D. Lawrence Wickerham

Gene Expression and Benefit of Chemotherapy in Women With Node-Negative, Estrogen Receptor–Positive Breast Cancer

PURPOSE The 21-gene recurrence score (RS) assay quantifies the likelihood of distant recurrence in women with estrogen receptor-positive, lymph node-negative breast cancer treated with adjuvant tamoxifen. The relationship between the RS and chemotherapy benefit is not known. METHODS The RS was measured in tumors from the tamoxifen-treated and tamoxifen plus chemotherapy-treated patients in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B20 trial. Cox proportional hazards models were utilized to test for interaction between chemotherapy treatment and the RS. RESULTS A total of 651 patients were assessable (227 randomly assigned to tamoxifen and 424 randomly assigned to tamoxifen plus chemotherapy). The test for interaction between chemotherapy treatment and RS was statistically significant (P = .038). Patients with high-RS (> or = 31) tumors (ie, high risk of recurrence) had a large benefit from chemotherapy (relative risk, 0.26; 95% CI, 0.13 to 0.53; absolute decrease in 10-year distant recurrence rate: mean, 27.6%; SE, 8.0%). Patients with low-RS (< 18) tumors derived minimal, if any, benefit from chemotherapy treatment (relative risk, 1.31; 95% CI, 0.46 to 3.78; absolute decrease in distant recurrence rate at 10 years: mean, -1.1%; SE, 2.2%). Patients with intermediate-RS tumors did not appear to have a large benefit, but the uncertainty in the estimate can not exclude a clinically important benefit. CONCLUSION The RS assay not only quantifies the likelihood of breast cancer recurrence in women with node-negative, estrogen receptor-positive breast cancer, but also predicts the magnitude of chemotherapy benefit.

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.

Lumpectomy Compared with Lumpectomy and Radiation Therapy for the Treatment of Intraductal Breast Cancer

BACKGROUND AND METHODS Women with ductal carcinoma in situ have been treated both by lumpectomy and by lumpectomy followed by radiation therapy, but the benefit of combined therapy is uncertain. A group of 818 women with ductal carcinoma in situ were randomly assigned to undergo lumpectomy or lumpectomy followed by breast irradiation (50 Gy). Sufficient tissue was removed that the margins of the resected specimens were histologically tumor-free. The mean duration of follow-up was 43 months (range, 11 to 86). The principal end point of the study was event-free survival, as defined by the presence of no new ipsilateral or contralateral breast cancers, regional or distant metastases, or other cancers and by no deaths from causes other than cancer. RESULTS Five-year event-free survival was better in the women who received breast irradiation (84.4 percent, vs. 73.8 percent for the women treated by lumpectomy alone; P = 0.001). The improvement was due to a reduction in the occurrence of second ipsilateral breast cancers; the incidence of each of the other events was similar in the two groups. Of 391 women treated by lumpectomy alone, ipsilateral breast cancer developed in 64 (16.4 percent); it was noninvasive in 32 and invasive in the remaining 32. Of 399 women treated with lumpectomy and breast irradiation, ipsilateral breast cancer developed in 28 (7.0 percent) (noninvasive in 20 and invasive in 8). The five-year cumulative incidence of second cancers in the ipsilateral breast was reduced by irradiation from 10.4 percent to 7.5 percent for noninvasive cancers and from 10.5 percent to 2.9 percent for invasive cancers (P = 0.055 and P < 0.001, respectively). CONCLUSIONS Breast irradiation after lumpectomy is more appropriate than lumpectomy alone for women with localized ductal carcinoma in situ.

The Effect on Tumor Response of Adding Sequential Preoperative Docetaxel to Preoperative Doxorubicin and Cyclophosphamide: Preliminary Results From National Surgical Adjuvant Breast and Bowel Project Protocol B-27

PURPOSE The National Surgical Adjuvant Breast and Bowel Project Protocol B-27 was designed to determine the effect of adding docetaxel after four cycles of preoperative doxorubicin and cyclophosphamide (AC) on clinical and pathological response rates and on disease-free and overall survival of women with operable breast cancer. PATIENTS AND METHODS Women (N = 2,411) with operable primary breast cancer were randomly assigned to receive either four cycles of preoperative AC followed by surgery (group I), or four cycles of AC followed by four cycles of docetaxel, followed by surgery (group II), or four cycles of AC followed by surgery and then four cycles of docetaxel (group III). Clinical and pathologic tumor responses to preoperative therapy were assessed. RESULTS Mean tumor size (4.5 cm) and other key characteristics were evenly balanced among the three treatment arms. Grade 4 toxicity was observed in 10.3% of 2,400 patients during AC treatment, and in 23.4% of 1584 patients during docetaxel treatment. Compared to preoperative AC alone, preoperative AC followed by docetaxel increased the clinical complete response rate (40.1% v 63.6%; P <.001), the overall clinical response rate (85.5% v 90.7%; P <.001), the pathologic complete response rate (13.7% v 26.1%; P <.001), and the proportion of patients with negative nodes (50.8% v 58.2%; P <.001). Pathologic primary breast tumor response was a significant predictor of pathologic nodal status (P <.001). CONCLUSION The addition of four cycles of preoperative docetaxel after four cycles of preoperative AC significantly increased clinical and pathologic response rates for operable breast cancer.

Pathological complete response and long-term clinical benefit in breast cancer: the CTNeoBC pooled analysis

BACKGROUND Pathological complete response has been proposed as a surrogate endpoint for prediction of long-term clinical benefit, such as disease-free survival, event-free survival (EFS), and overall survival (OS). We had four key objectives: to establish the association between pathological complete response and EFS and OS, to establish the definition of pathological complete response that correlates best with long-term outcome, to identify the breast cancer subtypes in which pathological complete response is best correlated with long-term outcome, and to assess whether an increase in frequency of pathological complete response between treatment groups predicts improved EFS and OS. METHODS We searched PubMed, Embase, and Medline for clinical trials of neoadjuvant treatment of breast cancer. To be eligible, studies had to meet three inclusion criteria: include at least 200 patients with primary breast cancer treated with preoperative chemotherapy followed by surgery; have available data for pathological complete response, EFS, and OS; and have a median follow-up of at least 3 years. We compared the three most commonly used definitions of pathological complete response--ypT0 ypN0, ypT0/is ypN0, and ypT0/is--for their association with EFS and OS in a responder analysis. We assessed the association between pathological complete response and EFS and OS in various subgroups. Finally, we did a trial-level analysis to assess whether pathological complete response could be used as a surrogate endpoint for EFS or OS. FINDINGS We obtained data from 12 identified international trials and 11 955 patients were included in our responder analysis. Eradication of tumour from both breast and lymph nodes (ypT0 ypN0 or ypT0/is ypN0) was better associated with improved EFS (ypT0 ypN0: hazard ratio [HR] 0·44, 95% CI 0·39-0·51; ypT0/is ypN0: 0·48, 0·43-0·54) and OS (0·36, 0·30-0·44; 0·36, 0·31-0·42) than was tumour eradication from the breast alone (ypT0/is; EFS: HR 0·60, 95% CI 0·55-0·66; OS 0·51, 0·45-0·58). We used the ypT0/is ypN0 definition for all subsequent analyses. The association between pathological complete response and long-term outcomes was strongest in patients with triple-negative breast cancer (EFS: HR 0·24, 95% CI 0·18-0·33; OS: 0·16, 0·11-0·25) and in those with HER2-positive, hormone-receptor-negative tumours who received trastuzumab (EFS: 0·15, 0·09-0·27; OS: 0·08, 0·03, 0·22). In the trial-level analysis, we recorded little association between increases in frequency of pathological complete response and EFS (R(2)=0·03, 95% CI 0·00-0·25) and OS (R(2)=0·24, 0·00-0·70). INTERPRETATION Patients who attain pathological complete response defined as ypT0 ypN0 or ypT0/is ypN0 have improved survival. The prognostic value is greatest in aggressive tumour subtypes. Our pooled analysis could not validate pathological complete response as a surrogate endpoint for improved EFS and OS. FUNDING US Food and Drug Administration.

Relation of number of positive axillary nodes to the prognosis of patients with primary breast cancer. An NSABP update.

The current findings completely affirm the validity of our original observations indicating the appropriateness of grouping primary breast cancer patients into those with negative, 1 to 3, or ≫4 positive nodes. Results, however, reveal that there is a risk in combining all patients with ≫4 positive nodes into a single group. Since there was a 25% greater disease‐free survival and an 18% greater survival in those with 4 to 6 than in those with ≫13 positive axillary nodes, such a unification may provide misleading information regarding patient prognosis, as well as the worth of a therapeutic regimen when compared with another from a putatively similar patient population. Of particular interest were findings relating the conditional probability, i.e., the hazard rate, of a treatment failure or death each year during the 5‐year period following operation to nodal involvement with tumor. Whereas the hazard rate for those with negative, or 1 to 3 positive nodes, was relatively low and constant, in those with ≫4 positive nodes the risk in the early years was much greater, but by the fifth year it was similar to that occurring when 1‐3 nodes were involved, and not much different from negative node patients. The same pattern existed whether 4 to 6 or ≫13 nodes were positive. When the current findings are considered relative to other factors with predictive import, it is concluded that nodal status still remains the primary prognostic discriminant.

Sequential Preoperative or Postoperative Docetaxel Added to Preoperative Doxorubicin Plus Cyclophosphamide for Operable Breast Cancer: National Surgical Adjuvant Breast and Bowel Project Protocol B-27

PURPOSE This study was designed to determine the effect of adding docetaxel (T) to preoperative doxorubicin and cyclophosphamide (AC) on breast cancer response rates and disease-free survival (DFS) and overall survival (OS). PATIENTS AND METHODS Women with operable breast cancer (N = 2,411) were randomly assigned to receive preoperative AC followed by surgery, AC followed by T and surgery, or AC followed by surgery and then T. Tamoxifen was initiated concurrently with chemotherapy. Median time on study for 2,404 patients with follow-up was 77.9 months. RESULTS Addition of T to AC did not significantly impact DFS or OS. There were trends toward improved DFS with addition of T. The addition of T reduced the incidence of local recurrences as first events (P = .0034). Preoperative T, but not postoperative T, significantly improved DFS in patients who had a clinical partial response after AC (hazard ratio [HR] = 0.71; 95% CI, 0.55 to 0.91; P = .007). Pathologic complete response, which was doubled by addition of preoperative T, was a significant predictor of OS regardless of treatment (HR = 0.33; 95% CI, 0.23 to 0.47; P < .0001). Pathologic nodal status after chemotherapy was a significant predictor of OS (P < .0001). CONCLUSION The addition of preoperative or postoperative T after preoperative AC did not significantly affect OS, slightly improved DFS, and decreased the incidence of local recurrences. The sample size of this study was not sufficient to yield significance for the moderate DFS improvement. Concurrent use of tamoxifen may have limited the impact of adding T.

Paclitaxel After Doxorubicin Plus Cyclophosphamide As Adjuvant Chemotherapy for Node-Positive Breast Cancer: Results From NSABP B-28

PURPOSE The primary aim of National Surgical Adjuvant Breast and Bowel Project (NSABP) B-28 was to determine whether four cycles of adjuvant paclitaxel (PTX) after four cycles of adjuvant doxorubicin/cyclophosphamide (AC) will prolong disease-free survival (DFS) and overall survival (OS) compared with four cycles of AC alone in patients with resected operable breast cancer and histologically positive axillary nodes. PATIENTS AND METHODS Between August 1995 and May 1998, 3,060 patients were randomly assigned (AC, 1,529; AC followed by PTX [AC --> PTX], 1,531). Patients > or = 50 years and those younger than 50 years with estrogen receptor (ER) or progesterone receptor (PR) -positive tumors also received tamoxifen for 5 years, starting with the first dose of AC. Postlumpectomy radiotherapy was mandated. Postmastectomy or regional radiotherapy was prohibited. Median follow-up is 64.6 months. RESULTS The addition of PTX to AC significantly reduced the hazard for DFS event by 17% (relative risk [RR], 0.83; 95% CI, 0.72 to 0.95; P = .006). Five-year DFS was 76% +/- 2% for patients randomly assigned to AC --> PTX compared with 72% +/- 2% for those randomly assigned to AC. Improvement in OS was small and not statistically significant (RR, 0.93; 95% CI, 0.78 to 1.12; P = .46). Five-year OS was 85% +/- 2% for both groups. Subset analysis of the effect of paclitaxel according to hormone receptors or tamoxifen administration did not reveal statistically significant interaction (for DFS, P = .30 and P = .44, respectively). Toxicity with the AC --> PTX regimen was acceptable for the adjuvant setting. CONCLUSION The addition of PTX to AC resulted in significant improvement in DFS but no significant improvement in OS with acceptable toxicity. No significant interaction between treatment effect and receptor status or tamoxifen administration was observed.

Tamoxifen, Radiation Therapy, or Both for Prevention of Ipsilateral Breast Tumor Recurrence After Lumpectomy in Women With Invasive Breast Cancers of One Centimeter or Less

PURPOSE This trial was prompted by uncertainty about the need for breast irradiation after lumpectomy in node-negative women with invasive breast cancers of </= 1 cm, by speculation that tamoxifen (TAM) might be as or more effective than radiation therapy (XRT) in reducing the rate of ipsilateral breast tumor recurrence (IBTR) in such women, and by the thesis that both modalities might be more effective than either alone. PATIENTS AND METHODS After lumpectomy, 1,009 women were randomly assigned to TAM (n = 336), XRT and placebo (n = 336), or XRT and TAM (n = 337). Rates of IBTR, distant recurrence, and contralateral breast cancer (CBC) were among the end points for analysis. Cumulative incidence of IBTR and of CBC was computed accounting for competing risks. Results with two-sided P values of.05 or less were statistically significant. RESULTS XRT and placebo resulted in a 49% lower hazard rate of IBTR than did TAM alone; XRT and TAM resulted in a 63% lower rate than did XRT and placebo. When compared with TAM alone, XRT plus TAM resulted in an 81% reduction in hazard rate of IBTR. Cumulative incidence of IBTR through 8 years was 16.5% with TAM, 9.3% with XRT and placebo, and 2.8% with XRT and TAM. XRT reduced IBTR below the level achieved with TAM alone, regardless of estrogen receptor (ER) status. Distant treatment failures were infrequent and not significantly different among the groups (P =.28). When TAM-treated women were compared with those who received XRT and placebo, there was a significant reduction in CBC (hazard ratio, 0.45; 95% confidence interval, 0.21 to 0.95; P =.039). Survival in the three groups was 93%, 94%, and 93%, respectively (P =.93). CONCLUSION In women with tumors </= 1 cm, IBTR occurs with enough frequency after lumpectomy to justify considering XRT, regardless of tumor ER status, and TAM plus XRT when tumors are ER positive.

Update of the national surgical adjuvant breast and bowel project Study of Tamoxifen and Raloxifene (STAR) P-2 trial: Preventing breast cancer

The selective estrogen-receptor modulator (SERM) tamoxifen became the first U.S. Food and Drug Administration (FDA)–approved agent for reducing breast cancer risk but did not gain wide acceptance for prevention, largely because it increased endometrial cancer and thromboembolic events. The FDA approved the SERM raloxifene for breast cancer risk reduction following its demonstrated effectiveness in preventing invasive breast cancer in the Study of Tamoxifen and Raloxifene (STAR). Raloxifene caused less toxicity (versus tamoxifen), including reduced thromboembolic events and endometrial cancer. In this report, we present an updated analysis with an 81-month median follow-up. STAR women were randomly assigned to receive either tamoxifen (20 mg/d) or raloxifene (60 mg/d) for 5 years. The risk ratio (RR; raloxifene:tamoxifen) for invasive breast cancer was 1.24 (95% confidence interval [CI], 1.05–1.47) and for noninvasive disease, 1.22 (95% CI, 0.95–1.59). Compared with initial results, the RRs widened for invasive and narrowed for noninvasive breast cancer. Toxicity RRs (raloxifene:tamoxifen) were 0.55 (95% CI, 0.36–0.83; P = 0.003) for endometrial cancer (this difference was not significant in the initial results), 0.19 (95% CI, 0.12–0.29) for uterine hyperplasia, and 0.75 (95% CI, 0.60–0.93) for thromboembolic events. There were no significant mortality differences. Long-term raloxifene retained 76% of the effectiveness of tamoxifen in preventing invasive disease and grew closer over time to tamoxifen in preventing noninvasive disease, with far less toxicity (e.g., highly significantly less endometrial cancer). These results have important public health implications and clarify that both raloxifene and tamoxifen are good preventive choices for postmenopausal women with elevated risk for breast cancer. Cancer Prev Res; 3(6); 696–706. ©2010 AACR.