D. L. Wickerham

Reanalysis and Results after 12 Years of Follow-up in a Randomized Clinical Trial Comparing Total Mastectomy with Lumpectomy with or without Irradiation in the Treatment of Breast Cancer

BACKGROUND Previous findings from a clinical trial (Protocol B-06) conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP) indicated the worth of lumpectomy and breast irradiation for treating breast cancer. After the discovery by NSABP staff members of falsified information on patients enrolled in the study by St. Luc Hospital in Montreal, separate audits were conducted at St. Luc Hospital and other participating institutions. We report the results of both audits and update the study findings through an average of 12 years of follow-up. METHODS Patients with either negative or positive axillary nodes and tumors 4 cm or less in diameter were randomly assigned to one of three treatments: total mastectomy, lumpectomy followed by breast irradiation, or lumpectomy without irradiation. Three cohorts of patients were analyzed. The first cohort included all 2105 randomized patients, who were analyzed according to the intention-to-treat principle. The second cohort consisted of 1851 eligible patients in the first cohort with known nodal status who agreed to be followed and who accepted their assigned therapy (among those excluded were 6 patients from St. Luc Hospital who were declared ineligible because of falsified biopsy dates). The third cohort consisted of the patients in the second cohort minus the 322 eligible patients from St. Luc Hospital (total, 1529 patients). RESULTS Regardless of the cohort, no significant differences were found in overall survival, disease-free survival, or survival free of disease at distant sites between the patients who underwent total mastectomy and those treated by lumpectomy alone or by lumpectomy plus breast irradiation. After 12 years of follow-up, the cumulative incidence of a recurrence of tumor in the ipsilateral breast was 35 percent in the group treated with lumpectomy alone and 10 percent in the group treated with lumpectomy and breast irradiation (P < 0.001). CONCLUSIONS Our findings continue to indicate that lumpectomy followed by breast irradiation is appropriate therapy for women with either negative or positive axillary nodes and breast tumors 4 cm or less in diameter.

A Randomized Clinical Trial Evaluating Tamoxifen in the Treatment of Patients with Node-Negative Breast Cancer Who Have Estrogen-Receptor–Positive Tumors

We conducted a randomized, double-blind, placebo-controlled trial of postoperative therapy with tamoxifen (10 mg twice a day) in 2644 patients with breast cancer, histologically negative axillary nodes, and estrogen-receptor-positive (greater than or equal to 10 fmol) tumors. No survival advantage was observed during four years of follow-up (92 percent for placebo vs. 93 percent for tamoxifen; P = 0.3). There was a significant prolongation of disease-free survival among women treated with tamoxifen, as compared with those receiving placebo (83 percent vs. 77 percent; P less than 0.00001). This advantage was observed in both the patients less than or equal to 49 years old (P = 0.0005) and those greater than or equal to 50 (P = 0.0008), particularly in the former, among whom the rate of treatment failure was reduced by 44 percent. Multivariate analysis indicated that all subgroups of patients benefited. Tamoxifen significantly reduced the rate of treatment failure at local and distant sites, tumors in the opposite breast, and the incidence of tumor recurrence after lumpectomy and breast irradiation. The benefit was attained with a low incidence of clinically appreciable toxic effects. The magnitude of the improvement obtained does not preclude the need for future trials in which patients given tamoxifen could serve as the control group in an evaluation of potentially better therapies. Tamoxifen treatment is justified in patients who meet the eligibility criteria of the present study and who refuse to participate in those trials. Since patients with tumors too small for conventional analysis of estrogen-receptor and progesterone-receptor concentrations were not eligible for this study, no information is available to indicate that such patients should receive tamoxifen.

Lumpectomy and radiation therapy for the treatment of intraductal breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-17.

PURPOSE In 1993, findings from a National Surgical Adjuvant Breast and Bowel Project (NSABP) trial to evaluate the worth of radiation therapy after lumpectomy concluded that the combination was more beneficial than lumpectomy alone for localized intraductal carcinoma-in-situ (DCIS). This report extends those findings. PATIENTS AND METHODS Women (N = 818) with localized DCIS were randomly assigned to lumpectomy or lumpectomy plus radiation (50 Gy). Tissue was removed so that resected specimen margins were histologically tumor-free. Mean follow-up time was 90 months (range, 67 to 130). Size and method of tumor detection were determined by central clinical, mammographic, and pathologic assessment. Life-table estimates of event-free survival and survival, average annual rates of occurrence for specific events, relative risks for event-specific end points, and cumulative probability of specific events comprising event-free survival are presented. RESULTS The benefit of lumpectomy plus radiation was virtually unchanged between 5 and 8 years of follow-up and was due to a reduction in invasive and noninvasive ipsilateral breast tumors (IBTs). Incidence of locoregional and distant events remained similar in both treatment groups; deaths were only infrequently related to breast cancer. Incidence of noninvasive IBT was reduced from 13.4% to 8.2% (P = .007), and of invasive IBT, from 13.4% to 3.9% (P < .0001). All cohorts benefited from radiation regardless of clinical or mammographic tumor characteristics. CONCLUSION Through 8 years of follow-up, our findings continue to indicate that lumpectomy plus radiation is more beneficial than lumpectomy alone for women with localized, mammographically detected DCIS. When evaluated according to the mammographic characteristics of their DCIS, all groups benefited from radiation.

A Randomized Clinical Trial Evaluating Sequential Methotrexate and Fluorouracil in the Treatment of Patients with Node-Negative Breast Cancer Who Have Estrogen-Receptor-Negative Tumors

We evaluated the postoperative use of sequential methotrexate and fluorouracil followed by leucovorin in 679 patients with primary breast cancer, histologically negative axillary nodes, and estrogen-receptor-negative (less than 10 fmol) tumors. No survival advantage was observed with this therapy as compared with no postoperative therapy during four years of follow-up (87 percent vs. 86 percent; P = 0.8). However, there was a significant prolongation of disease-free survival among women who received this therapy as compared with those who did not (80 percent vs. 71 percent; P = 0.003). An advantage was observed in both the patients less than or equal to 49 years old and those greater than or equal to 50. At four years, treatment failure was reduced by 24 percent in the younger group and by 50 percent in the older group. The rates of both local and regional and distant metastases were decreased. These benefits, achieved without the use of an alkylating agent, were associated with tolerable side effects. Multivariate analysis testing for potential interactions failed to identify subgroups of patients who did not benefit from the therapy. These results, although promising, do not obviate the need for additional trials to evaluate potentially better regimens of therapy, but they do suggest that sequential methotrexate-fluorouracil should be used in the control arm in such studies. Their use is also justified for the treatment of patients who refuse to participate in clinical trials, provided the patients meet the eligibility criteria of the present study. Since women with tumors too small for conventional analysis of estrogen-receptor and progesterone-receptor concentrations were not included in this study, we do not recommend systemic treatment for them outside of a clinical trial.

Sequential methotrexate and fluorouracil for the treatment of node-negative breast cancer patients with estrogen receptor-negative tumors: eight-year results from National Surgical Adjuvant Breast and Bowel Project (NSABP) B-13 and first report of findings from NSABP B-19 comparing methotrexate and fluorouracil with conventional cyclophosphamide, methotrexate, and fluorouracil.

PURPOSE To compare sequential methotrexate (M) and fluorouracil (F) (M-->F) with surgery (National Surgical Adjuvant Breast and Bowel Project [NSABP] B-13) and cyclophosphamide (C), M, and F with M-->F (NSABP B-19), in patients with estrogen receptor (ER)-negative tumors and negative axillary nodes. PATIENTS AND METHODS A total of 760 patients were randomized to B-13; 1,095 patients with the same eligibility requirements were randomized to B-19. Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were determined using life-table estimates. RESULTS A significant benefit in overall DFS (74% v 59%; P < .001) was demonstrated at 8 years in all B-13 patients who received M-->F (69% v 56% [P = .006] in those <or= 49 years of age, and 81% v 63% [P = .002] in those >or= 50 years). A survival advantage was evident in older patients (89% v 80%; P = .03). In B-19, through 5 years, an overall DFS advantage (82% v 73%; P < .001) and a borderline survival advantage (88% v 85%; P = .06) were evident with CMF. The DFS (84% v 72%; P < .001) and survival (89% v 84%; P = .04) benefits from CMF were greater in women aged <or= 49 years. M-->F or CMF after lumpectomy and breast irradiation resulted in a low probability of ipsilateral breast tumor recurrence (IBTR). In B-13, the frequency of IBTR was 2.6% following M-->F versus 13.4% in women treated by lumpectomy; it was 0.6% following CMF in B-19. Toxicity >or= grade 3 was more frequent among CMF patients in B-19. The age-related difference in CMF benefit was not related to amount of drug received. CONCLUSION M-->F and CMF are effective for node-negative patients with ER-negative tumors. The incidence of local-regional or distant metastases and IBTR decreased after either therapy. The benefit from either therapy was evident in all patients, but the CMF advantage was greater in those <or= 49 years. Because it is less toxic, M-->F may be used in patients with medical problems that would preclude CMF administration.

Doxorubicin-containing regimens for the treatment of stage II breast cancer: The National Surgical Adjuvant Breast and Bowel Project experience.

Despite numerous reports of findings obtained following the use of doxorubicin (Adriamycin [A]; Adria Laboratories, Columbus, OH) for the postoperative treatment of patients with primary breast cancer and positive axillary nodes, no clear consensus exists regarding its worth when used in that setting. In June 1981, the National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented two randomized clinical trials aimed at evaluating the worth of doxorubicin when administered in conjunction with melphalan (L-PAM) and fluorouracil (5-FU) (PF). A prior NSABP study identified cohorts of patients who did or did not benefit from tamoxifen (TAM, T) when used with chemotherapy. That information was employed in the design of the present studies. Women considered responsive to TAM (1,106) were randomized between PFT and PAFT, and those nonresponsive to TAM (707) were randomized between PF and PAF. Findings through 6 years of follow-up (mean duration of potential time on study, 64 months and 63 months, respectively) indicate that non-TAM-responsive patients who received PAF had a significantly better disease-free survival (DFS) (P = .003) and survival (P = .05) than did those receiving PF. By contrast, there was no significant difference in DFS (P = .6) or survival (P = .7) between PFT- and PAFT-treated patients. No disparity in the amount of drug received, whether related to the median amount or to dose-intensity, is present to account for the difference in findings between the studies. Aside from alopecia and emesis, the toxicity from the doxorubicin-containing regimens was similar to those in which doxorubicin was omitted. Cardiomyopathy was not a significant finding; there were no deaths from cardiac toxicity. The incidence of arterial and venous complications in patients receiving TAM was less than reported by others.

Body Mass Index and the Risk for Developing Invasive Breast Cancer among High-Risk Women in NSABP P-1 and STAR Breast Cancer Prevention Trials

High body mass index (BMI) has been associated with an increased risk for breast cancer among postmenopausal women. However, the relationship between BMI and breast cancer risk in premenopausal women has remained unclear. Data from two large prevention trials conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP) were used to explore the relationship between baseline BMI and breast cancer risk. The analyses included 12,243 participants with 253 invasive breast cancer events from the Breast Cancer Prevention Trial (P-1) and 19,488 participants with 557 events from the Study of Tamoxifen and Raloxifene (STAR). Both studies enrolled high-risk women (Gail score ≥ 1.66) with no breast cancer history. Women in P-1 were pre- and postmenopausal, whereas women in STAR (P-2) were all postmenopausal at entry. Using Cox proportional hazards regression, we found slight but nonsignificant increased risks of invasive breast cancer among overweight and obese postmenopausal participants in STAR and P-1. Among premenopausal participants, an increased risk of invasive breast cancer was significantly associated with higher BMI (P = 0.01). Compared with BMI less than 25, adjusted HRs for premenopausal women were 1.59 for BMI 25 to 29.9 and 1.70 for BMI 30 or more. Our investigation among annually screened, high-risk participants in randomized, breast cancer chemoprevention trials showed that higher levels of BMI were significantly associated with increased breast cancer risk in premenopausal women older than 35 years, but not postmenopausal women. Cancer Prev Res; 5(4); 583–92. ©2012 AACR.

Preliminary evaluation of factors associated with premature trial closure and feasibility of accrual benchmarks in phase III oncology trials

Background A major challenge for randomized phase III oncology trials is the frequent low rates of patient enrollment, resulting in high rates of premature closure due to insufficient accrual. Purpose We conducted a pilot study to determine the extent of trial closure due to poor accrual, feasibility of identifying trial factors associated with sufficient accrual, impact of redesign strategies on trial accrual, and accrual benchmarks designating high failure risk in the clinical trials cooperative group (CTCG) setting. Methods A subset of phase III trials opened by five CTCGs between August 1991 and March 2004 was evaluated. Design elements, experimental agents, redesign strategies, and pretrial accrual assessment supporting accrual predictions were abstracted from CTCG documents. Percent actual/predicted accrual rate averaged per month was calculated. Trials were categorized as having sufficient or insufficient accrual based on reason for trial termination. Analyses included univariate and bivariate summaries to identify potential trial factors associated with accrual sufficiency. Results Among 40 trials from one CTCG, 21 (52.5%) trials closed due to insufficient accrual. In 82 trials from five CTCGs, therapeutic trials accrued sufficiently more often than nontherapeutic trials (59% vs 27%, p = 0.05). Trials including pretrial accrual assessment more often achieved sufficient accrual than those without (67% vs 47%, p = 0.08). Fewer exclusion criteria, shorter consent forms, other CTCG participation, and trial design simplicity were not associated with achieving sufficient accrual. Trials accruing at a rate much lower than predicted (<35% actual/predicted accrual rate) were consistently closed due to insufficient accrual. Limitations This trial subset under-represents certain experimental modalities. Data sources do not allow accounting for all factors potentially related to accrual success. Conclusion Trial closure due to insufficient accrual is common. Certain trial design factors appear associated with attaining sufficient accrual. Defining accrual benchmarks for early trial termination or redesign is feasible, but better accrual prediction methods are critically needed. Future studies should focus on identifying trial factors that allow more accurate accrual predictions and strategies that can salvage open trials experiencing slow accrual. Clinical Trials 2010; 7: 312—321. http://ctj.sagepub.com

Breast cancer estrogen and progesterone receptor values: their distribution, degree of concordance, and relation to number of positive axillary nodes.

Increasing evidence indicates the importance of ascertaining the quantitative estrogen receptor (ER) and progesterone receptor (PR) content (in femtomoles per milligram cytosol protein) of primary breast cancers. Those values obtained from the tumors of 1,887 patients participating in National Surgical Adjuvant Breast and Bowel Project protocol B-09 have been analyzed to define (1) the distribution of tumor ER or PR according to patient age, (2) the distribution of tumor PR within a specific ER interval, and (3) the concordance of tumor ER and PR levels. The present findings indicate how predictive the knowledge of the amount of one receptor (e.g., ER) may be for estimating the amount of the other (PR), when the latter is unknown.

Achieving Sufficient Accrual to Address the Primary Endpoint in Phase III Clinical Trials from U.S. Cooperative Oncology Groups

Purpose: Assessing impact of poor accrual on premature trial closure requires a relevant metric. We propose defining accrual sufficiency on apparent ability to address primary endpoints (PE) rather than attaining accrual targets. Experimental Design: All phase III trials open January 1, 1993, to December 31, 2002, by five U.S. oncology Clinical Trials Cooperative Groups (CTCG) were evaluated for accrual sufficiency and scientific results. Sufficient accrual included meeting accrual target, CTCGs documentation attesting adequate accrual, or conclusive results at interim analysis; insufficient accrual included poor accrual as cited closure reason or other reasons rendering a trial unable to address its primary endpoints. Closure rates based on our accrual sufficiency definition are compared with rates of meeting accrual targets and addressing the primary endpoints. A percentage of target accrual above which trials commonly answer the intended scientific question was identified to serve as an alternative to meeting full target accrual in designating accrual success. Results: Of 238 eligible trials, 158 (66%) closed with sufficient accrual. Among 80 trials with insufficient accrual, 70 (29%) closed specifically because of poor accrual. Inadequate accrual rates are overemphasized when defining accrual success solely by meeting accrual targets. Nearly 75% of trials conclusively addressed the primary endpoints with positive results in 39% of trials. Exceeding 80% of target accrual serves as a reliable proxy for answering the intended scientific question. Conclusions: Approximately one third of phase III trials closed with insufficient accrual to address the primary endpoints, primarily due to poor accrual. Defining accrual sufficiency broader than meeting accrual targets represents a fairer account of trial closures. Clin Cancer Res; 18(1); 256–62. ©2011 AACR.