Adjuvant CMF chemotherapy in operable breast cancer: ten years later

Autologous stem cell transplantation in breast cancer

High-dose chemotherapy with autologous stem cell support is an investigational treatment for patients with breast cancer who have a high risk of recurrence or who have metastatic disease. In the adjuvant setting, there is a lack of survival data from randomized studies comparing high-dose to conventional-dose therapy. High-dose adjuvant chemotherapy was found to result in as high as 71% 5-year event-free survival in patients with more than nine metastatic axillary lymph nodes in one nonrandomized study, which appears to be superior to those achieved with conventional-dose therapy. In metastatic breast cancer the great majority of patients die of cancer despite high-dose therapy with the current regimens, and it is unclear whether survival of these patients is improved with high-dose therapy as compared to conventional-dose therapy. However, a few patients with breast cancer with distant metastases have enjoyed a disease-free interval lasting for several years after high-dose therapy, which is rarely seen with conventional-dose therapy, and one small randomized trial showed improved survival in the high-dose arm of the study. The more extensive patient selection for high-dose chemotherapy needs to be taken into account when comparing the results achieved with different dose levels, and therefore a high priority should be given for randomized studies where high-dose therapy is compared with conventional-dose therapy.

Higher frequency of gene amplification in breast cancer patients who received adjuvant chemotherapy

BACKGROUND

Amplification of certain genes is involved in resistance to chemotherapy. The development of such amplification in patients by drug treatment has not yet been established. We have assessed the appearance of gene amplification in breast cancer patients with recurrent disease. One group of patients had previously received adjuvant chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil [CMF]) after surgery. The second group had not. All of these patients had developed recurrent disease and were receiving first-line endocrine treatment (tamoxifen).

METHODS

Tumor cells were obtained from the recurrent carcinoma using fine-needle biopsies. Gene copy number was determined for dihydrofolate reductase and thymidylate synthase with semiquantitative polymerase chain reaction. Dihydrofolate reductase is involved in resistance to methotrexate (M) and thymidylate synthetase in resistance to 5-fluoropyrimidines (F), two targets for the CMF regime.

RESULTS

We found that amplification of the examined genes develops in higher frequency among patients who previously received chemotherapy (p = 0.002).

CONCLUSIONS

These findings provide strong evidence for gene amplification induced by drug treatment.

Adjuvant chemotherapy of breast cancer

Many women will not be cured of breast cancer by even the best early detection and surgical techniques because of micrometastases present at diagnosis. Adjuvant therapy has extended the disease-free interval for most patients and lengthens overall survival for many. Combination chemotherapy has become the standard form of adjuvant treatment for premenopausal women with breast cancer and positive lymph nodes after primary therapy. With minimal toxicity, disease-free and overall survival are improved. Results are less impressive or less clear-cut for postmenopausal women or any woman with negative lymph nodes. Long-term toxicities of adjuvant chemotherapy may include second malignancies and cardiac dysfunction. Although these complications probably are rare, they must be considered seriously when weighing chemotherapy for patients in whom its benefits may be slight. Innovations likely to become standard in adjuvant therapy decision making include risk assessment with new prognostic indicators (growth fraction, oncogene expression) and investigation of dose intensification using bone marrow growth factors and autologous stem-cell support.

Adjuvant systemic therapy for patients with node-negative tumors

Early adjuvant therapy studies, especially adjuvant chemotherapy studies, were performed almost exclusively on patients with histologically involved axillary lymph nodes ("node-positive" patients). These therapies were restricted to this group of patients because the toxicities of adjuvant therapy were believed too great to justify its use in patients with a very good prognosis until its benefits were fully established. However, after it was demonstrated that adjuvant therapy can significantly prolong the disease-free survival of almost all groups of node-positive patients and the overall survival of some patient subsets, adjuvant therapy trials specifically designed for patients without histologically involved lymph nodes ("node-negative" patients) were initiated. Results from some of the largest of these second generation trials were recently published, and the early results from these studies have generated new questions. For example, will the mature results from these studies be nearly identical to the results seen in node-positive patients, or will node-negative patients derive greater benefits from adjuvant therapy? Is it possible that adjuvant therapy will "cure" node-negative patients but not node-positive patients? (Cure is defined here as an effect of therapy that returns a patient to the life expectancy she might have had if she had never been diagnosed with breast cancer). Is it possible that the added years of life from adjuvant therapy or that the number of node-negative patients who benefit are so small that these benefits will be outweighed by delayed toxicities that appear in patients who might have been cured even without adjuvant therapy? At present the available data to answer these questions definitely are either contradictory or nonexistent.

Adjuvant therapy of stage II breast cancer

Breast cancer is being diagnosed earlier with about 94% of patients presenting with disease limited to the breast or axilla. Despite this trend, more and more patients are receiving adjunctive therapy. In Stage II disease the results of clinical trials suggest that single agent chemotherapy has little if any role in adjuvant therapy. Polychemotherapy can improve survival in premenopausal women with a gain in outcome of about 26%. The duration of therapy appears optimal when given for 6 months. In postmenopausal estrogen receptor-negative women, chemotherapy also has a major role. Tamoxifen appears to offer approximately a 22% improvement in mortality for postmenopausal women. The longer duration of tamoxifen as adjuvant therapy appears to enhance the effect. Premenopausal women may also benefit using tamoxifen but the gain is less clear. Adding tamoxifen to chemotherapy does not enhance the effect. Patients with more than four positive lymph nodes may require more intensive therapy to show a major benefit. Radiotherapy can be integrated along with chemotherapy as adjunctive therapy.

Adjuvant chemotherapy (CMF) for stage III breast cancer: a randomized trial

A randomized trial of the effect of adjuvant CMF chemotherapy in patients with Stage III breast cancer receiving primary local radiation or local radiation plus surgery, failed to reveal a survival benefit from early systemic treatment. The subset of premenopausal patients receiving chemotherapy did, however, show a significant prolongation of disease-free survival from 23 to 55 months. Overall survival of this subgroup was not increased. The study included the use of two dose levels of CMF to assess whether higher chemotherapy doses would be more effective. No dose effect was observed. Initial local control with radiation therapy or radiation plus surgery was achieved in the majority (90.9%). Distal recurrence and death from metastatic disease were the major causes of treatment failure. Treatment benefit among premenopausal patients was mainly delayed onset of distal metastatic disease. Among premenopausal patients, salvage therapy for metastatic disease appeared more effective in those not previously exposed to systemic treatment.

The efficacy of combined chemotherapy and radiotherapy in advanced non-metastatic breast cancer

Thirty-five patients with locally advanced (inoperable) breast cancer have been treated based on a regimen of chemotherapy-radiotherapy-chemotherapy. At the completion of all treatment a complete remission rate of 86% was achieved with acceptable toxicity. At a median follow-up of 24 months (range 4-60), relapse at the site of bulk disease occurred in 17% (10% isolated loco-regional relapse) and relapse at distant sites in 34%. The median relapse-free survival was 36 months and the median survival has not yet been reached. Following initial promising results in terms of loco-regional disease control in this group of high-risk patients, the protocol was extended to include 34 patients defined as having locally extensive disease. All patients in this subgroup had undergone a modified radical mastectomy and were categorized as (a) patients in whom the pre-operative clinical findings merited (in our opinion) inclusion in the category of locally advanced (inoperable) disease, (b) patients in whom the primary was operable but in whom extensive involvement of axillary nodes was found (greater than 10 nodes positive or greater than or equal to 70% nodes positive if less than 10 nodes found) and (c) patients without the above characteristics with a primary tumor greater than 8 cm. At a median follow-up of 23 months (range 4-48), loco-regional recurrence occurred in one patient (3%) but distant relapse occurred in 21%. Relapse-free and overall survival was not significantly different to that found in patients with locally advanced disease who did not undergo mastectomy.

Adjuvant Chemotherapy with Adriamycin, Fluorouracil, Cyclophosphamide, Methotrexate, with or without Tamoxifen in Operable Breast Cancer

Between January 1982 and February 1985, 70 breast cancer patients with histologically confirmed axillary node involvement and T1–3a were treated following surgery with a combination of adriamycin, fluorouracil, cyclophosphamide, methotrexate, with or without tamoxifen according to the estrogen and progesterone receptors state. At 60 months of study (median follow-up, 41 months), the estimated proportion remaining disease-free was 62%. The estimated survival rate was 81%. A comparison of the actuarial disease-free and overall survival with data reported in the literature indicates a similar positive effect of adjuvant systemic therapy as described in adjuvant studies using polychemotherapy regimens. Patient acception of chemotherapy regimen was generally good. This can be accounted for because of an adequate emesis control and real compliance of the patients with the oncologist.

Progesterone binding cyst protein (PBCP) in primary breast cancer: a new prognostic factor?

Different secretory proteins have been evaluated as possible tumor markers in breast cancer. In this study progesterone binding cyst protein (PBCP) has been quantitated in breast tumor tissue. We report on a correlation of PBCP in cytosols of primary breast cancer, with known prognostic factors. A significant difference (p less than 0.001, Chi-square) in the frequency of PBCP-negative patients in clinical Stage I and Stage II is found. This was mainly attributed to a difference between T1 and T2 tumors, with less contribution from nodal status. A biological function of PBCP in breast cancer is not known. The distribution of PBCP in our patients has a close resemblance with expected number of node positive patients, suggesting that PBCP as a tumor marker may aid in providing prognostic information in breast cancer patients.