Danish patients. Higher population death rates could explain some but not all of the residual elevated risk for Danish women.

Monitoring different stages of breast cancer using tumour markers CA 15-3, CEA and TPA.

The ability of the tumour markers Cancer Antigen 15-3 (CA 15-3), Carcinoembryonic Antigen (CEA), and Tissue Polypeptide Antigen (TPA) to signal progression in breast cancer patients was investigated in this study. Marker interpretation considered the analytical variation, intra-individual biological variation, and the rate of increase. Patient cohorts were as follows: (A) 90 stage II breast cancer patients who were monitored postoperatively, (B) 204 recurrent breast cancer patients who were monitored during first-line chemotherapy, and (C) 112 patients who were monitored during the time period after first-line chemotherapy. The sensitivity for progression was 44% (cohort A), 69% (cohort B), and 68% (cohort C) without any false progression signals. Marker lead-times exceeded 3 months in 20% (cohort A) and 27% (cohort C) of patients. Marker lead-times were 1-6 months among 33% of the patients receiving first-line chemotherapy (cohort B). Trials are necessary to determine whether tumour marker-guided therapy has any prognostic impact. The data suggest that tumour marker information may be used to stop ineffective treatments and reduce unnecessary adverse effects.

Combined epirubicin and vinorelbine as first-line therapy in metastatic breast cancer: a pilot study performed by the Danish Breast Cancer Cooperative Group.

This pilot study investigated the tolerability and efficacy of increasing doses of epirubicin and vinorelbine as first-line chemotherapy for metastatic breast cancer. Acute toxicity was manageable at all dose levels for combinations of epirubicin 60-90 mg/m2 on day 1 and vinorelbine 15-25 mg/m2 on days 1 and 8 repeated every 3 weeks. Myelotoxicity was the most frequent toxic event, with a significant increase in grade 4 leukopenia from 0% at dose level 1 (60+15 mg/m2) to 26% at dose level 6 (90+25 mg/m2). Signs of acute or chronic cardiotoxicity grades 2-4 were seen in 15% of the patients and included arrhythmia and decreased function. No significant association was established between dose and nonhematological toxicity. Objective responses were observed in 49 of the 99 evaluable patients (49.5%, 95% CI 39.9-59.2), 18 being complete and 31 partial responses. Responses were observed at all six dose levels. In conclusion, acute toxicity was manageable at all dose levels for combinations of epirubicin 60-90 mg/m2 on day 1 and vinorelbine 15-25 mg/m2 on days 1 and 8. In the treatment of advanced breast cancer, improvement of the antitumor efficacy by the addition of vinorelbine to epirubicin remains to be demonstrated in a randomized phase III trial.

Prognostic value of quality of life scores for time to progression (TTP) and overall survival time (OS) in advanced breast cancer.

The purpose of the study was to investigate whether baseline quality of life (QoL) and changes in QoL scores from baseline are prognostic for time to progression (TTP) and/or overall survival (OS) in patients with advanced breast cancer receiving docetaxel (T) or sequential methotrexate and 5-fluorouracil (MF). QoL was assessed at baseline and before each treatment using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30). Survival curves and probabilities were estimated using the Kaplan-Meier technique. The Cox proportional hazards regression model was used for both the univariate and multivariate analyses to explore relationships between baseline QoL variables and TTP, as well as OS. In the univariate analysis, more severe pain and fatigue at baseline were predictive for a shorter OS; global QoL, physical functioning and appetite loss had a borderline significance (P=0.0130 for global QoL; P=0.0256 for physical functioning: P=0.0149 for appetite loss). World Health Organization (WHO) performance status was significantly predictive for OS. In the multivariate analysis, more severe pain at baseline was predictive for a shorter OS. In contrast, baseline QoL had no prognostic value for the duration of TTP. QoL change scores from baseline QoL predicted neither OS nor TTP. Our findings suggest that while QoL measurements are important in evaluating patients' QoL, they have no great importance in predicting primary clinical endpoints such as TTP or OS in advanced breast cancer patients.

Immunoassays of urokinase (uPA) and its type-1 inhibitor (PAI-1) in detergent extracts of breast cancer tissue.

Two immunoassays for quantitation of the biological markers uPA and PAI-1 were evaluated for their use with detergent extracts of breast cancer tissue. Both assays were based on murine monoclonal capture antibodies and rabbit polyclonal detector antibodies. Horseradish peroxidase-conjugated goat anti-rabbit antibodies enabled measurement of the bound antigen. The detection limit of the uPA assay was 13 pg/ml, with a linear dose-response relationship up to 350 pg/ml. The assay detected free uPA as well as uPA in complex with PAI-1 and/or with its receptor. The detection limit of the PAI-1 assay was 50 pg/ml, with a linear dose-response relationship up to 1500 pg/ml. The assay detected both free PAI-1 and uPA:PAI-1 complex. Both assays were validated for detergent extracts using immunoabsorption and recovery tests. Highly significant associations between tumour tissue uPA and PAI-1 levels and prognosis were verified in a cohort of 164 lymph node-negative primary breast cancer patients. It is concluded that the two immunoassays are well-suited for the quantitation of uPA and PAI-1 in detergent extracts of breast cancer tissues.