Classification of ipsilateral breast tumor recurrences after breast conservation therapy can predict patient prognosis and facilitate treatment planning.

OBJECTIVE: To classify ipsilateral breast tumor recurrences (IBTR) as either new primary tumors (NP) or true local recurrence (TR). We utilized 2 different methods and compared sensitivities and specificities between them. Our goal was to determine whether distinguishing NP from TR had prognostic value. BACKGROUND: After breast-conservation therapy, IBTR may be classified into 2 distinct types (NP and TR). Studies have attempted to classify IBTR by using tumor location, histologic subtype, DNA flow cytometry data, or gene-expression profiling data. METHODS: A total of 447 (7.9%) of 5660 patients undergoing breast-conservation therapy from 1970 to 2005 experienced IBTR. Clinical data from 397 patients were available for review. We classified IBTRs as NP or TR on the basis of either tumor location and histologic subtype (method 1) or tumor location, histologic subtype, estrogen receptor status and human epidermal growth factor receptor 2 status (method 2). Kaplan-Meier curves and log-rank tests were used to evaluate overall and disease-specific survival differences between the 2 groups. Classification methods were validated by calculating sensitivity and specificity values using a Bayesian method. RESULTS: Of 397 patients, 196 (49.4%) were classified as NP by method 1 and 212 (53.4%) were classified as NP by method 2. The sensitivity and specificity values were 0.812 and 0.867 for method 1 and 0.870 and 0.800 for method 2, respectively. Regardless of method used, patients classified as NP developed contralateral breast carcinoma more often but had better 10-year overall and disease-specific survival rates than those classified as TR. Patients with TR were more likely to develop metastatic disease after IBTR. CONCLUSION: Ipsilateral breast tumor recurrences classified as TR and NP had clinically different features, suggesting that classifying IBTR may provide clinically significant data for the management of IBTR.

A CXCR4 antagonist CTCE-9908 inhibits primary tumor growth and metastasis of breast cancer.

BACKGROUND: CXCL12/CXCR4 signaling may be involved in tumor growth and angiogenesis, and homing of cancer cells to bone and other organs. Our purpose was to determine whether inhibition of CXCR4 with a peptide-based antagonist would reduce tumor growth and metastasis of breast cancer. METHODS: We used two mouse models of breast cancer. In the first model, 1 x 10(6) MDA-MB-231 breast cancer cells transfected with luciferase were implanted into the inguinal mammary fat pad to produce primary tumors. In the second model, 1 x 10(5) MDA-231-BSC12 cells were injected into the left cardiac ventricle to produce bone metastases. CTCE-9908, a peptide analog of CXCL12 that competitively binds to CXCR4, was used to test the effect of inhibiting CXCR4. Five mice from each mouse model were treated with CTCE-9908 (25 mg/kg, injected subcutaneously 5 d/wk). All mice were assessed weekly using bioluminescent imaging to quantify relative volumes of tumor burden. RESULTS: Bioluminescencent imaging showed that the mice treated with CTCE-9908 had significantly less primary tumor burden than the control mice. At 5 and 6 wk, the mice treated with CTCE-9908 had a 7-fold reduction and 5-fold reduction in primary tumor burden, respectively. Treatment with CTCE-9908 also significantly inhibited the rate of metastases compared with the control group. At 5 and 6 wk, the mice treated with CTCE-9908 demonstrated a 9-fold reduction and 20-fold reduction in metastatic tumor burden, respectively. CONCLUSION: Treatment with the CXCR4 antagonist CTCE-9908 significantly reduced metastasis as well as primary tumor growth in mouse models of breast cancer.

Long-term results of the M. D. Anderson randomized dose-escalation trial for prostate cancer.

PURPOSE: To report the long-term results of a randomized radiotherapy dose escalation trial for prostate cancer. METHODS AND MATERIALS: From 1993 to 1998, a total of 301 patients with stage T1b to T3 prostate cancer were accrued to a randomized external beam dose escalation trial using 70 Gy versus 78 Gy. The median follow-up is now 8.7 years. Kaplan-Meier analysis was used to compute rates of prostate-specific antigen (PSA) failure (nadir + 2), clinical failure, distant metastasis, disease-specific, and overall survival as well as complication rates at 8 years post-treatment. RESULTS: For all patients, freedom from biochemical or clinical failure (FFF) was superior for the 78-Gy arm, 78%, as compared with 59% for the 70-Gy arm (p = 0.004, and an even greater benefit was seen in patients with initial PSA >10 ng/ml (78% vs. 39%, p = 0.001). The clinical failure rate was significantly reduced in the 78-Gy arm as well (7% vs. 15%, p = 0.014). Twice as many patients either died of prostate cancer or are currently alive with cancer in the 70-Gy arm. Gastrointestinal toxicity of grade 2 or greater occurred twice as often in the high dose patients (26% vs. 13%), although genitourinary toxicity of grade 2 or greater was less (13% vs. 8%) and not statistically significantly different. Dose-volume histogram analysis showed that the complication rate could be significantly decreased by reducing the amount of treated rectum. CONCLUSIONS: Modest escalation in radiotherapy dose improved freedom from biochemical and clinical progression with the largest benefit in prostate cancer patients with PSA >10 ng/ml.

Comparison of outcomes for patients with unresectable, locally advanced non-small-cell lung cancer treated with induction chemotherapy followed by concurrent chemoradiation vs. concurrent chemoradiation alone.

PURPOSE: To retrospectively compare outcomes for patients with unresectable locally advanced non-small-cell lung cancer (NSCLC) treated at our institution with concurrent chemoradiation with or without induction chemotherapy. METHODS AND MATERIALS: We retrospectively analyzed 265 consecutive patients who received definitive treatment with three-dimensional conformal radiation and concurrent chemotherapy. Of these, 127 patients received induction chemotherapy before concurrent chemoradiation. RESULTS: The two groups of patients (with induction vs. without induction chemotherapy) were similar in age, performance status, weight loss, histology, grade, and stage. Patients who received induction chemotherapy had better overall survival (median, 1.9 vs. 1.4 years; 5-year rate, 25% vs. 12%; p < 0.001) and distant metastasis-free survival (5-year rate, 42% vs. 23%; p = 0.021). Locoregional control was not significantly different between the two groups. Multivariate analysis showed that induction chemotherapy was the most significant factor affecting overall survival, with a hazard ratio of 0.55 (95% confidence interval 0.40-0.75; p < 0.001). A planned subgroup analysis showed that induction chemotherapy was associated with a significant overall survival benefit for patients with adenocarcinoma or large-cell carcinoma (5-year rate, 24% vs. 8%; p = 0.003) but not for those with squamous cell carcinoma. A multivariate analysis of patients with adenocarcinoma or large-cell carcinoma confirmed that induction chemotherapy was the most significant factor associated with better overall survival, with a hazard ratio of 0.47 (95% confidence interval, 0.28-0.78; p = 0.003). CONCLUSION: Our retrospective analysis suggests that in combination with concurrent chemoradiation, induction chemotherapy may provide a small but significant survival benefit for patients with unresectable locally advanced adenocarcinoma or large-cell carcinoma of the lung.

Locoregional treatment outcomes for breast cancer patients with ipsilateral supraclavicular metastases at diagnosis.

PURPOSE: To evaluate the locoregional efficacy of multimodality treatment for breast cancer patients who present with ipsilateral supraclavicular (SCV) disease without systemic metastases. METHODS: We retrospectively reviewed the data from 71 patients with ipsilateral SCV involvement at presentation. SCV involvement in 16 patients (23%) was diagnosed by ultrasound examination only, without palpable disease. All patients were treated with curative intent using neoadjuvant chemotherapy, mastectomy or breast-conserving surgery (BCT), and radiotherapy. RESULTS: The 5-year SCV control, locoregional control (LRC), disease-free survival, and overall survival rate was 90%, 77%, 30%, and 47%, respectively. Patients with persistent SCV disease after neoadjuvant chemotherapy by physical examination had a lower rate of LRC (64% vs. 86%, p = 0.026), as did those with persistent SCV disease by ultrasound examination (66% vs. 96%, p = 0.007). Of those with a complete response of SCV disease by physical examination after neoadjuvant chemotherapy, those with persistently abnormal ultrasound findings had significantly worse disease-free survival (0% vs. 55%, p = 0.03). BCT was not associated with lower rates of LRC (82% for BCT vs. 76% for mastectomy, p = 0.80). CONCLUSION: Radiotherapy achieved excellent LRC after surgery for patients with ipsilateral SCV metastases who achieved a complete response of the SCV disease after neoadjuvant chemotherapy. For patients who achieved a complete response of the SCV disease by physical examination, ultrasonography of the SCV fossa may help assess the risk of disease recurrence. SCV involvement should not be considered a contraindication for BCT.

Postmastectomy radiation improves the outcome of patients with locally advanced breast cancer who achieve a pathologic complete response to neoadjuvant chemotherapy.

PURPOSE: The aim of this study was to investigate the role of postmastectomy radiation therapy in women with breast cancer who achieved a pathologic complete response (pCR) to neoadjuvant chemotherapy. METHODS AND MATERIALS: We retrospectively identified 226 patients treated at our institution who achieved a pCR at surgery after receiving neoadjuvant chemotherapy. Of these, the 106 patients without inflammatory breast cancer who were treated with mastectomy were analyzed. The patients' clinical stages at diagnosis were I in 2%, II in 31%, IIIA in 30%, IIIB in 25%, and IIIC in 11% (American Joint Committee on Cancer 2003 system). Of the patients, 92% received anthracycline-based chemotherapy, and 38% also received a taxane. A total of 72 patients received postmastectomy radiation therapy, and 34 did not. The actuarial rates of local-regional recurrence (LRR) and survival of the two groups were compared using the log-rank test. RESULTS: The median follow-up of surviving patients was 62 months. Use of radiation therapy did not affect the 10-year rates of LRR for patients with Stage I or II disease (the 10-year LRR rates were 0% for both groups). However, the 10-year LRR rate for patients with Stage III disease was significantly improved with radiation therapy (7.3% +/- 3.5% with vs. 33.3% +/- 15.7% without; p = 0.040). Within this cohort, use of radiation therapy was also associated with improved disease-specific and overall survival. CONCLUSION: Postmastectomy radiation therapy provides a significant clinical benefit for breast cancer patients who present with clinical Stage III disease and achieve a pCR after neoadjuvant chemotherapy.

Factors predictive of distant metastases in patients with breast cancer who have a pathologic complete response after neoadjuvant chemotherapy.

PURPOSE: To identify clinicopathological factors predictive of distant metastasis in patients who had a pathologic complete response (pCR) after neoadjuvant chemotherapy (NC). METHODS: Retrospective review of 226 patients at our institution identified as having a pCR was performed. Clinical stage at diagnosis was I (2%), II (36%), IIIA (27%), IIIB (23%), and IIIC (12%). Eleven percent of all patients were inflammatory breast cancers (IBC). Ninety-five percent received anthracycline-based chemotherapy; 42% also received taxane-based therapy. The relationship of distant metastasis with clinicopathologic factors was evaluated, and Cox regression analysis was performed to identify independent predictors of development of distant metastasis. RESULTS: Median follow-up was 63 months. There were 31 distant metastases. Ten-year distant metastasis-free rate was 82%. Multivariate Cox regression analysis using combined stage revealed that clinical stages IIIB, IIIC, and IBC (hazard ratio [HR], 4.24; 95% CI, 1.96 to 9.18; P < .0001), identification of < or = 10 lymph nodes (HR, 2.94; 95% CI, 1.40 to 6.15; P = .004), and premenopausal status (HR, 3.08; 95% CI, 1.25 to 7.59; P = .015) predicted for distant metastasis. Freedom from distant metastasis at 10 years was 97% for no factors, 88% for one factor, 77% for two factors, and 31% for three factors (P < .0001). CONCLUSION: A small percentage of breast cancer patients with pCR experience recurrence. We identified factors that independently predicted for distant metastasis development. Our data suggest that premenopausal patients with advanced local disease and suboptimal axillary node evaluation may be candidates for clinical trials to determine whether more aggressive or investigational adjuvant therapy will be of benefit.

Comparison of risk of local-regional recurrence after mastectomy or breast conservation therapy for patients treated with neoadjuvant chemotherapy and radiation stratified according to a prognostic index score.

PURPOSE: We previously developed a prognostic index that stratified patients treated with breast conservation therapy (BCT) after neoadjuvant chemotherapy into groups with different risks for local-regional recurrence (LRR). The purpose of this study was to compare the rates of LRR as a function of prognostic index score for patients treated with BCT or mastectomy plus radiation after neoadjuvant chemotherapy. METHODS: We retrospectively analyzed 815 patients treated with neoadjuvant chemotherapy, surgery, and radiation. Patients were assigned an index score from 0 to 4 and given 1 point for the presence of each factor: clinical N2 to N3 disease, lymphovascular invasion, pathologic size>2 cm, and multifocal residual disease. RESULTS: The 10-year LRR rates were very low and similar between the mastectomy and BCT groups for patients with an index score of 0 or 1. For patients with a score of 2, LRR trended lower for those treated with mastectomy vs. BCT (12% vs. 28%, p=0.28). For patients with a score of 3 to 4, LRR was significantly lower for those treated with mastectomy vs. BCT (19% vs. 61%, p=0.009). CONCLUSIONS: This analysis suggests that BCT can provide excellent local-regional treatment for the vast majority of patients after neoadjuvant chemotherapy. For the few patients with a score of 3 to 4, LRR was >60% after BCT and was <20% with mastectomy. If these findings are confirmed in larger randomized studies, the prognostic index may be useful in helping to select the type of surgical treatment for patients treated with neoadjuvant chemotherapy, surgery, and radiation.

Postmastectomy radiation improves local-regional control and survival for selected patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and mastectomy.

PURPOSE: To evaluate the efficacy of radiation in patients treated with neoadjuvant chemotherapy and mastectomy. PATIENTS AND METHODS: We retrospectively analyzed the outcomes of 542 patients treated on six consecutive institutional prospective trials with neoadjuvant chemotherapy, mastectomy, and radiation. These data were compared to those of 134 patients who received similar treatment in these same trials but without radiation. RESULTS: Irradiated patients had a lower rate of local-regional recurrence (LRR) (10-year rates: 11% v 22%, P = .0001). Radiation reduced LRR for patients with clinical T3 or T4 tumors, stage > or = IIB disease (AJCC 1988), pathological tumor size >2 cm, or four or more positive nodes (P < or = .002 for all comparisons). Patients who presented with clinically advanced stage III or IV disease but subsequently achieved a pathological complete response to neoadjuvant chemotherapy still had a high rate of LRR, which was significantly reduced with radiation (10-year rates: 33% v 3%, P = .006). Radiation improved cause-specific survival (CSS) in the following subsets: stage > or = IIIB disease, clinical T4 tumors, and four or more positive nodes (P < or = .007 for all comparisons). On multivariate analyses of LRR and CSS, the hazard ratios for lack of radiation were 4.7 (95% CI, 2.7 to 8.1; P < .0001) and 2.0 (95% CI, 1.4 to 2.9; P < .0001), respectively. CONCLUSION: After neoadjuvant chemotherapy and mastectomy, comprehensive radiation was found to benefit both local control and survival for patients presenting with clinical T3 tumors or stage III-IV (ipsilateral supraclavicular nodal) disease and for patients with four or more positive nodes. Radiation should be considered for these patients regardless of their response to initial chemotherapy.

Predictors of locoregional recurrence in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy, mastectomy, and radiotherapy.

PURPOSE: To identify the clinical and pathologic factors predictive of locoregional recurrence (LRR) after neoadjuvant chemotherapy, mastectomy, and radiotherapy. METHODS AND MATERIALS: We retrospectively reviewed the hospital records of 542 patients treated on six consecutive institutional prospective trials using neoadjuvant chemotherapy and postmastectomy radiotherapy. The clinical stage (American Joint Committee on Cancer, 1988) was Stage II in 17%, Stage IIIA in 30%, Stage IIIB in 43%, and Stage IV (ipsilateral supraclavicular disease) in 10%. All LRRs were considered events, irrespective of the timing to distant metastases. RESULTS: The median follow-up was 70 months. The 5-year and 10-year actuarial LRR rate was 9% and 11%, respectively. The clinical factors associated with LRR included combined clinical stage, clinical T stage, ipsilateral supraclavicular nodal disease, chemotherapy response, physical examination size after chemotherapy, and no tamoxifen use (p < or = 0.04 for all factors). The pathologic predictors of LRR included the number of positive nodes, dissection of <10 nodes, multifocal/multicentric disease, lymphovascular space invasion, extracapsular extension, skin/nipple involvement, and estrogen receptor-negative disease (p

Late rectal toxicity: dose-volume effects of conformal radiotherapy for prostate cancer.

PURPOSE: To identify dosimetric, anatomic, and clinical factors that correlate with late rectal toxicity after three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. METHODS AND MATERIALS: We retrospectively analyzed the dose-volume histograms and clinical records of 163 Stage T1b-T3c prostate cancer patients treated between 1992 and 1999 with 3D-CRT, to a total isocenter dose of 74-78 Gy at The University of Texas M. D. Anderson Cancer Center. The median follow-up was 62 months (range 24-102). All late rectal complications were scored using modified Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria. The 6-year toxicity rate was assessed using Kaplan-Meier analysis and the log-rank test. A univariate proportional hazards regression model was used to test the correlation between Grade 2 or higher toxicity and the dosimetric, anatomic, and clinical factors. In a multivariate regression model, clinical factors were added to the dosimetric and anatomic variables to determine whether they significantly altered the risk of developing late toxicity. RESULTS: At 6 years, the rate of developing Grade 2 or higher late rectal toxicity was 25%. A significant volume effect was observed at rectal doses of 60, 70, 75.6, and 78 Gy, and the risk of developing rectal complications increased exponentially as greater volumes were irradiated. Although the percentage of rectal volume treated correlated significantly with the incidence of rectal complications at all dose levels (p <0.0001 for all comparisons), the absolute rectal volume appeared to be a factor only at the higher doses of 70, 75.6, and 78 Gy (p = 0.0514, 0.0016, and 0.0021, respectively). The following variables also correlated with toxicity on the univariate analysis: maximal dose to the clinical target volume, maximal dose to rectum, maximal dose to the rectum as a percentage of the prescribed dose, and maximal dose delivered to 10 cm(3) of the rectum. Of the clinical variables tested, only a history of hemorrhoids correlated with rectal toxicity (p = 0.003). Multivariate analysis showed that the addition of hemorrhoids increased the risk of toxicity for each dosimetric variable found to be significant on univariate analysis (p <0.05 for all comparisons). CONCLUSION: Dose-volume histogram analyses clearly indicated a volume effect on the probability of developing late rectal complications. Therefore, dose escalation may be safely achieved by adherence to dose-volume histogram constraints during treatment planning and organ localization at the time of treatment to ensure consistent patient setup.

Comparison of rectal dose-wall histogram versus dose-volume histogram for modeling the incidence of late rectal bleeding after radiotherapy.

PURPOSE: To compare the fits of normal-tissue complication probability (NTCP) models based on rectal dose-wall histograms (DWHs) vs. dose-volume histograms (DVHs) when the two are used to analyze a common set of late rectal toxicity data. METHODS AND MATERIALS: Data were analyzed from 128 prostate cancer patients treated with 3-dimensional conformal radiotherapy (3D-CRT) at The University of Texas M.D. Anderson Cancer Center (UTMDACC). The DVH for total rectal volume, including contents, was obtained for each patient from the treatment-planning system. A DWH was also computed, using the outer rectal contour plus an autogenerated inner contour that corresponds to an assumed 3-mm rectal wall thickness. The endpoint for analysis was Grade 2 or higher late rectal bleeding within 2 years of treatment; all patients had at least 2 years of follow-up. Four different NTCP models were fitted to the response data by using either the DVH or the DWH to describe the dose distribution to rectum or rectal wall, respectively. The 4 models considered were the Lyman model, the mean dose model, the parallel-architecture model, and a model based on the volume of a organ receiving more than a specified dose (the "cutoff-dose" model). RESULTS: For each of the models, the fit to the late rectal bleeding data was slightly improved when the analysis was based on the rectal DWH instead of on the DVH. In addition, the results of the cutoff dose and parallel architecture models were consistent with one another for the DWH data but not for the DVH data. For the DWH data, both models predict a 50% or higher incidence of Grade 2 or worse late rectal bleeding within 2 years if 80% or more of the rectal wall is exposed to doses greater than 32 Gy. A 50% or higher incidence of rectal bleeding is also predicted if the mean dose to rectal wall exceeds 53.2 Gy. CONCLUSIONS: A consistent, although modest, improvement occurs in the fits of NTCP models to the UTMDACC 2-year late rectal bleeding data when the fit is based on the rectal dose-wall histogram instead of on the dose-volume histogram for entire rectum, including contents.

Dose-volume response analyses of late rectal bleeding after radiotherapy for prostate cancer.

PURPOSE: To compare the fits of various normal tissue complication probability (NTCP) models to a common set of late rectal toxicity data, with the aim of identifying the best model for predicting late rectal injury after irradiation. METHODS AND MATERIALS: Late toxicity data from 128 prostate cancer patients treated on protocol with three-dimensional conformal radiotherapy at The University of Texas M.D. Anderson Cancer Center (UTMDACC) were analyzed. The dose-volume histogram for total rectal volume, including contents, was obtained for each patient, and the presence or absence of Grade 2 or worse rectal bleeding within 2 years of treatment was scored. Five different NTCP models were fitted to the data using maximum likelihood analysis: the Lyman model, the mean dose model, a parallel architecture model, and models based on either a cutoff dose or a cutoff volume. RESULTS: All five of the NTCP models considered provided very similar fits to the UTMDACC rectal bleeding data. In particular, none of the more highly parameterized models (the four-parameter parallel model, three-parameter Lyman model, or three-parameter cutoff dose and volume models) provided a better fit than the simplest of the models, the two-parameter NTCP model describing rectal bleeding as a probit function of mean dose to rectum. CONCLUSION: No dose-volume response model has yet been identified that provides a better description of the UTMDACC rectal toxicity data than the mean dose model. Because this model has relatively low predictive accuracy, the need to identify a better model remains.

Her2/neu-positive disease does not increase risk of locoregional recurrence for patients treated with neoadjuvant doxorubicin-based chemotherapy, mastectomy, and radiotherapy.

PURPOSE: Preclinical data suggest that overexpression of Her2/neu confers cellular radioresistance. We retrospectively studied whether Her2/neu-positive disease was associated with locoregional recurrence (LRR) after postmastectomy radiotherapy (RT) for breast cancer. METHODS AND MATERIALS: Data from 337 patients treated in four institutional prospective clinical trials neoadjuvant doxorubicin-based chemotherapy, mastectomy, and RT were reviewed. The trials were conducted between 1989 and 2000. Of the 337 patients, 108 (32%) had tumors that were tested for Her2/neu, with positivity defined by 3+ immunohistochemistry staining or gene amplification detected by fluorescence in situ hybridization. RT was delivered to the chest wall and draining lymphatics (median dose, 50 Gy) followed by a chest wall boost (median dose, 10 Gy). RESULTS: Thirty-two patients had Her2/neu-positive disease and 76 patients had Her2/neu-negative disease. The Her2/neu-positive tumors were associated with a greater rate of estrogen receptor-negative disease (p = 0.03), the presence of supraclavicular disease at diagnosis (p = 0.027), and a greater number of positive lymph nodes after chemotherapy (p = 0.026). Despite these adverse features, the actuarial overall LRR rate was roughly equivalent for the patients with Her2/neu-positive tumors vs. those with Her2/neu-negative tumors (5-year rate 17.5% vs. 13.9%, respectively; 10-year rate 17.5% vs. 18.9%, respectively; p = 0.757). On Cox regression analysis of LRR adjusted for N stage and estrogen receptor status, the hazard ratio for Her2/neu positivity was 0.89 (95% confidence interval, 0.31-2.59; p = 0.83). CONCLUSION: Her2/neu overexpression does not appear to predispose to LRR after neoadjuvant doxorubicin-based chemotherapy, mastectomy, and RT.

Impact of internal metallic ports in temporary tissue expanders on postmastectomy radiation dose distribution.

PURPOSE: Temporary tissue expanders (TTE) with an internal magnetic metal port (IMP) have been increasingly used for breast reconstruction in post-mastectomy patients who receive radiation therapy (XRT). We evaluated XRT plans of patients with IMP to determine its effect on XRT dose distribution. METHODS AND MATERIALS: Original treatment plans with CT simulation scans of 24 consecutive patients who received XRT (ORI), planned without heterogeneity corrections, to a reconstructed breast containing an IMP were used. Two additional treatment plans were then generated: one treatment plan with the IMP assigned the electron density of the rare earth magnet, nickel plated neodymium-iron-boron (HET), and a second treatment plan with the IMP assigned a CT value of 1 to simulate a homogeneous breast without an IMP (BRS). All plans were prescribed 50 Gy to the reconstructed breast (CTV). RESULTS: CTV coverage by 50 Gy was significantly lower in the HET (mean 87.7% CTV) than in either the ORI (mean 99.7% CTV, P<.001) or BRS plans (mean 95.0% CTV, P<.001). The effect of the port was more pronounced on CT slices containing the IMP with prescription dose coverage of the CTV being less in the HET than in either ORI (mean difference 33.6%, P<.01) or BRS plans (mean difference 30.1%, P<.001). HET had a less homogeneous and conformal dose distribution than BRS or ORI. CONCLUSION: IMPs increase dose heterogeneity and reduce dose to the breast CTV through attenuation of the beam. For optimal XRT treatment, heterogeneity corrections should be used in XRT planning for patients with TTE with IMP, as the IMP impacts dose distribution.

Evaluation of a CXCR4 antagonist in a xenograft mouse model of inflammatory breast cancer.

CXCL12/CXCR4 signaling, being important in the homing of cancer cells to lungs, bone and other organs, is a promising therapeutic target. Our purpose was to determine whether a peptide-based antagonist of CXCR4 would reduce primary tumor growth and/or metastasis in a preclinical mouse model of inflammatory breast cancer. We improved an existing model of inflammatory breast cancer for this study by luciferase transfection of SUM149 cells and the monitoring of such cells in mice by imaging and the luciferase assay. We implanted 2 x 10(6) SUM49-Luc cells along with matrigel into the left thoracic mammary fat pad of nude mice to produce tumors. Our mouse model exhibited important features of inflammatory breast cancer, namely, aggressive local disease, local metastases and distant metastases. To evaluate the efficacy of a CXCR4 antagonist CTCE-9908, by itself or in combination with paclitaxel, we treated groups of ten mice each with CTCE-9908 (25 mg/kg, injected subcutaneously 5 days/week), control peptide SC-9908, paclitaxel (10 mg/kg, injected subcutaneously twice a week), and CTCE-9908 plus paclitaxel concurrently. We assessed all mice weekly by whole-body luciferase imaging to quantify relative primary tumor burden and distant metastases. At the end of the experiment, we quantified primary tumors by weight and lung metastases by luciferase activity assay on tissue lysates. Paclitaxel, a known chemotherapeutic, inhibited primary tumor growth in our model (P < 0.05). CTCE-9908 did not significantly inhibit primary tumor growth or lung metastases as compared to control groups, without or with paclitaxel (P > 0.05). However, CTCE-9908 as a single therapy inhibited organ-specific metastasis to leg (P < 0.05 by chi-squared test and by two-sample t-test).

African-American race is associated with a poorer overall survival rate for breast cancer patients treated with mastectomy and doxorubicin-based chemotherapy.

BACKGROUND: African-American (AA) race has been associated with a worse outcome in breast cancer. It is unclear whether this is due to biological factors, socioeconomic factors, or both. METHODS: The records from 2 independent cohorts of breast cancer patients treated on institutional protocols with mastectomy and adjuvant (n = 1456) or neoadjuvant (n = 684) doxorubicin-based chemotherapy were retrospectively reviewed. RESULTS: The adjuvant (Adj) chemotherapy cohort included 1142 Caucasian (CA), 186 Hispanic (HI), and 128 (AA) patients. The neoadjuvant (Neo) chemotherapy protocols included 448 CA, 114 HI, and 122 AA patients. In both groups, AA patients had later-stage tumors (Adj P = .017; Neo P = .051), a higher rate of estrogen receptor (ER)-negative disease (Adj P = .054; Neo P = .039), and a worse 10-year actuarial overall survival rate than CA or HI patients (Adj, 52%, 62%, and 62%, respectively, P = .009; Neo, 40%, 50%, and 56%, respectively, P = .015). In multivariate analyses, AA race remained independently associated with a poorer overall survival rate in both cohorts (Adj, hazard ratio = 1.39, P = .018; Neo, hazard ratio = 1.37, P = .02). CONCLUSIONS: The data suggest that AA race is associated with less favorable biological tumor features, such as an increased likelihood of ER-negative disease, than those found in CA and HI patients. Such differences in tumor biology, as well as previously described socioeconomic factors, likely contribute to the lower rate of survival in the AA breast cancer population.