Differences in risk factors for local and distant recurrence after breast-conserving therapy or mastectomy for stage I and II breast cancer: pooled results of two large European randomized trials.

PURPOSE: Risk factors for local and distant recurrence after breast-conserving therapy and mastectomy were compared to define guidelines for the decision making between both treatments. PATIENTS AND METHODS: The data of two randomized clinical trials for stage I and II breast cancer patients were pooled. The total number of patients in the study was 1,772, of whom 879 underwent breast conservation, and 893, modified radical mastectomy. Representative slides of the primary tumor were available for histopathologic review in 1,610 cases (91%). RESULTS: There were 79 patients with local recurrence after breast-conservation and 80 after mastectomy, the 10-year rates being 10% (95% confidence interval [CI], 8% to 13%) and 9% (95% CI, 7% to 12%), respectively. Age no more than 35 years (compared with age >60: hazard ratio [HR], 9.24; 95% CI, 3.74 to 22.81) and an extensive intraductal component (HR, 2.52; 95% CI, 1.26 to 5.00) were significantly associated with an increased risk of local recurrence after breast-conserving therapy. Vascular invasion was predictive of the risk of local recurrence, irrespective of the type of primary treatment (P <.01). Tumor size, nodal status, high histologic grade, and vascular invasion were all highly significant predictors of distant disease after breast-conserving therapy and mastectomy (P <.01). Age no more than 35 years and microscopic involvement of the excision margin were additional independent predictors of distant disease after breast-conserving therapy (P <.01). CONCLUSION: Age no more than 35 years and the presence of an extensive intraductal component are associated with an increased risk of local recurrence after breast-conserving therapy. Vascular invasion causes a higher risk of local recurrence after mastectomy as well as after breast-conserving therapy and should therefore not be used for deciding between the two treatments.

Variations in prognostic factors in primary breast cancer throughout the menstrual cycle.

AIMS: We investigated whether menstrual cycle dependent variations in prognostic factors are detectable in malignant breast tissue. METHODS: Since 1977 the Danish Breast Cancer Cooperative Group has collected population-based information about primary clinical data, treatment regimens and follow-up status on Danish women with breast cancer. Information about last menstrual periods prior to surgery was obtained from files recorded at the time of admission for primary surgery. Included in this study were 1060 patients self-reported to be regularly menstruating and with a menstrual period within 6 weeks of surgery and who were operated in a single-step procedure. None of the patients were current users of exogenous hormones at the time of surgery. Variations of prognostic factors throughout the menstrual cycle were evaluated. RESULTS: Overall, no significant correlation between endogenous hormone fluctuations and oestrogen receptor (ER) status and progesterone receptor (PgR) status were found. Furthermore, we observed no cycle-dependent variation for mitotic index, lymph node involvement or tumour size. CONCLUSIONS: The classical prognostic factors in breast cancer did not differ significantly throughout the menstrual cycle in the present study.

Prognosis after treatment for loco-regional recurrence after mastectomy or breast conserving therapy in two randomised trials (EORTC 10801 and DBCG-82TM). EORTC Breast Cancer Cooperative Group and the Danish Breast Cancer Cooperative Group.

The aim of this study was to investigate and compare the prognosis after treatment for loco-regional recurrences (LR) after (modified) radical mastectomy (MRM) or breast conserving therapy (BCT), in terms of overall survival and time to subsequent LR, in patients originally treated in two European randomised trials. In EORTC trial 10801 and DBCG trial 82-TM, 1,807 patients with stage I and II breast cancer were randomised to receive MRM or BCT from 1980 to 1989. All patients with a LR in these trials were analysed for survival and time to subsequent LR after salvage treatment. Of these, 133 patients had their LR as a first event, the majority within 5 years after initial treatment. The prognostic significance for survival and time to subsequent LR after salvage treatment was analysed in uni-, and multivariate analyses for a number of original tumour- and recurrence-related variables. After salvage treatment of LR after MRM or BCT, actuarial survival curves and the actuarial locoregional control curves were similar. The 5-year survival rates were 58% and 59% and the 5-year subsequent loco-regional control rates 62% and 63%, respectively. In a multivariate analysis, pN category (P = 0.03), pT category (P = 0.01) and vascular invasion (P = 0.02) of the primary tumour were the only independent prognostic factors for survival, whereas extensive LR (P < 0.001), interval < or = 2 years (P < 0.002) and pN+ at primary treatment (P = 0.004) were significant predictive factors for time to subsequent LR. The type of original treatment (MRM or BCT) did not have any prognostic impact. It is concluded that the survival and time to subsequent LR after treatment for an early loco-regional recurrence after MRM or BCT was similar in these two European randomised trials. This suggests that both after MRM and BCT an early LR is an indicator of a biologically aggressive tumour; early loco-regional relapse carries a poor prognosis and salvage treatment only cures a limited number of patients, whether treated by MRM or BCT originally.

Parity, age at first childbirth and the prognosis of primary breast cancer.

Reproductive factors are known to be aetiologically important in breast cancer, but less is known regarding their effect on breast cancer prognosis. We have investigated the prognostic effect of age at first birth and total parity using data from the Danish Breast Cancer Cooperative Group that, since 1977, has collected population-based information on tumour characteristics, treatment regimes and follow-up status on Danish women with breast cancer. Details of pregnancy history were added from the Danish Civil Registration System and the National Birth Registry. Included in the study were 10,703 women with primary breast cancer. After adjusting for age and stage of disease (tumour size, axillary nodal status and histological grading), the number of full-term pregnancies was found without prognostic value. However, women with primary childbirth between 20 and 29 years experienced a significantly reduced risk of death compared with women with primary childbirth below the age of 20 years [20-24 years: relative risk (RR) = 0.88, 95% confidence interval (CI) 0.78-0.99; 25-29 years: RR = 0.80, 95% CI 0.70-0.91]. Further adjustment for oestrogen receptor status did not influence these results. The effect was not modified by age at diagnosis, tumour size or nodal status. In conclusion, low age at first childbirth, but not parity, was associated with a poor prognosis of breast cancer. We speculate whether women who develop breast cancer despite an early first full-term pregnancy might represent a selected group with a more malignant disease.

Time since childbirth and prognosis in primary breast cancer: population based study.

OBJECTIVE: To investigate whether time since birth of last child was of prognostic importance in women with primary breast cancer. DESIGN: Retrospective cohort study based on a population based database of breast cancer diagnoses with detailed information on tumour characteristics, treatment regimens, reproductive factors, and vital status. SETTING: Denmark. SUBJECTS: 5652 women with primary breast cancer aged 45 years or less at the time of diagnosis. MAIN OUTCOME MEASURES: 5 and 10 year survival; relative risk of dying. RESULTS: Women diagnosed in the first 2 years after last childbirth had a crude 5 year survival of 58.7% and 10 year survival of 46.1% compared with 78.4% and 66.0% for women whose last childbirth was more than 2 years before their diagnosis. After adjustment for age, reproductive factors, and stage of disease (tumour size, axillary nodal status, and histological grading), a diagnosis sooner than 2 years since last childbirth was significantly associated with a poor survival (relative risk 1.58, 95% confidence interval 1.24 to 2.02) compared with women who gave birth more than 5 years previously. Further analyses showed that the effect was not modified by age at diagnosis, tumour size, and nodal status. CONCLUSIONS: A diagnosis of breast cancer less than 2 years after having given birth is associated with a particularly poor survival irrespective of the stage of disease at debut. Therefore, a recent pregnancy should be regarded as a negative prognostic factor and should be considered in counselling these patients and in the decisions regarding adjuvant treatment.

Quality control of end results in a Danish adjuvant breast cancer multi-center study.

In a Danish multi-center study, quality control was performed on off-study data for high-risk breast cancer patients included in protocols of adjuvant therapy. In the two protocols 4455 patients were randomized and 2477 were registered off-study. Data from these patients were validated by reviewing the patients' records. Incorrect data were observed in 16.2% of the cases who went off-study due to recurrence, other malignant disease or death. In 258 of 2133 patients unidentical locations were demonstrated. Of these, 104 showed a time difference also. A major difference in site of recurrence was found in 107 patients (5.0%), 43 of whom were upstaged from local to a distant recurrence and 64 were downstaged. A time difference of more than 30 days was found in 192 patients (9.0%) and in 17 the difference exceeded 366 days. A time difference only was found in 88 patients (4%). The major parameter in the statistical analysis of the two protocols, i.e. recurrence-free survival, was not significantly influenced by the validation.

Clinical trials.

The randomized clinical trial is a scientific method for solving clinical problems. The method is typically employed before a new type of treatment is offered on a major scale in order to safeguard patients against a less curative therapy. Especially with regard to cancer treatment, randomized studies are conducted in increasing numbers. However, there remains a considerable discrepancy between the actual number of patients entered in randomized trials and the eligible number available. The demand of obtaining informed consent is a major reason for not entering patients into randomized studies. The critical item is whether information about randomization as a method for allocation should be disclosed to the patient. The doctor feels embarrassed not to be able to advise and support the patient in decision making about treatment and finds his or her role as the caring doctor replaced by the roulette. The requirement to seek informed consent has increased the rate of denial to participate in randomized trials from a few percent, up to about 50% or even higher.

Femoral fractures in postmenopausal breast cancer patients treated with adjuvant tamoxifen.

The anti-estrogen tamoxifen is the prevalent endocrine treatment in postmenopausal breast cancer patients. However, nothing is known about the long-term effects of the drug on the skeleton as assessed by the occurrence of fractures. We investigated the occurrence of fractures of the femur in patients from a Danish Breast Cancer Cooperative Group (DBCG) trial initiated in 1977 by a linkage of data from the Danish National Registry of Patients with data from the DBCG registry. 1716 postmenopausal women with high-risk breast cancer were randomized to local radiotherapy with or without tamoxifen, 30 mg daily for 1 year. Fifty-one patients in the control group had one femoral fracture and 64 tamoxifen treated patients had one femoral fracture. Eleven patients in the control group had one trochanteric fracture compared to 27 patients in the tamoxifen group (logrank = 5.28. P = 0.022; hazard ratio = 2.12, 95% CL 1.12, 4.01). The results could not be explained by a longer survival in the tamoxifen group nor by bone metastases with pathological fractures. In conclusion, our study suggests that tamoxifen does not seem to offer protection against fractures in old age and may even increase the risk of fractures at particular sites. This hypothesis needs to be disproved or confirmed in other trials.

[Menstrual cycle and surgery of breast cancer. Point of time for the surgery of primary breast cancer in connection with menstrual cycle is without prognostic significance]. / Menstruationscyklus og operation for mammacancer. Tidspunktet for operation for primoer mammacancer i forhold til menstruationscyklus er uden prognostisk betydning.

From 1977 to 1989 6488 patients under fifty years with primary breast cancer were registered in the nationwide Danish Breast Cancer Cooperative Group (DBCG). Among these information on last menstrual period prior to surgery was available in 1635 cases which constitute the study group of the present analysis. The group was representative of the total group with regard to prognostic factors and survival. In the study group time of surgery in relation to last menstrual period was found to have no influence on five- and ten year survival.

[Mammographic examinations in Denmark, 1990-1991]. / Mammografiundersøgelser i Danmark, 1990-1991.

Diagnostic mammographic activity was studied in five regions in Denmark in 1990-1991. During this period there was only one organized mammography screening programme which started in the Copenhagen municipality on 1 April 1991. It is estimated that 49,000 diagnostic mammographic examinations were made in Denmark per year in the period 1990-1991. Almost two-thirds of these mammograms were taken in women below 50 years of age. It is important to monitor the diagnostic mammographic activity to ensure that this does not gradually develop into a screening activity. This is in particular important for women below 50 years for whom screening is not recommended.

[Improved prognosis of breast cancer]. / Prognoseforbedring for brystkraeft.

The trend in the prognosis of female patients with breast cancer has been investigated by comparing Kaplan-Meier survival curves of different patient cohorts diagnosed during the period 1948-87. The study is based on 71,448 patients from the Danish Cancer Registry. The cohorts were defined by age at diagnosis, year of diagnosis and residential area. The survival time from diagnosis to death nearly doubled from 1948-57 to 1978-87 with the most important improvement taking place after 1978. Patients diagnosed in 1948-77 in the Copenhagen area had a far better prognosis than patients during this period in the rest of the country. For patients diagnosed in 1978-87 the prognosis, however, reached an equal level in all parts of the country. Thus, it is reasonable to assume that the national programme introduced in 1977 by the Danish Breast Cancer Cooperative Group (DBCG) has played an important role in these improvements.

Timing of surgery in relation to menstrual cycle does not predict the prognosis in primary breast cancer. Danish Breast Cancer Cooperative Group.

From 1977 to 1989 6488 patients under 50 years with primary breast cancer were registered in the nationwide Danish Breast Cancer Cooperative Group (DBCG). Among these, information on last menstrual period prior to surgery was available in 1635 cases which constitute the study group of the present analysis. The group was representative of all women operated upon during the period with regard to prognostic factors and survival. In the study group time of surgery in relation to last menstrual period was found to have no influence on 5 and 10 years survival.

Regional trends in breast cancer incidence and mortality in Denmark prior to mammographic screening.

To provide a basis for the evaluation of mammographic screening programmes in Denmark, a study was undertaken of the regional differences in breast cancer incidence and mortality. All 16 regions were followed for the 20 year period, 1970-89, before the start of the first population-based mammographic screening programme in the Copenhagen municipality in 1991. Multiplicative Poisson models were used for the analysis. In general, the incidence increased during this period from 55 to 70 [per 100,000 standardised world standard population (WSP)], and the analysis shows this to be most pronounced among women below age 60. The mortality was more stable, changing only from 24 to 28 (per 100,000 standardised WSP), but a significant increase occurred in the late 1980s. The study showed regional differences in both incidence and mortality of breast cancer in Denmark. Both the incidence and the mortality varied between the regions, with maximum differences of 22%. The analysis showed no variation in the time trends in the different regions, and thus indicates that the use of a regional comparison group would be a valid basis for evaluation of the Copenhagen programme. Our study, however, underlies the difficulties inherent in the evaluation of screening programmes without internal control groups.

Equity and improvement in outcome of breast cancer in Denmark.

The trend in the prognosis for female breast cancer patients was investigated by comparing Kaplan-Meier survival curves of different patient cohorts diagnosed during the period 1948-87. The study is based on 71,448 patients from the Danish Cancer Registry. The cohorts were defined by age at diagnosis, year of diagnosis, and residential area. The survival time from diagnosis nearly doubled from 1948-57 to 1978-87, the most important improvement taking place after 1978. Patients diagnosed in 1948-77 in the Copenhagen area had a far better prognosis than patients diagnosed during this period in other parts of Denmark. For patients diagnosed in 1978-87 the prognosis, however, reached an equal level in all parts of the country. Thus, it is reasonable to assume that the national programme introduced in 1977 by the Danish Breast Cancer Cooperative Group (DBCG) has played an important role and not only brought about therapeutic improvements in breast cancer treatment in Denmark, but also ensured equity in the outcome on a national scale.

Classical prognostic factors in node-negative breast cancer: the DBCG experience.

Classical prognostic factors were analyzed in patients with low-risk primary breast cancer, defined as absence of tumor-positive axillary lymph nodes, tumor size less than or equal to 5 cm in diameter, and no invasion into skin or deep fascia. The primary surgical treatment was total mastectomy and lower axillary dissection. None of the patients received adjuvant therapy. Between 1977 and 1990, 7315 patients entered the study, and at the time of this analysis (January 1, 1990), the median follow-up time is 5 years. In univariate analyses, the following variables were significantly related to recurrence-free survival: age in premenopausal patients; tumor size; number of negative nodes removed; histological grade; and in premenopausal patients, estrogen receptor and progesterone (PgR) status. In multivariate analyses, age in premenopausal patients was the most important factor, followed by tumor size and histological grade, whereas PgR status in premenopausal patients was just of borderline significance. These variables should be included in multivariate analyses testing the value of more recently introduced prognostic factors.

Danish randomized trial comparing breast conservation therapy with mastectomy: six years of life-table analysis. Danish Breast Cancer Cooperative Group.

The Danish Breast Cancer Cooperative Group (DBCG) conducted a randomized trial comparing breast conservation with mastectomy in patients with invasive mammary carcinoma. From January 1983 to March 1989, the trial accrued a total of 1153 women. Of this number, 905 patients (79%) were randomly assigned to one of the two treatment options, whereas 248 patients (21%) did not accept randomization. Of the randomly assigned patients, 90% received the surgical option to which they had been originally assigned. In the breast conservation arm the tumor was excised with the intention of obtaining free margins determined at gross examination, and radiotherapy was subsequently administered to residual breast tissue. The axilla was dissected in all instances. Patient and tumor characteristics were similar in the two randomization arms. The median follow-up time was 40 months. At 6 years of life-table analysis the probability of recurrence-free survival was 70% in the breast conservation arm against 66% in the mastectomy arm. Survival figures were 79% against 82%, respectively.

[Rationalization profits of radiographic diagnosis with systematic follow-up DBCG (Danish Breast Cancer Cooperative Group) programs. 1]. / Rationaliseringsgevinster inden for billeddiagnostik ved systematiske opfølgningsprogrammer i DBCG's regi. 1.

In the follow-up programme of the DBCG-77 control and treatment protocols for primary operable breast cancer, bone scintigraphy and chest X-ray were performed 6 months after surgery and thereafter yearly until the diagnosis of any recurrence or another cancer. In the present study, the value of the two examinations was examined to the 6th year control. As a result of a low incidence of primary recurrence to the bone (0.6-3.9%) and to the chest (0.0-3.0%) the value was found to be low. About two thirds of the patients with primary chest recurrence addressed themselves with or had at the time of control pulmonary symptoms. About one half of those patients, in whom (during a 12-month period after the scheduled bone scintigraphy) bone metastases were diagnosed by another method, had a normal scheduled bone scintigraphy. False positive changes were not infrequent, especially at the bone scintigraphies. The diagnosis of asymptomatic chest recurrence did not reduce the mortality among stage II patients, among whom the greatest value of the control examination was found. It is concluded, that systematic use of bone scintigraphy and chest X-ray is not justified in a follow-up programme for stage I and II breast cancer patients.

[Prognosis after surgical treatment of breast cancer. 3. The low-risk group of the DBCG (Danish Breast Cancer Cooperative Group)]. / Prognosen efter kirurgisk behandling af cancer mammae. 3. DBCG's lavrisikogruppe.

The two therapeutic protocols of The Danish Breast Cancer Cooperative Group (DBCG) DBCG 77a (1977-1982) and 82a (1982-1990) comprise patients who were classified as low risk patients after operation for cancer of the breast, a total of 7,315 women. Treatment consisted of mastectomy and dissection of the lower and middle axillary levels. The median period of observation for DBCG 77a was 9 1/2 years and for DBCG 82a 3 1/3 years. The curves for recurrence-free survival and survival were found to be congruent in the two protocols. The recurrence-free survival after five years was 70% and 55% after ten years. Survival was 87% after five years and 70% after ten years. Local recurrence developed in 12.7% and 1.1% had distant recurrences simultaneously. Local recurrence was distributed with 60% in the scar or thoracic wall, 33% in the axilla and 7% in the clavicular lymph nodes. Distant recurrence alone developed in 11.4%. The time curves for development of local or distant recurrences were practically congruent. Local recurrence developed in 3.8% of the patients per annum during the first four years and after that in 1.5% per annum. Distant recurrence was found in 3.5% per annum in the first four years and after that in 1.8% per annum. The survival was significantly different after local and distant recurrence. Patients with tumours of grade 1 anaplasia had better prognoses than patient with grade 2 og 3 tumours as regards recurrence-free survival and survival. Multivariate analysis revealed that age under 40 years and anaplasia grad were significant prognostic variables for the parameters: distant recurrence and local recurrence. In addition, the number of lymph nodes in the operation specimen was a prognostic variable for local recurrence.

[Adjuvant endocrine treatment of postmenopausal patients with breast cancer with high risk of recurrence. 5. Results from the DBCG (Danish Breast Cancer Cooperative Group) 77C randomized trial]. / Adjuverende endokrin behandling af postmenopausale brystkraeftpatienter med høj risiko for recidiv. 5. Resultater fra DBCG 77C, en randomiseret undersøgelse.

The role of antiestrogen treatment of postmenopausal breast cancer patients with high risk of recurrent disease is evaluated in a nationwide, prospective trial conducted by the Danish Breast Cancer Cooperative Group (DBCG). After total mastectomy and postoperative radiotherapy (RT), 840 patients were randomized to treatment with tamoxifen (RT + TAM) for one year, and 824 were randomized to no further therapy (RT). The recurrenceree survival (RFS) after ten years of lifeable analysis is 31% in the RT + TAM treated group, and 28% in the RT group (p = 0.01). Survival is 38% and 34% in the two treatment groups, respectively (p = 0.04). The data were further analyzed with respect to prognostic factors such as age, number of positive nodes, tumour size, and degree of anaplasia. Survival is prolonged in nearly all subgroups of patients treated with RT + TAM. However, the prolongation is only significant in patients with four or more positive nodes, with tumours of less than 5 centimeters or with tumours of anaplasia grade II. Estrogen (ER) and progesterone receptor (PgR) concentrations were measured in tumours from 309 and 219 patients, respectively. Only patients with ER and PgR values above 100 fmol/mg cytosol protein seemed to have a prolongation of survival. In conclusion, a modest survival benefit is achieved with one year of adjuvant tamoxifen treatment. Nevertheless, this is the first example of a systemic treatment approach being able to change the fatal course of breast cancer in postmenopausal patients. By means of endocrine therapy, and in the context of a new randomized trial, the DBCG will try to improve the survival in these patients even further.