Annals of Oncology 12 81-87.2001 © 2001 Kluwer Academic Publishers Primed in the Netherlands Original article Prognostic factors and long-term survival in 585 patients with metastatic breast cancer treated with epirubicin-based chemotherapy M. Ryberg, D. Nielsen, K. 0sterlind, T. Skovsgaard & P. Dombernowsky Department of Oncology, Herlev Hospital, University of Copenhagen, Denmark Summary Background Analysis of prognostic factors in patients with metastatic breast cancer treated with epirubicin-based chemotherapy Patients and methods Data from 469 patients treated with epirubicin-based chemotherapy for metastatic breast cancer were used Prognostic factors were identified (Cox multivanate analysis). A prognostic index was compiled and risk groups were established accordingly. The applicability of the index was investigated in a series of 116 patients Results The prognostic factors identified were, liver, pleural, soft tissue, lung and bone metastases, performance status > 2, advancing age, abnormal elevation of serum lactate dehydrogenase and negative/unknown oestrogen receptor status. Four risk groups were established good, intermediate 1, intermediate II and poor The median and five-year survivals in percentage were, good 34 months (26%), intermediate I: 19 months (6%), intermediate II. 12 months (0%); poor. 7 months (1%) The corresponding values in the applicability group were 32 months (23%), 28 months (22%), 18 months (5%); and 6 months (0%) Conclusions It is more the number and impact on the organs involved, that predict the patients' survival The construction of a prognostic index could be helpful in assessing the outlook for patients, especially the quite dramatic difference in long-term survival between the good and poor risk patients. Key words epirubicin, metastatic breast cancer, prognostic factors Introduction Patients and methods The treatment of metastatic breast cancer is a tremendous challenge, and, despite intensive research, the treatment is still only palliative. In patients given chemotherapy, a median survival of 1.5-2 years has been found [1-4]. Prior studies have demonstrated that survival depends on several factors, such as the number and location of metastases, oestrogen receptor status (ER status) and performance status (PS) [2, 3, 5-7]. Metastases to the liver have been especially correlated with a poor survival [2, 3, 5, 8, 9]. Other factors also have a prognostic impact such as the stage of the primary disease [5, 8], prior adjuvant chemotherapy [3, 9, 10], a short disease-free interval (DFI) [2, 5, 6, 8-10], and advancing age [11-13]. Overall, these results are contradictory. The aim of the present study was to identify risk factors in patients with metastatic breast cancer at the time of initiation of chemotherapy, and thus to detect risk groups. A survival analysis was done on data from a cohort of 469 anthracycline-naive patients with metastatic breast cancer carried out in a single institution prospectively included in epirubicin-based chemotherapy trials from 1983 to 1992 followed by an applicability test in the subsequent period 1992 to 1995 Four hundred sixty-nine patients, consecutively treated with cpirubicinbased chemotherapy for metastatic breast cancer at Herlev Hospital during the period November 1983 to September 1992 were entered (old series) (Table I) Subsequently, data were accessed on 116 patients treated during the period October 1992 to May 1995 (new series) None of the patients had received anthracycline-based chemotherapy before The characteristics of all the patients are given in Table 1 Data on the 469 patients were used in a Cox multivanale analysis Two hundred sixty patients were entered in two prospective randomised phase III trials 1) epirubicin 60 mg/m 2 (days 1 + 8) or epirubicin 45 mg/m 2 (days 1 + 8) + vindesine 3 mg/m 2 (day 1) every 4 weeks (122 patients) [14], 2) epirubicin 70 mg/m 2 (days 1 + 8) or epirubicin 60 mg/m 2 (days 1 + 8) + cisplatin 100 mg/m 2 (day 1, the first six cycles) every 4 weeks (138 patients) [15] The inclusion criteria have been published earlier [14, 15] Patients who refused randomisation were treated with epirubicin 70 mg/m 2 (days 1 + 8) (115) every 4 weeks A further 94 patients received epirubicin 130 mg/m 2 (day 1) every 3 weeks Data on the new series with 116 patients were used for validation Eighty-five patients participated in a phase III study epirubicin 130 mg/m 2 every three weeks vs epirubicin 130 mg/m 2 and cyclophosphamide 2500 mg/m 2 alternately every three weeks for a total of eight cycles Thirty-one patients who refused randomisation were treated with epirubicin 130 mg/m 2 every three weeks Previous treatment Patients classified as high risk at the primary operation received adjuvant treatment Patients with positive regional lymph nodes and/ 82 or a tumour size > 5 cm were considered to be high nsk patients Premenopausal patients aged <50 years received cyclophosphamide, methotrexate, 5-fluorouracil (CMF) ± adjuvant irradiation From 1989 some premenopausal women, who were oestrogen receptor-posUive (ER-pos), were treated with ovarian irradiation Post-menopausal women and aged <50 years, were grVen the same treatment as high risk patients > 50 years these with an ER-pos or oestrogen receptor unknown tumour (ER-unknown) received tamoxifen for one year, and those with a receptor negative-tumour (ER-neg) received CMF A small group of patients were treated with tamoxifen or with CMF ± tamoxifen, (irrespective of age <50 years) Ninety-two patients included in the study had received first-line chemotherapy with CMF at the first relapse Pretreatment evaluation of all patients included a complete history and physical examination, blood cell counts, serum chemistry profiles. X-ray of the chest, and bone scans If the bone scan was abnormal, the axial skeleton was further evaluated with roentgenograms to determine the nature of the abnormalities Pleural metastases were documented either by a positive cytology or biopsy, and metastases to the bone marrow by aspirate from the iliac crest An ultrasound scan of the liver was performed in all cases with abnormal liver biochemistry After cessation of chemotherapy, the patients were followed-up every three months Potential prognostic characteristics The following factors were examined metastases to the liver, lung, pleura, bone, contralateral breast, lymph node(s), bone marrow, brain, soft tissue including skin with or without underlying connective tissue/ muscle (patients with only local soft tissue metastases underwent surgery/irradiation), other sites (abdomen, except the liver) and the number of metastatic sites Other factors examined were the age of the patient at the initiation of epirubicin treatment, PS according to WHO's definition, pretreatment biochemistry values such as haemoglobin (hgb), and serum lactate dehydrogenase (S-LDH), ER status, primary stage (lymph node status/tumour size), adjuvant chemotherapy/radiotherapy, DF1, time from the diagnosis of primary disease to treatment with epirubicin (TTE), the number of relapses and previous CMF treatment for recurrent disease Prognostic index A prognostic index was compiled from the prognostic factors identified by the Cox multivanate analysis and each factor in the final Cox model was assigned a prognostic score calculated as the rounded off regression coefficient x 10 Statistical analysis Analysis of the relation between pretreatment characteristics and survival was based on Kaplan-Meier's curves and Cox's proportional hazards model Categorisation of variables followed clinically objective criteria Thus, metastases to a certain site were assigned 0 for 'no' and 1 for 'yes' Non-examined and unconfirmed suspected sites were entered as missing Values within the normal range of hgb concentration scored as 0, while anaemia (hgb < 7 0 mmol/l) was assigned 1 S-LDH in normal range (upper limit 450 U/l) was assigned 0, values of 451-900 U/l scored 1, and values higher than 900 U/l scored 2 Distribution of the patients' age at the time epirubicin was initiated was divided into quartiles The age of the individual patient was assigned 0 for the youngest age group and 3 for the oldest The influences of age and LDH were tested for linearity in a separate Cox analysis DFI and TTE were divided as early < 3 years vs late 3 years With ER-pos as reference, ER-neg and ER-unknown were assigned to separate variables The Cox analysis was carried out as a stepwise entering analysis with Wald test statistics P > 0 10 to exclude a variable and P < 0 05 to Table I Characteristics of 585 patients Patients available for prognostic index n (%) validation n (%) Registered 469(100) 116(100) Primary local disease 422(90 0) 110(94 9) Lymph node negative < 4 positive lymph nodes > 4 positive lymph nodes Excact lymph node status unknown 71(15 177(39 98(19 123(26 1) 2) 4) 2) 37(31 9) 43(37 1) 27(23 3) 9(7 8) Tumour size < 5 cm Tumour size > 5 cm Unknown 218(46 4) 95 (20 2) 156(33 4) 72(62 1) 17(147) 27(23 3) Adjuvant therapy" None Chemotherapy Radiation therapy Ovanal irradiation Tamoxifen Chemotherapy and tamoxifen 120(25 6) 150(32 0) 176(7 5) 0(0) 60(128) 22 (4 5) 43(37 1) 39 (33 6) 31(26 7) 5(4 3) 21 (18 0) 1(0 9) ER-positive ER-negative ER-unknown 169(36 3) 102(21 5) 198(42 2) 74(63 8) 34 (29 3) 8(6 9) Performance status (WHO) 0-1 2-3 4 Unknown 322(69 7) 113(24 5) 2(0 4) 32(5.4) 107(92 2) 9(7 8) 0(0) 0(0) Primary advanced disease First relapse after primary disease Second relapse after primary disease Unknown 47(10 0) 233(49 7) 182(38 8) 7(1 5) 6(5 1) 79(68 1) 30 (25 9) 1(0 9) Age <46 46-52 53-58 >58 118(25 108(23 125(26 118(25 33(28 32(27 34 (29 17(14 Characteristics 1) 1) 7) 1) Patients available for 4) 6) 3) 7) DFI (months), median (range) 21 (0-343) 21 (0-268) TTE (months), median (range) 30(0-376) 25(0-284) Abbreviations ER - oestrogen receptor status, DFI time from the primary diagnosis to first recurrence, TTE - time from the primary diagnosis to the initiation of treatment with epirubicin ° Some patients have more than one treatment modality keep it in the model Interaction among these variables, e g , age and ER status was investigated The proportionality assumption was checked by log minus log plots The database and the statistical analyses were handled by the computer programme SPSS 90 for Windows (Statistical Solutions limited, Cork, Ireland) Ethics All the patients entered in the treatment trials gave oral and written informed consent to treatment and to the use of personal data for research purposes 83 Table 2 Distribution of individual sites, number of sites, LDH, and age in DBD pauenis Variables Factor Patients available for prognostic index n (%) Patients available for validation n (%) Individual site Liver Lung Pleura Bone Bone marrow Soft tissue Lymph node Contralateral breast CNS Other sites" 111(23 7) 113(24 1) 70(14 9) 248 (52 9) 80(17 1) 106(22 6) 179(39 0) 26(5 5) 7(2 0) 29 (6 2) 26 (22 2) 26 (22 2) 7 (6 0) 49 (41 9) 14 (12 0) 26 6 (22 2) 61 (52 1) 11 (9 4) 0 (0) 4 (3 4) Number of sites One site 161 (34 3) 54 (46 6) 152(32 4) 87(18 6) 42 (9 0) 27(5 8) 32 18 10 2 (27 5) (15 5) (8 6) (18) 249(53 1) 111 (23 7) 69(14 7) 40 (8 5) 83 17 13 3 (71 5) (14 6) (112) (2 6) Two sites Three sites Four or more sites One or more sites unknown LDH Normal (4450 U/l) 451-900 U/l >900U/1 Missing Table 3 The final Cox model with 469 patients " Other sites abdominal sites except the liver Results The data of 469 patients with advanced breast cancer were used in the survival analysis Table 2 shows the distribution of individual metastatic site(s), the number of sites, LDH, and age. The median survival time for all 469 patients was 14.7 months (range 0-122.3 months) with a median follow-up time of 76.3 months (range 0-122.3 months). The series included 14 patients younger than 35 years of age. Median survival in this subset of patients was 13.7 months. Liver metastases were more frequent (37.7%) among these patients, while metastases to other sites occurred with same incidence as in the entire series. Coefficient Coeff/SE" P-value Relative i lsk Soft tissue Lung Pleura Liver Bone PS S-LDH Age ER-negative ER-unknown 0444 0 363 0 542 3 35 2 86 3 58 < 0 002 0004 <0001 ~ n fin i £T) 1 AQ 3 Hy < U UU 1 0 362 0 377 0 580 0 185 0 527 0 544 2 83 2 69 6 89 3 70 3 35 4 47 <0 001 <0 009 <000l <0001 <0 002 <0001 ft U bZZ 56 44 72 oO 39 46 79 20 69 72 ° The Cox regression coefficient = coefficient/standard error Table 4 Calculation of score for prognostic factors Factor Score Soft tissue Lung Pleura Liver Bone PS (0-1 vs 2-4) LDH (450-900 vs normal) LDH ( > 9 0 0 v s normal) Age (years) 46-52 53-58 >58 ER-negative ER-unknown 4 4 5 6 4 4 6 12 2 4 6 5 5 " Score the regression coefficient x 10, rounded off to the nearest integer, maximum score = 50 example, the hazard rate for early compared to late relapse was 1.15, P = 0.22. The variables, lymph node status and tumour size, were excluded from the final Cox model, because data were only available on 288 patients. A separate analysis, however, was carried out on the data from the 228 patients, and this showed a significant influence of > 4 positive lymph nodes (RR = 1.35, P = 0.02) The final Cox model is presented in Table 3. Cox multivariate analysis Prognostic index Individual metastastic sites such as the skin, pleura, liver, and bone, had a significant negative impact on survival (Table 3) There was no major correlation between impacts of lung and pleura metastases (r = -0.10). The influence of bone marrow was correlated to that of S-LDH, and therefore bone marrow was not kept in the final Cox model. Preclinical variables such as S-LDH, age, and PS had an influence on survival (Table 3) Variables, such as number of metastastic sites, anaemia, adjuvant chemotherapy, adjuvant irradiation, relapse number (first vs. subsequent), TTE, and DFI, did not have a significant influence on survival. For DFI, for Each prognostic factor was assigned a score defined as the rounded off value of the Cox regression coefficient x 10 (Table 4). This enabled us to calculate a patient's personal prognostic score. For instance, a young patient ( < 4 6 years of age) with an ER-pos tumour, normal S-LDH, good PS, whose relapse was not located in skin, lung, pleura, liver or bones would score 0 for all factors in Table 4, the sum score would be 0, and the patient would represent the most favourable category in this series. When the sum score is applied as a prognostic index (PI) it can deduced from Table 4 that a similar patient with skin and liver metastases would have a PI of 84 Table 5 Distribution of 585 patients with metastatic breast cancer into risk groups and their corresponding PI, median, one-, two, and five-year survival Risk groups Series Number of patients (%) Median survival (months) One-year survival (%) Two-year survival (%) Five-year survival (%) 0-10 Old New 113(29) 21(19) 34 32 87 90 63 67 26 23 Intermediate 1 11-15 Old New 95(25) 38(34) 19 28 68 76 34 52 6 22 Intermediate II 16-22 Old New 86(22) 38 (33) 12 18 51 71 17 35 0 5 Poor >22 Old New 95(24) 16(14) 19 31 4 13 1 0 Good PI score" 70 57 " PI score the individual prognostic sum score (seeTable 4) 10. The maximum sum in this system is 50, although 44 was the highest value found Risk groups The patients were categorised into one of the four risk groups: good, intermediate I, intermediate II, or poor according to their PI (Table 5). The PI ranges were 0-10 for good; 11-15 for intermediate I; 15-22 intermediate II; and > 22 for poor The median and five-years survival; were good (113 patients)' 34 months and 26%, intermediate I group (95 patients): 19 months and 6%; intermediate II (86 patients) 12 months and 0%; and poor (95 patients) 7 months and 1% (Table 5). New series A new series consisted of 116 patients. The median survival was 20 6 months (range 0-85.5 months) and the median follow-up time was 74.8 months (range 0-85.5 months). No patient was younger than 35 years. One hundred thirteen patients were available for a survival analysis based on the PI score. All metastastic sites necessary for the PI score were represented and the incidence rates were similar to those in the original series The median and five-years survival, were good (21 patients): 32 months and 23%; intermediate I (38 patients)- 29 months and 22%; intermediate II (38 patients): 18 months and 5%, and poor (16 patients) 6 months and 0% The survival data were similar to that of the old series in the good and poor risk groups, but differed considerably in the intermediate groups I + II (Table 5). The Kaplan-Meier survival plots for the four risk groups in both series are given in Figure la and b Discussion Studies on prognostic factors in patients with metastatic breast cancer vary considerably with respect to the selection of patients, availability of clinical parameters, and methods of analysis. Differences in patient selection is momentous, when the results of different multivanate analyses are to be interpreted. Definition of risk groups is only appropriate, if patients are selected on similar criteria [16] Some studies, like ours, enter any patient with metastatic breast cancer selected for treatment with chemotherapy [3, 7, 9, 10], other studies enter patients only at first recurrence [2, 5, 8, 12]. One study solely concerns first-relapse patients earlier treated with adjuvant chemotherapy. One must assume, that such patients have a poor prognosis compared to that of others, because the disease is more aggressive at the time of diagnosis [6]. Information about the location of metastatic sites varies considerably. Some specify the location of the metastases to liver, lung, etc. [5, 7, 10], whereas others classify the metastases for instance in 'classical dominant sites', which include three groups: 1) visceral dominant sites (liver, lung, brain, pleura or pleural effusion); 2) bone, and 3) soft tissue dominant site; (local skin, distant skin, subcutaneous masses, and lymph nodes) [2, 3]. Details are lost, when a variable comprises many different locations, and the contribution from a specific metastatic site therefore tends to be overridden by the less informative variables included in 'classical dominant sites'. Consequently, each individual site must be considered separately in the analysis, thereby permitting the role of interactions between variables to be investigated. In the present study, we analysed the influence of different metastatic sites and found that liver, lung, pleural, bone and soft tissue metastases had negative impact. Liver metastases have been identified as a prognostic factor by many authors [3, 5, 8-10], whereas this could not be confirmed by Hortobagyi et al. [7]. However, alkaline phosphatase, S-LDH, and extension of disease were analysed together with liver metastases, and interactions between these four factors may have influenced the outcome of the analysis [7]. Lung metastases as a prognostic factor was proved by Clark et al. and Hortobagyi et al. [5, 7]. When lung, liver and pleural metastases were all comprised in the variable 'visceral dominant site', they became a strong negative prognostic factor [2, 5] Bone metastases were identified 85 (a) Percent surviving 100 50 Old Good New Good 1 (b) 100 2 3 4 5 9 10 Years 6 Percent surviving 50 \ \ Old Inter II 1 New Inter II "L ; -L New Inter 1 . Old Inter 1 1 Years Figure 1 (a) Kaplan-Meier survival plot The survival for boths series in the good and the poor groups, x-axis percentage of patients alive, y-axis survival in years, the old series, the new series (b) Kaplan-Meier survival plot The survival for boths series in the intermediate 1 + II groups, X-axis percentage of patients alive, Y-axis survival in years, the old series intermediate I and intermediate II, the new series intermediate I and intermediate II as a prognostic factor in the study by Clark et al. [5]. A negative impact of soft tissue metastases in patients being treated with chemotherapy has been demonstrated by other authors [2, 9]. Conversely, metastases solely confined to soft tissue as the first recurrence is not a significant negative prognostic factor [5, 8]. Abnormally increased pretreatment S-LDH was the strongest single prognostic factor in our study, although there was interactions with both liver and bone metastases. This findings has been confirmed by other authors [7, 10, 17]. Furthermore, several authors have demonstrated that a high tumor burden was associated with a short survival [3, 7, 18, 19]. In the present study only the amount of metastatic sites were included, not a measurement of the patients tumour mass. A PS > 2 at the initiation of chemotherapy resulted in a significantly decreased survival, as has also been observed by two other authors [7, 10], although PS was only included in univariate analysis in the study of Yamamoto et al. [10]. The present study restricts the considerations to a cohort of patients aged less than 74 years, however, advancing age at the time of initiation of chemotherapy was a prognostic factor. This has been confirmed in a further three studies [10-12, 18], but not in others [3, 7]. Because of the lack of patients with age under 35 years we were not able to individualise the prognostics for these young patients as done by the study ofFalkson[20]. The prognostic impact of the disease-free interval is still under discussion. The definitions of DFI, patient selection criteria and methods to estimate the survival rate are essential for this discussion. Are patients with primary advanced disease included or not? It is reasonable to assume that patients with primary advanced disease have a more aggressive disease than other patients. Furthermore, the proportions of patients with first vs later relapse should be given. In our study, we omitted patients with primary advanced disease in the analysis of DFI and 38.8% had second relapse. The DFI was not significant in the final multivariate analysis, as was also found by other authors, who used a similar definition of DFI and patient selection criteria [7, 9] DFI was identified as a strong prognostic factor in the study of Yamamoto et al. However, they included patients with primary advanced disease. Furthermore, there was no information about the number of relapses. In that study, a group of patients was used to confirm the strong influences of the duration of DFI, but the estimation of survival was not the same in the Cox series and the validation series. Survival was estimated from the day of randomisation in the Cox analysis but from the date of first relapse in the validations series [10]. However, the duration of DFI may carry some basic biological information, provided that the DFI is defined solely as the time to the first recurrence In studies which entered patients only at their first relapse, DFI was significant in three multivariate analyses [2, 6, 8] and in one univariate analysis [9]. We also examined the prognostic impact TTE and found that TTE < 3 years was associated with a poor survival in the univariate analysis, but insignificant in the final Cox model. Prior adjuvant chemotherapy was a prognostic factor in our univariate analysis, but became insignificant when the primary stage was included in the Cox multivariate analysis, an observation also done by others [3, 5]. In three studies adjuvant chemotherapy was a significant prognostic factor after relapse in a multivariate analysis [3, 9, 10]. However, the primary stage was not included in two of these [3, 9], and the type of adjuvant treatment and clinical characteristics of the patients were missing in the third [10]. The proportion of patients receiving adjuvant chemotherapy was 74% in the Yamamoto study as compared to 36.7% in ours [10]. Treatment related infections and cardiotoxicity had no impact on 86 the survival [21]. The influence of dose schedules, dose intensity, response rates and second/third-line chemotherapy were not evaluated. The impact of these factors on survival is going to be investigated. A prognostic index can be used to allocate patients into risk groups We defined four risk groups: good (score ^ 10) with a median survival of 34 months and a five-year survival of 26%; intermediate I (score 11-15) with a median survival of 19 months and a five-year survival of 6.0%, intermediate II (score 16-22) with a median survival of 12 months and a five-year survival of 0%; and poor (score > 22) with a median survival of 7 months and a five-year survival of about 1% In the new applicability series, the survival data were similar in the good and the poor groups, but not in the intermediate groups I + II, where the survival figures were better The reason could be staging of patients with a more sensitive procedure in the new series and/or the result of a more effective treatment. Other studies have defined risk groups with similar survival in the groups [4, 10]. Thus, Yamamoto et al. defined three risk groups with a median duration of survival: 45.5 months, 24.6 months and 10.6 months [10]. Rahman et al. investigated patients complying with the institution's eligibility criteria (normal S-LDH, PS 0-1, and younger age) for high-dose chemotherapy with stem-cell rescue [4]. These patients had a median survival of 30 months and a fiveyear survival rate of 21%, when treated with conventional doxorubicin. From a clinical point of view, it is important to be aware of the substantial difference in the survival between good and poor risk patients Patients with no or few negative prognostic factors have a long median survival of 3-3.5 years, which is probably longer than usually expected in patients with metastatic breast cancer given conventional chemotherapy. We therefore suggest the use of a prognostic index comprising all the influential prognostic variables and the application of their regression coefficients as weighting factors, in order to give us a more balanced view of the outlook for patients Conclusions The present study has substantiated, that a number of prognostic factors, and not just one factor, is predictive for the survival of patients treated with epirubicin for metastatic breast cancer. The construction of a scoring system, allows us to characterise risk groups with a considerable difference in median survival and a quite dramatic difference in long-term survival rates, especially between the good and the poor risk patients We recommend the use of these risk categories for pre-treatment stratification in randomised trials, but must at the same time warn against comparison of results derived from different clinical trials or from trials undertaken in different periods of time at the same institution. Acknowledgements This work was supported by a grant from the foundation of Elly Valborg and Niels Mikkelsen The authors are grateful to K. Kjaer and H. Larsen, MD, for their excellent technical assistance References 1 Tormey DC Adnamycin (NSC-123 127) in breast cancer An overview of studies Cancer Chemother Rep 1975, 6 319-27 2 Vogel CL, Azevedo S, Hilsenbeck S et al Survival after first recurrence of breast cancer Cancer 1992, 70 129-35 3 Falkson G, Gelman R, Falkson CI et al Factors predicting for response, time to treatment failure, and survival in women with metastastic breast cancer treated with DAVTH A prospective Eastern Cooperative Oncology Group study J Clin Oncol 1991, 9 2153-61 4 Rahman ZU, Frye DK, Budzar AU et al. 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Falkson G, Gelman RS, Pretonus FJ Age as a prognostic factor in recurent breast cancer J Clin Oncol 1986, 4 663-71 21 Ryberg M, Nielsen D, Skovsgaard Tet al Epirubicin cardiotoxlcity An analysis of 469 patients with metastatic breast cancer J Clin Oncol 1998, 16 3502-8 Received 4 April 2000, accepted 25 September 2000 Correspondence lo M Ryberg, MD Department of Oncology Herlev Hospital, University of Copenhagen Herlev Ringvej DK-2730 Herlev Denmark E-mail mananneryberg@dadlnet dk
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