Phase II trial of N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine.HCl and doxorubicin chemotherapy in metastatic breast cancer: A National Cancer Institute of Canada clinical trials group study

PURPOSE

This multicenter phase II trial investigated the efficacy and toxicity of a combination of the novel intracellular histamine antagonist, N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine.HCl (DPPE), and doxorubicin in patients with anthracycline-naïve metastatic breast cancer. Preclinical models and early single institutional studies suggested DPPE could potentiate the cytotoxicity of doxorubicin.

PATIENTS AND METHODS

Forty-two women, 32 to 77 years old (median, 59 years), with anthracycline-naïve metastatic breast cancer were treated. Patients may have had one previous regimen of nonanthracycline chemotherapy, either in the adjuvant or metastatic disease treatment setting. DPPE (6 mg/kg) was administered as an 80 minute intravenous infusion with doxorubicin (60 mg/m(2)) given intravenously over the last 20 minutes of the DPPE infusion. Patients were premedicated with an antiemetic and sedating regimen. The DPPE/doxorubicin treatment was given every 21 days for a maximum of seven cycles.

RESULTS

All 42 patients were assessable. Overall, toxicity was comparable to that expected with doxorubicin alone, with the exception of DPPE-related motion sickness, mild hallucinations, and cerebellar signs at the time of the infusion. These CNS side effects were manageable in an ambulatory care setting, improved with subsequent cycles of treatment, and did not usually require hospitalization. Four patients developed febrile neutropenia. Thirty-five patients received four or more cycles of chemotherapy. The overall response rate was 52.5% (95% confidence interval, 36% to 68%), with 9.5% complete responses (n = 4), 43% partial responses (n = 18), and 38% of patients with stable disease (n = 16).

CONCLUSION

The antitumour effects of DPPE/doxorubicin the 52.5% response rate seems encouraging, particularly in consideration of the fact that a recently reported randomized National Cancer Institute of Canada Clinical Trials Group trial using single-agent doxorubicin 60 mg/m(2) in one of the treatment arms achieved a 31% response rate. Thus, a randomized phase III trial of doxorubicin versus doxorubicin plus DPPE is being conducted in this clinical setting.

Pretreatment factors predict overall survival for patients with low-grade glioma: a recursive partitioning analysis

PURPOSE

Three databases were pooled and analyzed to determine which groupings of prognostic factors best predicted overall survival for patients with low-grade gliomas treated with surgery and immediate or delayed radiotherapy.

METHODS AND MATERIALS

Databases of patients with low-grade gliomas compiled at the London Regional Cancer Centre (LRCC), the Norwegian Radium Hospital (NRH), and the University of California, San Francisco (UCSF) were merged. Inclusion criteria for the pooled analysis included: age > or =18 years and histologically confirmed low-grade (World Health Organization Grade II) supratentorial fibrillary astrocytoma, oligodendroglioma or mixed oligoastrocytoma. Factors analyzed for prognostic significance included: age at diagnosis, gender, seizures at presentation, presence of enhancement on computed tomography (CT) or magnetic resonance imaging (MRI), Karnofsky Performance Status (KPS) at diagnosis, histology, extent of surgical resection, timing of radiotherapy, and treating institution. Univariate and multivariate analysis of overall survival for these factors was performed. Recursive partitioning was performed to generate prognostic groups using these factors.

RESULTS

From the combined databases, 401 patients were eligible for analysis. Median survival for the entire group was 95 months/7.9 years. On univariate analysis age 18-40, presence of seizures at presentation, KPS > or =70, treating institution, and absence of contrast enhancement were associated with improved overall survival. On multivariate analysis, these factors remained independent predictors of improved overall survival. Recursive partitioning analysis yielded four prognostic groups with statistically different median survivals (MS): Group I (n = 41: KPS <70, age >40) MS 12 months; Group II (n = 34: KPS > or =70, age >40, enhancement present) MS 46 months; Group III (n = 138: KPS <70, age 18-40 or KPS > or =70 age >40, no enhancement) MS 87 months; Group IV (n = 188: KPS > or =70, age 18-40) MS 128 months.

CONCLUSION

Clusters of pretreatment prognostic factors described subgroups of low-grade glioma patients with divergent overall survivals. Consideration of these prognostic subgroups may be important when considering timing of interventions for these patients and in the stratification of patients for clinical trials.

Clinical trial to assess the relative efficacy of fluorouracil and leucovorin, fluorouracil and levamisole, and fluorouracil, leucovorin, and levamisole in patients with Dukes' B and C carcinoma of the colon: results from National Surgical Adjuvant Breast and Bowel Project C-04

PURPOSE

To compare the efficacy of leucovorin-modulated fluorouracil (FU+LV) with that of fluorouracil and levamisole (FU+LEV) or with the combination of FU+LV and levamisole (FU+LV+LEV).

PATIENTS AND METHODS

Between July 1989 and December 1990, 2,151 patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the colon were entered onto National Surgical Adjuvant Breast and Bowl Project protocol C-04. Patients were randomly assigned to receive FU+LV (weekly regimen), FU + LEV, or the combination of FU+LV+LEV. The average time on study was 86 months.

RESULTS

A pairwise comparison between patients treated with FU+LV or FU+LEV disclosed a prolongation in disease-free survival (DFS) in favor of the FU+LV group (65% v 60%; P =.04); there was a small prolongation in overall survival that was of borderline significance (74% v 70%; P =.07). There was no difference in the pairwise comparison between patients who received FU+LV or FU+LV+LEV for either DFS (65% v 64%; P =.67) or overall survival (74% v 73%; P =.99). There was no interaction between Dukes' stage and the effect of treatment.

CONCLUSION

In patients with Dukes' B and C carcinoma of the colon, treatment with FU+LV seems to confer a small DFS advantage and a borderline prolongation in overall survival when compared with treatment with FU+LEV. The addition of LEV to FU+LV does not provide any additional benefit over and above that achieved with FU+LV. These findings support the use of adjuvant FU+LV as an acceptable therapeutic standard in patients with Dukes' B and C carcinoma of the colon.

Randomized phase II study of high-dose paclitaxel with or without amifostine in patients with metastatic breast cancer

PURPOSE

To determine whether the neurotoxicity of paclitaxel 250 mg/m(2) given over 3 hours every 3 weeks could be reduced by pretreatment with amifostine 910 mg/m(2). Secondary objectives included comparing myelosuppression, myalgias, and response rates of the two groups.

PATIENTS AND METHODS

Forty women with metastatic breast cancer were randomized to receive either paclitaxel alone (arm 1) or paclitaxel preceded by amifostine (arm 2). All were assessable for toxicity, and 37 were assessable for response. At baseline and after each cycle, all patients completed questionnaires for neurologic symptoms and had standardized neurologic examinations, including objective assessments of power and vibration sense. In addition, standard follow-up assessments for other toxicities and tumor response were undertaken. Changes from baseline after courses 1, 2, and 3 were assessed. The sample size was sufficient to detect a 50% improvement in the expected determination in sensory change.

RESULTS

There were no differences observed in any of the measures of neurotoxicity. Other toxicity was similar in arms 1 and 2, including hair loss (95% v 90%), neurosensory changes (100% v 100%), fatigue/lethargy (85% v 90%), myalgia (95% v 90%), and grade 4 neutropenia (47% v 60%). Nausea, vomiting, dizziness, hypotension, and sneezing were more common in the amifostine arm. Response rates (22.2% v 36.8%) and paclitaxel pharmacokinetics were not significantly different.

CONCLUSION

There was no protection from paclitaxel-related neurotoxicity or hematologic toxicity in this study. These results suggest that the mechanism of action of paclitaxel-related toxic effects is not amenable to the cytoprotective action of amifostine.

Phase II study of first-line LY231514 (multi-targeted antifolate) in patients with locally advanced or metastatic colorectal cancer: an NCIC Clinical Trials Group study

BACKGROUND

Metastatic colon cancer is difficult to treat with treatment being palliative and with little effect on survival. This trial has evaluated the effects of LY231514 (Multitargeted antifolate (MTA)) given to previously untreated patients with recurrent or metastatic colorectal carcinoma.

PATIENTS AND METHODS

All patients were required to have a histological diagnosis of colorectal adenocarcinoma with measurable disease and no prior chemotherapy for metastatic disease. Patients had to have had performance status of 0-2, pretreatment absolute granulocyte count of > or = 1.5 x 10(9)/l and a platelet count of > or = 150 x 10(9)l. Patients received MTA at a dose of 600 mg/m2 by 10 minute infusion on day 1 repeated every 21 days. After the first 9 patients, this dose was reduced down to 500 mg/m2 every 21 days because of toxicity. Doses of MTA were modified depending on nadir counts.

RESULTS

Thirty-two eligible patients were enrolled and twenty-nine were evaluable for response. Three patients did not have repeat radiological testing to determine response because they went off study after only one cycle of treatment due to toxicity. In the 29 evaluable patients, there was 1 complete response, 4 partial responses and 14 patients with stable disease. Response rate was 17.2% (95% confidence intervals: 5.8%-35.8%). All responses occurred in the patients receiving a starting dose of MTA 500 mg/m2. Median time to progression for all eligible patients was 3.3 months. The most common toxicities experienced were mild to moderate fever, lethargy, anorexia, nausea, vomiting, stomatitis, abdominal pain, diarrhea, and skin rash. There was one death due to sepsis.

CONCLUSION

Single-agent MTA at 500 mg/m2 given every three weeks has modest activity in metastatic colorectal carcinoma.

Health-related quality of life and tamoxifen in breast cancer prevention: a report from the National Surgical Adjuvant Breast and Bowel Project P-1 Study

PURPOSE

This is the initial report from the health-related quality of life (HRQL) component of the National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention Trial. This report provides an overview of HRQL findings, comparing tamoxifen and placebo groups, and advice to clinicians counseling women about the use of tamoxifen in a prevention setting.

PATIENTS AND METHODS

This report covers the baseline and the first 36 months of follow-up data on 11,064 women recruited over the first 24 months of the study. Findings are presented from the Center for Epidemiological Studies-Depression Scale (CES-D), the Medical Outcomes Study 36-Item Short Form Health Status Survey (MOS SF-36) and sexual functioning scale, and a symptom checklist.

RESULTS

No differences were found between placebo and tamoxifen groups for the proportion of participants scoring above a clinically significant level on the CES-D. No differences were found between groups for the MOS SF-36 summary physical and mental scores. The mean number of symptoms reported was consistently higher in the tamoxifen group and was associated with vasomotor and gynecologic symptoms. Significant increases were found in the proportion of women on tamoxifen reporting problems of sexual functioning at a definite or serious level, although overall rates of sexual activity remained similar.

CONCLUSION

Women need to be informed of the increased frequency of vasomotor and gynecologic symptoms and problems of sexual functioning associated with tamoxifen use. Weight gain and depression, two clinical problems anecdotally associated with tamoxifen treatment, were not increased in frequency in this trial in healthy women, which is good news that also needs to be communicated.

Cardiac arrest induced by blunt trauma in children

BACKGROUND

There is incomplete knowledge regarding the outcome of children who suffer a cardiac arrest after blunt trauma. We sought to determine mechanisms of injury, mortality, and rate of organ donation in this population of children.

METHODS

Since 1984, all traumatically injured children in San Diego County, California, have been treated at San Diego Children's Hospital. This review encompasses 10,979 pediatric trauma patients evaluated from August 1, 1984 through September 30, 1996. All patients who did not meet the following two criteria were eliminated from the review: 1) a mechanism of blunt trauma, and 2) cardiopulmonary resuscitation performed by a trained medical provider prior to arriving or on arrival to the hospital. A chart review of this set of patients was undertaken to determine mechanism of injury, severity of injury, mortality, and rate of organ donation.

RESULTS

In this large metropolitan county, 65 children suffered cardiac arrest following blunt trauma. Accidents involving motor vehicles were the mechanisms responsible for 80% of these injuries. The average Injury Severity Score was 50.3. Mortality was largely related to severe head injury as manifested by a mean Abbreviated Injury Score for head and neck equal to 5.9. All but one of these patients died despite resuscitation. Ninety-four percent of these children died within the first 24 hours of injury. The single survivor was discharged in a vegetative state. Solid organs were obtained from 9% of the patients.

CONCLUSION

The outcome from blunt cardiac arrest in children is rapidly and nearly uniformly fatal despite resuscitation. Because severe head injuries resulting in brain death are the leading cause of mortality, a significant percentage of organ donations are obtained from these patients.

Pathologic findings from the National Surgical Adjuvant Breast Project (NSABP) eight-year update of Protocol B-17: intraductal carcinoma

BACKGROUND

This report is an 8-year update of the authors' previous findings from National Surgical Adjuvant Breast Project (NSABP) Protocol B-17, which relates to the influence of pathologic characteristics on the natural history and treatment of intraductal carcinoma (DCIS).

METHODS

Nine pathologic features observed in a pathologic subset of 623 of 814 evaluable women enrolled in this randomized clinical trial were assessed for their role in the prediction of second ipsilateral breast tumors (IBT), other events, and selection of breast irradiation (XRT) following lumpectomy.

RESULTS

The frequency of subsequent IBT was reduced from 31% to 13% (P = 0.0001) by XRT. The average annual hazard rates for IBT were reduced by XRT for all pathologic features examined. Four characteristics were individually noted to be significantly related to IBT, but only moderate-to-marked and absent-to-slight comedo necrosis were found to be independent high and low risk predictors, respectively, for such an event in patients of both treatment groups. XRT effected a 7% absolute reduction at 8 years in the low risk group. Despite a relatively high incidence (approximately 40%) of IBT consisting of invasive cancer, mortality due to breast carcinoma after DCIS for the entire cohort was found to be only 1.6% at 8 years.

CONCLUSIONS

The degree of comedo necrosis in patients with DCIS appears to be sufficient for discriminating between high and low risks for IBT following lumpectomy for DCIS. Although margin status, unlike in our previous report, was found to have only a slight or borderline influence on the frequency of IBT at 8 years, excision of DCIS with free margins is advised. The low risk group exhibits a statistically significant reduction of IBT from XRT. The decision to forgo XRT in the treatment of this singular subset of patients would appear to depend on clinical considerations and the input of informed patients rather than being standard practice. [See editorial on pages 375-7, this issue.]

Measuring worksite resources for employee heart health

PURPOSE

Intervention at the organizational rather than the individual level is gaining greater attention in worksite health promotion efforts. However, little research has been done on instruments to measure this domain. Therefore, the purpose of this study was to further test the utility of an existing organizational heart health support instrument by examining relationships among worksite structural characteristics and comparing these results to other survey findings.

DESIGN

One-time cross-sectional.

SETTING

New York State.

SUBJECTS

One hundred fifteen volunteer worksites in the New York State Healthy Heart Program, representing manufacturing, government, education, health care, and other industries.

MEASURES

A survey was conducted using HeartCheck, an organizational assessment of employee support for heart health. HeartCheck contains 175 items measuring organizational support for tobacco control, nutrition, physical activity, stress, screening, and administrative support structure.

RESULTS

On average, only 22% of all worksite resources assessed were present in the sample. Having a workforce greater than 250 provided a 12% increase in predicted overall worksite resources. A predominantly female workforce (> 75%) provided 10% higher levels of worksite stress resources. Worksites with unions had higher levels of resources for physical activity (10%), screening (13%), and general supportive structures (10%). The presence of manual labor diminished support for tobacco control resources (-13%). Finally, manufacturing worksites demonstrated a clear advantage for all types of worksite resources, except for stress.

CONCLUSION

A number of trends found in this study are consistent with earlier work. Industry type and size both predict worksite supports similar to previous studies. Other findings that appear to contradict previous work, including the relatively low level of support observed in this sample, can be explained by the comprehensive nature of the instrument. Overall, these findings demonstrate the utility of HeartCheck.

Tamoxifen in treatment of intraductal breast cancer: National Surgical Adjuvant Breast and Bowel Project B-24 randomised controlled trial

BACKGROUND

We have shown previously that lumpectomy with radiation therapy was more effective than lumpectomy alone for the treatment of ductal carcinoma in situ (DCIS). We did a double-blind randomised controlled trial to find out whether lumpectomy, radiation therapy, and tamoxifen was of more benefit than lumpectomy and radiation therapy alone for DCIS.

METHODS

1804 women with DCIS, including those whose resected sample margins were involved with tumour, were randomly assigned lumpectomy, radiation therapy (50 Gy), and placebo (n=902), or lumpectomy, radiation therapy, and tamoxifen (20 mg daily for 5 years, n=902). Median follow-up was 74 months (range 57-93). We compared annual event rates and cumulative probability of invasive or non-invasive ipsilateral and contralateral tumours over 5 years.

FINDINGS

Women in the tamoxifen group had fewer breast-cancer events at 5 years than did those on placebo (8.2 vs 13.4%, p=0.0009). The cumulative incidence of all invasive breast-cancer events in the tamoxifen group was 4.1% at 5 years: 2.1% in the ipsilateral breast, 1.8% in the contralateral breast, and 0.2% at regional or distant sites. The risk of ipsilateral-breast cancer was lower in the tamoxifen group even when sample margins contained tumour and when DCIS was associated with comedonecrosis.

INTERPRETATION

The combination of lumpectomy, radiation therapy, and tamoxifen was effective in the prevention of invasive cancer.

Highlights from recent National Surgical Adjuvant Breast and Bowel Project studies in the treatment and prevention of breast cancer

Findings from major National Surgical Adjuvant Breast and Bowel Project studies in women with breast cancer and negative axillary nodes are reported and discussed. Results of the B-13 and B-19 studies demonstrated that systemic chemotherapy (either with methotrexate and sequentially administered fluorouracil followed by leucovorin, or with cyclophosphamide plus methotrexate and fluorouracil) increased overall disease-free survival in women 49 years of age or younger, as well as in those 50 years old or older. Women older than 50 also experienced a survival advantage with chemotherapy. Moreover, women who received systemic chemotherapy after lumpectomy plus radiation therapy were significantly less likely to develop an ipsilateral recurrence of tumor. The B-14 study established the benefit of tamoxifen. When chemotherapy was added to tamoxifen in the B-20 trial, there was an increased benefit. The B-18 trial demonstrated that the outcome of patients who received preoperative chemotherapy was comparable to that of patients who received the same therapy postoperatively. Moreover, results suggested that breast tumor response to preoperative chemotherapy correlated with outcome. Also, larger tumors were sufficiently downstaged by preoperative chemotherapy to permit lumpectomy rather than mastectomy. The B-17 study in women with ductal carcinoma in situ concluded that radiation therapy should follow lumpectomy in women with localized, mammographically detected lesions. The P-1 Breast Cancer Prevention trial showed that tamoxifen was effective in significantly reducing the incidence of both invasive and noninvasive breast tumors in women at high risk for the disease. Although many questions remain, and a new study, P-2, has been designed to compare tamoxifen and raloxifene, it is appropriate to offer tamoxifen to women who are similar to those in the P-1 study and who may benefit from it.

Multitargeted antifolate LY231514 as first-line chemotherapy for patients with advanced non-small-cell lung cancer: A phase II study. National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To evaluate the efficacy and safety of the multitargeted antifolate LY231514 (MTA) in patients receiving initial chemotherapy for unresectable, advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with measurable, advanced NSCLC who had not received previous chemotherapy for advanced disease were considered for this study. Eligible patients who gave written informed consent initially received MTA 600 mg/m(2) intravenously (IV) for 10 minutes every 3 weeks. After three patients received treatment at this dose, the dose was reduced to 500 mg/m(2) IV at the same infusion time and frequency because of toxicity seen in this study and another Canadian MTA trial in colorectal cancer. Patients received up to four cycles after complete or partial remission or six cycles after stable disease was documented.

RESULTS

Thirty-three patients were accrued onto the study. All were assessable for toxicity, and 30 patients were assessable for response. All but one patient had an Eastern Cooperative Oncology Group performance status score of 0 or 1, 18 patients (55%) had adenocarcinoma, and nine patients (27%) had squamous cell carcinoma. Twenty-five patients (76%) had stage IV disease, and the remainder had stage IIIB disease at trial entry. Seven patients experienced a confirmed partial response and no complete responses were seen; thus, the overall response rate was 23.3% (95% confidence interval, 9.9% to 42.3%). The median duration of response was 3.1 months (range, 2. 3 to 13.5 months) after a median follow-up period of 7.9 months. Four (67%) of six patients with stage IIIB disease and three (12.5%) of 24 with stage IV disease responded to treatment. Four patients (13.3%) experienced febrile neutropenia and 13 (39%) experienced grade 3 or 4 neutropenia, whereas only one patient (3%) developed grade 4 thrombocytopenia. Nonhematologic toxicity was generally mild or moderate, but 39% of patients developed a grade 3 skin rash. Most other toxicities comprised grade 1 or 2 stomatitis, diarrhea, lethargy, and anorexia. Ten patients stopped protocol therapy because of toxicity.

CONCLUSION

MTA seems to have clinically meaningful activity as a single agent against advanced NSCLC. Toxicity is generally mild and tolerable. Further study of this agent in combination with cisplatin and other active drugs is warranted in this disease.

S-phase fraction combined with other patient and tumor characteristics for the prognosis of node-negative, estrogen-receptor-positive breast cancer

Women with estrogen-receptor (ER)-positive breast cancer and no axillary lymph-node involvement are considered to have excellent overall prognosis. However, this population is not homogeneous with regard to risk of recurrence; in fact, some of these patients have a prognosis no better than that of many women with ER-negative tumors or positive axillary nodes. Consequently, better tumor markers and better use of those currently available are needed to distinguish patients who would benefit from more aggressive therapy from those for whom such therapy is unnecessary. A well-defined cohort of over 4000 breast cancer patients from National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol B-14 who had ER-positive tumors and no axillary lymph-node involvement was analyzed to ascertain the usefulness of tumor cell S-phase fraction for prognosis. The significance of clinical tumor size, patient age at surgery, ER and progesterone receptor (PgR) expression, and nuclear grade was also explored. Statistical methods based on smoothing splines were used to relate treatment failure and mortality rates to patient and tumor characteristics. Models for 5- and 10-year disease-free survival (DFS) and overall survival were developed and summarized. The attenuation of the prognostic importance of covariates over time was investigated. After other characteristics were accounted for, a strong association was found between S-phase fraction and DFS, as well as survival. Tumor size, patient age at surgery, and PgR status were also significantly associated with outcome. The diversity of risk in the B-14 population was more extreme than is generally recognized. The prognostic capabilities of S-phase, tumor size, and PgR status were sharply attenuated as the time from surgery increased.

Low grade glioma: a measuring radiographic response to radiotherapy

PURPOSE

We set out to determine the rate of response of low-grade (WHO Grade II) gliomas to radiotherapy and analyze the relationship between radiographic response, symptom control and patient survival.

METHODS

Patients were eligible for this study if they had received radiotherapy for pathologically confirmed, residual, supratentorial low-grade astrocytoma, oligodendroglioma, or mixed glioma, and imaging studies (baseline and follow-up) were available for review. Percent change in tumor size and rate and timing of response were determined by maximum linear measurement, area measurement, volume measurement using an ellipsoid model, and volume measurement by image segmentation. For each method, response to radiotherapy was defined firstly as a > or = 50% decrease in tumor size (partial response), and secondly as a decrease equivalent to a 50% area decrease (normalized partial response). Relationships between radiographic response, clinical improvement and progression-free survival were analyzed using a Cox Proportional Hazard's model.

RESULTS

Twenty-one patients in a database (13 male, 8 female; ages 22-66 years) met the eligibility criteria. Twenty were imaged by computed tomography, 18 had an astrocytoma and 15 were irradiated soon after surgery. Responses were common and not felt to be due to a steroid effect. Use of normalized response criteria improved agreement between assessment of response as determined by the 4 methods. Median time to maximum radiographic improvement was 2.8 months (range, 1.5-11). Sixteen patients (76%) were improved neurologically, the median time to progression was 4.8 years and the 5-year progression-free survival rate was 43%. We did not detect a statistically significant association between response (as measured by any method), symptomatology and progression-free survival.

CONCLUSIONS

Low-grade gliomas are moderately radioresponsive. Use of volume measurement may over-estimate the number of partial responses unless a volume reduction equivalent to a 50% area decrease is used to define response. The best way to measure response remains uncertain because neither visual, area, nor volume changes confidently predicted clinical outcomes.

Adjuvant 5-fluorouracil and leucovorin with or without interferon alfa-2a in colon carcinoma: National Surgical Adjuvant Breast and Bowel Project protocol C-05

BACKGROUND

National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol C-03 showed a benefit from leucovorin (LV)-modulated 5-fluorouracil (5-FU) adjuvant therapy (5-FU + LV) in patients with Dukes' stage B or C carcinoma of the colon. Preclinical and clinical phase I/II data suggested that interferon alfa-2a (IFN) enhanced the efficacy of 5-FU therapy. Accordingly, in NSABP protocol C-05, the addition of recombinant IFN to 5-FU + LV adjuvant therapy was evaluated.

METHODS

Data are presented for 2176 patients with Dukes' stage B or C cancer entered onto protocol C-05 during the period from October 1991 through February 1994. Individuals with an Eastern Cooperative Oncology Group performance status of 0-2 (ranges from fully active to ambulatory and capable of self-care but unable to work), a life expectancy of at least 10 years, and curative resection were stratified by sex, disease stage, and number of involved lymph nodes and were randomly assigned to receive either 5-FU + LV or 5-FU + LV + IFN; the mean time on the study as of June 30, 1997, was 54 months. All statistical tests were two-sided.

RESULTS

There was no statistically significant difference in either disease-free survival (5-FU + LV, 69%; 5-FU + LV + IFN, 70%) or overall survival (5-FU + LV, 80%; 5-FU + LV + IFN, 81%) at 4 years of follow-up. Toxic effects of grade 3 or higher were observed in 61.8% of subjects in the group treated with 5-FU + LV and in 72.1% of subjects in the group treated with 5-FU + LV + IFN; fewer patients in the latter group completed protocol-mandated 5-FU + LV therapy than in the former group (77.1% versus 88.5%).

CONCLUSION

The addition of IFN to 5-FU + LV adjuvant therapy confers no statistically significant benefit, but it does increase toxicity.

Early stopping of a clinical trial when there is evidence of no treatment benefit: protocol B-14 of the National Surgical Adjuvant Breast and Bowel Project

Although several randomized clinical trials in the 1980s indicated a benefit from the use of tamoxifen in the treatment of early-stage breast cancer, questions have remained regarding the optimal duration of drug administration. In 1982, the National Surgical Adjuvant Breast and Bowel Project (NSABP) initiated a randomized trial to compare 5 years of tamoxifen to placebo among breast cancer patients with estrogen receptor-positive tumors and no evidence of axillary node involvement. By 1987, evidence of a substantial benefit for tamoxifen led the NSABP to extend this trial to determine whether longer duration tamoxifen therapy would be additionally beneficial. This study randomized patients who had completed 5 years of tamoxifen free of breast cancer recurrence or other events to either tamoxifen or placebo for an additional 5 years. By 1994, 1172 women had entered the study and accrual was closed. In late 1995, the trial was terminated on the basis of interim findings indicating that a benefit for continuing tamoxifen would not be realized. The closure has prompted controversy among cancer researchers, because there are currently at least three tamoxifen duration trials in progress, whereas results from two other studies evaluating 5-year duration therapy versus longer therapy were recently published. Here, we provide details of the statistical rationale contributing to our decision to recommend early closure of the study. We then consider other possible approaches to assessing the appropriateness of early termination in the face of evidence against a benefit, including Bayesian methods, which can be used to incorporate a range of prior beliefs regarding the efficacy of a treatment with accruing information from the trial. We also briefly discuss results of the other published studies.