Adjuvant chemotherapy with and without tamoxifen in the treatment of primary breast cancer: 5-year results from the National Surgical Adjuvant Breast and Bowel Project Trial

The role of tamoxifen in the treatment and prevention of breast cancer

Tamoxifen is a nonsteroidal antiestrogen that has found successful applications for each stage of breast cancer in the treatment of selected patients. Tamoxifen was originally introduced for the treatment of advanced disease in postmenopausal women; however, the drug is now also available for the palliative treatment of premenopausal women with estrogen receptor (ER) positive disease. The proven efficacy of tamoxifen and the low incidence of side effects made the drug an ideal agent to test as an adjuvant therapy for women with node-positive breast cancer. Laboratory studies indicate that long-term treatment schedules may provide maximal benefit in preventing recurrence, and recent analysis of clinical trials demonstrates that between 2 and 5 years of adjuvant tamoxifen therapy provides a survival advantage for postmenopausal women with node-positive disease. Similarly, adjuvant studies in node-negative breast cancer have demonstrated an increase in the disease-free survival of both pre- and postmenopausal patients with ER-positive tumors. However, the extended use of tamoxifen has raised questions about the long-term safety of antiestrogen therapy. Of special concern is the impact of tamoxifen on ovarian function in premenopausal women and the potential risks to the fetus if pregnancy occurs. Fortunately, there are no reports about the teratogenicity of tamoxifen in the human, but it is important that physicians counsel women about the risk of pregnancy. Tamoxifen should not be used if a patient is pregnant. Initial concerns that the long-term administration of an antiestrogen would increase bone loss and increase the risks of coronary heart disease appear to be unwarranted. Tamoxifen has some estrogen-like activities in postmenopausal women and causes a preservation of bone in the lumbar spine and a decrease in circulating cholesterol. Indeed, a reduction in fatal myocardial infarction (MI) has been noted during 5 years of tamoxifen therapy, possibly the direct result of a prolonged reduction in circulating cholesterol. However, the estrogen-like qualities of tamoxifen that could be valuable as a hormone replacement therapy for all postmenopausal women following a diagnosis of breast cancer may also increase the risk for developing endometrial carcinoma. To date, there are only a few reports of endometrial carcinoma being diagnosed during adjuvant therapy with tamoxifen; however, any instances of uterine bleeding or spotting should be followed up with an endometrial biopsy. There are some concerns about large doses of tamoxifen promoting liver cancer in rats. These results are of particular concern if tamoxifen is to be used as a preventive in normal women.(ABSTRACT TRUNCATED AT 400 WORDS)

Adjuvant systemic therapy of stage I and II breast cancer

The value of adjuvant systemic therapy has been clearly demonstrated in both node-positive and node-negative patients. However, there are many women with favorable prognoses whose breast cancer recurs. It has been possible only recently to identify subsets of patients who are at definite risk for recurrence. Advances both in selection and treatment of patients with early-stage breast cancer are being made as critical research questions are delineated and examined in prospective randomized trials.

Primary systemic therapy for operable breast cancer

Eighty-eight patients presenting with operable breast cancer of 4 cm or greater in diameter (T2, T3, N0, N1, M0) have received primary systemic therapy. Response was assessed following 12 weeks of systemic therapy by linear regression analysis of changes in tumour volume. Definitive locoregional surgery (mastectomy n = 82, wide local excision n = 6) was performed on completion of systemic therapy (3-6 months). Response was observed in 24 (39%) of the 61 patients who received endocrine therapy; all 24 had tumours with an oestrogen receptor (ER) concentration of greater than or equal to 20 fmol mb-1 cytosol protein. Cytotoxic therapy was reserved for patients with tumours of ER concentration less than 20 fmol mg-1 cytosol protein (n = 27) or when endocrine therapy had failed (n = 20). Response was observed in 34 patients (72%). The overall survival rate at 3 years was 86%, with 81% remaining free from local relapse. We propose that the treatment policy outlined in this paper should now be tested against orthodox management by controlled randomised trial.

New hormonal approaches to the treatment of breast cancer

From this data we can draw several conclusions. Although many new hormonal agents have been developed, there has not been significant improvement in tumor response to single agents over the past several decades. By applying knowledge of tumor ER and PR patient populations can be selected which will have a higher response rate to a given hormonal agent. The approach of combining chemotherapy and hormonal therapy does not appear to significantly alter the course of the disease. Sequential use of Tamoxifen, Premarin, and chemotherapy has been shown in cell lines and animal models to synchronize cells thus increasing the efficacy of chemotherapy. Clinical trials of this synchronization generally show higher response rates including significantly higher CR rates than chemotherapy alone. This approach appears promising and is undergoing further trials. LHRH agonists and tamoxifen are effective in premenopausal women with receptor positive tumors and may replace surgical ablative therapy. Aminoglutethimide is gaining wider acceptance as second-line therapy in postmenopausal ER-positive patients. The new agent 4-OHA may be as effective as AG but with fewer side effects. Toremifine a new antiestrogen and RU486 a new antiprogesterone are undergoing trials. While these new agents appear promising with fewer side effects or greater specificity of action, with the exception of sequential hormone priming/chemotherapy they represent 'the same old approach'. By this we mean manipulation of the hormonal environment of the cell in a continuous fashion acting via the estrogen receptor mechanism to achieve tumor regression. While certain new agents may be more tolerable, it is unlikely that a 'break through' will occur with this approach. The problem is the emergence of cells resistant to hormonal therapy. This occurs either through proliferation of a preexisting resistant clone or development under selective pressure of resistant tumors. Some but not all of these resistant clones have escaped by virtue of not having estrogen receptor present. Others have defects further along the action cascade of estrogen stimulation, such as a defective receptor which cannot bind effectively to the nuclear acceptor sites, or lacking certain other growth factors such as TGF-beta. Whatever the deficit, most patients eventually develop resistant tumors. It is in this direction, toward manipulating later points in the estrogen cascade which our attention should turn to achieve more effective hormonal therapy.

Keynote address: integration of cytostatic agents and radiation therapy: a different approach to "proliferating" human tumors

Failure to achieve local and regional tumor control with radiation therapy remains a significant problem for a number of anatomic sites and can have a negative impact upon survival. There is emerging clinical and laboratory evidence that proliferation of tumor clonogens during the course of radiation treatment significantly impairs local control. Recent in situ studies suggest that as many as half of all human carcinomas have the potential to double their cell number in 5 or fewer days. Thus, cells that survive the initial treatments might rapidly repopulate a tumor, resulting in local failure. One potential clinical approach to reduce the impact of tumor cell repopulation during treatment would be to administer biological or chemical modifiers to slow or inhibit tumor proliferation. Examples of these cytostatic modifiers which are available for clinical testing now, or in the near future, include hormones, anti-hormones, growth factors, growth factor antagonists and other biologicals (e.g., interferons). Clinical alteration of the proliferative status of tumors could influence tumor control by reducing the impact of tumor cell proliferation during therapy, by modifying tumor cell radiosensitivity, or by favourably altering both. To appreciate the magnitude and the cumulative effect of these factors, newer technologies and experimental model systems need to be exploited in investigating correlations between proliferation and tumor control and between proliferative status and radiosensitivity. The design of future clinical trials using cytostatic agents and radiotherapy will rely heavily upon such basic information.

Antiestrogen therapy for breast cancer: current strategies and potential causes for therapeutic failure

There is an enormous literature that supports the use of tamoxifen as the treatment of choice for breast cancer. However, preliminary evidence suggests that long-term treatment with tamoxifen may expose the women to an increased risk of liver and endometrial cancer. This is probably only of concern to young women with stage I (node negative) disease. It remains to be seen whether any of the new strategies, including the new antiestrogens discussed here and novel endocrine therapies, will prove any better as an antitumor treatment. Treatments will probably be directed initially at treating patients after tamoxifen failure and ultimately at treating hormone-independent cancers. These therapies may involve the autocrine growth factors produced by breast cancer cells as potential targets. Such development of novel treatments will be extremely beneficial to these women, who face a worrying lack of therapeutic opportunities, with the exception of chemotherapy.

Adjuvant therapy of breast cancer. International Breast Cancer Study Group

Adjuvant systemic therapy has been shown to reduce relapses in treated women and to prolong their survival. This is true for all studied subpopulations. Multidrug chemotherapy for the duration of 6 months for the premenopausal patients, and tamoxifen or short-term chemotherapy with long-term tamoxifen for the postmenopausal patients represent the treatments of choice to reduce the risk of relapse. Some of the high priority questions relate to i) the definition of a population for which the risk of relapse is low enough to avoid the use of systemic adjuvant therapy, and ii) the definition of an optimal way of using available adjuvant therapies. These might find answers from ongoing research. The modest but real improvement of the prognosis in operable breast cancer was exclusively obtained only by means of clinical trials, and it is mandatory that participation in programs of clinical research becomes medically and socially the treatment of choice.

Sensitivity and insensitivity of breast cancer to tamoxifen

Tamoxifen is the endocrine treatment of choice for breast cancer. In several laboratory models in vivo tamoxifen is a tumoristatic agent. When MCF-7 breast cancer cells are inoculated into athymic mice, palpable tumors do not grow unless the animals are treated with estrogen, and tamoxifen inhibits estrogen-stimulated growth. If tamoxifen is stopped, tumors regrow. These results suggest that adjuvant tamoxifen therapy should involve long treatment periods (even lifetime) to prevent tumor recurrence. Unfortunately resistance to therapy and patient relapse inevitably occur, and such disease recurrence involving tamoxifen resistance is difficult to treat successfully. A laboratory model of endocrine therapy failure has been developed. When athymic mice with MCF-7 tumors are treated for 6-8 months with tamoxifen, several tumors grew and continued to grow in tamoxifen-treated mice. These estrogen receptor-positive tumors grow with either tamoxifen or estradiol. Tamoxifen-stimulated tumor growth has been observed in human endometrial tumors implanted into athymic animals. Growth of these tamoxifen-stimulated tumors can be inhibited with the pure antiestrogen ICI 164,384 upon withdrawal of tamoxifen. These data are discussed in terms of treatment strategies for tamoxifen-failed patients.

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 antiestrogen therapy for breast cancer. Past, present, and future

Laboratory investigations using animal models of breast cancer growth have indicated that the antiestrogenic compound tamoxifen is a tumoristatic agent. It is therefore effective in suppressing, rather than destroying, the breast tumor. Its use as an adjuvant in breast cancer management has been successful, with a proportion of women benefiting from long periods of tamoxifen treatment. All the initial studies recruited postmenopausal women, but tamoxifen is now proposed for the treatment of premenopausal women for an extended time. Naturally, there are many aspects of the toxicology of tamoxifen to consider; however, careful monitoring of clinical trials will determine the safety of the drug for the general patient population.

In vitro sensitivity testing of human breast cancer cells to hormones and chemotherapeutic agents

The sensitivities of human breast cancer cells to hormones and chemotherapeutic agents were measured using a new in vitro assay. Tumor cells from individual patients were cultured on collagen-coated dishes in medium containing the patient's serum. The rationale for use of the patient's serum is that the components of this serum interact with the cells and therapeutic agents in vivo. Cells were incubated for the length of the assay in the presence or absence of estrogen (E2) with or without tamoxifen (TAM) or in the presence or absence of cortisol (F). At 1 day after cell seeding, cells were exposed to a chemotherapeutic agent, Adriamycin, melphalan, or 5-fluorouracil, for 24 h. After a 48-h recovery period, [3H]-thymidine ([3H]-TdR) was added to the cultures for 24 h. Depending on the concentration, E2 generally stimulated or inhibited incorporation of [3H]-TdR into the DNA of cells from estrogen-receptor (ER)-positive tumors. TAM eliminated the effects of E2. F generally stimulated or inhibited incorporation in cells with no correlation to ER status. Stimulation of [3H]-TdR incorporation by hormones increased cell sensitivity to Adriamycin. In contrast, hormone inhibition of [3H]-TdR incorporation decreased cell responsiveness to this drug. This rapid assay, which can measure the sensitivities of breast carcinoma cells to hormones and drugs and identify effective combinations of therapeutic agents, should lead to a rational selection of treatment for the individual patient.

Response to endocrine manipulation and oestrogen receptor concentration in large operable primary breast cancer

Forty-three patients with large (greater than or equal to 4 cm) but operable carcinoma of the breast have been treated by endocrine manipulation before definitive local surgery. This has allowed the study of the relationship between response to therapy and pretreatment oestrogen receptor (ER) concentration, as measured by a dextran-coated charcoal adsorption method. Premenopausal patients (17) were treated by surgical (4) or medical (13) oophorectomy. Post-menopausal patients (26) received either tamoxifen (10) or an aromatase inhibitor (16). Response was assessed from statistical analysis of the changes in tumour size. On completion of 12 weeks of endocrine therapy, there was significant regression of tumour size in 18 of the 43 patients. All 18 patients had tumours with ER concentrations of greater than or equal to 20 fmol mg-1 cytosol protein. Conversely all patients except one progressing on treatment had tumours with ER concentrations of less than 20 fmol mg-1 cytosol protein. This relationship applied for both premenopausal and post-menopausal patients. The overall response rate of patients with tumours of ER concentration greater than or equal to 20 fmol mg-1 cytosol protein was 60%.

Randomized trial to evaluate the addition of tamoxifen to cyclophosphamide, 5-fluorouracil, prednisone adjuvant therapy in premenopausal women with node-positive breast cancer

A randomized clinical trial was performed to determine if the addition of hormonal therapy with tamoxifen to a combination chemotherapy regimen was superior to the chemotherapy alone for adjuvant treatment of premenopausal women after mastectomy for node-positive breast cancer. The chemotherapy regimen utilized consisted of cyclophosphamide (C), 5-fluorouracil (F), and prednisone (P), and the doses employed were: C, 150 mg/m2 IV days 1 to 5; F, 300 mg/m2 IV days 1 to 5; and P, 10 mg orally three times daily on days 1 to 7. A total of ten courses of therapy, given every 6 weeks, was planned. Tamoxifen (T) was given at a dose of 10 mg twice daily and was stopped 6 weeks after the last course of CFP. Four hundred patients are fully eligible and evaluable. With a median observation time of 5.3 years, the proportion of recurrences on each arm were: CFP, 95 of 202 (47%); CFPT, 77 of 198 (39%). The relapse-free survival distribution for CFPT was superior to that for CFP, at a borderline level of significance (two-sided P = 0.06). When significant prognostic factors were considered in covariate analysis, CFPT was not significantly better than CFP (P = 0.43). This marked change in level was due to imbalance in several factors not considered in stratification. Currently, 31% of CFP and 25% of CFPT patients have died, and although there is a slight separation of the survival curves in favor of CFPT, the difference is not significant (P = 0.21). Analysis within receptor subsets also showed no significant advantage for the addition of tamoxifen. This study does not establish a significant advantage for the concurrent administration of tamoxifen with the CFP regimen. It does, however, clearly demonstrate the importance of examination of clinically important prognostic factors, even those not utilized in stratification, and consideration of these factors in covariate analysis if imbalances are present.

Tamoxifen. A reappraisal of its pharmacodynamic and pharmacokinetic properties, and therapeutic use

Tamoxifen, a non-steroidal antioestrogen, represents a significant advance in treatment of female breast cancer. In trials of tamoxifen as postsurgical adjuvant treatment of early breast cancer, disease-free survival is consistently prolonged, representing an enhanced quality of life in association with tamoxifen's favourable adverse effect profile. Moreover, overview analysis indicates a survival benefit of approximately 20% at 5 years for all women, most clearly evident in women over 50 years, while a survival benefit independent of menopausal, nodal or oestrogen receptor status has been demonstrated in some individual trials. Thus, for postmenopausal women, tamoxifen is clearly optimal adjuvant treatment, although the relative benefit of adjuvant chemotherapy in node-negative patients requires clarification. A survival benefit for women under 50 has not been clearly demonstrated in overview analysis, but is not precluded by these rather limited data, and adjuvant treatment of premenopausal women with tamoxifen may also warrant serious consideration. Response rates to tamoxifen in advanced breast cancer are around 30 to 35%, increasing with patient selection for oestrogen receptor positivity. Tamoxifen must be regarded as first-line endocrine treatment in postmenopausal women, and may represent an alternative to first-line ovarian ablation in premenopausal women. An emergent role in primary therapy of elderly and frail patients with operable disease is apparent. Tamoxifen is also of benefit following surgery in male breast cancer, and may have a role as first-line endocrine treatment. Tamoxifen also has a potential role in other hormone-sensitive malignancies such as pancreatic carcinoma, and in treatment of benign breast disease. Finally, tamoxifen has a place in treatment of male and female infertility. because of adverse effects is rarely necessary. The most frequent adverse effects are related to the drug's anti-oestrogenic activity, and include hot flushes, nausea and/or vomiting, vaginal bleeding or discharge, and menstrual disturbances in premenopausal patients. Thus, tamoxifen continues to play a major role in management of female breast cancer in both early and advanced stages of disease, with a place also in treatment of male breast cancer and of infertility.

Radiotherapy, chemotherapy, and tamoxifen as adjuncts to surgery in early breast cancer: a summary of three randomized trials

The paper summarizes up-dated results of three randomized adjuvant trials from the Stockholm Breast Cancer Group. The objective of all studies included an evaluation of the role of megavoltage radiation in the primary management of patients with early breast cancer. The first trial was started in 1971 and included 960 pre- and postmenopausal patients with operable disease. The study compared adjuvant radiotherapy with surgery alone. All patients were treated with a modified radical mastectomy. There was a sustained improvement of the recurrence-free survival with radiotherapy (p less than 0.001). Among node positive cases radiation reduced the frequency of both loco-regional recurrence (p less than 0.001) and distant metastasis (p less than 0.01). This observation indicates that distant dissemination in subgroups of patients can originate from uncontrolled local deposits of tumor cells, for instance in the regional lymph nodes. No adverse effect from radiation on long-term survival was observed. The second study was started in 1976 and compared postmastectomy radiation with adjuvant chemotherapy in pre- and postmenopausal high-risk patients. At a mean follow-up of 6 1/2 years there was no significant difference in recurrence-free survival between the two treatments. However, postmenopausal patients fared better with radiotherapy (p less than 0.01). In this subgroup, radiation was more effective than adjuvant chemotherapy in reducing both distant metastases (p less than 0.01) and loco-regional recurrences (p less than 0.001). In the third trial--which only included postmenopausal patients--2 years of adjuvant tamoxifen was compared with no adjuvant endocrine treatment. The number of treatment failures was significantly reduced with tamoxifen (p less than 0.01) but there was no significant overall survival benefit. Subset analysis indicated that tamoxifen improved the recurrence-free survival among patients treated with adjuvant chemotherapy (p less than 0.01) but only to a level close to that achieved with radiotherapy alone. Addition of tamoxifen to radiotherapy failed to further increase the recurrence-free survival.

Adjuvant therapy of breast cancer with or without additional treatment with alternate drugs

Three hundred ten patients with Stage II or Stage III breast cancer were entered on an adjuvant protocol consisting of a combination of 5-fluorouracil, doxorubicin, cyclophosphamide, vincristine, and prednisone (FACVP). In the second phase of the study, patients with estrogen receptor-negative tumors received sequential courses of methotrexate and vinblastine. Other patients, who were estrogen receptor-positive or unknown, were randomized to receive either tamoxifen alone or tamoxifen plus methotrexate and vinblastine. All therapy was completed within 1 year. The estimated disease-free rate at 5 years was 68% among patients with Stage II disease and 52% for patients who had Stage III disease. Among patients with estrogen receptor-positive tumors, disease-free survival was significantly prolonged in patients who received methotrexate and vinblastine in addition to tamoxifen (P = 0.04). However, this difference was less pronounced when all randomized patients (including those whose estrogen receptor status was unknown) were included in the comparison. Although most patients experienced moderate to severe granulocytopenia, infectious complications were infrequent. One patient died of septicemia. Congestive heart failure developed in two patients, one of whom had a history of myocardial infarction and congestive heart failure.

Combination adjuvant chemotherapy for node-positive breast cancer. Inadequacy of a single perioperative cycle

We studied the timing and duration of adjuvant chemotherapy for operable breast cancer with axillary-node involvement in a randomized trial including 1229 patients divided into three treatment groups. One group received a single perioperative course of adjuvant combination chemotherapy beginning within 36 hours of mastectomy; a second received six cycles of conventionally timed adjuvant chemotherapy starting 25 to 32 days after operation; and a third received both the perioperative cycle and the conventionally timed regimen. The chemotherapy consisted of cyclophosphamide, methotrexate, and fluorouracil. Tamoxifen was added to the conventionally timed regimen in postmenopausal women. At a median follow-up of 42 months, the estimated four-year disease-free survival was 40 percent for the single perioperative cycle, 62 percent for the longer, conventionally timed regimen, and 60 percent for the combined program (P less than 0.0001). Overall survival differences also favored the longer treatments (P = 0.011). We conclude that a single perioperative cycle of adjuvant combination chemotherapy is less effective than prolonged therapy in patients with operable breast cancer and involved axillary nodes. Furthermore, starting the prolonged therapy perioperatively is no more effective than starting treatment four weeks after mastectomy.

Oestradiol enhances doxorubicin uptake and cytotoxicity in human breast cancer cells (MCF-7)

The cytotoxic effect of doxorubicin on human breast cancer cells (MCF-7) appeared to be correlated with drug concentration, exposure time and cellular uptake of doxorubicin. The effects of short-term stimulation of the growth of MCF-7 cells with 30 pM oestradiol was investigated with respect to the uptake of doxorubicin and cell kill. Culture of MCF-7 cells in steroid hormone-deprived medium resulted in an approx. 90% arrest of the cells in the G0G1-phase of the cell cycle. Growth stimulation with 30 pM oestradiol caused a 3-5-fold increase in the number of cells in S-G2M phase at between 18 and 24 h after administration of oestradiol to the medium. Incubation of oestradiol-stimulated cells with 0.37 microM doxorubicin during both 1 and 6 h resulted in an augmented inhibition of cell growth compared to unstimulated controls. An enhanced cellular uptake of doxorubicin after administration of oestradiol was observed only after an incubation period of 6 h and not of 1 h. These observations suggest that both an increased sensitivity to doxorubicin and an augmented cellular uptake of the drug may underlie the cytotoxic effects of doxorubicin after pretreatment with oestradiol.

Anti-oestrogens in the treatment of breast and gynaecological cancers

Tamoxifen is an effective therapy for advanced breast cancer and is well tolerated. In elderly patients or in those with inoperable primary disease tamoxifen is as effective as surgery or radiotherapy. In early breast cancer tamoxifen is associated with a prolongation of disease-free and overall survival, at least in women over the age of 50 with nodal involvement. Major trials now suggest that the effectiveness of tamoxifen may, however, be independent of age, menopausal status and of nodal status, but this remains the subject of substantial controversy. These trials also suggest that longer periods of tamoxifen treatment (more than 2 years) are better than shorter treatments and, therefore, adjuvant tamoxifen until recurrence may be the final treatment of choice for such patients. Tamoxifen is also effective in the treatment of endometrial cancer; however, there seems little advantage in combining the drug with progestogens, either concurrently or sequentially. Modest clinical benefit has been seen in patients with ovarian cancer treated with tamoxifen but the majority of patients have been heavily pretreated. Clinical trials of tamoxifen as primary therapy for this disease are warranted. Tamoxifen has probably been the most widely studied endocrine therapy for breast cancer and the subject of some of the longest and best controlled studies. Although there is no doubt that tamoxifen is effective in adjuvant therapy of breast cancer, the precise position and duration of treatment remains to be defined unequivocally. Future use in the treatment of women at high risk of developing breast cancer--so-called prophylactic therapy--depends on improvements in risk factor determination and a continuing evaluation of the possible clinical relevance of findings in animals given long-term treatment with high doses of the drug.

The development of tamoxifen for breast cancer therapy: a tribute to the late Arthur L. Walpole

Tamoxifen, a nonsteroidal antiestrogen, is now the endocrine treatment most widely used in breast cancer, both in the adjuvant and advanced disease settings. Here we will trace the development of tamoxifen for advanced breast cancer in postmenopausal patients, consider the biological basis for the recent successful use of tamoxifen for long-term adjuvant therapy, and discuss the use of tamoxifen in premenopausal patients with advanced disease. In part, this will be a historical review offered as a tribute to the late Dr. Arthur L. Walpole, who must receive the chief credit for the discovery of tamoxifen and its subsequent application as an anticancer agent.

Systemic treatment of cancer in the elderly

The goal of this review is to provide a readable and exhaustive reference in three major areas of geriatric oncology: complications of chemotherapy and radiotherapy, responsiveness of cancer to systemic treatment, social issues in the care of elderly patients with terminal illnesses. The conclusions of this study are: 1. Progressive deterioration of renal function is the most consistent change of aging. Adjustment of doses of renally excreted drugs to individual creatinine clearance may prevent life-threatening myelotoxicity in the elderly. 2. Intensive chemotherapy regimens (acute leukemia, non Hodgkin's lymphoma) cause more serious and prolonged myelotoxicity in the elderly. Elderly are more susceptible than younger patients to cardiotoxicity and central and peripheral neurotoxicity. Age is a poor predictor of complications in other organs or systems. 3. The prognosis of patients with Hodgkin's disease worsens with aging, possibly due to increased prevalence of mixed cellularity histology. It is controversial whether the prognosis of other neoplasias is poorer. Prognosis is not age-related in multiple myeloma. In general, elderly in good performance status may benefit from systemic cancer treatment to the same extent as younger patients, except for Hodgkin's disease. 4. The Informal Support Network, epitomized by the family, appears the most suitable environment to care for the elderly with cancer.

Adjuvant trial for stage II receptor-positive breast cancer: CMF vs. CMF + tamoxifen in a single centre

The purpose of a randomized trial achieved in a single centre (Fondation Bergonié, Bordeaux, France) was to compare chemotherapy alone (intravenous CMF) versus chemotherapy and hormonotherapy (CMF plus tamoxifen-30 mg per day during 2 years), for patients with stage II breast carcinoma and positive values of estrogen and/or progesterone receptor (EPR) (greater than 10 and greater than 15 fmoles mg protein-1 respectively). Three hundred and thirty four women treated by surgery +/- radiotherapy are included in this trial from 06.01.81 to 12.31.84. No patient is lost for follow-up. Eight are excluded. Three hundred and twenty six patients are evaluable with a 38 month median follow-up. For EPR assay, the dextran charcoal micromethod was used in the same centre. The two groups are identical as far as age, hormonal status, TNM, EPR values, and histological features are concerned. Analysis of results shows a significant improvement of relapse free survival (p = 0.018) and also overall survival (p = 0.04) for the CMF+ tamoxifen group.

Chemoresistance is not a cause of the apparent failure of adjuvant chemotherapy in postmenopausal women

Chemotherapeutic regimens used for the adjuvant treatment of breast carcinoma are less effective when applied to postmenopausal women than when applied to premenopausal women. Differences in growth fraction or altered chemosensitivity of tumors are potential causes of the differential effects of chemotherapy in younger and older patients. We have attempted to identify the presence of these putative causes by measuring size of clonogenic cell fraction and drug sensitivity of progenitor cells on the tumors from pre- and postmenopausal women. We found that the chemosensitivity of tumors was similar for patients of all ages. We further observed that the clonogenic cell fraction of tumors from women older than 65 years tended to be smaller compared to those of all other patients, while the hormone-sensitivity of tumors from these patients was higher. Our observations thus suggest that drug resistance related to inherent metabolic characteristics of tumor cells may not be a major contributing cause of failure of adjuvant chemotherapy in the treatment of postmenopausal women.

Adjuvant therapy for operable breast cancer with medroxyprogesterone acetate alone in postmenopausal patients or in combination with CMF in premenopausal patients

The present paper concerns two multicenter studies on adjuvant therapy with medroxyprogesterone acetate (MAP) for operable N+ breast cancer. The patients entered the study between April 1979 and March 1986. One hundred and fifty-one premenopausal patients were randomly assigned to receive either polychemotherapy (CMF) or CMF + MAP. One hundred and thirty-eight postmenopausal patients were randomized to receive either MAP h.d. or no treatment. CMF was administered according the following schedule: cyclophosphamide mg 100/ms p.o. 1-4 days; methotrexate mg 40/ms i.v. and fluorouracil mg 600/ms i.v. 1st and 8th days. The cycle was repeated six times every 28 days. MAP was administered at 1000 mg X 2/daily p.o. for 30 days and afterwards 500 mg X 2/daily for 5 months. In the premenopausal study after a median follow-up of 36 months no difference was observed in the incidence of recurrence, site of recurrence, actuarial 5-year disease-free survival (DFS) or overall survival (OS). In the postmenopausal study a statistically significant lower number of recurrences was observed in MAP-treatment patients after a median follow-up of 37 months. The effect of MAP was limited to patients with less than or equal to 3 metastatic axillary lymph nodes. In addition, there are suggestions that only patients with ER+ tumors draw some advantage from the treatment. On the other hand, no difference exists in the OS. The treatments were substantially well tolerated. The MAP + CMF regimen induces lower vomiting compared to the CMF alone. The most frequent MAP side-effects were vaginal spotting (16%) and tremors (12%). We conclude that MAP h.d., like tamoxifen and aminoglutethimide, can improve the DFS of operable N+ breast cancer in postmenopausal patients.

Hormone receptor assays: clinical usefulness in the management of carcinoma of the breast

The revision of the subcellular model of hormone action is described, with an incorporation of potential autocrine mechanisms. A general overview of available assay methodologies considers the major disadvantages of earlier methods and describes in detail the current methodologies (sucrose gradient analysis, dextran-coated charcoal assays, ER-EIA, ERICA). A major concern with clinical correlations of response to hormone receptor levels is the quality assurance of the multicentric programs. Results from national and international programs are considered. The clinical correlations are divided into four major categories: (1) the response to hormone deprivation (oophorectomy or adrenalectomy), (2) the development of specific agents which exploit receptor mechanisms (antiestrogens) or inhibit steroid biosynthesis (aminoglutehimide), (3) the rates of recurrence of tumors following mastectomy, and (4) the correlation of hormone receptors with current adjuvant therapies.

Adjuvant chemotherapy for breast cancer

The development of the use of chemotherapy in the treatment of breast cancer is discussed. Its contribution in the primary management of this disease lies not only in the limited but consistent reduction in mortality, but it has helped to elucidate the biological complexity of breast cancer. Also, it has stimulated basic scientists and research physicians to integrate their efforts, which is expected to result in further clinical progress.

Adjuvant therapy of premenopausal and menopausal high-risk breast cancer patients. Present status of the Danish Breast Cancer Cooperative Group Trials 77-B and 82-B

From September 1977 to November 1987 high-risk (i.e. with positive axillary lymph nodes, or tumor size greater than 5 cm or skin/facia invasion) premenopausal and menopausal breast cancer patients have been included in 2 randomized trials. In both trials the primary surgical treatment was total mastectomy with axillary sampling. In the first trial (DBCG 77-B) 1034 patients all received postoperative radiotherapy (RT) and were further randomized to 1) no systemic treatment (0), 2) cyclophosphamide (C), or 3) cyclophosphamide + methotrexate + 5-fluorouracil (CMF). The chemotherapy was given for 1 year. With a median observation time of 7 years the actuarial survival after 9 years is 50, 60 and 65% respectively. Retrospectively, the survival benefit was observed to be most pronounced in patients with tumor size less than or equal to 5 cm and with less than or equal to 3 positive lymph nodes. In the subsequent study initiated in 1982 (82-B) all patients received CMF for 9 months. Furthermore they were randomized to 1) RT, 2) no further treatment, or 3) tamoxifen (TAM) for 1 year. As of November 1, 1987, 1308 patients have been included. At 4 years and with a median observation time of 2 years the survival is similar in the 3 groups. In conclusion, in high-risk premenopausal and menopausal patients adjuvant chemotherapy combined with RT resulted in a 20-30% relative reduction in mortality at 9 years compared with RT alone. Preliminary analysis of adjuvant CMF + RT, compared with CMF alone or with CMF + TAM, shows after a median observation time of more than 2 years no significant survival differences.

Teratogenic effects of clomiphene, tamoxifen, and diethylstilbestrol on the developing human female genital tract

The potential estrogenicity and teratogenicity of triphenylethylene antiestrogens were examined in 54 genital tracts isolated from 4- to 19-week-old human female fetuses and grown for 1 to 2 months in untreated athymic nude mice or host mice treated by subcutaneous pellet with the antiestrogens clomiphene and tamoxifen or the synthetic estrogen diethylstilbestrol (DES). In specimens grown to a gestational age equivalent of 15 weeks or less, the vagina and urogenital sinus were lined by an immature squamous epithelium, which were similar in both drug-treated and untreated specimens. Proliferation and maturation of the squamous vaginal epithelium were observed in specimens treated with clomiphene, tamoxifen, or DES only when grown to a gestational age equivalent of 16 weeks or more. Formation of endometrial and cervical glands proceeded in 87 per cent (13 of 15) of control specimens grown to a gestational age equivalent of 13 weeks or more in untreated hosts. By contrast, age-matched drug-treated specimens contained glands in only 44 per cent (12 of 27) of specimens. In the developing uterine corpus of untreated controls, the uterine mesenchyme segregated into inner (endometrial stroma) and outer (myometrial) layers; whereas in drug-treated specimens, condensation and segregation of the mesenchyme were greatly impaired. The fallopian tube was also affected by clomiphene and tamoxifen (and to a lesser extent by DES) in that its epithelium was hyperplastic and disorganized. The complex mucosal plications characteristic of the fallopian tube were also distorted in drug-treated specimens. These results emphasize the heretofore unrecognized estrogenicity and potential teratogenicity of triphenylethylene antiestrogens on the developing human genital tract and emphasize the need for caution to prevent inadvertent exposure of the developing fetus to these compounds.

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.