Phase II Trial of Definitive Therapy for Osseous Oligometastases in Breast Cancer

PURPOSE/OBJECTIVE(S)

Phase II data for consolidative local therapy for oligometastatic disease demonstrated improved outcomes for various malignancies. However, a randomized phase II study of oligometastatic breast cancer patients testing predominantly ablative dose radiotherapy (RT) did not demonstrate progression-free survival (PFS) benefit. We conducted a single-arm phase II trial evaluating local therapy as part of the multidisciplinary management of breast cancer patients with limited bone metastases.

MATERIALS/METHODS

Patients with synchronous (n = 15) and metachronous (n = 15) oligometastatic breast cancer involving ≤3 osseous sites were enrolled from July 2009 to April 2016 and treated to a total of 44 bone metastases. The trial closed early due to slow accrual. Following ≤9 months of systemic therapy, local therapy entailed surgery (n = 3) or RT delivered via conventional fractionation (≥60 Gy, n = 36) or stereotactic technique (27 Gy/3 fractions for spine mets, n = 6). When indicated, RT to the primary was delivered concurrently (n = 15). The primary endpoint was to determine PFS. Secondary endpoints were overall survival (OS), local control (LC) and toxicity. Outcomes were evaluated with Kaplan-Meier and univariate Cox proportional hazards analyses.

RESULTS

Of the 30 patients included in the trial, 23 (77%) had ER+ or PR+/HER2- disease, 4 (13%) had Her2+ disease, and 3 (10%) were triple negative. Median age was 53, and 20 patients (67%) presented with 1 distant metastasis. A total of 21 patients (70%) experienced disease progression at a median 20.5 months (IQR: 8.2-41.2), including 5 local failures among 44 treated bone metastases (11%). At a median follow-up of 76.7 mon (IQR: 45.4-108.8), the median PFS was 37.8 mon, with 2- and 5-year rates (95% CI) of 60% (45-80%) and 32% (19-55%), respectively. The 2- and 5-year OS rates were 93% (85-100%) and 64% (48-85%), respectively, and the 2- and 5-year LC rates were 91% (80-100%) and 71% (51-98%). For patients who achieved LC, median PFS was 47.7 months (IQR 12.2-73.0). Twenty-one patients (70%) received cytotoxic chemotherapy with or without endocrine therapy for newly diagnosed oligometastatic disease. Nine patients (30%) were still alive with no evidence of disease (NED) at a median 96.9 mon (range: 47.7-158.6). PFS was worse among triple negative patients (p = 0.03), with no difference based on synchronous vs non-synchronous presentation (p = 0.10), receipt of cytotoxic chemotherapy prior to definitive therapy (p = 0.08) or Her2+ status (p = 0.21). There were no Grade ≥3 adverse events.

CONCLUSION

Definitive, predominantly conventionally fractionated local therapy was associated with long-term NED status for 30% of patients with oligometastatic breast cancer involving osseous sites, with minimal treatment-associated toxicity. Developing randomized trials for breast cancer subsets may warrant consideration of standard fractionation regimen data and the need for strategies to identify patients who may benefit from definitive local therapy.

Evaluation of the GeneQuence® DNA Hybridization Method in Conjunction with 24-Hour Enrichment Protocols for Detection of Salmonella spp. in Select Foods: Collaborative Study

A multilaboratory study was conducted to compare performance of the GeneQuence® DNA hybridization (DNAH) method incorporating new 24 h enrichment protocols and reference culture procedures for detection of Salmonella spp. in select foods. Six food types (raw ground turkey, raw ground beef, dried whole egg, milk chocolate, walnuts, and dry pet food) were tested by the DNAH method and by the culture methods of either the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) or the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM). Fifteen laboratories participated in the study. Four of the foods tested (raw ground turkey, dried whole egg, milk chocolate, and dry pet food), showed no statistically significant differences in performance between the DNAH method and the reference procedure as determined by Chi square analysis. Sensitivity rates for the DNAH method ranged from 92 to 100. The DNAH method, with the specific enrichment protocol evaluated, was found to be ineffective for detection of Salmonella spp. in walnuts. For raw ground beef, results from one trial showed a statistically significant difference in performance, with more positives obtained by the reference method. However, evidence suggests that the difference in the number of positives was likely due to lack of homogeneity of the test samples rather than to DNAH method performance.

Abstract ES7-3: Indications for radiation treatments after neoadjuvant chemotherapy while awaiting the results of clinical trials

Using systemic therapy prior to surgery has become an accepted standard for patients with lymph node-positive disease at presentation. Studies demonstrate that this approach can eradicate the disease in lymph nodes prior to local-regional interventions. This occurs particularly frequently for patients with HER2/neu-positive disease and to a relevant degree for those with triple negative disease. Patients with an excellent pathological response to treatment have improved outcomes compared to those with extensive residual disease. However, it is less clear whether local-regional therapies can be diminished or omitted in patients with an excellent pathological response. Accordingly, such questions are currently being investigated in phase III clinical trials.

Unfortunately, local-regional therapeutic trials require long-term outcome data, particularly for the endpoints of distant disease control and overall survival. Therefore, the ongoing studies addressing whether regional lymph node radiation can be omitted in selected patients after neoadjuvant chemotherapy will not provide clinically useful information in the near term. This is unfortunate because such questions arise with a high degree of frequency in oncology practices. This topic has also become increasingly important because completed clinical trials indicate that regional lymph node radiation combined with treatment of the chest wall/breast improves the outcome of patients with pathologically positive lymph node(s) and who are treated with surgery first followed by adjuvant systemic therapy.

While the sequencing of chemotherapy and surgery does not affect the risk of local-regional recurrence for populations of patients, it does affect an individual patient's risk. For example, patients with clinically stage II, lymph node-positive disease (who do not receive radiation) will have lower risk of local-regional recurrence if they achieve a pathological complete response to neoadjuvant chemotherapy compared to those with residual positive lymph nodes. This is also true for patients with clinical stage III disease, although patients with locally advance breast cancer have a high enough risk for local recurrence even with a complete pathological response to warrant adjuvant radiation.

Based on the data outlined above, the current standard outside the setting of clinical protocols is to recommend regional lymph node radiation with chest wall/breast radiation for all patients with residual positive lymph nodes after neoadjuvant chemotherapy and all patients who present with clinically stage III disease.

For patients with stage II disease who achieve a pathological complete response, the available evidence suggests that their predicted local regional recurrence risk without regional or postmastectomy radiation is 10% or less. Therefore the benefit from radiation is likely low and it is reasonable weigh out these small potential benefits in the context of associated treatment morbidities and costs. It is also important to further consider additional local-regional risk factors such as patient age, tumor biology, plans for prolonged systemic therapies, and other pathological factors at presentation in making radiation treatment decisions for such patients.

Citation Format: Buchholz T. Indications for radiation treatments after neoadjuvant chemotherapy while awaiting the results of clinical trials [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr ES7-3.

TRIP12 as a mediator of human papillomavirus/p16-related radiation enhancement effects

Patients with human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) have better responses to radiotherapy and higher overall survival rates than do patients with HPV-negative HNSCC, but the mechanisms underlying this phenomenon are unknown. p16 is used as a surrogate marker for HPV infection. Our goal was to examine the role of p16 in HPV-related favorable treatment outcomes and to investigate the mechanisms by which p16 may regulate radiosensitivity. HNSCC cells and xenografts (HPV/p16-positive and -negative) were used. p16-overexpressing and small hairpin RNA-knockdown cells were generated, and the effect of p16 on radiosensitivity was determined by clonogenic cell survival and tumor growth delay assays. DNA double-strand breaks (DSBs) were assessed by immunofluorescence analysis of 53BP1 foci; DSB levels were determined by neutral comet assay; western blotting was used to evaluate protein changes; changes in protein half-life were tested with a cycloheximide assay; gene expression was examined by real-time polymerase chain reaction; and data from The Cancer Genome Atlas HNSCC project were analyzed. p16 overexpression led to downregulation of TRIP12, which in turn led to increased RNF168 levels, repressed DNA damage repair (DDR), increased 53BP1 foci and enhanced radioresponsiveness. Inhibition of TRIP12 expression further led to radiosensitization, and overexpression of TRIP12 was associated with poor survival in patients with HPV-positive HNSCC. These findings reveal that p16 participates in radiosensitization through influencing DDR and support the rationale of blocking TRIP12 to improve radiotherapy outcomes.

Abstract S3-07: Complication and economic burden of local therapy options for early breast cancer

Background: Guideline-concordant local therapy options for early breast cancer include lumpectomy plus whole breast irradiation (lump+WBI), lumpectomy plus brachytherapy (lump+brachy), mastectomy without reconstruction or radiation (mast alone), mastectomy with reconstruction without radiation (mast+recon), and, in older women, lumpectomy without radiation (lump alone). Little is known regarding the comparative complication and economic burden of these options in the general population.

Methods: We used the MarketScan database which includes younger women with private insurance and the SEER-Medicare database which includes older women with Medicare. Women were included if they had early stage disease (T1/2 N0/1 M0) diagnosed in 2000-2011, no prior cancer, and complete insurance coverage from 12 months prior through 24 months after diagnosis. A complication from local therapy was defined as a diagnosis or procedure code for any of the following within 24 months of diagnosis: wound complication, local infection, seroma/hematoma, fat necrosis, breast pain, pneumonitis, rib fracture, and implant removal. Total costs and complication-related costs within 24 months of diagnosis were calculated from a payer's perspective and are reported in 2014 dollars. Logistic regression compared complications by local therapy and generalized linear regression (log link function, gamma distribution) compared complication-related and total costs by local therapy; all models adjusted for relevant covariables.

Results: We selected 44,344 patients from the MarketScan cohort, median age of 53, and 50,562 patients from the SEER-Medicare cohort, median age of 75. For the MarketScan cohort, risk of complications varied as follows: 29% risk in patients treated with lump+WBI (referent), 44% with lump+brachy (adjusted odds ratio [AOR]=2.00;P<.001), 25% with mast alone (AOR=0.85;P<.001), and 54% with mast+recon (AOR=2.89;P<.001). For the SEER-Medicare cohort, risk of complications varied as follows: 37% with lump+WBI (referent), 52% with lump+brachy (AOR=1.91;P<.001), 37% with mast alone (AOR=0.97;P=.17), 65% with mast+recon (AOR=3.17; P<.001), and 30% with lump alone (AOR=0.81; P<.001). Compared to lump+WBI, mean adjusted complication-related cost was $8,085 higher per patient with mast+recon in the MarketScan cohort and $3,711 higher per patient with mast+recon in the SEER-Medicare cohort. In contrast, complication-related costs were similar (+/- $750) for all other local therapy options relative to lump+WBI in both cohorts. For total cost, mast+recon was the most expensive local therapy in the MarketScan cohort, with mean adjusted total cost of $77,321, which was $15,181 more expensive than lump+WBI. In the SEER-Medicare cohort, lump+brachy was the most expensive option ($39,534), followed by mast+recon ($35,269), lump+WBI ($32,562), mast alone ($26,401), and lump alone ($24,455).

Conclusion: Mast+recon results in the highest complication rate and complication-related cost in both younger women and older women with early breast cancer. These findings are relevant to defining which local therapies offer the highest value to patients, payers, and society, and are relevant to patients when evaluating their local therapy options.

Citation Format: Smith BD, Jiang J, Shih Y-CT, Giordano SH, Huo J, Jagsi R, Caudle AS, Hunt KK, Shaitelman SF, Buchholz TA, Shirvani SM. Complication and economic burden of local therapy options for early breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S3-07.

Survival of women with inflammatory breast cancer: a large population-based study

BACKGROUND

Our group has previously reported that women with inflammatory breast cancer (IBC) continue to have worse outcome compared with those with non-IBC. We undertook this population-based study to see if there have been improvements in survival among women with stage III IBC, over time.

PATIENT AND METHODS

We searched the Surveillance, Epidemiology and End Results Registry to identify female patients diagnosed with stage III IBC between 1990 and 2010. Patients were divided into four groups according to year of diagnosis: 1990-1995, 1996-2000, 2001-2005, and 2006-2010. Breast cancer-specific survival (BCSS) was estimated using the Kaplan-Meier method and compared across groups using the log-rank test. Cox models were then fit to determine the association of year of diagnosis and BCSS after adjusting for patient and tumor characteristics.

RESULTS

A total of 7679 patients with IBC were identified of whom 1084 patients (14.1%) were diagnosed between 1990 and 1995, 1614 patients (21.0%) between 1996 and 2000, 2683 patients (34.9%) between 2001 and 2005, and 2298 patients (29.9%) between 2006 and 2010. The 2-year BCSS for the whole cohort was 71%. Two-year BCSS were 62%, 67%, 72%, and 76% for patients diagnosed between 1990-1995, 1996-2000, 2001-2005, and 2006-2010, respectively (P < 0.0001). In the multivariable analysis, increasing year of diagnosis (modeled as a continuous variable) was associated with decreasing risks of death from breast cancer (HR = 0.98, 95% confidence interval 0.97-0.99, P < 0.0001).

CONCLUSION

There has been a significant improvement in survival of patients diagnosed with IBC over a two-decade time span in this large population-based study. This suggests that therapeutic strategies researched and evolved in the context of non-IBC have also had a positive impact in women with IBC.

Abstract P5-14-08: Prospective phase II study of concurrent capecitabine and radiation demonstrates futility in triple negative chemo-resistant breast cancer

Background: Capecitabine is an established radiosensitizer in rectal and other cancers. We conducted a prospective single arm phase II study to examine the response rate of gross chemo-refractory breast cancer treated with concurrent capecitabine and radiotherapy.

Methods: Patients who had inoperable or marginally operable gross disease in the breast and/or lymph node(s) after chemotherapy or gross disease on the chest wall or in the regional lymphatics after mastectomy were eligible. Patients 1-9 received capecitabine 825 mg/m2 BID daily beginning on the first day of radiotherapy. Excess grade 3 toxicity (%) was observed; the protocol was amended and subsequent patients received drug only on radiation treatment days. Radiation dose was at the discretion of the treating physician (50Gy-72 Gy, with no more than 2.5 Gy/fraction). Response was assessed by a single physician using paired radiation planning CTs (pretreatment and on-treatment after 45 Gy). Clinical correlation to all other available imaging was also made. Kaplan-Meier curves were used to estimate overall survival (OS) and local recurrence-free survival (LRFS). Circulating tumor cells (CTCs) in blood were examined in consenting patients.

Results: The trial was stopped early after an unplanned interim analysis prompted by slow accrual suggested futility independent of response. From 2009-2012, 32 patients were accrued; 26 completed protocol specific treatment (17 post-mastectomy radiation with gross nodes, 4 pre-op, 5 aggressive palliation) and are included in this analysis. Median follow up was 7.3 months (interquartile range 6.7 – 17.4). Nineteen patients (73%) had a partial or complete response. Fourteen patients (53.9%) experienced at least one grade 3 non-dermatitis toxicity including 7/9 treated with continuous dosing. Four inoperable patients were treated with pre-op radiation therapy and 3 converted to operable. None achieved a pCR or near pCR. One-year actuarial OS was 52%. There was no difference in OS comparing among PMRT vs. preoperative or palliative RT (P = 0.90). One-year actuarial local recurrence free survival among PMRT patients was 38%. Ten patients had triple negative (TN) receptor status. There was no difference in radiation response by receptor status (P = 0.56); however, treatment was deemed subjectively futile (i.e., converted to operable but death secondary to new widespread M1 disease immediately post-op) in 9 of the 10 patients with TN disease versus 6 of the 16 patients with non-TN disease (P = 0.014). Median OS and 1-yr actuarial OS, among non-TN vs. TN patients were not reached vs. 6.1 months and 77% vs. 10% (P &lt; 0.001), respectively. Eight/fifteen patients tested were positive for CTCs. CTCs did not correlate to receptor status, futility of RT or OS.

Conclusions: Capecitabine can be safely administered as a daily concurrent chemoradiation regimen with weekend holidays. However, in this small, prospective and selected cohort, concurrent chemoradiation with capecitabine was futile among patients with TN breast cancer. Alternative strategies are urgently needed in TN patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-08.

Accelerated partial-breast irradiation using intensity-modulated proton radiotherapy: do uncertainties outweigh potential benefits?

OBJECTIVE

Passive scattering proton beam (PSPB) radiotherapy for accelerated partial-breast irradiation (APBI) provides superior dosimetry for APBI three-dimensional conformal photon radiotherapy (3DCRT). Here we examine the potential incremental benefit of intensity-modulated proton radiotherapy (IMPT) for APBI and compare its dosimetry with PSPB and 3DCRT.

METHODS

Two theoretical IMPT plans, TANGENT_PAIR and TANGENT_ENFACE, were created for 11 patients previously treated with 3DCRT APBI and were compared with PSPB and 3DCRT plans for the same CT data sets. The impact of range, motion and set-up uncertainties as well as scanned spot mismatching between fields of IMPT plans was evaluated.

RESULTS

IMPT plans for APBI were significantly better regarding breast skin sparing (p<0.005) and other normal tissue sparing than 3DCRT plans (p<0.01) with comparable target coverage (p=ns). IMPT plans were statistically better than PSPB plans regarding breast skin (p<0.002) and non-target breast (p<0.007) in higher dose regions but worse or comparable in lower dose regions. IMPT plans using TANGENT_ENFACE were superior to that using TANGENT_PAIR in terms of target coverage (p<0.003) and normal tissue sparing (p<0.05) in low-dose regions. IMPT uncertainties were demonstrated for multiple causes. Qualitative comparison of dose-volume histogram confidence intervals for IMPT suggests that numeric gains may be offset by IMPT uncertainties.

CONCLUSION

Using current clinical dosimetry, PSPB provides excellent dosimetry compared with 3DCRT with fewer uncertainties compared with IMPT.

ADVANCES IN KNOWLEDGE

As currently delivered in the clinic, PSPB planning for APBI provides as good or better dosimetry than IMPT with less uncertainty.

Pathologic complete response to neoadjuvant chemotherapy with trastuzumab predicts for improved survival in women with HER2-overexpressing breast cancer

BACKGROUND

We sought to determine the prognostic value of pathologic response to neoadjuvant chemotherapy with concurrent trastuzumab.

PATIENTS AND METHODS

Two hundred and twenty-nine women with HER2/neu (HER2)-overexpressing breast cancer were treated with neoadjuvant chemotherapy plus trastuzumab between 2001 and 2008. Patients were grouped based on pathologic complete response (pCR, n = 114) or less than pCR (<pCR, n = 115); as well as by pathologic stage. Locoregional recurrence-free (LRFS), distant metastasis-free (DMFS), recurrence-free (RFS), and overall survival (OS) rates were compared.

RESULTS

The median follow-up was 63 (range 53-77) months. There was no difference in clinical stage between patients with pCR or <pCR. Compared with patients achieving <pCR, those with the pCR had higher 5-year rates of LRFS (100% versus 95%, P = 0.011), DMFS (96% versus 80%, P < 0.001), RFS (96% versus 79%, P < 0.001), and OS (95% versus 84%, P = 0.006). Improvements in RFS and OS were seen with decreasing post-treatment stage. Failure to achieve a pCR was the strongest independent predictor of recurrence (hazard ratio [HR] = 4.09, 95% confidence interval [CI]: 1.67-10.04, P = 0.002) and death (HR = 4.15, 95% CI: 1.39-12.38, P = 0.011).

CONCLUSIONS

pCR and lower pathologic stage after neoadjuvant chemotherapy with trastuzumab are the strongest predictors of recurrence and survival and are surrogates of the long-term outcome in patients with HER2-overexpressing disease.

Abstract S2-3: Disparities in the utilization of axillary sentinel lymph node biopsy among black and white patients with node-negative breast cancer from 2002–2007

Background: Disparities exist in many aspects of standard breast cancer treatment in certain patient populations. In the mid-1990s, axillary sentinel lymph node biopsy (SLNB) was introduced as an alternative to axillary lymph node dissection (ALND) for staging clinically node-negative breast cancer. During the early 2000s, the validity of SLNB was being determined and its technique was being disseminated throughout the surgical community. By the mid to late-2000s, SLNB had been shown to provide accurate axillary staging with lower complications and no difference in survival compared to ALND in node-negative patients. SLNB has now replaced ALND as the accepted method for staging early breast cancer. The purpose of this study is to examine differences in the utilization of SLNB in pathologic node-negative invasive black breast cancer patients compared to white patients as SLNB became standard axillary staging and whether this difference impacted patient complications.

Methods: Using the population-based Surveillance, Epidemiology, and End Results (SEER)-Medicare data, cases of incident, non-metastatic, pathologic node-negative breast cancer in women age≥66 were identified. Patients were considered to have undergone SLNB if specified by SEER records or if a billing claim for axillary lymphatic mapping was identified. Unadjusted associations of SLNB with race were evaluated using the chi-square test. The Cochran-Armitage test evaluated trends over time. Multivariate logistic regression tested whether race was associated with the use of SLNB after adjustment for clinicopathologic factors. Five-year cumulative incidence of lymphedema assessed via ICD-9 diagnosis codes was measured using the Kaplan-Meier method. Adjusted proportional hazards regression evaluated assiciations of race and ALND with lymphedema risk.

Results: Of 31,274 women identified, 1,767 (5.7%) were Black, 27,856 (89%) were White and 1,651 (5.3%) were of other/unknown race. SLNB was performed in 74% of white patients compared to 62% of black patients (P&lt;0.001). Although use of SLNB increased by year for both black and white patients (P&lt;0.001), a fixed disparity in the use of SLNB persisted through 2007.

Abstract P5-03-05: Histone deacetylase (HDAC)-inhibitor mediated reprogramming drives cancer cells to the pentose phosphate metabolic pathway

Recent studies have shown that energy metabolism in human pluripotent cells contrasts sharply with energy metabolism in differentiated cell types. Specifically, it has been shown that nuclear reprogramming from somatic cells to induced pluripotent stem cells is associated with a switch from oxidative to glycolytic metabolism. Whether a metabolic switch also occurs in reprogrammed/dedifferentiated breast cancer cells is unknown. Moreover, the function of the metabolic state in stemness is poorly understood and no data are available on whether breast cancer stem cells (CSCs) are metabolically different from committed cancer cells. Herein we demonstrated that HDAC inhibitors reprogram committed single aldefluor negative breast cancer cells into aldefluor positive cells (10.3 ± 2.8 vs 21.3 ±3.7% untreated vs treated P &lt;0.05, representing an average of 5 single cell derived clones) and promoted tumor initiation from non-initiating committed cells (p = 0.004). Further, induced stem-like cells were resistant to taxol and salinomycin, a drug previously described to target CSCs. These reprogrammed cancer cells have enhanced activity of the pentose phosphate pathway (PPP) with upregulation of G6PD expression and activity and higher levels of NADPH and ROS. Hypothesizing that CSCs may favor the PPP in order to survive and self renew, we used G6PD inhibitors, 6-AN and Imatinib, to target mammosphere formation and aldefluor activity in HDAC inhibition induced stem-like cells. Not only was there a significant decrease in mammospheres from reprogrammed cells, the aldefluor activity was totally blocked at a concentration that does not affect proliferation. This work demonstrates that HDAC inhibition mediated cancer cell dedifferentiation promotes metabolic reprogramming and highlights an FDA approved drug that targets metabolism in stem cell plasticity. Further functional endpoint studies are underway to validate these findings.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-03-05.

Multifocality and multicentricity in breast cancer and survival outcomes

BACKGROUND

The clinicopathological characteristics and the prognostic significance of multifocal (MF) and multicentric (MC) breast cancers are not well established.

PATIENTS AND METHODS

MF and MC were defined as more than one lesion in the same quadrant or in separate quadrants, respectively. The Kaplan-Meier product limit was used to calculate recurrence-free survival (RFS), breast cancer-specific survival (BCSS), and overall survival (OS). Cox proportional hazards models were fit to determine independent associations of MF/MC disease with survival outcomes.

RESULTS

Of 3924 patients, 942 (24%) had MF (n = 695) or MC (n = 247) disease. MF/MC disease was associated with higher T stages (T2: 26% versus 21.6%; T3: 7.4% versus 2.3%, P < 0.001), grade 3 disease (44% versus 38.2%, P < 0.001), lymphovascular invasion (26.2% versus 19.3%, P < 0.001), and lymph node metastases (43.1% versus 27.3%, P < 0.001). MC, but not MF, breast cancers were associated with a worse 5-year RFS (90% versus 95%, P = 0.02) and BCSS (95% versus 97%, P = 0.01). Multivariate analysis shows that MF or MC did not have an independent impact on RFS, BCSS, or OS.

CONCLUSIONS

MF/MC breast cancers were associated with poor prognostic factors, but were not independent predictors of worse survival outcomes. Our findings support the current TNM staging system of using the diameter of the largest lesion to assign T stage.

P1-04-03: The Effect of Survivin Downregulation on Radiosensitization of Breast Cancer Cell Lines Grown under Adherent and Stem Cell Promoting Culture Conditions

Survivin, the smallest member of the inhibitor of apoptosis protein (IAP) family, is a bifunctional protein that has been implicated in both control of cell division and inhibition of apoptosis. Survivin has been shown to be involved in radiation resistance of various cancer types and its expression is increased by sublethal doses of irradiation in both differentiated and cancer stem cell (CSC) population. However, it is unknown whether suppression of survivin radiosensitizes the CSC population or diminishes its self renewal ability. Herein, we cloned the survivin dominant-negative mutant lacking a phosphorylation site (T34A) (Mesri et al., 2001 JCI) into the lentiviral LeGo vectors and assessed mammosphere formation and radiosensitization in MCF7, SUM149 and SUM159 cell lines grown under adherent or stem cell promoting conditions. We found an induction of survivin by western blotting in the dominant negative mutant (T34A)-transfected cell lines. Moreover, we observed a higher than two-fold increase in the Sub-G1 population as well as an increased Caspase 3 activity in the T34A-transfected SUM149 and SUM159 cells compared to control cells indicating an anti-apoptotic function of survivin. We also found that T34A-transfected cells showed a 1.5 to 2-fold decrease in the number of mammospheres compared to the control-transfected cells. Furthermore, T34A-transfected cells showed radiosensitization in adherent cells from SUM149 and SUM159 cells but no effect was observed in MCF7 cells. However, no radiosensitization was observed in stem cell promoting culture conditions with increasing doses of radiation in all tested cell lines. This indicates that the widely used standard clonogenic assays do not optimally select anti-CSC agents and that targeted therapies should be specifically tested for their activity against the CSC population. Further functional endpoint studies will be conducted to validate the in vitro findings.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-04-03.

MS4-3: Radiation for Patients Treated with Neoadjuvant Chemotherapy

The increased use of neoadjuvant systemic therapy for patients with stage II or stage III breast cancer has raised a number of important questions concerning local-regional treatments, particularly within the field of radiation oncology. Historically, the indications for radiation use after mastectomy and treatment of regional lymph node fields were determined on the basis of pathological extent of disease. It is clear that neoadjuvant systemic treatments changes the pathological extent of disease in most cases. Additional data are needed to determine how the degree of disease response should guide radiation oncologists to the tailor treatment approaches. Specifically, there is potential for minimizing local-regional treatments in those with favorable responses and intensifying therapy for those with unfavorable responses. One surgical success in de-intensification of local treatment has been the ability to safely treat with breast conservative therapy for selected patients with advanced primary tumors that respond favorably to neoadjuvant chemotherapy. It may also be possible to limit radiation treatments for selected patients with favorable disease response. Specifically, data from M. D. Anderson and the NSABP suggest that patients with clinical stage II breast cancer who have negative axillary lymph nodes after neoadjuvant chemotherapy have low rates of recurrence after mastectomy and low rates of regional lymph node recurrences. (1-4) This may permit a more selective approach to using radiation after mastectomy or regional lymph node radiation for patients with stage II disease. In contrast, data suggest that patients who present with clinical stage III disease maintain high rates of local-regional recurrence independent of treatment response and therefore all such patients are recommended to postmastectomy and regional lymph node irradiation.(1,3)

Patients with a poor response to neoadjuvant chemotherapy unfortunately remain a therapeutic challenge. In addition to high persistent rates of distant metastases, these patients have clinically relevant rates of local-regional recurrence despite mastectomy and high dose postmastectomy radiation. For such patients, new protocols are needed to evaluated novel systemic approaches and radiation sensitizer strategies.

1. Buchholz TA, et al. Predictors of local-regional recurrence after neoadjuvant chemotherapy and mastectomy without radiation. J Clin Oncol. Jan 1 2002;20(1):17–23.

2. Garg AK, et al. T3 disease at presentation or pathologic involvement of four or more lymph nodes predict for locoregional recurrence in stage II breast cancer treated with neoadjuvant chemotherapy and mastectomy without radiotherapy. Int J Radiat Oncol Biol Phys. May 1 2004;59(1):138–145.

3. McGuire SE, et al. Postmastectomy radiation improves the outcome of patients with locally advanced breast cancer who achieve a pathologic complete response to neoadjuvant chemotherapy. Int J Radiat Oncol Biol Phys. Apr 5 2007.

4. Mamounas E, et al. Predictors of locoregional failure (LRF) in patients receiving neoadjuvant chemotherapy (NC): Results from combined analysis of NSABP B-18 and NSABP B-27. Abstracts from the ASCO 2010 Breast Cancer Symposium [2010; http://www.asco.org/ASCOv2/Meetings/Abstracts?&vmview=abst_detail_view&confID=100&abstract ID=60279.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr MS4-3.

Risk factors and incidence of thromboembolic events (TEEs) in older men and women with breast cancer

BACKGROUND

The purpose of this study is to evaluate the risk factors and the prevalence of thromboembolic events (TEEs) in breast cancer patients.

PATIENTS AND METHODS

This is a retrospective cohort study using the Surveillance, Epidemiology, and End Results-Medicare database. Breast cancer patients diagnosed from 1992 to 2005 ≥66 years old were identified. International Classification of Diseases, Ninth Revision, and Healthcare Common Procedure Coding System codes were used to identify TEEs within 1 year of the breast cancer diagnosis. Analyses were conducted using descriptive statistics and logistic regression.

RESULTS

A total of 89 841 patients were included, of them 2658 (2.96%) developed a TEE. In the multivariable analysis, males had higher risk of a TEE than women [odd ratio (OR) = 1.57; confidence interval (CI) 1.10-2.25] and blacks had higher risk than whites (OR = 1.20; CI 1.04-1.40). Compared with stage I patients, patients with stage II, III and IV had 22%, 39% and 98% increase, respectively, in risk. Placement of central catheters (OR = 2.71; CI 2.43-3.02), chemotherapy treatment (OR = 1.66; CI 1.48-1.86) or treatment with erythropoiesis-stimulating agents (ESAs) (OR = 1.33; CI 1.33-1.52) increase the risk. Other significant predictors included comorbidities, age, receptor status, marital status and year of diagnosis. Similar estimates were seen for pulmonary embolism, deep vein thromboembolism and other TEEs.

CONCLUSIONS

In total, 2.96% of patients in this cohort developed a TEE within 1 year from breast cancer diagnosis. Stage, gender, race, use of chemotherapy and ESAs, comorbidities, receptor status and catheter placement were associated with the development of TEEs.

Identifying factors that impact survival among women with inflammatory breast cancer

BACKGROUND

The objective of this retrospective study was to determine factors impacting survival among women with inflammatory breast cancer (IBC).

METHODS

The Surveillance, Epidemiology and End Results Registry (SEER) was searched to identify women with stage III/IV IBC diagnosed between 2004 and 2007. IBC was identified within SEER as T4d disease as defined by the sixth edition of the American Joint Committee on Cancer. The Kaplan-Meier product-limit method was used to describe inflammatory breast cancer-specific survival (IBCS). Cox models were fitted to assess the multivariable relationship of various patient and tumor characteristics and IBCS.

RESULTS

Two thousand three hundred and eighty-four women with stage IIIB/C and IV IBC were identified. Two-year IBCS among women with stage IIIB, IIIC and IV disease was 81%, 67% and 42%, respectively (P < 0.0001). In the multivariable model, patients with stage IIIB disease and those with stage IIIC disease had a 63% [hazard ratio (HR) 0.373, 95% confidence interval (CI) 0.296-0.470, P < 0.001] and 31% (HR 0.691, 95% CI 0.512-0.933, P = 0.016) decreased risk of death from IBC, respectively, compared with women with stage IV disease. Other factors significantly associated with decreased risk of death from IBC included low-grade tumors, being of white/other race, undergoing surgery, receiving radiation therapy and hormone receptor-positive disease. Among women with stage IV disease, those who underwent surgery of their primary had a 51% decreased risk of death compared with those who did not undergo surgery (HR = 0.489, 95% CI 0.339-0.704, P < 0.0001).

CONCLUSIONS

Although IBC is an aggressive subtype of locally advanced breast cancer, it is heterogeneous with various factors affecting survival. Furthermore, our results indicate that a subgroup of women with stage IV IBC may benefit from aggressive combined modality management.

Abstract P1-17-01: Differences in Survival among Women with Stage III Inflammatory and Non-Inflammatory Locally Advanced Breast Cancer Appear Early: A Large Population Based Study

Background

Significant improvements in the survival of women with breast cancer have been observed and are attributed to a multidisciplinary approach and the introduction of polychemotherapy regimens. The objective of this population based study was to determine if differences, if any, in survival exist among women with inflammatory (IBC) and non-IBC locally advanced breast cancer (LABC) diagnosed in this era.

Methods

The Surveillance, Epidemiology and End Results Registry was searched to identify women with stage IIIB and C breast cancer who were diagnosed between 2004 and 2007 who had undergone surgery and radiation therapy. Patients were categorized as either having IBC or non-IBC LABC according the AJCC 6th edition criteria. Breast cancer specific survival (BCS) was estimated using the Kaplan-Meier product limit method and compared across groups using the log rank statistic. Cox models were then fitted to compare the association between breast cancer type and BCS after adjusting for patient and tumor characteristics.

Results

Eight hundred and twenty eight (19.2%) women and 3476 (80.8%) women had stage IIIB/C IBC and non-IBC LABC respectively. Median follow up was 19 months. 2-year BCS was 90% (95% CI 88-91%) for the whole cohort and 84% (95% CI 80%-87%) and 91% (95% CI 90%-91%) among women with IBC and non-IBC LABC respectively. In the multivariable model compared to women with non-IBC LABC women with IBC had a 43% increased risk of death from breast cancer that was statistically significant (HR=1.43, 95% CI 1.10-1.86, p=0.008). Conclusion

In the era of multidisciplinary management and anthracycline and taxane based polychemotherapy regimens women with IBC continue to have inferior survival outcomes compared to women with non-IBC LABC with differences in survival appearing early.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-17-01.

Abstract P4-04-05: Histone Deacetylase Inhibitors Increase Markers of the Dedifferentiated Cancer Stem Cell Phenotype in Human Breast Cancer Cells

It has been suggested that differentiated cancer cells can de-differentiate into the cancer stem cell phenotype (Meyers et al., 2009; Gupta et al., 2009) and that Histone Deacetylase (HDAC) inhibitors enable efficient induction of pluripotent stem cells from adult fibroblasts (Huangfu et al., 2009). Moreover, we have recently demonstrated that the HDAC inhibitor valproic acid radiosensitized breast cancer cells grown on plastic with serum while it radioprotected breast cancer cells grown in stem cell promoting culture conditions (Debeb et al., 2010). Based on these data, we hypothesized that HDAC inhibitors increase the cancer stem cell population via dedifferentiation of differentiated cancer cells. To examine our hypothesis, Sum159 breast cancer cells were FACS-sorted based on ALDH activity and subsequently treated with one of two HDAC inhibitors, valproic acid or SAHA (suberoylanilide hydroxamic acid). After sorting, ALDH-negative cells were treated either with valproic acid, SAHA, or vehicle. After a week, the percentage of ALDH-positive cells (passage 0, P0) was examined with flow cytometry while the remaining cells were passaged and incubated with and without valproic acid or SAHA for a week and the percentage of ALDH-positive cells again evaluated (P1). This was repeated for the third time (P2). Samples from each generation were also collected to examine the protein expression. On average, a 3-fold increase in ALDH positive cells was seen in valproic acid-treated cells (35.6% vs.12.6%) and a 1.5-fold increase in SAHA-treated cells (41% vs. 28%) compared to vehicle-treated controls. This effect was maintained through multiple passages. Moreover, the expression of Beta-catenin and EMT associated genes like vimentin, fibronectin, n-cadherin, which have been implicated in generating cancer stem cells was significantly increased withtreatment in initial and passaged cells. Further functional endpoint studies are needed to validate these in vitro marker-based findings.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-04-05.

Abstract P2-09-02: Validation of a Novel Staging System for Disease-Specific Survival in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy

Purpose We previously described a novel breast cancer staging system for assessing prognosis after neoadjuvant chemotherapy based on pretreatment clinical stage (CS), estrogen receptor status (E), grade (G) and post-treatment pathologic stage (PS). This CPS+EG staging system assigned and summed points for each factor, allowing for better determination of breast cancer-specific survival than CS or PS alone. The current study was undertaken to validate this staging system using internal and external cohorts.

Methods We identified 804 patients treated with neoadjuvant chemotherapy at our institution from 2003-2005 who were not part of the original determination of the CPS+EG staging system and an external cohort of 165 patients treated at another institution. Clinicopathologic characteristics, treatment regimens, and patient outcomes were assessed. Outcomes were stratified by CPS+EG score in order to test whether the 5-year disease-specific survival (DSS) in each CPS+EG group was numerically as predicted.

Results The 5-year DSS for the internal cohort was 77% (95% CI: 72-82) at a median follow-up of 3.4 years (range, 03-5.9). The 5-year DSS for the external cohort was 86% (95% CI: 7 -91) at a median follow-up of 4.7 years (range, 0.5-10.5). The ability of the CPS+EG score to distinguish outcomes based on good or poor prognosis was confirmed in both the internal and external cohorts. In both cohorts, application of the CPS+EG staging system facilitated more accurate categorization of patients into prognostic subgroups than CS or final PS as defined by the American Joint Committee on Cancer (AJCC) staging system.

Disease-Specific Survival Outcomes Based on the CPS+EG Staging System

Application of the CPS+EG to all three cohorts combined, demonstrated 5-year DSS ranging from 23% to 99% versus 5-year DSS ranging from 61% to 92% based on presenting CS or 58% to 95% based on post-treatment PS.

Conclusion The current study validates the CPS+EG staging system in independent patient cohorts. We recommend that biologic markers and response to treatment be incorporated into revised versions of the AJCC staging system for patients receiving neoadjuvant chemotherapy.

Abstract P4-11-15: Outcomes for Breast Cancer Patients with Isolated Metastasis or Recurrence to the Contralateral Nodal Basins

Background: Aggressive treatment of isolated breast cancer metastasis to either bone or lung has been reported to achieve long term survival. For the first time, we analyzed outcomes for patients (pts) with isolated metastasis to the contralateral (contra) supraclavicular (SCV) and/or axillary nodal basins.

Material and Methods: Pts treated with definitive or palliative radiation to the contra nodal basin(s) at M.D. Anderson were analyzed from the period of 2005-2010. They were divided into two groups: pts initially diagnosed with contra SCV and/or axilla as the only site of metastasis (designated Primary), and pts with recurrence in the contra SCV and/or axilla, without other distant metastasis (designated Recurrent).

Results: Of 34 potential pts with contra lymph node metastasis, 13 had isolated disease and were analyzed. In the Primary group (N=8, T4d N1- 3c M1), median survival was 25 mos, and 2-yr actuarial overall survivalwas 62.5%. All received neoadjuvant anthracycline and/or taxane-based chemotherapy followed by ipsilateral (ipsi) modified radical mastectomy and ipsi axillary lymph node dissection (ALND). The contra lymphatics were treated with ALND followed by radiation (N=5, 56-60 Gy) or with radiation alone (N=3, 45-66 Gy). Radiation fields included ipsi chest wall as well as ipsi and involved contra lymphatics. The contra chest wall or breast was radiated in 3 of the 8 pts. Two pts had estrogen receptor (ER) positive disease, and all had Her2-neu negative disease. Both ER+ pts are alive with no evidence of disease (NED; 1 had contra ALND; survival 25 and 51 mos). All 6 ER-pts died with disease (WD; 4 had contra ALND; survival 10 to 32 mos). One pt had an in-field recurrence in the contra nodal basin (51 Gy post ALND). No contra chest wall/breast recurrences were seen. All ER-pts developed additional distant metastasis, most within 4 mos of starting adjuvant radiation.

Regarding the Recurrent group (N=5), median survival was 25 mos after recurrence. Two ER+ pts received initial anti-estrogen therapy; all ER-pts initially received a taxane-based chemotherapy. The contra chest wall or breast was radiated in addition to the involved contra lymphatics in 3 of the 5 pts. Two pts had adjuvant radiation treatment with definitive intent to the contra lymphatics after ALND (50-50.4 Gy), with 1 alive/NED (66 mos from recurrence, no radiation to the contra breast) and 1 dead/WD (25 mos from recurrence). Radiation intent was palliation in 3 pts (none received ALND) with 1 alive/WD (60 Gy, 64 mos from recurrence) and 2 dead/WD (53.8 and 45 Gy, 6 and 18 mos from recurrence, respectively). In-field recurrence in the contra nodal basin occurred in 1 pt (50.4 Gy). Pts who died had progressive disease or additional distant metastasis within 3 mos of starting radiation.

Discussion: In this uncommon clinical scenario, locoregional control of the contra lymphatics was achieved with radiation alone or with surgery followed by radiation for a select group of pts; control was achieved without radiating the contra chest wall/breast. Only ER+ pts were rendered NED. Most ER-pts quickly developed other distant metastasis, highlighting the need for more effective systemic therapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-15.

Abstract P1-17-02: Outcome after Locoregional Recurrence in Patients with Inflammatory Breast Cancer

Purpose: High rates of locoregional recurrence (LRR) have been reported in spite of comprehensive tri-modality therapy for patients with inflammatory breast cancer (IBC). The aim of this study was to examine the prognosis of patients who have experienced LRR after treated primary IBC. Methods:

We retrospectively reviewed information for 124 IBC patients who experienced a LRR seen in our institution from 1990-2008. 63 patients had simultaneous distant disease (DM) +/−3 months of LRR (simLRR),

5 patients had LRR &gt; 3 months subsequent to DM, while 56 patients had isolated LRR &gt;3 months prior to DM (isLRR). Overall survival (OS) was calculated from date of recurrence using the Kaplan-Meier method. Results:

Median time to LRR from diagnosis was 13 months (interquartile range 8-21 months). Median survival after LRR was 15 months. 2-yr OS was 46%. Regarding the primary tumors, 23% were estrogen receptor positive (ER+), 33% were HER2-neu positive (H2N+), 81% had lymph vascular space invasion (LVSI), and 83% were grade 3. Comparing isLRR and simLRR cohorts, median survival was 18 months vs. 10 months and 2 yr-OS was 66% vs. 28%, respectively. ER+ and H2N+ primary status predicted for longer 2 yr OS among patients with simLRR but not among isLRR patients. (simLRR, ER+ 57% vs. ER-19% p = 0.02, H2N+ 45% vs. H2N-17% p = 0.01; IsLRR ER+ vs. ER-92% vs. 55% p = 0.15, H2N+ 86% vs. H2N-57% p = 0.11). LVSI was not prognostic in either group and Grade 3 primary trended towards worse outcome among isLRR cohort only, Grade 2 83% vs. Grade 3 64% P = 0.08. Molecular subtyping using ER and H2N status to group tumors demonstrates basal subtype in the primary tumor compared to H2N, luminal B and luminal A is associated with significantly worse 2 yr OS after isLRR (43% vs. 88%, 82%, and 83%, P = 0.04) and simLRR (13% vs. 34%, 80%, 32% P = 0.005) respectively. Conclusions:

Forty-five% of LRR occurred as isolated first events. LRRs generally occur within 2 years after primary IBC treatment and are associated with poor outcomes even as first events. Basal subtype predicts for worse overall survival regardless of distant disease.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-17-02.

International expert panel on inflammatory breast cancer: consensus statement for standardized diagnosis and treatment

BACKGROUND

Inflammatory breast cancer (IBC) represents the most aggressive presentation of breast cancer. Women diagnosed with IBC typically have a poorer prognosis compared with those diagnosed with non-IBC tumors. Recommendations and guidelines published to date on the diagnosis, management, and follow-up of women with breast cancer have focused primarily on non-IBC tumors. Establishing a minimum standard for clinical diagnosis and treatment of IBC is needed.

METHODS

Recognizing IBC to be a distinct entity, a group of international experts met in December 2008 at the First International Conference on Inflammatory Breast Cancer to develop guidelines for the management of IBC.

RESULTS

The panel of leading IBC experts formed a consensus on the minimum requirements to accurately diagnose IBC, supported by pathological confirmation. In addition, the panel emphasized a multimodality approach of systemic chemotherapy, surgery, and radiation therapy.

CONCLUSIONS

The goal of these guidelines, based on an expert consensus after careful review of published data, is to help the clinical diagnosis of this rare disease and to standardize management of IBC among treating physicians in both the academic and community settings.

Incidence of and survival following brain metastases among women with inflammatory breast cancer

BACKGROUND

The purpose of this study was to determine the incidence of and survival following brain metastases among women with inflammatory breast cancer (IBC).

PATIENTS AND METHODS

Two hundred and three women with newly diagnosed stage III/IV IBC diagnosed from 2003 to 2008, with known Human epidermal growth factor receptor 2 (HER2) and hormone receptor status, were identified. Cumulative incidence of brain metastases was computed. Survival estimates were computed using the Kaplan-Meier product limit method. Multivariable Cox proportional hazards models were fitted to explore the relationship between breast tumor subtype and time to brain metastases.

RESULTS

Median follow-up was 20 months. Thirty-two (15.8%) patients developed brain metastases with a cumulative incidence at 1 and 2 years of 2.7% and 18.7%, respectively. Eleven (5.3%) patients developed brain metastases as the first site of recurrence with cumulative incidence at 1 and 2 years of 1.6% and 5.7%, respectively. Compared with women with triple receptor-negative IBC, those with hormone receptor-positive/HER2-negative disease [hazard ratio (HR) = 0.55, 95% confidence interval (CI) 0.19-1.51, P = 0.24] had a decreased risk of developing brain metastases, and those with HER2-positive disease (HR = 1.02, 95% CI 0.43-2.40, P = 0.97) had an increased risk of developing brain metastases, although these associations were not statistically significant. Median survival following a diagnosis of brain metastases was 6 months.

CONCLUSION

Women with newly diagnosed IBC have a high early incidence of brain metastases associated with poor survival and may be an ideal cohort to target for site-specific screening.

Clinical Data Do Not Support the Hypothesis That Irradiation Promotes Biologically Aggressive Local Recurrences through Stromal Activation

Objective: Recent data in select pre-clinical models suggest that radiation can activate normal stroma to promote tumor metastases and aggressiveness. We hypothesized that if these were occurring clinically, there would be a lower survival after locoregional recurrence (LRR) in patients after post-mastectomy radiation therapy (PMRT) compared to mastectomy (Mx) alone. This study used two independent datasets to compare survival after LRR in women treated with versus without PMRT.Methods: Data from 229 of 1,505 patients who experienced LRR after treatment on sequential non-randomized institutional prospective trials at the MD Anderson Cancer Center (MDA) and 66 of 318 patients enrolled in the British Columbia (BC) PMRT randomized trial who experienced LRR were analyzed. All patients underwent Mx and level I/II axillary dissection. In both data sets analysis was based on treatment received. Patients from MDA received doxorubicin based chemotherapy +/- PMRT, with 45 LRR after PMRT and 184 LRR after Mx alone). Patients treated on the BC trial received CMF chemotherapy +/- PMRT, with LRR in 14/160 after PMRT versus 52/158 after Mx alone. Survival was calculated from time of LRR to death using Kaplan-Meier and log rank statistics.Results:MDA Data: Median follow up of living patients was 192 months. Analyzing data from all patients with LRR regardless of distant metastasis (DM), patients with LRR after PMRT were younger (47 vs. 51 y, p = 0.033) and had shorter time to first LRR (40mo vs. 51 mo, p = 0.018). 5-yr/10-yr OS were 31%/16% without PMRT and 20%/7% after PMRT (p = 0.008). However, PMRT-treated patients had increased risk factors for DM (advanced T and N stage) and more PMRT-treated patients developed DM prior to LRR (58% vs. 36% p = 0.009). Analyzing only patients without DM there was no difference in OS between groups (p = 0.67), and a separate analysis of all patients who developed metastatic disease (N = 385 no PMRT, 233 after PMRT) revealed no difference in 5 or 10-yr OS after DR (15%/4% without PMRT vs. 13%/6% after PMRT, p = 0.5).BC Data: Median follow up of living patients was 235 months. The distributions of age, T stage, N stage, grade, LVI, ER status, excised nodes and nodal ratio were similar between patients with LRR after Mx alone vs. Mx plus PMRT. (all p &gt; 0.05). The mean time to first LRR was 39 mo in patients treated with Mx alone and 57 mo in patients treated with PMRT, p= 0.27). The rate of DM was similar in patients with LRR after Mx with vs without PMRT (93% vs. 96%, p=0.60). Distant relapse free survival after LRR was similar in Mx alone vs. PMRT-treated patients (log rank p=0.75). Overall survival was also similar in the two groups (5-yr/10-yr OS 21%/8% without PMRT vs. 23%/12% with PMRT, log rank p=0.93).Conclusions: Decades of randomized data have demonstrated that PMRT reduces LRR and improves overall survival. In the non-randomized dataset, removing the competing risk of DM which is higher in patients selected for PMRT by studying patients with isolated LRR, we find no difference in survival after LRR in the PMRT setting. Analysis of the randomized PMRT trial dataset confirmed the finding of similar survival among women with LRR irrespective of PMRT use.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4101.

Brain Metastases in Women with Inflammatory Breast Cancer (IBC): Incidence, Treatment and Outcome

Background: Brain metastases are an uncommon metastatic recurrence site in breast cancer with a median incidence of approximately 6% in unselected populations. Inflammatory breast cancer (IBC) is an aggressive disease associated with dismal outcome. The purpose of this study was to determine the incidence of and survival following brain metastases among women with IBC.Material and Methods: Two hundred and six women with newly diagnosed stage III or IV IBC diagnosed between the period of between 2003 and 2008 were identified in a prospectively maintained IBC database at the MD Anderson Cancer Center. Cumulative incidence of brain metastases was computed. Cox proportional hazards models were fitted to explore factors that predict for the development of brain metastases. Survival was computed using the Kaplan-Meier product limit method.Results: Median follow-up was 20 months. Eighty three (40.3%) women had de-novo stage IV disease and 123 (59.7%) had stage III disease at diagnosis. Thirty-three (16%) patients developed brain metastases with a cumulative incidence at 1 and 3 years of 2.7% and 22% respectively. Eleven (5.3%) patients developed brain metastases as the first site of recurrence with cumulative incidence at 1 and 3 years of 1.6% and 6.7% respectively. In the multivariable model, no specific factor was observed to be significantly associated with time to brain metastases, including HER-2 status. Median overall survival for the whole cohort was not reached. 3-year overall survival for the whole cohort was 78% (95% CI 69%-86%). Median survival following a diagnosis of brain metastases for all women who developed brain metastases or those who developed brain metastases as the first site of recurrence was 6 months.Conclusion: In this single-institutional study, women with IBC demonstrated a high early incidence of brain metastases associated with poor survival. As such IBC may be an ideal cohort to target screening procedures for brain metastases and/or enrollment of these women in clinical trials evaluating additional adjuvant preventive strategies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2102.

Value of adjuvant radiation therapy in breast cancer patients with one to three positive lymph nodes undergoing a modified radical mastectomy and systemic therapy

507

Background: Whether adjuvant radiation therapy should be utilized for patients (pts) with early stage breast cancer with up to 3 positive axillary lymph nodes treated with mastectomy and systemic therapy is controversial. This retrospective study was performed to determine if adjuvant radiation therapy had an impact on survival for this cohort of pts. Methods: 4240 pts with T1–2N0–1 breast cancers, diagnosed between 1980–2007, who underwent either mastectomy without adjuvant radiation therapy or segmental mastectomy with adjuvant radiation therapy were identified. All pts received systemic treatment. Women with >3 positive axillary lymph nodes were excluded. Overall (OS) and distant disease free survival (DDFS) were estimated using the Kaplan-Meir product method. Cox proportional hazards were used to determine associations between OS/DDFS and type of surgery after controlling for pt and disease characteristics. Results: 1336 (18.8%) had T1N0 disease, 1114 (26.27%) had T2N0 disease, 989 (23.33%) had T1N1 disease and 801 (18.89%) had T2N1 disease. Median follow-up was 54 months.5- year DDFS among women who underwent mastectomy and segmental mastectomy was 81% (95% 78%-83%) and 86% (95% CI 84%-87%), respectively (p < 0.0001). In the Cox analysis, pts who had mastectomy without radiation had a significantly increased risk of distant recurrence (HR= 1.39, 95% CI 1.14–1.70, p= 0.0013) than pts treated with segmental mastectomy and radiation. When looking at subgroups, no significant difference in DDFS was observed between the two groups in pts with lymph node negative disease. However, for pts with 1–3 positive lymph nodes, pts treated with mastectomy without radiation had significantly increased risk of distant recurrence compared to pts treated with segmental mastectomy with radiation (HR=1.614, 95% CI 1.198–2.177, p= 0.002). This difference was most pronounce in the subset of patients with T2N1 disease (HR= 1.794, 95% CI 1.220–2.637, p=0.003). Similar trends were observed for OS. Conclusions: This study provides provocative evidence for benefit of radiation therapy among pts with 1–3 positive axillary lymph nodes who are treated with surgery and systemic therapy.

No significant financial relationships to disclose.

Local-regional recurrence with and without radiation after neoadjuvant chemotherapy and mastectomy for T3N0 breast cancer patients

Abstract #74

Purpose: The goal of this study was to compare the local-regional recurrence (LRR) risk in patients with clinical T3N0 breast cancer who were treated with neoadjuvant chemotherapy (NeoChemo) and mastectomy (Mastx) according to the use of adjuvant radiation (RT).&#x2028; Methods: Clinicopathologic data from 164 patients with clinical T3N0 breast cancer who received NeoChemo and Mastx from 1985 to 2004 were retrospectively reviewed. In this cohort, 121 (74%) patients received adjuvant radiation (RT) while 43 (26%) patients did not. The median number of axillary lymph nodes (LN) dissected was 15. After NeoChemo, 54% of patients (n=89) had no pathologically involved lymph nodes at the time of surgery (ypLN-) while 46% (n=75) had at least 1 lymph node pathologically positive (ypLN+). Actuarial rates were calculated using Kaplan-Meier analysis and compared using log-rank test. Cox proportional hazards models were fit to determine the association of RT with the risk of LRR after adjustment for other patient and disease characteristics.&#x2028; Results: At a median follow-up of 77 months, 17 of the 164 patients had a LRR. For all patients, the 5-year local-regional control rates (5-yr LRC) were 90%. The 5-yr LRC for those who received RT (n=121) was 95% and for those who did not received RT (n=43) was 76% (p = 0.002), with a higher proportion of the patients who received RT having pathologically involved LN (+RT 53% vs –RT 23%, p=0.002).&#x2028; Among the entire cohort, the 5-yr LRC was 85% for patients with ypLN+ disease and 94% for patients with ypLN- disease (p=0.093). In patients with ypLN+, the 5-yr LRC with no RT (n=11) was 47% and with RT (n=64) was 92% (p&lt;0.001). In patients with ypLN-, the 5-yr LRC with no RT (n=32) was 86% and with RT (n=57) was 98% (p=0.063). Patients who had tumors with high nuclear grade had worse 5-yr LRC (Grade low 100%, intermediate 97%, high 81%, p=0.023). The presence of lymphovascular invasion, close/positive margin, or estrogen receptor status did not statistically correlate with LRC. In a Cox regression model, patients with tumor exhibiting high nuclear grade (Hazard Ratio (HR) 5.0, 95% Confidence Interval (CI) 1.6-15.4), ypLN+ (HR 6.6, 95% CI 2.0-22.1) and no adjuvant RT (HR 7.6, 95% CI 2.4-24.0) had increased risk of LRR.&#x2028; Conclusions: Post mastectomy adjuvant RT appears to improve LRC in clinical T3N0 breast cancer patients treated with neoadjuvant chemotherapy and mastectomy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 74.

Breast cancer in the United States: the burden on an aging, changing nation

Abstract #6076

Background: Over the next 20 years, important demographic changes in the US will emerge, with the number of older and non-white Americans increasing dramatically. Though breast cancer incidence is known to vary by both age and race, the projected impact of impending population changes on breast cancer incidence has never been quantified. To delineate the future burden of breast cancer, we calculated population-based projections of breast cancer incidence through 2030.&#x2028; Material and Methods: SEER data provided current age- and race-specific incidence rates for invasive or in situ female breast cancer. Age- and race-specific projections for the US population through 2030 were derived from Census Bureau data. Assuming stable race- and age-adjusted incidence, the total number of breast cancer cases by race and age through 2030 was estimated.&#x2028; Results: From 2008 to 2030, the total number of breast cancer cases is expected to increase from 264,000 to 357,000. Of cases diagnosed in 2030, 60% will occur in women ages 65 and older. This represents a 67% increase in the number of breast cancer cases in women age 65 and over (from 127,000 to 212,000), compared to a 6% increase in women under age 65 (from 137,000 to 145,000). In 2030, 19% of all cases will occur in non-whites, representing a 70% increase in non-whites (from 40,000 to 68,000), compared to a 29% increase in whites (from 224,000 to 289,000). While cases in older non-white women currently represent only 13% of older patients, they will comprise 17% by 2030.&#x2028; Discussion: With major demographic shifts on the horizon, an imminent wave of older breast cancer patients will impose a substantial burden on the US healthcare system. Efforts to expand capacity, contain cost, and define optimal treatment for older patients are urgently needed. Moreover, the projected increase in the percentage of breast cancer in non-whites heightens the importance of efforts to identify and minimize health care disparities.&#x2028; &#x2028;

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6076.

Breast brachytherapy in the United States: how is this emerging modality being incorporated into the care of older breast cancer patients?

Abstract #6087

Introduction: Several studies have demonstrated the potential value of brachytherapy in the treatment of breast cancer, either as local boost irradiation, or alone as accelerated partial breast irradiation, after breast conserving surgery (BCS). In 2002, the Food and Drug Administration approved the first balloon-based brachytherapy delivery system, signaling the beginning of broader incorporation of partial breast irradiation into breast cancer treatment. While subsequent studies have been seeking to define the patient population that will derive optimal clinical benefit from breast brachytherapy, this treatment option has remained widely available for use in a variety of settings. However, no prior study has described the frequency of breast brachytherapy use in the US. In a population-based cohort of older breast cancer patients, we characterized utilization of breast brachytherapy across the nation at the inception of this era.&#x2028; Methods: A cross-sectional sample from a national Medicare database identified 37,323 beneficiaries (age≥65) with newly diagnosed invasive breast cancer treated with BCS in 2003. ICD-9 and CPT codes indicated receipt of external beam radiotherapy (EBRT) and brachytherapy. Percent use by state, region, age, and race was compared using Pearson χ2.&#x2028; Results: Across the nation, 73% of older patients were treated with any radiotherapy after BCS. Of these patients, 97% were treated with EBRT alone, 3% with brachytherapy alone, and &lt;1% with EBRT plus brachytherapy boost. For patients treated with brachytherapy, 98% received interstitial therapy and 2% intracavitary therapy. Though percent utilization of brachytherapy modalities ranged from 1% to 4% across different locations in the US, no statistically significant variation was detected by state (P=0.62) or by region (P=0.32). In addition, brachytherapy use did not differ by race (P=0.63) or age (P=0.59).&#x2028; Conclusions: At the inception of the era in which partial breast irradiation was becoming incorporated into the care of breast cancer patients, only a small percentage of all patients received breast brachytherapy across the US. As contemporary data become available, future studies may seek to trace how this new treatment strategy is becoming more widely integrated into routine breast cancer treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6087.

Trastuzumab treatment and the risk of central nervous system (CNS) metastases

1018

Background: In the era of trastuzumab, HER2-positive breast cancer confers an increased risk of central nervous system (CNS) metastases. While several studies have examined CNS metastases in trastuzumab-treated patients, data are sparse regarding CNS metastases in trastuzumab-naïve HER2-positive patients. We evaluated time to CNS metastasis, death, and death subsequent to brain metastasis in relation to trastuzumab treatment. Methods: The study population included 750 patients diagnosed with HER2-positive metastatic breast cancer (HER2+ MBC) between June 1977 and January 2006. The association between trastuzumab treatment and the outcomes of time to CNS metastasis and time to death following CNS metastasis were determined using Cox proportional hazards models that included trastuzumab treatment as a time-dependent covariate. Multivariable Cox proportional hazards models were fit to determine the association between trastuzumab treatment and outcomes after adjustment for known prognostic factors. Patients with HER2+ MBC treated at our institution before trastuzumab was available served as our control group. Results: Of the 750 patients included, 689 patients received trastuzumab during the follow-up period while 61 patients were not treated with trastuzumab. Median follow-up was 32 months. A total of 251 patients developed CNS metastases. After adjusting for other prognostic variables including age, ER status, PR status, pathological stage, and site of initial metastasis, patients who received trastuzumab had 2.84 times the risk of CNS metastases (95 % CI = 1.87, 4.30, p < 0.0001) compared to patients who did not receive trastuzumab. Time to death following brain metastasis did not differ significantly between trastuzumab- treated and -untreated patients. Conclusions: In our large series, patients with HER2+ MBC treated with trastuzumab were at significantly increased risk of developing CNS metastases compared to patients who did not receive trastuzumab. This finding warrants further investigation into biological mechanisms that may account for this difference.

No significant financial relationships to disclose.

Inclusion of taxanes, particularly weekly paclitaxel, in preoperative chemotherapy improves pathologic complete response rate in estrogen receptor-positive breast cancers

BACKGROUND

We examined if inclusion of a taxane and more prolonged preoperative chemotherapy improves pathologic complete response (pCR) rate in estrogen receptor (ER)-positive breast cancer compared with three to four courses of 5-fluorouracil, doxorubicin, cyclophosphamide (FAC).

PATIENTS AND METHODS

Pooled analysis of results from seven consecutive neo-adjuvant chemotherapy trials including 1079 patients was carried out. These studies were conducted at MD Anderson Cancer Center from 1974 to 2001. Four hundred and twenty-six (39.5%) patients received taxane-based neo-adjuvant therapy. pCR rates and survival times were analyzed as a function of chemotherapy regimen and ER status. Multivariate logistic and Cox regression analysis were carried out to identify variables associated with pCR and survival.

RESULTS

Patients with ER-negative cancer had higher overall pCR rate than patients with ER-positive tumors (20.1% versus 4.9%, P < 0.001). In ER-negative patients, the pCR rates were 29% and 15% with and without a taxane (P < 0.001). In ER-positive patients, the pCR rates were 8.8% and 2.0% with and without a taxane (P < 0.001). In multivariate analysis, clinical tumor size (P < 0.001), ER-negative status (P < 0.001) and inclusion of a taxane (P = 0.01) were independently associated with pCR. For patients with pCR, survival was similar regardless of ER status or the type of regimen that induced pCR.

CONCLUSION

pCR rates increased for patients with both ER-positive and ER-negative tumors as regimens started to include a taxane and became longer. This indicates that a subset of patients with ER-positive breast cancer benefits from more aggressive chemotherapy, similarly to patients with ER-negative tumors.

High-dose chemotherapy and autologous peripheral blood stem cell transplantation for primary breast cancer refractory to neoadjuvant chemotherapy

The role of high-dose chemotherapy (HDCT) in patients with refractory breast cancer is not well established. Forty-two female patients (median age of 46 years) with breast cancer refractory to neoadjuvant chemotherapy received HDCT (cyclophosphamide, carmustine and thiotepa) supported by an autologous peripheral blood stem cells transplant. Their disease had been refractory (defined as less than partial response) to one (18 patients) or two (24 patients) regimens of neoadjuvant chemotherapy. Twenty-nine patients had surgery before HDCT. The best response after surgery, HDCT, and radiation therapy was assessed 60 days after transplantation. Thirty patients had complete remission, eight had a PR, one had a minor response, and three had progressive disease. In seven of 13 patients whose disease was inoperable before HDCT, it became operable. After a median follow-up of 42 months, 21 patients were alive, and 15 remained disease free. Five-year overall survival (OS) was 57% (CI, 50-64%), and the estimated 5-year progression-free survival was 40% (CI, 32-48%). Both OS and PFS were better in patients whose disease became operable after chemotherapy than in those whose disease remained inoperable. A randomized study is warranted in this patient population.

Biphasic metaplastic sarcomatoid carcinoma of the breast

BACKGROUND

Breast biphasic metaplastic sarcomatoid carcinoma (MSC) is rare and aggressive. We analyzed 100 patients treated at M. D. Anderson Cancer Center (MDACC) with 213 MSC and 98 carcinosarcoma patients identified through the Surveillance, Epidemiology and End-Results (SEER) database to describe clinical and pathologic characteristics.

PATIENTS AND METHODS

We searched the MDACC (1985-2001) and SEER databases (1988-2001) for breast MSC and carcinosarcoma patients.

RESULTS

We identified 100 MDACC MSC patients: 66% had node-negative disease and 6% distant metastases at presentation. Median recurrence-free survival (RFS) of 94 patients with stages I-III disease was 74 months (range 3-74), with 52% 5-year RFS [95% confidence interval (CI) 0.42-0.63]. Median overall survival in these patients was not reached, with 64% 5-year survival (95% CI 0.54-0.75). The initial stage of the tumor, but not use of adjuvant chemo- or radiotherapy, had a strong association with outcome. The pathologic complete response rate to neoadjuvant chemotherapy was 10%. Median survival from the time of recurrent disease was 14 months (range 1-55). Tumors were usually hormone receptor- and HER2/neu-negative. SEER data were consistent with MDACC findings.

CONCLUSIONS

Breast MSC and carcinosarcoma are aggressive, treatment-refractory tumors with shared clinical features and outcome similar to poorly differentiated receptor-negative adenocarcinomas. New therapeutic agents are needed.

Polymorphisms in the ACE and PAI-1 genes are associated with recurrent spontaneous miscarriages

BACKGROUND

Successful pregnancies require fine tuning of fibrinolytic activities in order to secure fibrin polymerization and stabilization of the placental basal plate as well as to prevent excess fibrin deposition in placental vessels and intervillous spaces. Fibrinolysis is tightly regulated by plasminogen activator inhibitor-1 (PAI-1). Endothelial PAI-1 synthesis is induced by angiotensin II, which is generated by angiotensin I-converting enzyme (ACE).

METHODS

We studied the ACE deletion (D)/insertion (I) polymorphism and the PAI-1 4G/5G polymorphism in women with recurrent spontaneous miscarriages (RM). Both polymorphisms have been shown to be associated with ACE and PAI-1 expression levels respectively. A study group of 184 patients with a history of two or more consecutive unexplained spontaneous miscarriages was compared with a control group of 127 patients with uneventful term deliveries and no history of miscarriages.

RESULTS

Our findings show: (i) homozygosity for the D allele of the ACE gene, which results in elevated PAI-1 concentrations and hypofibrinolysis, is associated with an elevated risk of RM; (ii) the combination of the D/D genotype with two 4G alleles of the PAI-1 promoter, which further increases PAI-1 plasma levels, is significantly more frequent in RM patients compared with controls.

CONCLUSIONS

Based on these results, we recommend the incorporation of these two polymorphisms into the spectrum of thrombophilic mutations which should be analysed in individuals with recurrent spontaneous miscarriages. Patients homozygous for both the ACE D and PAI-1 4G alleles may benefit from the application of low molecular weight heparin as early as possible in the pregnancy in order to prevent uteroplacental microthromboses.