Adjuvant systemic therapy in high-risk breast cancer: the Danish Breast Cancer Cooperative Group's trials of cyclophosphamide or CMF in premenopausal and tamoxifen in postmenopausal patients

Tamoxifen and oxidative stress: an overlooked connection

Tamoxifen is the gold standard drug for the treatment of breast cancer in pre and post-menopausal women. Its journey from a failing contraceptive to a blockbuster is an example of pharmaceutical innovation challenges. Tamoxifen has a wide range of pharmacological activities; a drug that was initially thought to work via a simple Estrogen receptor (ER) mechanism was proven to mediate its activity through several non-ER mechanisms. Here in we review the previous literature describing ER and non-ER targets of tamoxifen, we highlighted the overlooked connection between tamoxifen, tamoxifen apoptotic effects and oxidative stress.

Adjuvant chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil, vincristine, and prednisone compared with single-agent L-phenylalanine mustard for patients with operable breast carcinoma and positive axillary lymph nodes: 20-year results of a Southwest Oncology Group study

BACKGROUND

Adjuvant combination chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil plus vincristine and prednisone (CMFVP) was compared with single-agent L-phenylalanine mustard (L-PAM) for the treatment of patients with axillary lymph node positive primary breast carcinoma over 20-years of follow-up.

METHODS

Four hundred forty-one women with axillary lymph node positive breast carcinoma were randomized to receive either combination chemotherapy with cyclophosphamide (60 mg/m(2) orally every day for 1 year), fluorouracil (300 mg/m(2) intravenously [IV] weekly for 1 year), methotrexate (15 mg/m(2) IV weekly for 1 year), vincristine (0.625 mg/m(2) IV for 10 weeks), prednisone (30 mg/m(2) orally on Days 1-14, 20 mg/m(2) on Days 15-28, and 10 mg/m(2) on Days 29-42), or single-agent chemotherapy with L-PAM (5 mg/m(2) orally every day for 5 days every 6 weeks for 2 years) after undergoing surgery. Patients were stratified according to menopausal status and number of positive lymph nodes (1-3 positive lymph nodes or > 3 positive lymph nodes). Seventy-seven patients were ineligible.

RESULTS

The maximum follow-up is 24 years, with a median follow-up of 21.5 years. Disease free survival and overall survival were superior with CMFVP (two-sided log-rank test; P = 0.0008 and P = 0.007, respectively). For all patients, the estimated 20-year survival rate of patients who received CMFVP was 40% compared with 27% for patients who received L-PAM. There was a substantial survival benefit for CMFVP compared with L-PAM in the subsets of premenopausal patients and patients with four or more positive lymph nodes. The estimated 20-year survival rate for premenopausal women who received CMFVP was 49% compared with 33% for premenopausal women who received L-PAM. Among women with > or = 4 positive lymph nodes, the estimated survival rate for patients who received CMFVP was 31% compared with 15% for patients who received L-PAM. Both regimens were tolerated well. Toxicity was more severe and frequent among patients who received CMFVP.

CONCLUSIONS

The authors conclude that, after 20 years of follow-up, adjuvant chemotherapy with CMFVP remains superior to L-PAM for the treatment of patients with lymph node positive breast carcinoma.

MMP-2 positivity and age less than 40 years increases the risk for recurrence in premenopausal patients with node-positive breast carcinoma

Node-positive breast carcinoma is associated with a poor prognosis. Some patients benefit from adjuvant chemotherapy but new treatment modalities should still be developed in order to further increase the cure rate in this patient group. Prognostic factors are needed to define patients for such studies. Here, the prognostic value of matrix metalloproteinase-2 (MMP-2) and age was evaluated in 108 premenopausal, node-positive breast carcinoma patients treated with an adjuvant chemotherapy. Expression of MMP-2 protein was studied in paraffin-embedded tissue sections from primary tumors by using specific MMP-2 monoclonal antibody in an immunohistochemical staining. Age less than 40 years predicted 5-year recurrence free survival (RFS) as unfavorable, being 74% in patients 41-49 years of age and 54% in those under age 40 (p = 0.02). The 5-year RFS rate was 85% in patients with an MMP-2 negative primary tumor while it was 65% in the MMP-2 positive patient group. This difference was not, however, statistically significant (p = 0.07). Correlation between hematogenous metastasis and MMP-2 positivity in breast carcinoma was demonstrated for the first time (p = 0.03). A risk group for a relapse was identified using MMP-2 immunohistochemistry and age. The RFS rate in patients less than 40 years with an MMP-2 positive primary tumor was only 50% while it was 74% in other premenopausal patients (p = 0.007). Young age and MMP-2 positivity may, thus, associate with early relapse in node-positive breast carcinoma.

Leucocyte nadir as a marker for chemotherapy efficacy in node-positive breast cancer treated with adjuvant CMF

The purpose of this study was to examine the association between the leucocyte nadir and prognosis in breast cancer patients receiving adjuvant chemotherapy consisting of cyclophosphamide, methotrexate and fluorouracil (CMF). Three hundred and sixty-eight patients with node-positive breast cancer without distant metastases were treated with six cycles of adjuvant CMF. Some patients (n = 60) also received tamoxifen. All patients underwent surgery and received radiotherapy to the axillary and supraclavicular lymph nodes and the chest wall. The effect of leucopenia caused by CMF on distant disease-free survival (DDFS) and overall survival (OS) was assessed. A low leucocyte nadir during the chemotherapy was associated with a long DDFS in univariate analysis when tested as a continuous variable (the relative risk (RR) 1.3, 95% confidence interval (CI) 1.04-1.06, P = 0.02). Similarly, when the leucocyte nadir count was divided into tertiles, the patients who had the highest nadir values during the six-cycle treatment had worst outcome (RR 1.6, 95% CI 1.07-2.5, P = 0.02). However, in a multivariate analysis only the number of affected lymph nodes, tumour size, progesterone receptor status, surgical procedure, age and adjuvant tamoxifen therapy retained prognostic significance, whereas the leucocyte nadir count did not. A low leucocyte nadir during the adjuvant CMF chemotherapy is associated with favourable DDFS and it may be a useful biological marker for chemotherapy efficacy.

Dose-response effect of adjuvant cyclophosphamide, methotrexate, 5-fluorouracil (CMF) in node-positive breast cancer. International Breast Cancer Study Group

There is evidence in the literature of a relationship between dose and response to adjuvant chemotherapy for breast cancer, although published results are conflicting. We therefore retrospectively analysed the role of dose response in patients included in four adjuvant trials of the International Breast Cancer Study Group (IBCSG, formerly the Ludwig Breast Cancer Study Group (trials I, II, III and V), all using 'classical' cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). A total of 1385 node-positive patients were treated with oral cyclophosphamide, and intravenous methotrexate plus 5-fluorouracil (CMF) for at least six 4 week courses. 1350 of these were included in 6 month landmark treatment outcome analyses. A total of 1029 patients were premenopausal, 321 were postmenopausal; 800 had one to three and 550 more than three involved axillary nodes at surgery. The median follow-up ranged from 12 years for trial V to 15 years for trials I-III. Patients were grouped according to three prospectively defined dose levels based on the percentage of the protocol prescribed dose that was actually administered (level I > or = 85%, level II 65-84%, level III < 65%). Patients who received dose level II had a higher disease-free (P = 0.07) and overall survival (P = 0.03) than those who received a higher (level I) or lower (level III) percentage. The 10 year overall survival was 60% for dose level II, 56% for dose level I, 51% for dose level III. The results were generally consistent within trial, menopausal status, and oestrogen receptor status groups. The results within nodal groups showed a large difference among the dose levels for the group with one to three positive nodes (P = 0.02), but no difference for the group with four or more positive nodes. Our results indicate that the dose-response effect remains a crucial factor in adjuvant chemotherapy of breast cancer. Reductions larger than 35% in the dose administered of oral CMF adversely influenced the outcome of breast cancer patients and should be avoided. The better outcome of the intermediate dose group indicates the need to investigate other aspects involved in the cytotoxicity of adjuvant CMF chemotherapy.

Pattern of dissemination and survival following isolated locoregional recurrence of breast cancer. A prospective study with more than 10 years of follow up

PURPOSES

The study evaluated prognostic factors for dissemination and survival in patients with local or regional recurrence of breast cancer. Furthermore, the aim was to define subgroups of patients at different risk of developing metastases in specific anatomical sites.

PATIENTS AND METHODS

The study included 140 patients with isolated local or regional node recurrence, who entered a prospective study for staging of patients with first recurrence of breast cancer in the period 1983-85. The primary treatment was a simple mastectomy; node positive patients received adjuvant radiotherapy and chemotherapy or tamoxifen. If possible, the locoregional recurrence was treated with surgery and/or radiotherapy, otherwise by systemic therapy.

RESULTS

Median follow up was 10.4 years; 78 patients developed distant metastases (soft tissue, 32%; bone, 45%; viscera 40%). Median time to dissemination was 4.4 years, and the ten year dissemination rate was 72%. Median time to dissemination was 3.7 years for patients with recurrence in the regional nodes compared to 6.5 years for patients with chest wall recurrence only, p = 0.05. No specific time sequence (temporal pattern) was observed in the anatomical distribution of metastases, and the anatomical site of recurrence could not be predicted by any of the prognostic factors. At follow up, 93 patients had died. The median survival was 5.6 years and 30% were alive after 10 years. Forty-three of the 99 patients who received local therapy only did not develop metastases. Fifteen of these patients died without evidence of metastatic disease while 28 patients were still alive without distant recurrence after a median follow up time of 9.3 years (range, 6.5-11.9 years). Level of LDH and the number of positive regional nodes (NPOS) at primary diagnosis were significant independent prognostic factors for survival after recurrence.

CONCLUSIONS

Approximately one third of the patients receiving local treatment only, were alive and without distant metastases up to ten years after locoregional recurrence, indicating that there is a subset of patients which may be long term survivors after local treatment only (surgery or radiotherapy). The duration of survival can be estimated by LDH and NPOS, but the model needs validation in a separate data set before clinical use.

Haematological toxicity: a marker of adjuvant chemotherapy efficacy in stage II and III breast cancer

Two hundred and eleven patients with node-positive stage II and III breast cancer were treated with eight cycles of adjuvant chemotherapy comprising cyclophosphamide, doxorubicin and oral ftorafur (CAFt), with and without tamoxifen. All patients had undergone radical surgery, and 148 patients were treated with post-operative radiotherapy in two randomized studies. The impact of haematological toxicity of CAFt on distant disease-free (DDFS) and overall survival (OS) was recorded. Dose intensity of all given cycles (DI), dose intensity of the two initial cycles (DI2) and total dose (TD) were calculated separately for all chemotherapy drugs and were correlated with DDFS and OS. Patients with a lower leucocyte nadir during the chemotherapy had significantly better DDFS and OS (P = 0.01 and 0.04 respectively). Dose intensity of the two first cycles also correlated significantly with DDFS (P = 0.05) in univariate but not in multivariate analysis, while the leucocyte nadir retained its prognostic value. These results indicate that the leucocyte nadir during the adjuvant chemotherapy is a biological marker of chemotherapy efficacy; this presents the possibility of establishing an optimal dose intensity for each patient. The initial dose intensity of adjuvant chemotherapy also seems to be important in assuring the optimal effect of adjuvant chemotherapy.

Is the negative prognostic value of high oestrogen receptor (ER) levels in postmenopausal breast cancer patients due to a modified ER gene product?

Recently, it was found that, among post menopausal breast cancer patients receiving no adjuvant therapy, the highest oestrogen receptor (ER) levels (ER++) as opposed to the intermediate ER levels (ER+) indicated a poorer prognosis in terms of recurrence-free survival (Thorpe et al. Eur J Cancer 1993, 29A, 971-977). In the present study, we confirm, in a series of 218 node negative, postmenopausal patients in whom ER was determined using a one-dose saturating method, that ER+ tumours have a more negative effect on disease-free survival (DFS) than ER+ tumours (P = 0.02). In another series of 87 ER positive, postmenopausal patients, we found a significant correlation (P = 0.04) between the ER level and ER+R ratio (ER protein/ER-specific mRNA): the higher the ER level, the more numerous the high ER+R ratio cases (ER+R > 1.5), reflecting an imbalance between the ER protein level and ER-specific mRNA. From these results, we hypothesise that high ER levels related to a high ER+R ratio suggest the presence of a modified ER gene product.

Short recurrence-free survival associated with high oestrogen receptor levels in the natural history of postmenopausal, primary breast cancer

The ability of oestrogen and progesterone receptor (ER and PgR, respectively) status to discriminate recurrence-free survival (RFS) among a cohort of consecutively accrued 952 postmenopausal patients has been studied. None of the cohort members investigated were treated with adjuvant therapy. Using a graduated scale of receptor status [low, intermediate and high receptor levels (< 10 vs. 10-107 vs. > or = 108 fmol/mg cytosol protein, respectively)] instead of the more commonly used dichotomous subdivision (positive vs. negative), ER level significantly discriminated between groups of patients with long vs. short RFS. Contrary to our expectations, patients with highest ER levels have as poor a prognosis as ER-negative patients, while patients with intermediate ER levels have longest RFS. The group of patients with ER levels > or = 108 fmol/mg cytosol protein comprises 47% of the cohort. The independent significance of overexpression of ER as a prognostic factor among this patient group is demonstrated in multivariate analysis where ER level is more significant than either grade of anaplasia or tumour size. PgR status did not significantly predict RFS among these patients. While the highest ER levels predispose for poorer prognosis among postmenopausal patients, it is precisely this group that experiences greatest benefit from adjuvant treatment with tamoxifen. Thus, patients who might otherwise go untreated due to their node-negative status can be readily identified and offered adjuvant treatment.

Pattern of spread and progression in relation to the characteristics of the primary tumour in human breast cancer

Characteristics of primary breast tumours were related to the extent of dissemination, the anatomical location of metastases, and the rate of progression in 863 patients with recurrent breast cancer. The following features were examined: tumour laterality, location within the breast, size, invasion of skin or fascia, presence of residual cancer tissue (RCT) in the mastectomy specimen, and number of positive lymph nodes. Increasing tumour size, increasing number of nodes, and the presence of local invasion and RCT were all associated with a short duration of survival both from initial diagnosis and from first recurrence. None of the factors were related to either the extent of dissemination or the rate of progression. Patients who had their primary tumours located in the medial or central part of the breast had an increased incidence of mediastinal and pleural recurrences respectively. Primary tumours greater than 5 cm, invasion of skin or fascia, and presence of RCT were all associated with an increased incidence of local recurrences. In addition, both RCT and fascial invasion were associated with increased occurrence of brain metastases. Most differences were explainable on the basis of local and regional lymphodynamics. Since the status of the features examined here all vary with time from tumour inception, it is suggested that the impact on prognosis is related to variations in tumour age from inception to primary diagnosis rather than to qualitative biological differences.

Clinical and electrodiagnostic findings in breast cancer patients with radiation-induced brachial plexus neuropathy

The clinical and neurophysiological characteristics of radiation-induced brachial plexopathy (RBP) were assessed in 79 breast cancer patients without signs of recurrent disease at least 60 months after radiotherapy (RT). Clinically, 35% (95% confidence limits: 25-47%) had RBP. Fifty percent (31-69%) had affection of the entire plexus, 18% (7-36%) of the upper trunk only, and 4% (1-18%) of the lower trunk. In 28% (14-48%), assessment of a definite level was not possible. In most, symptoms began during or immediately after RT, thus being without significant latency. Numbness or paresthesias (71%, 52-86%) and pain (43%, 25-62%) were the most prominent symptoms, while the most prominent objective signs were decreased or absent muscle stretch reflexes (93%, 77-99%) closely followed by sensory loss (82%, 64-93%) and weakness (71%, 52-86%). Neurophysiological investigations were carried out in 46 patients (58%). The most frequent abnormalities in patients with RBP were signs of chronic partial denervation with increased mean duration of individual motor unit potentials, and decreased amplitude of compound muscle and sensory action potentials. Nerve conduction velocities were normal.

Radiation-induced brachial plexus neuropathy in breast cancer patients

The incidence and latency period of radiation-induced brachial plexopathy (RBP) were assessed in 79 breast cancer patients by a neurological follow-up examination at least 60 months (range 67-130 months) after the primary treatment. All patients were treated primarily with simple mastectomy, axillary nodal sampling and radiotherapy (RT). Postoperatively, pre- and postmenopausal patients were randomly allocated chemotherapy or antiestrogen treatment. All patients were recurrence-free at time of examination. Clinically, 35% (25-47%) of the patients had RBP; 19% (11-29%) had definite RBP, i.e. were physically disabled, and 16% (9-26%) had probable RBP. Fifty percent (31-69%) had affection of the entire plexus, 18% (7-36%) of the upper trunk only, and 4% (1-18%) of the lower trunk. In 28% (14-48%) of cases assessment of a definite level was not possible. RBP was more common after radiotherapy and chemotherapy (42%) than after radiotherapy alone (26%) but the difference was not statistically significant (p = 0.10). The incidence of definite RBP was significantly higher in the younger age group (p = 0.02). This could be due to more extensive axillary surgery but also to the fact that chemotherapy was given to most premenopausal patients. In most patients with RBP the symptoms began during or immediately after radiotherapy, and were thus without significant latency. Chemotherapy might enhance the radiation-induced effect on nerve tissue, thus diminishing the latency period. Lymphedema was present in 22% (14-32%), especially in the older patients, and not associated with the development of RBP. In conclusion, the damaging effect of RT on peripheral nerve tissue was documented. Since no successful treatment is available, restricted use of RT to the brachial plexus is warranted, especially when administered concomitantly with cytotoxic therapy.

Adjuvant systemic treatment and the pattern of recurrences in patients with breast cancer

The aim was to analyze the impact of adjuvant systemic treatment (AST) on the anatomical distribution, the number, and the temporal relationship of the first metastases in 635 patients (pts) with breast cancer. These patients participated in the prospective studies of AST of the Danish Breast Cancer Cooperative Group (DBCG) 77-program. All patients had primary high-risk breast cancer (i.e. node positive or local invasion or tumor size greater than 5 cm). The initial treatment was mastectomy with axillary sampling, followed by postoperative radiotherapy. The types of AST and the number of patients with recurrence were: chemotherapy (CT), 134 pts; levamisole (LEV), 96 pts; tamoxifen (TAM), 154 pts. The pattern of recurrence in these patients was compared with the pattern of recurrence in 251 pts who did not receive AST (controls). Although CT reduced the total number of metastatic sites (P = 0.04), the incidence of liver metastases was increased compared to untreated controls (P = 0.02). The median number of metastatic sites was equal in TAM- and LEV-treated pts compared to controls. The incidence of lung metastases was increased in TAM-treated pts (P = 0.03), and LEV-treated pts had a decreased incidence of lymph node (P = 0.01) and pleural recurrences (P = 0.01) compared to controls. The results may suggest that mechanisms of clonal selection during the metastatic process involve differences in sensitivity to antineoplastic treatments of metastases at various anatomical locations.

The pattern of metastases in human breast cancer. Influence of systemic adjuvant therapy and impact on survival

Of the 3,802 patients enrolled in the DBCG 77 protocols, 863 developed clinical recurrence within a median follow-up time of 4.9 years (range 2.0-7.0). More than 69% of these had their first recurrence confined to a single anatomical site and 12% had more than two metastatic sites. The most common sites were bone (35%), lung (23%), skin (22%), and regional lymph nodes (16%). The observation period after first recurrence was 3.6 years (range 0.8-6.4). Survival after recurrence was significantly related both to the location and the number of metastases. Patients who were given adjuvant chemotherapy (n = 134) had significantly fewer metastatic sites and significantly more frequent liver metastases than untreated patients (n = 50). Patients who received adjuvant tamoxifen (n = 154) had the same number of metastatic sites, but more often had lung metastases than untreated patients (n = 201). These results probably reflect that metastases in different anatomical locations differ with respect to sensitivity to antineoplastic treatments.

Stage and pattern of metastases in patients with breast cancer

This study compares the pattern of metastases in 228 patients with initial stage I and 635 patients with initial stage II breast cancer. All these patients had recurrence within a median time of follow-up of 4.9 years (range 2.0-7.0 years). All patients were initially mastectomized, and staging was based on histopathological evaluation of mastectomy specimens. Patients with stage II disease received postoperative radiotherapy; 67% also received systemic adjuvant therapy. Locoregional recurrences were the most common sites of recurrence in stage I, whereas distant metastases occurred more often in stage II patients. Stage II patients had a significantly higher number of metastatic sites than stage I patients. Among patients with a single site of recurrence the frequency of local or regional recurrence was 62% in stage I patients compared to 16% in stage II patients. When correcting for this difference, which was ascribed to the effect of radiotherapy, the number and the distribution of metastatic sites were almost equal in stage I and II patients. The anatomical distribution of metastatic sites in different periods after mastectomy was almost the same in stage I and stage II patients; extraregional lymph node metastases, however, occurred earlier in stage II than in stage I patients. The recurrence-free interval, the survival after recurrence (SAR), and the overall survival were all significantly shorter for stage II than for stage I patients. The reduced SAR for patients with stage II disease hints that tumours of higher stages have a higher rate of progression. The progression time, however, was of the same duration in patients with initial stage I and II breast cancer. The prognostic significance of the classification of patients with breast cancer according to stage does not seem to discriminate tumours with different biological properties with regard to the rate as well as the pattern of dissemination. Postmastectomy follow-up of patients with stage I and II disease should therefore, follow the same guide-lines. Since the anatomical distribution of metastases was the same in different periods after mastectomy, the screening for recurrent disease should not be directed towards any specific sites in certain periods after initial diagnosis.