Preoperative chemotherapy in patients with operable breast cancer: nine-year results from National Surgical Adjuvant Breast and Bowel Project B-18.

National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol B-18 was initiated in 1988 to determine whether four cycles of doxorubicin/cyclophosphamide given preoperatively improve survival and disease-free survival (DFS) when compared with the same chemotherapy given postoperatively. Secondary aims included the evaluation of preoperative chemotherapy in downstaging the primary breast tumor and involved axillary lymph nodes, the comparison of lumpectomy rates and rates of ipsilateral breast tumor recurrence (IBTR) in the two treatment groups, and the assessment of the correlation between primary tumor response and outcome. Initially published findings were based on a follow-up of 5 years; this report updates results through 9 years of follow-up. There continue to be no statistically significant overall differences in survival or DFS between the two treatment groups. Survival at 9 years is 70% in the postoperative group and 69% in the preoperative group (P =.80). DFS is 53% in postoperative patients and 55% in preoperative patients (P =.50). A statistically significant correlation persists between primary tumor response and outcome, and this correlation has become statistically stronger with longer follow-up. Patients assigned to preoperative chemotherapy received notably more lumpectomies than postoperative patients, especially among patients with tumors greater than 5 cm at study entry. Although the rate of IBTR was slightly higher in the preoperative group (10.7% versus 7.6%), this difference was not statistically significant. Marginally statistically significant treatment-by-age interactions appear to be emerging for survival and DFS, suggesting that younger patients may benefit from preoperative therapy, whereas the reverse may be true for older patients.     

HER2 and choice of adjuvant chemotherapy for invasive breast cancer: National Surgical Adjuvant Breast and Bowel Project Protocol B-15

BACKGROUND: Recent retrospective analyses have suggested that breast cancer patients whose tumors overexpress HER2 derive preferential benefit from treatment with anthracyclines such as doxorubicin. This has led some clinicians to propose that HER2 should be used as a predictive marker in choosing between anthracycline-based regimens and combination chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). We evaluated this recommendation in a retrospective study of National Surgical Adjuvant Breast and Bowel Project Protocol B-15, in which patients received a combination of doxorubicin and cyclophosphamide (AC), CMF, or AC followed by CMF. We hypothesized that AC would be superior to CMF only in the HER2-positive patients. METHODS: Immunohistochemical detection of HER2 was performed on tumor sections from 2034 of 2295 eligible patients. We used statistical analysis to evaluate the interaction between the efficacy of the assigned treatments and HER2 overexpression. All statistical tests were two-sided. RESULTS: Tumor sections from 599 patients (29%) stained positive for HER2. AC was superior to CMF in HER2-positive patients only, although differences in outcomes did not reach statistical significance. In the HER2-positive cohort, relative risks of failure (i.e., after AC treatment as compared with CMF treatment) were 0.84 for disease-free survival (DFS) (95% confidence interval [CI] = 0.65--1.07; P =.15), 0.82 for survival (95% CI = 0.63--1.06; P =.14), and 0.80 for recurrence-free survival (RFS) (95% CI = 0.62--1.04; P =.10). Tests for interaction between treatment and HER2 status were suggestive but not statistically significant (P =.19 for DFS, P =.11 for survival, and P =.08 for RFS). CONCLUSIONS: These results, together with overview results indicating minor overall superiority for anthracycline-based regimens relative to CMF, indicate a preference for the AC regimen in patients with HER2-positive tumors. Both AC and CMF regimens may be considered for patients with HER2-negative tumors.     

Sentinel lymph node biopsy in breast cancer patients after neoadjuvant chemotherapy

BACKGROUND AND OBJECTIVES: Sentinel lymph node biopsy (SLNB) is an accurate method for axillary staging in patients with early breast cancer. The aim of this study was to evaluate the accuracy and the feasibility of SLNB in breast cancer patients who had received preoperative (neoadjuvant) chemotherapy. METHODS: Patients with advanced breast cancer stage II or III who were treated with neoadjuvant chemotherapy were included in the study. Sentinel lymph node (SLN) identification and biopsy was attempted and performed, and axillary lymph node dissection (ALND) was performed in the same surgical procedure after SLNB. The histopathologic examination of the SLNs and the dissected axillary lymph nodes was performed and nodal status was compared. RESULTS: Thirty patients were included in the study. After peritumoural injection of technetium-99m labelled human albumin and subareolar subcutaneous injection of blue dye, the SLNs could be identified in 26/30 patients (identification rate 86.7%). In 4/30 patients (13.3%) SLNs could not be identified. In 25/26 patients (96.2%) SLNs accurately predicted the axillary status. Eleven patients had negative SLNs and negative nodes in ALND. Six patients had positive SLNs and positive nodes in ALND. In eight patients SLNs only were positive and nodes in ALND were negative. One patient had a false-negative SLNB, calculating a false-negative rate of 6.7% (1/15). CONCLUSIONS: SLNB is a well introduced technique for axillary staging in patients with early breast cancer. The accuracy of SLNB after neoadjuvant chemotherapy is similar to patients with primary surgery. SLNB could be an alternative to ALND in a subgroup of patients after neoadjuvant chemotherapy, and therefore could reduce morbidity due to surgery in those patients. Due to small numbers of patients, further evaluation in this subset of patients is required.     

Tamoxifen and chemotherapy for axillary node-negative, estrogen receptor-negative breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-23.

PURPOSE: Uncertainty about the relative worth of doxorubicin/cyclophosphamide (AC) and cyclophosphamide/methotrexate/fluorouracil (CMF), as well as doubt about the propriety of giving tamoxifen (TAM) with chemotherapy to patients with estrogen receptor-negative tumors and negative axillary nodes, prompted the National Surgical Adjuvant Breast and Bowel Project to initiate the B-23 study. PATIENTS AND METHODS: Patients (n = 2,008) were randomly assigned to CMF plus placebo, CMF plus TAM, AC plus placebo, or AC plus TAM. Six cycles of CMF were given for 6 months; four cycles of AC were administered for 63 days. TAM was given daily for 5 years. Relapse-free survival (RFS), event-free survival (EFS), and survival (S) were determined by using life-table estimates. Tests for heterogeneity of outcome used log-rank statistics and Cox proportional hazards models to detect differences across all groups and according to chemotherapy and hormonal therapy status. RESULTS: No significant difference in RFS, EFS, or S was observed among the four groups through 5 years (P =.96,.8, and.8, respectively), for those aged < or = 49 years (P =.97,.5, and.9, respectively), or for those aged > or = 50 years (P =.7,.6, and.6, respectively). A comparison between all CMF- and all AC-treated patients demonstrated no significant differences in RFS (87% at 5 years in both groups, P =.9), EFS (83% and 82%, P =.6), or S (89% and 90%, P =.4). There were no significant differences in RFS, EFS, or S between CMF and AC in patients aged < or = 49 or > or = 50 years. No significant difference in any outcome was observed when chemotherapy-treated patients who received placebo were compared with those given TAM. RFS in both groups was 87% (P =.6), 87% in patients aged < or = 49 (P =.9), and 88% and 87%, respectively (P =.4), in those aged > or = 50 years. CONCLUSION: There was no significant difference in the outcome of patients who received AC or CMF. TAM with either regimen resulted in no significant advantage over that achieved from chemotherapy alone.     

Sentinel lymph node biopsy is accurate after neoadjuvant chemotherapy for breast cancer.

PURPOSE: Sentinel lymph node (SLN) biopsy has proved to be an accurate method for detecting nodal micrometastases in previously untreated patients with early-stage breast cancer. We investigated the accuracy of this technique for patients with more advanced breast cancer after neoadjuvant chemotherapy. PATIENTS AND METHODS: Patients with stage II or III breast cancer who had undergone doxorubicin-based neoadjuvant chemotherapy before breast surgery were eligible. Intraoperative lymphatic mapping was performed with peritumoral injections of blue dye alone or in combination with technetium-labeled sulfur colloid. All patients were offered axillary lymph node dissection. Negative sentinel and axillary nodes were subjected to additional processing with serial step sectioning and immunohistochemical staining with an anticytokeratin antibody to detect micrometastases. RESULTS: Fifty-one patients underwent SLN biopsy after neoadjuvant chemotherapy from 1994 to 1999. The SLN identification rate improved from 64.7% to 94.1%. Twenty-two (51.2%) of the 43 successfully mapped patients had positive SLNs, and in 10 of those 22 patients (45.5%), the SLN was the only positive node. Three patients had false-negative SLN biopsy; that is, the sentinel node was negative, but at least one nonsentinel node contained metastases. Additional processing revealed occult micrometastases in four patients (three in sentinel nodes and one in a nonsentinel node). CONCLUSION: SLN biopsy is accurate after neoadjuvant chemotherapy. The SLN identification improved with experience. False-negative findings occurred at a low rate throughout the series. This technique is a potential way to guide the axillary treatment of patients who are clinically node negative after neoadjuvant chemotherapy.     

Sentinel lymph node biopsy in breast cancer after neoadjuvant chemotherapy. A pilot study.

AIMS: Sentinel lymph node biopsy (SLN) seems to represent a reliable method for early breast cancer staging, offering an alternative to complete axillary dissection. METHODS: The identification of sentinel node(s), their localization and the predictive capacity of SLN were analysed in 42 patients who had neoadjuvant chemotherapy for breast cancer. Dextran labelled with (99m)Tc was injected close to the tumor. The radioactive uptake in the axilla was detected by scintigraphic images and by a hand-held probe guided the SLN. RESULTS: One or more sentinel nodes were identified in 41 patients (97.6%). We could accurately predict axillary lymph nodes status in 93% of the cases. CONCLUSIONS: SLN can predict the status of the axilla in patients who have received primary chemotherapy.     

Sentinel lymph node biopsy after neoadjuvant chemotherapy

BACKGROUND: We surveyed single-center and multi-center studies pertaining to sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy to compare the results with those of our current study to evaluate the feasibility and accuracy of SLNB after neoadjuvant chemotherapy. METHODS: From October 2001 to July 2003, 80 patients who had neoadjuvant chemotherapy underwent curative surgery and axillary lymph node dissection (ALND) after SLNB at the Center for Breast Cancer, National Cancer Center. A MEDLINE search was performed using the keywords breast cancer, sentinel lymph node biopsy, and neoadjuvant chemotherapy. RESULTS: Our results showed that 42 (52.6%) of 80 patients had downstaging of the primary tumor; 9 patients (11.3%) had pathologic complete response (pCR) and 33 (41.3%) had pathologic partial response (pPR). 26 patients (32.5%) showed complete axillary clearance after neoadjuvant chemotherapy. Among them, 5 patients (6.3%) revealed pCR of both the primary tumor and axillary metastasis. SLNB was successful in 61 of 80 patients (76.3%) and there were 3 false negatives, yielding a false negative rate (FNR) of 7.3% (3/41), a negation prediction value (NPV) of 87.0%(20/23), and an accuracy of 95.1% (58/61). Thirteen out of 16 studies retrieved by to MEDLINE pertaining SLNB after neoadjuvant chemotherapy concluded its feasibility and accuracy with a identification rate of 82%-100% and a FNR of 17-100%. CONCLUSION: Most studies, including ours, concluded that SLNB after neoadjuvant chemotherapy is accurate and could be an alternative to ALND.     

Sentinel lymph node biopsy is feasible for breast cancer patients after neoadjuvant chemotherapy

BACKGROUND: Despite the increasing use of both sentinel lymph node (SLN) biopsy and neoadjuvant chemotherapy (NAC) in patients with operable breast cancer, information on the feasibility and accuracy of sentinel node biopsy following neoadjuvant chemotherapy is still quite limited. Therefore, we investigated the feasibility and accuracy of sentinel lymph node biopsy for breast cancer patients after NAC. METHODS: A total of 104 patients with Stage II and III breast cancers, previously treated by NAC, were enrolled in the study. All patients were clinically node-negative after NAC. The patients underwent SLN biopsy, which involved a combination of an intradermal injection of radiocolloid and a subareolar injection of blue dye over the tumor. This was followed by completion axillary lymph node dissection (ALND). RESULTS: SLN could be identified in 97 of 104 patients (identification rate, 93.3%). In 93 of the 97 patients (95.9%), the SLN accurately predicted the axillary status. Four patients' SLN biopsies were false negative, resulting in a false-negative rate of 10.0%. The SLN identification rate tended to be lower among patients with T4 primary tumors prior to NAC (62.5%). CONCLUSION: The SLN identification and false-negative rates were similar to rates in non-neoadjuvant studies. The SLN accurately predicted metastatic disease in the axilla of patients with tumor response following NAC.     

Sentinel node biopsy in breast cancer patients treated with neoadjuvant chemotherapy

A sentinel node biopsy (SNB) has been proved to be an accurate method to estimate the axillary lymph node status as a replacement for axillary lymph node dissection (AxLND) in patients with early breast cancer who have not been treated with neoadjuvant chemotherapy (NAC). We examined the feasibility and accuracy of performing SNB after NAC. Seventy breast cancer patients treated with NAC were enrolled in the current study during the period between March 2001 and June 2005. NAC performed preoperatively consisted of three to four times of CAF chemotherapy. Moreover, intra-arterial (subclavian artery and internal mammary artery) infusion of epirubicin and 5-fluorouracil was performed in addition to systemic CAF chemotherapy once to three times in patients with large breast tumors or bulky axillary lymph node metastases. The sentinel nodes were successfully identified in 63 out of 70 patients (identification rate: 90%). The mean number of sentinel nodes removed per patient was 1.5 (range 1-6). Of the 43 patients in whom AxLND was performed after the sentinel nodes were identified, 19 (44.2%) had positive sentinel nodes. In 8 of those 19 patients, the sentinel node was the only cancer positive lymph node. Among the 24 patients who had negative sentinel nodes it was found that one patient had a confirmed false negative result, thus yielding a false negative rate of 5%, and a sensitivity of 95%. There was no false negative patient who had a clinically negative lymph node status (N0) before NAC (17 patients), whereas the false negative rate was 6.3% in the subgroup of patients with a clinically positive lymph node status (N1, N2) before NAC (26 patients). As a result, SNB after NAC is thus considered to be able to effectively predict the axillary lymph node status in patients with a clinically negative lymph node status before NAC.     

美国乳腺与肠道外科辅助治疗研究组（NSABP）乳腺癌临床试验进展

美国乳腺与肠道外科辅助治疗研究组（National Surgical Adjuvant Breast and Bowel Project,简称NSABP）是一个进行大规模乳腺癌和结,直肠癌临床试验的合作团体,本文就NSABP有关乳腺癌的临床试验作一综述。     

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

In this National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trial, 1,891 women with primary operable breast cancer and positive axillary nodes were randomized between Jan, 1977 and May 1980 to receive L-phenylalanine mustard (L-PAM) and 5-fluorouracil (5-FU) either with or without tamoxifen (TAM)-PFT. This report presents life table probabilities, cumulative odds ratios, and P values for disease-free survival (DFS) and survival at yearly intervals through 5 years of observation (mean time on study, 72 months). When patients were examined overall without regard for any discriminant associated with outcome, ie, age, number of positive nodes, or tumor receptor status, there was a significant prolongation of DFS (P = .002), but not survival through the fifth postoperative year. The benefit was almost entirely restricted to those greater than or equal to 50 years with greater than or equal to 4 positive nodes. In that group there was a 66% greater chance of remaining disease free if PFT was received (P less than .001), and there was also a significant survival benefit (P = .02). The advantage from PFT was found to be associated with tumor estrogen receptor (ER) and progesterone receptor (PR) as well as patient age and nodal status. Overall there was a significant improvement in DFS from PFT in those having tumors with an ER or PR level greater than or equal to 10 femtomole (fmol) (P = .01 and .009, respectively). No significant benefit in DFS or survival has been observed in patients less than or equal to 49 years old related either to nodes or tumor receptor status. Survival continues to be adversely affected by TAM in those patients (less than or equal to 49 years old), particularly when their tumors have a PR of 0 to 9 fmol (P = .007). In patients greater than or equal to 50 years old with four or more positive nodes, a significant DFS benefit persisted through the fifth year of observation in those having tumor ER or PR levels greater than 10 fmol (P less than .001 and .002). The advantage was observed in patients 50 to 59 years old as well as those 60 to 70. Women in the older decade demonstrated some advantage from PFT when their tumor ER or PR was 0 to 9 fmol. The most likely explanation for this finding is analytical error in receptor analyses.(ABSTRACT TRUNCATED AT 400 WORDS)     

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.     

Findings from recent National Surgical Adjuvant Breast and Bowel Project adjuvant studies in stage I breast cancer.

Before 1989, credible information about the treatment of breast cancer was derived mainly from randomized clinical trials that enrolled women with either metastatic (stage IV); locally advanced (stage III); or primary, operable, axillary lymph node-positive (stage II) disease. This report provides information from six recent National Surgical Adjuvant Breast and Bowel Project (NSABP) trials involving lymph node-negative (stage I) patients. Findings from NSABP B-13 demonstrated, through 14 years of follow-up, improvements in disease-free survival (DFS) and overall survival from methotrexate and fluorouracil (MF), regardless of age, in women with estrogen receptor (ER)-negative tumors. Results from NSABP B-19, which was conducted with similar patients, demonstrated, through 8 years, a greater overall DFS and survival advantage with cyclophosphamide and MF (CMF) than that observed with MF. Findings from NSABP B-23, in which patients similar to those in B-13 and B-19 were randomly assigned to receive CMF plus placebo, CMF plus tamoxifen (TAM), doxorubicin (Adriamycin) and cyclophosphamide (AC) plus placebo, or AC plus TAM, demonstrated no difference in relapse-free survival (RFS) or overall survival among the four groups through 5 years, either for all patients or relative to age. NSABP B-14, which was carried out in women with ER-positive tumors, compared the outcomes of those who received either placebo or TAM. Through 14 years, superior DFS and overall survival advantages, as well as a reduction in contralateral breast cancer, were observed with TAM. No additional benefit resulted from TAM administration beyond 5 years. Findings from NSABP B-20, a second study conducted in patients with ER-positive tumors, showed, after 8 years, both a DFS and an overall survival advantage from TAM plus either MF or CMF over that achieved with TAM alone. A recent meta-analysis in women with negative lymph nodes and either ER-negative or ER-positive tumors of less than or equal to 1 cm in size was conducted using patients from five NSABP trials. After 8 years, the RFS in women with ER-negative tumors was greater in the group treated with surgery and chemotherapy than in those who underwent surgery alone. In women with ER-positive tumors, RFS and overall survival advantages were observed from the addition of chemotherapy to TAM when that treatment regimen was compared with TAM alone. In addition, evidence has been presented from NSABP B-21, a trial evaluating radiation therapy (XRT) and/or TAM for the prevention of ipsilateral breast tumor recurrence (IBTR) after lumpectomy in women with tumors less than or equal to 1 cm. Findings have shown that XRT is superior to TAM and that XRT + TAM is superior to XRT alone for preventing IBTR. The findings demonstrate that chemotherapy and/or hormonal therapy is effective for the management of women with negative axillary lymph nodes and either ER-negative or ER-positive tumors. Because it also has been proven effective in women with tumors less than or equal to 1 cm, such therapy might also be considered in the treatment of that patient population.     

Sentinel lymph node biopsy in breast cancer patients treated with neoadjuvant chemotherapy

BACKGROUND:

Sentinel lymph node biopsy (SLNB) is a widely used staging method for patients with early breast cancer. Neoadjuvant chemotherapy modifies the anatomical conditions in the breast and axilla, and thus SLNB remains controversial in patients treated preoperatively. The aim of this study was to demonstrate the reliability and accuracy of this procedure in this particular group of patients.

METHODS:

The retrospective study analyzed medical records of patients diagnosed with primary breast cancer between the years 2005 and 2009. Of the patients treated by neoadjuvant therapy, 343 underwent lymphatic mapping to identify sentinel lymph nodes, and these were included in the analysis.

RESULTS:

The overall detection rate of sentinel lymph nodes was 80.8%. It was strongly influenced by clinical lymph node status (significantly higher success rate in lymph node‐negative patients); higher detection rates were also associated with age <50 years, estrogen receptor positivity, lower proliferation index, and absent lymphovascular space invasion. The false‐negative rate was 19.5% and was only marginally significantly dependent on lymphovascular space invasion. The overall accuracy of the method was 91.5%.

CONCLUSIONS:

By using the present technique, sentinel lymph node biopsy cannot be recommended as a reliable predictor of axillary lymph node status when performed at the authors' institution after neoadjuvant chemotherapy. Infrequent use of blue dye for lymphatic mapping, low number of resected sentinel lymph nodes, and absence of any selection among patients included in the study could be the main factors responsible for the low detection rate and high false‐negative rate. Cancer 2011;. © 2011 American Cancer Society.     

Evaluation of the worth of corynebacterium parvum in conjunction with chemotherapy as adjuvant treatment for primary breast cancer. Eight-year results from the National Surgical Adjuvant Breast and Bowel Project B-10

During the 1970s, information obtained from animal tumor models and from patients with a spectrum of solid tumors indicated the worth of a variety of immunostimulating agents. These findings provided a biological and clinical rationale for conducting randomized trials to evaluate the worth of those agents. Consequently, in May 1977 the National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented a randomized trial to determine whether Corynebacterium parvum (C. parvum, CP) plus chemotherapy would be more effective than chemotherapy alone in prolonging the disease-free survival (DFS) and survival (S) of patients with primary operable breast cancer and positive axillary nodes. The results of that trial through 8 years of follow-up fail to indicate that treatment with CP used in conjunction with l-phenylalanine mustard (L-PAM) plus 5-fluorouracil (PF) results in a better DFS and S than that observed after chemotherapy alone. Use of the immunomodulator has instead resulted in a poorer, but not statistically significant, outcome. Despite adjustments made to account for any imbalance in distribution of prognostic factors between the two treatment groups and despite considering treatment compliance as a factor, the unfavorable outcome persisted. A high incidence of fever and chills was associated with the administration of CP. The administration of hydrocortisone before each CP treatment reduced the frequency of those and other systemic effects. The failure to demonstrate a benefit from CP is in keeping with the failure of other nonspecific stimulating agents to contribute to the creation of a new paradigm for the treatment of breast 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.     

美国乳腺与肠道外科辅助治疗研究组结直肠癌临床试验研究进展

美国乳腺与肠道外科辅助治疗研究组由美国国家癌症研究中心资助,主要进行大规模乳腺癌和结直肠癌临床试验.其临床试验为乳腺癌以及结直肠癌的治疗提供了重要的参考和指导价值.近5年来,NSABP结直肠癌临床试验就新的辅助化疗方案、靶向药物的作用以及直肠癌的新辅助治疗和辅助治疗的作用进行了深入的研究,取得了一些新的进展.