Early Clinical Experience of Utilizing Online Adaptive Radiotherapy for Accelerated Partial Breast Irradiation with Stereotactic Body Radiation Therapy for Early-Stage Breast Cancer Patients

PURPOSE/OBJECTIVE(S)

Accelerated partial breast irradiation (APBI) with stereotactic body radiation therapy (SBRT) is becoming popular for early-stage breast cancer (ESBC) due to decreased treatment time and dose to healthy breast tissue. With variability in lumpectomy cavity size post-surgery, CBCT-guided online adaptive RT (oART) may improve target coverage and reduce normal tissue exposure by accounting for inter- and intrafractional cavity variations. In this study, we report our initial clinical experience utilizing APBI oART for patients with ESBC.

MATERIALS/METHODS

A total of 15 patients with 17 ESBC cavities (2 with bilateral disease) were treated with SBRT using oART over one year. Patients were immobilized using standard breast simulation setup with free breathing and breath hold (if left sided). The clinical target volume consisted of an isometric 1 cm expansion off the lumpectomy cavity, which was expanded another 3 mm (cropped 3mm from surface) to create the planning target volume (PTV). 95% of the PTV received prescription dose (30 Gy in 5 fractions). The oART delivery process (supervised by physician and physicist) initially coregisters the daily CBCT to the treatment planning CT with alignment to lumpectomy cavity. Target volumes and organs-at-risk were modified at each treatment and the plan re-optimized. Either the re-optimized oART plan or scheduled plan was chosen for each fraction pending which plan best met prespecified clinical goals. Acute toxicity was assessed at one-month follow-up using CTCAE.

RESULTS

Patients were age 56 or older, ECOG 0-1, with no known genetic abnormality, and with anatomic stage 0-1A ESBC. Most tumors were located in the upper outer quadrant (n = 12, 70.6%) at middle or posterior depth (n = 15, 88.2%). Final margins were negative. 88% had tantalum clips placed. One patient had an Oncotype DS score of 34 and received systemic therapy. 82.3% met suitable APBI criteria and 3 met cautionary criteria due to high grade, of which 2 had ipsilateral trimodality treatment 10+ years prior and denied mastectomy at recurrence. Mean time to starting RT after lumpectomy was 2.5 months. Mean PTV to breast ratio was 0.12. From simulation to end of treatment, lumpectomy cavity size decreased a median of 27%. oART plans were chosen 89% of the time. VMAT was utilized 52.9% of the time compared to static-field IMRT (47.1%). Three patients were treated with breath hold. 93% of patients were treated on non-consecutive days with average treatment lasting 9.1 ± 2.2 days. CTCAE grade 1 toxicities were hyperpigmentation (n = 6, 40%), breast pain (n = 2, 13.3%), persistent seroma (n = 1, 6.7%), and fatigue (n = 7, 46.7%). No patients experienced fat necrosis, telangiectasias, breast shrinkage, lymphedema, or CTCAE grade 2+ toxicities.

CONCLUSION

oART for APBI using SBRT for patients with ESBC is clinically feasible and allows for variations in lumpectomy cavity size. Nearly half of patients had no complaints or breast changes at one-month follow-up and the remaining had CTCAE grade 1 toxicities alone.

Abstract P4-01-02: Choosing wisely: Radiographic surveillance after breast conservation therapy in HER2+ breast cancer

Purpose/Objective(s): ASTRO Choosing Wisely campaign recommends no more than annual mammography after breast conservation therapy (BCT). HER2+ disease portends increased risk of locoregional recurrence in comparison to Luminal A disease. Our previous institutional practice included surveillance imaging every 6 months for the first 2-3 years after BCT. The purpose of this study is to evaluate surveillance imaging intervals as a means of detecting early locoregional recurrence at one institution.

Materials/Methods: Women with HER2+ locoregionally confined invasive breast cancer treated with lumpectomy and radiation as part of breast conservation therapy at one institution were retrospectively identified after IRB approval. Patient demographics, treatment, surveillance, and outcomes data were captured. BRCA+ patients or those without available surveillance follow-up at our institution were excluded. Surveillance period started after the last fraction of radiation was completed.

Results: In 86 women treated from 2008-2016, median age at diagnosis was 57, and 69% were Caucasian. Most patients were treated for Stage I-II invasive ductal carcinoma. All but one were treated with chemotherapy, with similar distribution between adjuvant and neoadjuvant regimens. Receptor status was as follows: ER+ 66%, PR+ 59%, ER+/PR+/HER2+ in 58%, ER-/PR-/HER2+ in 33%. Mammography +/- ultrasound was utilized, with infrequent use of magnetic resonance imaging. Median time from end of radiation to first surveillance imaging was 4 months. All women had 1 post-BCT imaging, with 2nd, 3rd, and 4th available in 91%, 85%, 73% respectively. Interval frequency between first 4 images was 6 months. No patients had expired at the time of analysis. Recurrence were identified in 2 women: 1 identified clinically after negative mammography, and 1 identified on mammography at 27 months.

Conclusion: While overall events are small, discordant biannual mammography did not identify locoregional recurrences in this biologically higher risk group in the first two years post-treatment. This data supports current guideline recommendations limiting surveillance breast imaging in patients undergoing breast conservation to an annual frequency.

Citation Format: Everett A, Wallace AS, De Los Santos JF, Rocgue GB, Parker CS, Keene KS. Choosing wisely: Radiographic surveillance after breast conservation therapy in HER2+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-01-02.

Abstract P3-04-01: Molecular determinants of post-mastectomy breast cancer recurrence

Introduction

The management of breast cancer (BC) patients who undergo mastectomy in the setting of 1-3 positive lymph nodes has been controversial. This retrospective Translational Breast Cancer Research Consortium study evaluated the molecular aberrations associated with locoregional recurrence (LRR) or distant metastasis (DM) compared to controls in an effort to identify molecular predictors associated with recurrence.

Methods/Materials

We identified 115 HER2 negative, therapy naïve, T 1-3 and N 0-1 BC patients treated with mastectomy and no post mastectomy radiation therapy from 1997 to present with available FFPE tissue blocks. The cohort included 32 patients with LRR, 34 with DM, and 49 controls (without recurrence) who were matched for stage, grade, hormone receptor status, age ≤ or > 50, chemotherapy receipt, and margin status. Matched primary and recurrent LRR samples were available for 3 patients. Hybrid capture next generation sequencing (NGS) of 142 cancer related genes and RNAseq were performed to identify DNA/RNA alterations associated with LRR or DM. The frequency of common alterations on NGS was compared with Fisher's exact test. Expression of each gene from mRNA-Seq was treated as an explanatory variable. Immunohistochemistry (IHC) was performed for PTEN, Ki-67 and cleaved caspase 3 (CC3). PTEN loss and percentage of Ki-67 and CC3 positive cells were compared between groups with Fisher's exact test and nonparametric methods, respectively.

Results

RNAseq was performed on 115 patients; there was no difference in RNA expression levels between the groups. DNA analysis was performed on 57 patients (17 LRR, 15 DM and 25 controls), NF1 mutation rate was significantly elevated in both the LRR (24%) and DM (27%) samples compared to controls 0%; (p=0.0070). The mitogen activated protein kinase (MAPK) pathway was significantly mutated in both LRR (47%) and DM (40%) samples compared to the controls 0%; (p<0.0001). There was no significant difference in the rate of alterations of the PI3K/Akt/mTOR pathway among the three groups. Of three patients with matched primary vs LRR samples, one had concordant mutations. The second patient had additional mutations in the LRR, including gain of a NF1 mutation. The third patient had complete discordance of mutations identified in primary and LRR and had gain of HER2 amplification, suggestive of a new primary. There was no significant association between the groups and the loss of PTEN expression or CC3 expression. There was a significant difference between Ki 67 positive cells in patients with LRR (mean 29%), DM (mean 26%) versus controls (mean 14%, p= 0.0011). HR+ patients were significantly more likely to have a positive PTEN, lower Ki-67 and lower CC3 expression, p=0.0004, p<0.0001, and p<0.0001 respectively.

Conclusions

In this matched cohort analysis, mutations in the MAPK pathway, specifically NF1, were associated with both LRR and DM, suggesting that alterations in this pathway are associated with a more aggressive tumor phenotype. However, there were no molecular features that discriminated between those likely to recur locally alone versus distantly. Further study is needed to validate these findings, and to determine whether targeting alterations in this pathway could decrease the risk of recurrence.

Citation Format: Keene KS, King T, Hwang ES, Peng B, McGuire K, Tapia C, Zhang H, Bae S, Nakhlis F, Klauber-Demore N, Meszoely I, Sabel MS, Willey SC, Eterovic KA, Hudis C, Wolff A, De Los Santos J, Thompson A, Mills GB, Meric-Bernstam F. Molecular determinants of post-mastectomy breast cancer recurrence [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-04-01.

Abstract P3-03-03: A tri-modality imaging assessment algorithm to evaluate neoadjuvant therapy response in patients with operable breast cancer

Background: To determine the negative predictive value (NPV), positive predictive value (PPV), accuracy, sensitivity and specificity of a pre-surgical tri-modality imaging assessment algorithm to determine complete pathologic response (pCR) post neoadjuvant therapy in patients with operable breast cancer.

Methods: A retrospective analysis was performed on data collected from patients receiving neoadjuvant therapy and pre-surgical breast magnetic resonance imaging (MRI), ultrasound (US) and mammography between 2004 and 2010 at our institution. Tri-modality imaging was reviewed by a single blinded breast radiologist and evaluated for predetermined modality specific parameters as defined in Table 1. The NPV, PPV, accuracy, sensitivity, and specificity were calculated on the basis of the final surgical pathology report with a complete pathologic response in the breast defined as no residual invasive disease or in situ disease.

Results. Eighty-three tumors in 83 patients with a mean age of 50 (range 27–70) were evaluated. Twenty-three patients had a pCR. The NPV, PPV, sensitivity, specificity, and accuracy of tri-modality imaging algorithm for pCR were 0.87, 0.95, 0.95, 0.87 and 0.93 utilizing a cut-point of ≤ 5 for complete response by imaging. The mean score for patients with pCR was 4.61 (range 3–10) with 3 patients scoring above 5. The mean score for patients with residual disease was 7.73 (range 5–11).

Conclusions: A tri-modality imaging scoring algorithm is predictive of complete pathologic response. This algorithm will be tested in a developing prospective trial that will also assess the additive value of tumor bed biopsy in patients who achieve a score of 5 or less.

Abstract P6-07-37: Impact of body mass index on recurrence risk in patients with ductal carcinoma in situ

Background: Body mass index (BMI) has been correlated with risk of recurrence in invasive breast cancer, but the association between BMI and recurrence in ductal carcinoma in situ (DCIS) is less clear. Recent retrospective data indicates that local recurrence is not related to BMI at initial diagnosis. Here we examine the relationship between initial BMI and recurrence in a separate cohort of patients with DCIS.

Methods: One hundred eighty-nine patients with DCIS treated between the years of 1999 and 2005 at the University of Alabama at Birmingham were analyzed. BMI was divided into 4 categories as follows: underweight (BMI <18.5 kg/m (2)), normal weight (BMI 18.5–24.9 kg/m (2)), overweight (BMI 25–29.9 kg/m (2)), and obese (BMI ≥30 kg/m (2)). Fisher's exact test was used to evaluate the association between likelihood of recurrence based on initial BMI and the log rank test was used to evaluate recurrence-free survival. Risk of both overall recurrence and specifically local recurrence were analyzed.

Results: There were 199 cases of DCIS identified in our cohort of 189 patients (10 patients had bilateral disease). Of these 189 patients, 1.1% (2/189) were underweight, 31.2% (59/189) were normal weight, 22.7% (43/189) were overweight, and 21.7% (41/189) were obese. BMI could not be obtained for 23.3% (44/189) of patients. With a median follow-up of 87.2 months, there were 28 total recurrences identified in the 199 cases (14.1%) with 85.7% of these including a local recurrence. No significant associations were found between the likelihood of overall or local recurrence and any of the four BMI categories. Further, analysis of recurrence-free survival did not show any significant associations between BMI and recurrence.

Conclusions: Our data supports recently reported evidence that BMI at diagnosis does not affect the risk of overall or local recurrence in patients with DCIS.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-37.

Abstract P5-17-07: Influence of bevacizumab on local-regional recurrence in triple negative breast cancer

Background: Triple negative breast cancer (TNBC) comprises 15–20% of newly diagnosed invasive breast cancers and has been associated with an elevated risk of both local-regional recurrence (LRR) as well as distant failure. Bevacizumab (BEV) has been shown to improve pathologic complete response rates in the setting of neoadjuvant chemotherapy (NCT), but its effect on LRR remains undefined. This study reports the impact of adding BEV to standard breast cancer therapy in TNBC patients treated at a single institution.

Methods: One hundred and eighty-five consecutive TNBC patients treated at the University of Alabama Birmingham from May 2005 to August 2010 were reviewed. Thirty-one TNBC patients treated with chemotherapy (CT) and BEV on prospective studies were matched (1:2) with 62 TNBC patients treated with CT alone, controlling for age, stage, and use of radiation (RT). The Kaplan-Meier method was used to estimate LRR, distant metastasis-free survival (DMFS), and overall survival (OS), and cohorts were compared using Cox proportional hazards models and the 2-sided log-rank test.

Results: Mean age was 47 and 46 years in the cohorts with and without BEV, respectively. Stage in each cohort was as follows: 32% stage I, 61% stage II, and 7% stage III. Use of adjuvant RT was 81% in each cohort (25/31 BEV, 50/62 no BEV). BEV was delivered with NCT in 17 patients (55%) and with adjuvant CT in the remaining 14 patients (45%). Eleven patients (35%) completed an additional 1 year of maintenance therapy with BEV. LRR occurred in 2 (6%) patients treated with BEV vs. 16 (26%) treated with CT alone (HR = 0.25, 95% CI 0.06–1.07, p = 0.04). Distant recurrence occurred in 3 (10%) patients treated with BEV vs. 11 (18%) patients in the CT group HR=0.6, 95% CI 0.2–1.8, p = 0.48). There were 2 (6%) deaths in the BEV group vs. 12 (19%) in the CT alone group (HR = 0.55, 95% CI 0.13–2.3, p = 0.19).

Conclusions: In a matched-pair analysis of TNBC patients, the addition of BEV to conventional breast cancer management was associated with a reduction in LRR. Further prospective study is necessary to examine the impact of BEV on local-regional control in TNBC.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-17-07.

P3-14-26: The Effect of Biologic Subtype in Patients Treated with Neoadjuvant Chemotherapy: A UAB Experience

Purpose: Previous studies have suggested that the pre treatment clinical stage drives loco-regional recurrence (LRR), distant metastasis (DM) and survival in patients treated with neoadjuvant chemotherapy. This retrospective analysis was performed to look at the effect of biologic subtype on patient outcomes.

Methods: Between 1999 and 2005, 115 patients treated with neoadjuvant chemotherapy, surgery, and +/−radiation therapy at UAB were identified. Patient, tumor, and treatment characteristics were recorded. Pathologic complete response was defined as resolution of both invasive disease and DCIS in both the primary and nodal disease. Survival was measured using the Kaplan Meier statistics. Univariate and multivariate analyses of covariates associated with LRR, DM, progression-free (PFS) and overall survival (OS) were performed. Results: The mean age was 49 years, with a mean follow-up of 5.8 years. Subtype distribution was as follows: 52 luminal A, 17 luminal B, 36 triple negative, 9 Her2+ and one patient with an unknown biologic subtype. Distribution of clinical stage was as follows: 40 IIA, 34 IIB, 26 IIIA, 10 IIIB, and 5 IIIC. Tumors were down-staged following neoadjuvant therapy as follows: 18: pCR, 6: residual DCIS, 17: I, 38: IIA, 11: IIB, 13: IIIA, 5: IIIB, and 7: IIIC. Pre-treatment clinical stage did not significantly influence LRR, DM or progression free and overall survival; however, final pathologic T, N and group stage were associated with both progression free, p=0.003, 0.011, 0.005 and overall survival, p=0.02, 0.037, and 0.009. Complete resolution of tumor by mammographic or MR imaging to neoadjuvant chemotherapy, was associated with an increased overall survival, p=0.0025. Univariate analysis did not show a significant effect of biologic subtype, age, grade, use of radiation therapy or anti-hormonal therapy.

Discussion: In this retrospective series, response to chemotherapy and the final pathologic stage, representing the volume of residual disease, were important predictors of survival. Further study to determine factors predictive of chemotherapy response is needed.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-26.

P3-07-06: Prognostic Utility of Upfront Nodal Staging Prior to Neoadjuvant Chemotherapy: The UAB Experience

Purpose: Controversy exists regarding the prognostic utility of upfront lymph node staging in patients receiving neoadjuvant chemotherapy. This retrospective study explores whether upfront verses outback nodal staging influenced locoregional control and survival endpoints. Methods: Between 1999 and 2005 one hundred and fifteen patients treated with neoadjuvant chemotherapy at UAB were identified. Patient, tumor, and treatment variables were recorded. Timing of nodal assessment was based on either surgeon preference or stipulated upfront per several clinical protocols. Survival was measured using the Kaplan Meier statistics. Univariate and multivariate analyses of covariates associated with local-regional control (LRC), progressionfree (PFS) and overall survival (OS) were performed. Results: Mean age was 49 years and mean follow-up was 5.8 years. Stage distribution was as follows: 40 IIA, 34 IIB, 26 IIIA, 10 IIIB, and 5 IIIC. Definitive surgery included breast conservation in 49 patients, total mastectomy in 21 and modified radical mastectomy in 44. Seventy-two patients had upfront nodal sampling before neoadjuvant therapy, 36 by fine needle assessment and the remainder by sentinel node biopsy. Forty-three patients had their nodal assessment following neoadjuvant chemotherapy. Of those with upfront nodal staging: forty nine patients had a positive nodal result and 23 had negative findings. In those that were sampled at the time of definitive surgery: 21 had positive results, 21 had a negative result, and 1 patient did not have any nodes in the specimen. One hundred five patients had post-operative radiation therapy. Overall there was no difference in LRC, PFS or OS outcomes between patients that had an upfront nodal staging procedure and those that had their nodes sampled at the time of definitive surgery. Patients achieving pCR had a non-significant trend towards improved overall survival (p=0.12). Final pathologic T, N and group stage were statistically significant in determining the progression free, p=0.003, 0.011, 0.005 and overall survival, p=0.02, 0.037, and 0.009. Lymphovascular space invasion was associated with progression free survival on univariate analysis, p=0.0179, but not multivariate analysis. Other covariates including age, biologic subtype, grade, type of chemotherapy, use of radiation therapy, radiation volume, time to complete radiation therapy, and use of hormonal therapy did not affect outcomes. Discussion: Upfront as compared with outback lymph node staging did not influence locoregional control or survival endpoints. Final pathologic stage and not initial clinical stage remains the most important prognostic factor associated with survival.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-07-06.

A phase I study evaluating the role of the anti-epidermal growth factor receptor (EGFR) antibody cetuximab as a radiosensitizer with chemoradiation for locally advanced pancreatic cancer

PURPOSE

(1) To determine the safety of the epidermal growth factor receptor (EGFR) antibody cetuximab with concurrent gemcitabine and abdominal radiation in the treatment of patients with locally advanced adenocarcinoma of the pancreas. (2) To evaluate the feasibility of pancreatic cancer cell epithelial-mesenchymal transition (EMT) molecular profiling as a potential predictor of response to anti-EGFR treatment.

METHODS

Patients with non-metastatic, locally advanced pancreatic cancer were treated in this dose escalation study with gemcitabine (0-300 mg/m(2)/week) given concurrently with cetuximab (400 mg/m(2) loading dose, 250 mg/m(2) weekly maintenance dose) and abdominal irradiation (50.4 Gy). Expression of E-cadherin and vimentin was assessed by immunohistochemistry in diagnostic endoscopic ultrasound fine-needle aspiration (EUS-FNA) specimens.

RESULTS

Sixteen patients were enrolled in 4 treatment cohorts with escalating doses of gemcitabine. Incidence of grade 1-2 adverse events was 96%, and incidence of 3-4 adverse events was 9%. There were no treatment-related mortalities. Two patients who exhibited favorable treatment response underwent surgical exploration and were intraoperatively confirmed to have unresectable tumors. Median overall survival was 10.5 months. Pancreatic cancer cell expression of E-cadherin and vimentin was successfully determined in EUS-FNA specimens from 4 patients.

CONCLUSIONS

Cetuximab can be safely administered with abdominal radiation and concurrent gemcitabine (up to 300 mg/m(2)/week) in patients with locally advanced adenocarcinoma of the pancreas. This combined therapy modality exhibited limited activity. Diagnostic EUS-FNA specimens could be analyzed for molecular markers of EMT in a minority of patients with pancreatic cancer.

Abstract P4-11-04: The Influence of Radiation on Survival in Patients with Triple Negative Stage II Breast Cancer

Background: Prospective trials of locally advanced breast cancer patients treated with adjuvant radiation (RT) have demonstrated a survival advantage; however, use of postmastectomy RT in stage II patients is controversial. This study explores the possibility that patients with aggressive variant molecular subtypes [triple receptor negative (TN)] treated with modern chemotherapy, may experience a survival benefit from adjuvant RT.

Methods: Billing codes for all breast cancer patients treated with chemotherapy between 1/1998 and 5/2005 at the University of Alabama at Birmingham were reviewed to comprehensively capture all Stage II and III patients with intact data. Patient, tumor, and treatment related variables were recorded and patients were divided into 3 molecular subtypes based on receptor status: hormone receptor (HR) positive, Her2 negative; HR+/− , Her2+; and TN. Kaplan Meier curves to assess survival were performed by dividing the TN group into 2 groups: those who did or did not receive adjuvant RT.

Results: 409 patients with stage II-III disease with were identified. Out of this group, 81 patients had TN breast cancer (60 Stage II and 21 Stage III). RT data was known in 79 of these patients. Median age was 49 years. Median follow-up was 72 months. Thirty-seven stage II and 18 stage III patients received adjuvant RT. Of the stage II patients who received radiation, 25 underwent lumpectomy and 11 underwent mastectomy. Stage II patients who received adjuvant RT had a statistically significant improvement in DFS (p=0.03), and had a trend towards improvement in OS (p=0.07) when compared with those who did not receive adjuvant RT. There was no significant difference in survival for the stage III patients with use of RT, however numbers in this group were small. Conclusion: Adjuvant RT was associated with an improvement in DFS and a trend towards improvement in OS in patients with Stage II, TN breast cancers treated with modern chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-04.

Abstract P5-10-19: The Influence of Time to Completion of Chemotherapy on Survival in Patients with Triple Negative Stage III Breast Cancer

Background: Neoadjuvant chemotherapy is increasingly delivered to facilitate breast conserving surgery through tumor downstaging. Prospective trials of neoadjuvant chemotherapy from the NSABP suggest no difference in survival outcomes in patients receiving neoadjuvant versus adjuvant therapy; however, subset analysis in 2 combined trials (B-18 and B-27) demonstrated a trend in DFS improvement in young patients (<50 yrs), who often have more aggressive variant tumors. This study explores the possibility that patients with aggressive variant molecular subtypes [triple receptor negative (TN)] treated with modern chemotherapy, may significantly benefit from earlier completion of drug delivery. Methods: Billing codes for all breast cancer patients treated with chemotherapy between 1/1998 and 5/2005 at the University of Alabama at Birmingham were reviewed to comprehensively capture all Stage II and III patients with intact data. Patient, tumor, and treatment related variables were recorded and patients were divided to 4 molecular subtypes based on receptor status: hormone receptor (HR) positive, Her2 negative; HR+/− , Her2+; and triple receptor negative (TN). Kaplan Meier curves to assess survival were performed by dividing the TN group into 2 groups: those completing chemotherapy ≥5 vs > 5 months from diagnosis. Results: 409 patients with Stage II-III disease with were identified: 124 received neoadjuvant and 285 received adjuvant chemotherapy. Out of this group, 81 patients had TN breast cancer (60 Stage II and 21 Stage III). Median age was 49 years. Median follow-up was 72 months. Chemotherapy consisted of adriamycin, taxol and cytoxan for a median of 9 cycles. Stage III patients who completed chemotherapy within 5 months had a statistically significant improvement in OS and DFS (p=0.03), and had a trend towards improvement in DMFS (p=0.10) when compared with those who took longer than 5 months to complete chemotherapy. Conclusion: Completion of chemotherapy in a shorter time interval in patients with Stage III, TN breast cancers was associated with an improvement in DFS and OS. Consideration of timing of chemotherapy warrants further study.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-10-19.

The Accuracy of MRI in Predicting Pathologic Complete Response in Invasive Breast Cancer Patients Receiving Neoadjuvant Systemic Treatment

Background: Magnetic resonance imaging (MRI) has increased sensitivity to detect abnormalities in breast tissue as compared with mammography or ultrasound. Published reports of MRIs ability to predict pathologic response to neoadjuvant chemotherapy have shown conflicting results that vary depending on baseline molecular characteristics and chemotherapeutic regimens, with some studies suggesting higher predictive accuracy in Her2 positive patients receiving trastuzumab. This study examines both the ability of MRI to predict pathologic response and how tumor molecular profiles and treatment regimens influence MRI sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Sensitivity, specificity, PPV, and NPV for the combination of post-treatment mammogram, ultrasound, and MRI studies in predicting pathologic complete response (pCR) was also explored.Methods: Eighty-one patients with invasive breast cancer treated with neoadjuvant systemic therapy between 2002 to 2009 and imaged pre and post-treatment with breast MRI were reviewed. Patient, tumor, and treatment characteristics including tumor grade, histologic type, receptor status (ER, PR, and Her2), breast cancer subtype [luminal A, luminal B, Her2 positive, triple negative (TN)], correlative pre- and post-treatment mammographic and ultrasound imaging, drug regimen, and pathologic findings were recorded. Complete pathologic response was defined as no residual invasive or pre-invasive disease in the breast.Results: Patients had the following subtypes of breast cancer: 21/81 (26%) luminal A, 13/81 (16%) luminal B, 23/81 (28%) Her2 positive, and 24/81(30%) TN. Of the Her2 positive, only 12/23 (52%) treated after May 2005 received adjuvant trastuzumab. Twenty patients (25%) had a complete radiographic response (rCR) on post-treatment MRI and 23/81(28%) had a pCR. The sensitivity, specificity, PPV, and NPV of MRI for predicting pathologic response was 57%, 88%, 65%, and 84%, respectively. Analysis of breast cancer subtype did not demonstrate a predilection in any particular subtype for correlation of radiographic and pathologic response, although MRI sensitivity (100%) and NPV (100%) were highest in luminal A disease, and specificity and PPV were highest for patients with ER negative (96% and 90%) and triple negative (100% and 100%) disease, respectively. Mammographic and ultrasound post-treatment findings of residual disease did not significantly correlate with pathologic findings in the setting of a rCR on MRI. Multivariate analysis of factors potentially influencing MRIs sensitivity and specificity failed to show that tumor characteristics (ER status, PR status, HER2 status) or neoadjuvant treatment (ACT vs other or trastuzumab) had any effect on these parameters.Conclusions: MRI has the highest specificity and PPV in the setting of ER negative and TN breast cancer. Although treatment results and breast cancer subtype did not influence the sensitivity, specificity, PPV, or NPV of MRI in predicting pathologic response, only half of the Her2 positive subset received trastuzumab. Results from an ongoing large multi-institutional study will further clarify these results.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4022.

The effect of nicotine on growth of Streptococcus mutans

There is little information available concerning the effects of nicotine on oral bacteria; and in particular, Streptococcus mutans, an important microbe in the etiology of dental caries. To test the effects of nicotine, Streptococcus mutans were incubated in either 0 or 10(-1)-10(-7) M concentrations of nicotine and then plated onto mitis-salivarius-bacitracin agar. Colonies were counted and treatment groups compared. Both 10(-1) and 10(-2) M nicotine caused total inhibition of bacterial growth, while 10(-3) and 10(-4) M produced significantly more colonies than control. Also, 10(-6) and 10(-7) M nicotine produced a significant reduction in the mean number of colonies. These results suggest a biphasic, dosage-dependent effect of nicotine on the growth of Streptococcus mutans. Since 10(-3) M nicotine has been reported within the saliva of smokeless tobacco users, use of these products could stimulate growth of Streptococcus mutans and possibly place the user at increased risk for dental caries.

Angiotensin I-converting enzyme antisense gene therapy causes permanent antihypertensive effects in the SHR

The renin-angiotensin system plays a critical role in the control of blood pressure (BP), and its hyperactivity is associated with the development and maintenance of hypertension. Although traditional pharmacological therapies targeted toward the inhibition of the renin-angiotensin system are effective in the control of this disease, they pose significant limitations. We used an antisense gene delivery strategy to circumvent these limitations and established that a single intracardiac administration of angiotensin type 1 receptor antisense (AT(1)R-AS) causes permanent prevention of hypertension in the spontaneously hypertensive rat (SHR), an animal model of primary human hypertension. Our objectives in this study were 2-fold: to determine (1) whether the targeting of angiotensin I-converting enzyme (ACE) mRNA by a similar antisense strategy would prevent the SHR from developing hypertension and (2) whether the antihypertensive phenotype is transmitted to the offspring from the antisense-treated parents. Administration of a retroviral vector containing ACE antisense (LNSV-ACE-AS) caused a modest yet significant attenuation of high BP ( approximately 15+/-2 mm Hg) exclusively in the SHR. This was associated with a complete prevention of cardiac and renovascular pathophysiological alterations that are characteristic of hypertension. Like their parents, the F(1) generation offspring of the LNSV-ACE-AS-treated SHR expressed lower BP, decreased cardiac hypertrophy, and normalization of renal arterial excitation-coupling compared with offspring derived from the LNSV-ACE-tS (truncated sense)-treated SHR. In addition, the endothelial dysfunction commonly observed in the SHR renal arterioles was significantly prevented in both parents and offspring of the LNSV-ACE-AS-treated SHR. Polymerase chain reaction followed by Southern analysis revealed that the ACE-AS was integrated into the SHR genome and transmitted to the offspring. These observations suggest that transmission of ACE-AS by retroviral vector may be responsible for the transference of normotensive phenotypes in the SHR offspring.

Angiotensin I-converting enzyme antisense prevents altered renal vascular reactivity, but not high blood pressure, in spontaneously hypertensive rats

The renin-angiotensin system plays a critical role in the control of blood pressure, and its hyperactivity is associated with the development of human primary hypertension. Because low-dose angiotensin I-converting enzyme (ACE) inhibitors cause small reductions in blood pressure that are associated with the complete reversal of altered vascular pathophysiology, our objective in this study was to determine whether ACE antisense (ACE-AS) gene delivery prevents alterations in renal vascular physiology in the parents and F(1) offspring of AS-treated spontaneously hypertensive rats (SHR). A single bolus intracardiac injection of ACE-AS (2x10(8) colony-forming units) in SHR neonates caused a modest (18+/-3 mm Hg, n=7 to 9) lowering of blood pressure, which was maintained in the F(1) generation offspring (n=7 to 9). Alterations in renal vascular reactivity, electrophysiology, and [Ca(2+)](i) homeostasis are underlying mechanisms associated with the development and establishment of hypertension. Renal resistance arterioles from truncated ACE sense-treated SHR showed a significantly enhanced contractile response to KCl and phenylephrine (n=24 rings from 6 animals, P<0.01) and significantly attenuated acetylcholine-induced relaxations (n=24 rings from 6 animals, P<0.01) compared with arterioles from ACE-AS-treated SHR. In addition, compared with cells dissociated from arterioles of ACE-AS-treated SHR, cells from truncated ACE sense-treated animal vessels had a resting membrane potential that was 22+/-4 mV more depolarized (n=38, P<0.01), an enhanced L-type Ca(2+) current density (2.2+/-0.3 versus 1.2+/-0.2 pA/pF, n=23, P<0.01), a decreased Kv current density (16.2+/-1.3 versus 5.4+/-2.2 pA/pF, n=34, P<0.01), and increased Ang II-dependent changes in [Ca(2+)](i) (n=142, P<0.01). Similar effects of ACE-AS treatment were observed in the F(1) offspring. These results demonstrate that ACE-AS permanently prevents alterations in renal vascular pathophysiology in spite of the modest effect that ACE-AS had on high blood pressure in SHR.

Distance learning: an innovative approach to nursing education

This article presents four views encompassing one nursing department's experience using distance learning technology. The challenge of presenting a nursing class through distance technology is discussed from the perspective of the telecommunication faculty providing the technological support, the nursing faculty teaching the on-campus course, the off-campus nursing faculty coordinating the course at the outreach site, and the head of the Department of Nursing. Review of course grades demonstrated that off-campus students achieved higher grades than on-campus students. All students evaluated the teacher as being effective; however, off-campus students were not as strong in their opinion.