Epidemiology and survival outcomes of colorectal mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinoma

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine neoplasms are a rare subtype of neuroendocrine neoplasm consisting of ≥30% each of neuroendocrine and non-neuroendocrine differentiation. Neuroendocrine carcinomas are poorly differentiated neuroendocrine tumors. The epidemiology and prognosis of colorectal mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas are not clearly defined in the literature. We sought to examine the presentation, patterns of care, and outcomes of patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas.

METHODS

We identified patients diagnosed with stage I-III colorectal (excluding appendix) mixed neuroendocrine-non-neuroendocrine neoplasms or neuroendocrine carcinomas with only one-lifetime cancer diagnosis who underwent surgical resection between 2010 and 2018 from the National Cancer Database. We performed bidirectional selection to identify variables to include in a multivariable Cox proportional hazards model.

RESULTS

We identified 189 patients with a diagnosis of stage I to III colorectal mixed neuroendocrine-non-neuroendocrine neoplasms, 66% of whom had poorly differentiated tumors and 482 with neuroendocrine carcinomas. Among patients with stage III disease, 68% of patients with mixed neuroendocrine-non-neuroendocrine neoplasms and 54% of patients with neuroendocrine carcinomas received adjuvant chemotherapy. The median survival for the overall patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas cohorts were 38 and 42 months, respectively (P = .22), and the median survival for patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas with stage III disease were 30 and 25 months, respectively (P = .27). In multivariable analysis, fewer number of positive nodes and receipt of adjuvant chemotherapy were independently associated with decreased risk of mortality for patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas.

CONCLUSION

Adjuvant chemotherapy is associated with improved survival in stage III mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas. Future studies are warranted to identify subsets of patients benefiting most from adjuvant therapy.

ATA risk stratification in papillary thyroid microcarcinoma has low positive predictive value when identifying recurrence

BACKGROUND

Rising incidence of papillary thyroid microcarcinomas (PTMC) has raised concerns for overdiagnosis. Utility of the American Thyroid Association Risk Stratification System (ATA-RSS) 2015 in predicting risk of disease recurrence in patients with PTMC was assessed.

METHODS

Electronic health records of patients who underwent total thyroidectomy were queried. ATA-RSS 2015 risk stratification was performed on those with PTMC, and validity for predicting disease recurrence was calculated.

RESULTS

With 10-year median follow up, recurrence was higher in PTMC patients with high/intermediate vs low ATA risk (33 ​% vs 4 ​%, p ​= ​0.002). Sensitivity of ATA-RSS for detecting recurrence was 60 ​%, specificity 90 ​%, PPV 33.3 ​%, NPV 96.6 ​%, and accuracy 88 ​%. When microscopic extrathyroidal extension (ETE) was excluded as an intermediate risk criterion, PPV improved to 50 ​% and accuracy improved to 92.5 ​% CONCLUSIONS: ATA-RSS 2015 predicts recurrence in PTMC with high NPV but low PPV. Exclusion of microscopic ETE improved PPV, which may help prevent overtreatment.

Analysis of the Understanding and Worry about Lymphedema of Patients with Breast Cancer

BACKGROUND

Lymphedema is a potential lifelong sequela of breast cancer treatment. We sought to: (1) evaluate the worry and knowledge of patients about lymphedema, (2) quantify patients reporting lymphedema education and screening, and (3) determine willingness to participate in lymphedema screening and prevention programs.

PATIENTS AND METHODS

A survey evaluating lymphedema-related knowledge and worry was sent to patients treated for stage 0-III breast cancer. Exclusion criteria included > 10 years since diagnosis, missing clinical staging, and those without axillary surgery. Responses were linked with clinicopathologic information.

RESULTS

Of 141 patients meeting inclusion criteria, 89% of those without lymphedema were not at all or slightly worried about lymphedema. Higher levels of worry were associated with clinical stage II-III disease [odds ratio (OR) 2.63, p = 0.03], a history of axillary lymph node dissection (ALND) (OR 4.58, p < 0.01), and employment (OR 2.21, p = 0.05). A total of 102 (72%) patients recalled receiving lymphedema education. Lymphedema knowledge was limited, with < 25% of respondents answering > 50% of the risk factor questions correctly. Worry and knowledge were not significantly associated. Of patients without lymphedema, 36% were interested in learning more about lymphedema and 64% were willing to participate in or learn more about a screening program. Most (66%) felt that lymphedema information should be provided before and after cancer treatment.

DISCUSSION

A majority of our breast cancer survivors had limited knowledge about lymphedema risk factors. While most patients were not worried about developing lymphedema, higher worry was seen in patients with a higher clinical stage at diagnosis, ALND, and employment. Our findings suggest potential targets and timing for patient-centered educational interventions.

The impact of KRAS mutation, microsatellite instability, and tumor laterality on the prognosis of nonmetastatic colon cancer

BACKGROUND

KRAS mutations, microsatellite instability, and tumor location have been found to be significant prognostic factors in colorectal cancer. The interaction between these variables and its effect on overall survival in nonmetastatic colon cancer has not been well elucidated.

METHODS

The National Cancer Database (2010-2016) was queried for patients with stage I-III colon cancer and known microsatellite instability and KRAS status undergoing curative resection.

RESULTS

A total of 5,292 patients were identified: 60.4% had right-sided cancers, 36.4% had KRAS mutations, and 15.6% had microsatellite instability. Right-sided tumors were more likely to have microsatellite instability and KRAS mutations compared to left-sided tumors. On univariable analysis, KRAS mutations and microsatellite instability status were not associated with differences in survival, whereas right-sided cancers had worse overall survival compared to left-sided cancers (hazard ratio 1.32, 95% confidence interval: 1.18-1.47). On multivariable analysis, right-sided location, KRAS mutations, and microsatellite instability were not independent prognostic factors. However, a significant interaction between laterality and KRAS status was observed. In patients with mutated KRAS cancers, left-sided tumors were at increased risk of death compared to right-sided tumors (hazard ratio: 1.30, 95% confidence interval: 1.03-1.63), whereas in patients with wild-type KRAS cancers, left-sided tumors were at decreased risk of death (hazard ratio: 0.81, 95% confidence interval: 0.67-0.97).

CONCLUSION

In patients with stage I-III colon cancer, laterality, KRAS mutation, and microsatellite instability status were not independently prognostic after curative resection. However, the effect of laterality was opposite based on KRAS status, with left-sided (compared to right-sided) tumors associated with worse overall survival in mutated KRAS patients and better overall survival in wild-type KRAS individuals. Laterality itself may not be an independent prognostic factor but a reflection of differing genetic profiles within the colon.

A Pilot Study of Preoperative Vandetanib on Markers of Proliferation and Apoptosis in Breast Cancer

INTRODUCTION

Preclinical data supports antitumor activity of tyrosine kinase inhibitor vandetanib with Ret as the therapeutic target in breast cancer. We investigated the effect of preoperative vandetanib on markers of proliferation and apoptosis in breast cancer.

METHODS

Patients with invasive breast cancer were randomly assigned vandetanib 300 mg or placebo PO daily for 2 weeks before operative resection from January 2014 to June 2017. Pretreatment and posttreatment specimens were analyzed by immunohistochemistry for Ki-67, TUNEL, and p-ERK with stratification by Ret expression by immunohistochemistry.

RESULTS

Ten patients were enrolled. There was no statistically significant difference in ERK activation compared with placebo (P=0.45); however, ERK activation was reduced 74% compared with pretreatment biopsy with vandetinib treatment (P=0.005) without a significant reduction in the placebo group (-29%, P=0.55). Mean change in Ki-67 after vandetanib treatment was +0.3% compared with +2.0% in placebo treated patients, P=0.72. Mean change in TUNEL was +0.48 apoptotic nuclei per HPF in the vandetanib arm compared with +1.02 in the placebo arm, P=0.32. In vandetanib treated patients, Ki-67 was reduced 0.3% in RET-positive tumors compared with increased 1.0% in RET-negative tumors, P=0.43 and TUNEL was increased 0.77 in RET-positive tumors and 0.2 in RET-negative tumors, P=0.21.

CONCLUSIONS

In this pilot study, no statistically significant differences on prespecified markers were seen with vandetanib compared with placebo. In accordance with the investigational hypothesis, there was a nonsignificant trend with vandetanib treatment of reduction in p-ERK and increased effects in Ret expressing tumors.

Targeting Gi/o protein-coupled receptor signaling blocks HER2-induced breast cancer development and enhances HER2-targeted therapy

GPCRs are highly desirable drug targets for human disease. Although GPCR dysfunction drives development and progression of many tumors, including breast cancer (BC), targeting individual GPCRs has limited efficacy as a cancer therapy because numerous GPCRs are activated. Here, we sought a new way of blocking GPCR activation in HER2⁺ BC by targeting a subgroup of GPCRs that couple to G_i/o proteins (G_i/o-GPCRs). In mammary epithelial cells of transgenic mouse models, and BC cell lines, HER2 hyperactivation altered GPCR expression, particularly, G_i/o-GPCR expression. G_i/o-GPCR stimulation transactivated EGFR and HER2 and activated the PI3K/AKT and Src pathways. If we uncoupled G_i/o-GPCRs from their cognate G_i/o proteins by pertussis toxin (PTx), then BC cell proliferation and migration was inhibited in vitro and HER2-driven tumor formation and metastasis were suppressed in vivo. Moreover, targeting G_i/o-GPCR signaling via PTx, PI3K, or Src inhibitors enhanced HER2-targeted therapy. These results indicate that, in BC cells, HER2 hyperactivation drives aberrant G_i/o-GPCR signaling and G_i/o-GPCR signals converge on the PI3K/AKT and Src signaling pathways to promote cancer progression and resistance to HER2-targeted therapy. Our findings point to a way to pharmacologically deactivate GPCR signaling to block tumor growth and enhance therapeutic efficacy.

Expression of cancer stem cell markers in tall cell variant papillary thyroid cancer identifies a molecular profile predictive of recurrence in classic papillary thyroid cancer

BACKGROUND

Tall cell variant of papillary thyroid carcinoma is an aggressive subtype of papillary thyroid carcinoma. We examined expression of cancer stem cell markers in tall cell variant compared with other well-differentiated thyroid cancers.

METHODS

Expression of cancer stem cell markers was examined in 572 thyroid tumors from The Cancer Genome Atlas Thyroid Cancer database and tall cell variant and papillary thyroid carcinoma tumors by immunohistochemistry.

RESULTS

Expression of the PROM1 gene, encoding the cancer stem cell marker CD133, was elevated in tall cell variant compared to classic papillary thyroid carcinoma in a large cohort of unmatched samples from The Cancer Genome Atlas Thyroid Cancer database (P < .001). By immunohistochemistry in age and stage matched samples, CD133 protein was confirmed to be significantly increased in tall cell variant versus classic papillary thyroid carcinoma (P = .006). Analyzing all thyroid cancers, high PROM1 expression was associated with worse disease-specific survival. Optimal cutoffs were determined to define a tall cell variant-like cancer stem cell signature characterized by high PROM1, high ALDH1A3, and low CD24 expression. Classic papillary thyroid carcinoma with a tall cell variant-like gene signature had worse recurrence disease-free survival compared to classic papillary thyroid carcinoma with a non-tall cell variant signature (P = .02).

CONCLUSION

Tall cell variant of papillary thyroid carcinoma has increased expression of cancer stem cell markers compared to classic papillary thyroid carcinoma. The tall cell variant-like cancer stem cell gene signature identified a molecular subtype of classic papillary thyroid carcinoma that has a worse recurrence-free survival.

Influence of endocrine multidisciplinary tumor board on patient management and treatment decision making

BACKGROUND

Multidisciplinary Tumor Boards (MDT) are used to obtain input regarding cancer management. This study assessed the impact of our institutional Endocrine MDT.

METHODS

MDT notes on patients with thyroid cancer treated during 2012-2018 were abstracted retrospectively from the electronic medical record. Management change (MC) was prospectively collected by the MDT coordinator. Biannual evaluations reviewed the impact of the MDT as observed by attendees.

RESULTS

MC was recommended in 47 (15%) of 286 presentations, with additional imaging being the most frequent (43%). Presentation of recurrences were more likely to result in MC (24% vs. 13% initial, p = 0.03). Overall, 98% of attendees found the conference exceeded educational expectations. About 24% reported intending to use a more evidence/guideline-based approach after attending and this trend increased over time (p = 0.002).

CONCLUSION

MDT presentations led to a higher rate of MC particularly in recurrent TC patients and increased evidenced-based practice for attendees.

AP-2α-Mediated Activation of E2F and EZH2 Drives Melanoma Metastasis

In melanoma metastasis, the role of the AP-2α transcription factor, which is encoded by TFAP2A, is controversial as some findings have suggested tumor suppressor activity while other studies have shown high TFAP2A expression in node-positive melanoma associated with poor prognosis. Here we demonstrate that AP-2α facilitates melanoma metastasis through transcriptional activation of genes within the E2F pathway including EZH2. A BioID screen found that AP-2α interacts with members of the nucleosome remodeling and deacetylase (NuRD) complex. Loss of AP-2α removed activating chromatin marks in the promoters of EZH2 and other E2F target genes through activation of the NuRD repression complex. In melanoma cells, treatment with tazemetostat, an FDA-approved and highly specific EZH2 inhibitor, substantially reduced anchorage-independent colony formation and demonstrated heritable antimetastatic effects, which were dependent on AP-2α. Single-cell RNA sequencing analysis of a metastatic melanoma mouse model revealed hyperexpansion of Tfap2a ^High/E2F-activated cell populations in transformed melanoma relative to progenitor melanocyte stem cells. These findings demonstrate that melanoma metastasis is driven by the AP-2α/EZH2 pathway and suggest that AP-2α expression can be used as a biomarker to predict responsiveness to EZH2 inhibitors for the treatment of advanced melanomas. SIGNIFICANCE: AP-2α drives melanoma metastasis by upregulating E2F pathway genes including EZH2 through inhibition of the NuRD repression complex, serving as a biomarker to predict responsiveness to EZH2 inhibitors.

AP-2α Regulates S-Phase and Is a Marker for Sensitivity to PI3K Inhibitor Buparlisib in Colon Cancer

Activating protein 2 alpha (AP-2α; encoded by TFAP2A) functions as a tumor suppressor and influences response to therapy in several cancer types. We aimed to characterize regulation of the transcriptome by AP-2α in colon cancer. CRISPR-Cas9 and short hairpin RNA were used to eliminate TFAP2A expression in HCT116 and a panel of colon cancer cell lines. AP-2α target genes were identified with RNA sequencing and chromatin immunoprecipitation sequencing. Effects on cell cycle were characterized in cells synchronized with aphidicolin and analyzed by FACS and Premo FUCCI. Effects on invasion and tumorigenesis were determined by invasion assay, growth of xenografts, and phosphorylated histone H3 (PHH3). Knockout of TFAP2A induced significant alterations in the transcriptome including repression of TGM2, identified as a primary gene target of AP-2α. Loss of AP-2α delayed progression through S-phase into G₂-M and decreased phosphorylation of AKT, effects that were mediated through regulation of TGM2. Buparlisib (BKM120) repressed in vitro invasiveness of HCT116 and a panel of colon cancer cell lines; however, loss of AP-2α induced resistance to buparlisib. Similarly, buparlisib repressed PHH3 and growth of tumor xenografts and increased overall survival of tumor-bearing mice, whereas, loss of AP-2α induced resistance to the effect of PI3K inhibition. Loss of AP-2α in colon cancer leads to prolonged S-phase through altered activation of AKT leading to resistance to the PI3K inhibitor, Buparlisib. The findings demonstrate an important role for AP-2α in regulating progression through the cell cycle and indicates that AP-2α is a marker for response to PI3K inhibitors. IMPLICATIONS: AP-2α regulated cell cycle through the PI3K cascade and activation of AKT mediated through TGM2. AP-2α induced sensitivity to Buparlisib/BKM120, indicating that AP-2α is a biomarker predictive of response to PI3K inhibitors.

AP-2γ Is Required for Maintenance of Multipotent Mammary Stem Cells

Mammary gland ductal morphogenesis depends on the differentiation of mammary stem cells (MaSCs) into basal and luminal lineages. The AP-2γ transcription factor, encoded by Tfap2c, has a central role in mammary gland development but its effect in mammary lineages and specifically MaSCs is largely unknown. Here, we utilized an inducible, conditional knockout of Tfap2c to elucidate the role of AP-2γ in maintenance and differentiation of MaSCs. Loss of AP-2γ in the basal epithelium profoundly altered the transcriptomes and decreased the number of cells within several clusters of mammary epithelial cells, including adult MaSCs and luminal progenitors. AP-2γ regulated the expression of genes known to be required for mammary development, including Cebpb, Nfkbia, and Rspo1. As a result, AP-2γ-deficient mice exhibited repressed mammary gland ductal outgrowth and inhibition of regenerative capacity. The findings demonstrate that AP-2γ can regulate development of mammary gland structures potentially regulating maintenance and differentiation of multipotent MaSCs.

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AP-2γ-deficient mice exhibit repressed ductal outgrowth and regenerative capacity

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Loss of AP-2γ reduced cells within mammary stem and luminal progenitor clusters

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AP-2γ target genes, including Cebpb, Nfkbia, and Rspo1, regulate mammary development

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AP-2γ potentially regulates maintenance of multipotent mammary stem cells

Unanticipated Admission Following Outpatient Laparoscopic Cholecystectomy: Identifying Opportunities for Improvement

BACKGROUND

Unanticipated admissions are a burden to the health care system. Over 400 000 outpatient laparoscopic cholecystectomies (LCs) are performed annually in the United States. The aim of this study is to identify causes of unanticipated admissions and modifiable risk factors.

METHODS

Patients undergoing elective outpatient LCs were identified from the 2013-2015 American College of Surgeons National Surgical Quality Improvement Program database.

RESULTS

A total of 69 376 patients underwent outpatient LC or LC+ intraoperative cholangiogram (IOC); 2027 (2.9%) were admitted after a median of 5 days (interquartile range 3-8). Admission rates varied by preoperative indications: pancreatitis (4.9%), gallstones with obstruction (3.9%), cholecystitis (3.0%), and gallstones without obstruction (2.6%) (P = .003). The most frequent causes were infection, retained stones, and other GI complications. Patients admitted for infection or cardiopulmonary complications were older with higher American Society of Anesthesiologists (ASA) (P < .01), while patients with pain and retained stones were younger with lower ASA (P < .01). Patients who underwent LC+IOC had a lower admission rate due to retained stones (.17% vs. .31% LC, P = .006).

CONCLUSIONS

Unanticipated admissions following outpatient LC occur infrequently for diverse reasons usually within the first week after surgery. Associated factors are patient and disease related and not at all modifiable. In selected patients, increased IOC use may decrease admissions from retained stones.

Chemoradiation versus local excision in treatment of stage I anal squamous cell carcinoma: A population-based analysis

INTRODUCTION

Chemoradiation therapy (CRT) is the standard treatment for anal squamous cell carcinoma (ASCC) but can have significant treatment related toxicities. Recent studies have demonstrated the effectiveness of local excision (LE) for stage I ASCC with comparable oncologic outcomes to CRT. We aimed to evaluate this finding in a large population-based database.

METHODS

Patients diagnosed with stage I (T1N0M0) ASCC were identified from the Surveillance, Epidemiology, and End Results database, 2004-2015. Treatment approach was categorized as CRT or LE. Factors associated with treatment approach and cause-specific survival (CSS) were analyzed for the entire cohort and after stratification by tumor size (≤1 cm and 1-2 cm).

RESULTS

Among 883 patients, 56% had ASCCs 1-2 cm in size and 77% received CRT. Mean age was 60 years, 65% were female, and 90% were White. Factors independently associated with receiving CRT were, being female, higher tumor grade, and tumor size 1-2 cm. Unadjusted 5-year CSS for CRT was 96% while for LE it was 98% (p = 0.048). After adjusting for available confounders, treatment approach was not associated with worse CSS, however being Black (HR = 8.7) and uninsured (HR = 13.7) were independently associated with worse prognosis. After stratification by tumor size, there was still no significant difference in 5-year CSS by treatment approach.

CONCLUSIONS

LE was performed in a significant proportion of patients but was not independently associated with worse CSS compared to CRT. In appropriately selected patients with well differentiated ASCCs ≤1 cm, LE could be an acceptable management option but studies measuring outcomes such as local recurrence are needed.

The Impact of KRAS Mutation on the Presentation and Prognosis of Non-Metastatic Colon Cancer: an Analysis from the National Cancer Database

INTRODUCTION

Approximately 40% of colorectal cancers have a KRAS mutation. The prognostic significance of KRAS mutations in patients with non-metastatic colon cancer has not been well elucidated. The National Cancer Database (NCDB) was used to analyze factors associated with KRAS mutation as well as its impact on the presentation and survival of patients with stages I-III colon cancer.

METHODS

The NCDB was queried to identify patients diagnosed with stages I-III adenocarcinoma of the colon from 2004 to 2015.

RESULTS

A total of 19,877 patients with known KRAS status were identified: mutation rates were 33% in stage I, 35% in stage II, and 38% in stage III patients (p < 0.01). On multivariable analysis, black race and right-sided location were independently associated with KRAS-mutated cancers (all p < 0.01). On univariate analysis for overall survival (OS), KRAS mutation was not significantly associated with a worse 5-year OS for stages I and II patients (p = 0.60 and 0.88, respectively). However, stage III KRAS-mutated colon cancers had a lower OS as compared with KRAS wild type cancers both on univariate and multivariable analysis. Right-sided colon cancers were independently associated with a worse prognosis compared with left-sided lesions (p < 0.01).

CONCLUSIONS

KRAS-mutated colon cancers were more frequently observed in black patients, right-sided locations, and higher-stage tumors. These mutations had a negative prognostic impact for stage III patients, suggesting that the incorporation of genotypic data into colon cancer staging may help to guide systemic therapy and prognostication of colon cancer patients.

Racial disparities in comorbid conditions among patients undergoing thyroidectomy for Graves' disease: An ACS-NSQIP analysis

BACKGROUND

Studies indicate that racial disparities exist in the presentation and outcomes of patients undergoing thyroidectomy for cancer and benign disease. We examined the relationship between race, pre-operative characteristics and outcomes in patients undergoing thyroidectomy for GD.

METHODS

Patients were identified from the 2013-2016 American College of Surgeons NSQIP database using ICD-9/10 codes consistent with diffuse toxic goiter.

RESULTS

AA patients were more likely to have an ASA classification of ≥3 (41% vs 30%, p < 0.001), a higher rate of CHF (2.1% vs 0.5%, p = 0.01), hypertension (46% vs 32%, p < 0.001) and dyspnea (10% vs 5%, p < 0.001) compared to Non-Hispanic Caucasians (NH-C) patients. Complications were higher in patients with ASA≥3 and CHF but not affected by race.

CONCLUSIONS

Analysis of a national database of thyroidectomy for GD revealed a higher burden of preoperative comorbidities in AA patients compared to other races, although race was not an independent predictor of outcomes.

Cancer cell-intrinsic function of CD177 in attenuating β-catenin signaling

Aiming to identify immune molecules with a novel function in cancer pathogenesis, we found the cluster of differentiation 177 (CD177), a known neutrophil antigen, to be positively correlated with relapse-free (RFS), metastasis-free (MFS) or overall survival (OS) in breast cancer. Additionally, CD177 expression is correlated with good prognosis in several other solid cancers including prostate, cervical, and lung. Focusing on breast cancer, we found that CD177 is expressed in normal breast epithelial cells and is significantly reduced in invasive cancers. Loss of CD177 leads to hyperproliferative mammary epithelium and contributes to breast cancer pathogenesis. Mechanistically, we found that CD177-deficiency is associated with an increase in β-Catenin signaling. Here we identified CD177 as a novel regulator of mammary epithelial proliferation and breast cancer pathogenesis likely via the modulation of Wnt/β-Catenin signaling pathway, a key signaling pathway involved in multiple cancer types.

Rate of BRCA mutation in patients tested under NCCN genetic testing criteria

BACKGROUND

BRCA genetic testing is recommended by the National Comprehensive Cancer Network (NCCN) in breast cancer patients who meet specific criteria. Limited data are available on the likelihood of detecting a mutation when these guidelines are followed.

METHODS

A retrospective chart review examined patients with breast cancer who underwent BRCA testing based on NCCN guidelines.

RESULTS

Twelve (6.0%) of the 199 patients had a deleterious BRCA mutation. Family history of BRCA mutations (50%, p = 0.019), age ≤45 at diagnosis (9.7%, p = 0.034) and meeting ≥3 NCCN criteria (13.3%, p = 0.03) yielded the highest rates of BRCA mutation. Having a family history of BRCA mutation and age ≤45 were associated with increased rate of BRCA mutation on multivariate analysis (OR 14.3, CI 1.2-166.3; OR 11.6, CI 1.2-108.6).

CONCLUSION

Select NCCN criteria are associated with higher rates of BRCA mutations. Waiting for genetic testing results to guide surgical management may be warranted in this subset of patients.

A TFAP2C Gene Signature Is Predictive of Outcome in HER2-Positive Breast Cancer

The AP-2γ transcription factor, encoded by the TFAP2C gene, regulates the expression of estrogen receptor-alpha (ERα) and other genes associated with hormone response in luminal breast cancer. Little is known about the role of AP-2γ in other breast cancer subtypes. A subset of HER2⁺ breast cancers with amplification of the TFAP2C gene locus becomes addicted to AP-2γ. Herein, we sought to define AP-2γ gene targets in HER2⁺ breast cancer and identify genes accounting for physiologic effects of growth and invasiveness regulated by AP-2γ. Comparing HER2⁺ cell lines that demonstrated differential response to growth and invasiveness with knockdown of TFAP2C, we identified a set of 68 differentially expressed target genes. CDH5 and CDKN1A were among the genes differentially regulated by AP-2γ and that contributed to growth and invasiveness. Pathway analysis implicated the MAPK13/p38δ and retinoic acid regulatory nodes, which were confirmed to display divergent responses in different HER2⁺ cancer lines. To confirm the clinical relevance of the genes identified, the AP-2γ gene signature was found to be highly predictive of outcome in patients with HER2⁺ breast cancer. We conclude that AP-2γ regulates a set of genes in HER2⁺ breast cancer that drive cancer growth and invasiveness. The AP-2γ gene signature predicts outcome of patients with HER2⁺ breast cancer and pathway analysis predicts that subsets of patients will respond to drugs that target the MAPK or retinoic acid pathways. IMPLICATIONS: A set of genes regulated by AP-2γ in HER2⁺ breast cancer that drive proliferation and invasion were identified and provided a gene signature that is predictive of outcome in HER2⁺ breast cancer.

The Prognostic Impact of KRAS Mutation in Patients Having Curative Resection of Synchronous Colorectal Liver Metastases

BACKGROUND

m-KRAS has been recently reported to be a significant prognostic factor in patients undergoing resection of colorectal liver metastases. This is due to the lack of response to monoclonal epithelial growth factor receptor antibodies, and potentially as a result of a more aggressive tumor biology.

METHODS

The National Cancer Database was queried to identify patients with known KRAS status presenting with colorectal cancer and liver metastases who underwent resection of the primary tumor and metastatic disease between 2010 and 2015.

RESULTS

A total of 2655 patients were identified of which 1116 (42%) had m-KRAS. Tumor size, lymph node involvement rates, and margin status of the primary tumor were similar between patients with m-KRAS and wild-type KRAS (wt-KRAS). In the multivariable analysis, African-American race and right-sided colon cancers were independently associated with m-KRAS (both p < 0.001). m-KRAS patients had a significantly lower overall survival (OS) than those with wt-KRAS, with a 3- and 5-year OS of 51 vs. 64% and 31 vs. 42%, respectively (p < 0.001). After adjustment for available prognostic confounders, factors independently associated with worse OS were increasing age, receipt of monoagent chemotherapy, tumor size, positive lymph node, and resection margin status of the primary tumor, right-sided cancers, and m-KRAS.

CONCLUSIONS

m-KRAS is associated with worse OS in patients presenting with colorectal cancer and liver metastases undergoing resection of the primary tumor and metastatic disease. Right-sided lesions and African-American race were associated with m-KRAS. However, while right-sided remained an independent prognostic factor for OS, race did not.

Timing of Esophagectomy after Neoadjuvant Chemoradiation Therapy Affects the Incidence of Anastomotic Leaks

Background

Neoadjuvant chemoradiation therapy (nCRT) has become the standard of care for esophageal cancer patients prior to esophagectomy. However, the optimal timing for surgery after completion of nCRT remains unclear.

Methods

A retrospective review was performed of patients who underwent esophagectomy with cervical anastomosis for esophageal cancer at a single institution between January 2000 and June 2015. Patients were categorized into 3 cohorts: those who did not receive nCRT prior to esophagectomy (no nCRT), those who underwent esophagectomy within 35 days after nCRT (≤35d), and those who underwent esophagectomy more than 35 days after nCRT (>35d).

Results

A total of 366 esophagectomies were performed during the study period, and 348 patients met the inclusion criteria. Anastomotic leaks occurred in 11.8% of all patients included in the study (41 of 348). Within each cohort, anastomotic leaks were detected in 14.7% of patients (17 of 116) in the no nCRT cohort, 7.3% (13 of 177) in the ≤35d cohort, and 20.0% (11 of 55) in the >35d cohort (p=0.020). Significant differences in the occurrence of anastomotic leaks were observed between the no nCRT and ≤35d cohorts (p=0.044), and between the ≤35d and >35d cohorts (p=0.007).

Conclusion

Esophagectomy with cervical anastomosis within 35 days of nCRT resulted in a lower percentage of anastomotic leaks.

Risk factors for 30-day readmission after adrenalectomy

BACKGROUND

Readmissions represent a substantial burden to the health care system. Risk factors for 30-day readmission after adrenalectomy were examined.

METHODS

Patients who underwent adrenalectomy were selected from the American College of Surgeons National Surgical Quality Improvement Program database from 2011 to 2015.

RESULTS

Among 4,221 patients who underwent adrenalectomy, 216 (5.1%) were readmitted. On multivariate analysis, pre-operative predictive factors associated with readmission were American Society of Anesthesiologists classification (odds ratio [OR] 1.4, confidence interval [CI] 1.1-1.8), disseminated cancer (OR 1.6, CI 1.1-2.5), and adrenal injury (OR 10.9, CI 1.8-68.9). Elective procedures had fewer readmissions (OR 0.50, CI 0.33-0.76). and procedures with greater relative value units had greater readmission rates (OR 1.01, CI 1.004-1.02). An open adrenalectomy (21% of patients) had a higher rate of readmission than a laparoscopic approach (8.0% vs 4.3%, OR 1.5, CI 1.1-2.0). Postoperative risk factors affecting readmission included reoperations (OR 3.2, CI 1.3-8.0), wound complications (OR 6.6, CI 3.8-11.7), systemic infection (OR 6.5, CI 3.9-10.7), renal complications (OR 7.1, CI 2.6-19.2), venous thrombotic events (OR 11.3, CI 5.6-22.6), and discharge to home (OR 0.40, CI 0.22-0.73).

CONCLUSION

Encouraging the appropriate use of laparoscopic adrenalectomy, preventing venous thrombotic events and surgical infections, and improving early post-operative follow-up in high-risk patients may decrease readmissions.

Intraoperative Radiotherapy for Breast Cancer Treatment in a Rural Community

BACKGROUND

Access to health care poses particular challenges for patients living in rural communities. Intraoperative radiotherapy (IORT) offers a treatment alternative to traditional whole-breast radiation therapy (WBRT) for select patients. This study aimed to analyze the use of IORT for patients undergoing breast-conserving surgery at an academic institution located in a rural state.

METHODS

A retrospective review analyzed all patients at a single institution with a diagnosis of ductal carcinoma in situ (DCIS) or invasive breast cancer from April 2012 to January 2017 who were undergoing breast-conserving surgery with either IORT or WBRT. Student's t test or Fisher's exact test was used to make statistical comparisons.

RESULTS

Patients undergoing IORT (n = 117) were significantly older than patients treated with WBRT (n = 191) (65.6 vs 58.6 years; p < 0.001) and had smaller tumors on both preoperative imaging (1.04 vs 1.66 cm; p < 0.05) and final pathology (0.99 vs 1.48 cm; p < 0.05). Patients receiving IORT lived farther from the treating facility than patients treated with WBRT (67.2 vs 30.8 miles; p < 0.05). To account for biases created in the IORT selection criteria, subgroup analysis was performed for women receiving WBRT who fulfilled IORT selection criteria, and distance traveled remained significant (67.2 vs 31.4 miles; p < 0.05). Neither recurrence nor survival differed between the IORT and WBRT groups. Medicare reimbursement for IORT was approximately 50% more than for WBRT.

CONCLUSIONS

For women from rural communities, IORT appears to be an attractive option because these women tend to be older and to live farther from the treatment facility.

Nipple-Sparing Mastectomy is Not Associated with a Delay of Adjuvant Treatment

BACKGROUND

High-volume single-institution studies support the oncologic safety of nipple sparing mastectomy (NSM). Concerns remain regarding the increased potential for complications, recurrence, and delays to subsequent adjuvant therapy. A national database was used to examine treatment and outcomes for NSM patients.

METHODS

Women undergoing unilateral NSM or skin sparing mastectomy (SSM) for stage 0-4 breast cancer from 2004 to 2013 were identified from the National Cancer Database. Demographic and oncologic characteristics, short-term outcomes and time to local and systemic treatment were compared.

RESULTS

NSM was performed on 8173 patients: 8.7% were node positive, and for stage 1-4 disease, 10.6% were triple negative (TN) and 15.3% were HER2-positive. NSM patients were less likely than SSM patients to receive chemotherapy [CT] (37.4 vs. 43.4%) or radiation [PMRT] (15.6 vs. 16.9%), and were also more likely to present with clinically early-stage disease. NSM patients with high-risk features were more likely to receive CT in the neoadjuvant [NCT] than adjuvant setting [AC] (OR 3.76, 1.81, and 1.99 for clinical N2/3, TN, and HER2-positive disease, all p < 0.001). On multivariate analysis, NSM patients had a higher rate of pathologic complete response [pCR] (OR 1.41, p < 0.001). Readmission rate, positive margin rate and time to CT, PMRT or hormonal therapy were not increased for NSM compared to SSM patients.

CONCLUSIONS

Over one third of NSM patients received chemotherapy and/or radiation. NSM patients with high-risk features were more likely to receive NAC and obtain a pCR. NSM patients did not experience worse outcomes or delayed adjuvant therapy compared to SSM.

Targeting the SUMO pathway as a novel treatment for anaplastic thyroid cancer

Cancer stem cells (CSCs) are expanded in anaplastic thyroid cancer (ATC) and standard treatment approaches have failed to improve survival, suggesting a need to specifically target the CSC population. Recent studies in breast and colorectal cancer demonstrated that inhibition of the SUMO pathway repressed CD44 and cleared the CSC population, mediated through SUMO-unconjugated TFAP2A. We sought to evaluate effects of inhibiting the SUMO pathway in ATC. ATC cell lines and primary ATC tumor samples were evaluated. The SUMO pathway was inhibited by knockdown of PIAS1 and use of SUMO inhibitors anacardic acid and PYR-41. The expression of TFAP2A in primary ATC was examined by immunohistochemistry. All ATC cell lines expressed TFAP2A but only 8505C expressed SUMO-conjugated TFAP2A. In 8505C only, inhibition of the SUMO pathway by knockdown of PIAS1 or treatment with SUMO inhibitors repressed expression of CD44 with a concomitant loss of SUMO-conjugated TFAP2A. The effect of SUMO inhibition on CD44 expression was dependent upon TFAP2A. Treatment with SUMO inhibitors resulted in a statistically improved tumor-free survival in mice harboring 8505C xenografts. An examination of primary ATC tissue determined that TFAP2A was expressed in 4 of 11 tumors surveyed. We conclude that inhibition of the SUMO pathway repressed the CSC population, delaying the outgrowth of tumor xenografts in ATC. The effect of SUMO inhibition was dependent upon expression of SUMO-conjugated TFAP2A, which may serve as a molecular marker for therapeutic effects of SUMO inhibitors. The findings provide pre-clinical evidence for development of SUMO inhibitors for the treatment of ATC.

Incidence, characteristics, and management of recently diagnosed, microscopically invasive breast cancer by receptor status: Iowa SEER 2000 to 2013

BACKGROUND

Recent incidence, treatment patterns, and outcomes for node negative microscopically invasive breast cancer (MIBC) have not been reported.

METHODS

State Health Registry of Iowa data identified women with ductal carcinoma in situ (DCIS), MIBC, and stage I breast cancer excluding MIBC (stage 1BC).

RESULTS

From 2000 to 2013, 1,706, 193, and 4,514 women were diagnosed with DCIS, MIBC, and stage 1BC, respectively. MIBC increased at an annual percentage change of 2.1 (P = .041). MIBC was more frequently human epidermal growth factor receptor 2 positive than stage 1BC (39.7% vs 9.6%, P < .001). Mastectomy was performed more frequently in MIBC than DCIS (40.9% vs 30.6%, P = .014) or stage 1BC (40.9% vs 33.8%, P = .119). Chemotherapy was given to 4.1% of women with MIBC. Survival for women with MIBC was intermediate between DCIS and stage 1BC.

CONCLUSIONS

Management of MIBC is an increasingly frequent clinical scenario. Women with MIBC receive more aggressive local and systemic therapy than women with DCIS.

Abstract 5529: CD177 suppresses breast cancer progression by regulating the canonical WNT β-Catenin pathway

To better treat breast cancer patients, it is imperative to be able to predict breast cancer relapse and metastasis. Here, we identified the cluster of differentiation 177 (CD177) expression is positively correlated with relapse-free and metastasis-free survival of breast cancer patients. CD177 protein is highly expressed in normal breast epithelial cells and is significantly reduced in invasive cancers. Using mouse models, we found that CD177 suppresses breast cancer, primarily by forming a complex with E-Cadherin and b-Catenin at adherens junctions. The physical interaction prevents the activation of b-Catenin-mediated transcription by the canonical WNT signaling as demonstrated by a TOP-flash dual luciferase assay. In conclusion, we have identified CD177 as a novel breast cancer suppressor and uncovered a new regulatory mechanism for the canonical WNT/b-Catenin-mediated oncogenic signaling transduction.

Citation Format: Paige N. Kluz, Ryan Kolb, Qing Xie, Nicholas Borcherding, Linna Wang, James P. De Andrade, Phillip M. Spanheimer, Wei Li, Katherine N. Gibson-Corley, Andy W. Tao, Sonia Sugg, Ronald J. Weigel, Weizhou Zhang. CD177 suppresses breast cancer progression by regulating the canonical WNT β-Catenin pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5529. doi:10.1158/1538-7445.AM2017-5529

Inhibiting the SUMO Pathway Represses the Cancer Stem Cell Population in Breast and Colorectal Carcinomas

Many solid cancers have an expanded CD44^+/hi/CD24^−/low cancer stem cell (CSC) population, which are relatively chemoresistant and drive recurrence and metastasis. Achieving a more durable response requires the development of therapies that specifically target CSCs. Recent evidence indicated that inhibiting the SUMO pathway repressed tumor growth and invasiveness, although the mechanism has yet to be clarified. Here, we demonstrate that inhibition of the SUMO pathway repressed MMP14 and CD44 with a concomitant reduction in cell invasiveness and functional loss of CSCs in basal breast cancer. Similar effects were demonstrated with a panel of E1 and E3 SUMO inhibitors. Identical results were obtained in a colorectal cancer cell line and primary colon cancer cells. In both breast and colon cancer, SUMO-unconjugated TFAP2A mediated the effects of SUMO inhibition. These data support the development of SUMO inhibitors as an approach to specifically target the CSC population in breast and colorectal cancer.

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Sumoylation regulates CD44 and MMP14 expression in basal breast and colon cancer

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SUMO inhibition clears cancer stem cells, repressing invasiveness and tumor growth

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Anacardic acid functions as a SUMO inhibitor to repress cancer stem cells

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TFAP2A mediates anti-tumor effects of SUMO inhibition in breast and colon cancers

Abstract P1-07-24: Increased risk of contralateral breast cancer after diagnosis of microscopically invasive breast cancer: SEER 1998-2012

Node negative microscopically invasive breast cancer (BC) is frequently associated with ductal carcinoma in situ (DCIS) and considered to have a similar prognosis. We evaluated women with T1micN0M0 (T1mic), DCIS and Stage I BC and report clinical characteristics, risk for subsequent contralateral breast cancer (CBC) and overall survival (OS).

Methods:

The study cohort included women diagnosed 1998-2012 and reported to Surveillance, Epidemiology, and End Result (SEER) data with DCIS, T1mic, or Stage I BC (not including T1mic). Subsequent CBCs were identified in patients with known laterality without contralateral mastectomy. Kaplan Meier models were used to estimate survival and time to CBC. Log-rank tests assessed differences in survival across groups

Results:

During the study period, 9,785 women were diagnosed with T1mic. Clinical features and risk of CBC are shown in the Table 1. Women with DCIS and T1mic were younger than those with Stage I BC. T1mic was more likely to be hormone receptor (HR) negative. Women with T1mic underwent mastectomy significantly more often than women with DCIS or Stage 1 BC. T1mic occurred more frequently in non-white women. Women with T1mic were significantly more likely to develop subsequent CBC than women with Stage 1 BC with a trend for increased CBC compared to women presenting initially with DCIS. Of those who develop CBCs 5.9% (DCIS), 11.2% (T1mic), and 14.6% (Stage 1) developed within 1 year (YR) of diagnosis of the index cancer. At 10 YRS these numbers were 73.7%(DCIS), 82.7%(T1mic) and 83.2% (Stage 1) (DCIS vs T1mic, p&lt;0.001 T1mic vs Stage 1, P= 0.048). At 10 YRS OS for women with CBC after initial BC was 89.5%(DCIS), 86.6%(T1mic) and 84.3%(Stage1) (DCIS vs T1mic, p=0.077, T1mic vs Stage1 p=0.293), Table 2.

Table 1 DCIS, T1mic, Stage I BC: Clinical Features and Contralateral Breast Cancer DCIST1micStage 1 (excluding T1mic)   %%%p ^p ^^N49,6829,785248,307  Median Age5858620.719&lt;0.001HR positive85.0%72.8%86.5%&lt;0.001&lt;0.001Grade     Well-moderately differentiated56.3%61.1%76.6%  Poorly-undifferentiated43.7%38.9%23.4%&lt;0.001&lt;0.001Mastectomy22.7%36.7%24.1%&lt;0.001&lt;0.001Race     White79.7%77.3%84.2%  Black10.8%11.0%7.9%&lt;0.001&lt;0.001Other9.4%11.6%7.9%  CBC*4.1%4.3%3.4%0.317&lt;0.001CBC**57.9%72.9%77.0%&lt;0.0010.021* Portion of full sample, **Of those who had a subsequent BC (ipsilateral or contralateral),^ DCIS vs T1mic,^^ stage I vs T1mic

Table 2 OS by Initial Stage and with CBC  5 YR10 YRp*  OSOS DCISall97.3%88.4%  develop CBC97.8%89.5%0.037T1micall96.3%88.9%  develop CBC95.0%86.6%0.036Stage1 (excluding T1mic)all95.9%85.0%  develop CBC86.9%84.3%0.001*Comparing survival of the stage cohort (all) with women diagnosed with that stage who develop CBC

Conclusion:

Women with T1mic were at increased risk for subsequent CBC relative to women with Stage I BC. When subsequent CBC occurred it developed earlier in women with T1mic than those with DCIS. Time course for this second event and survival with CBC at 10 years matched more closely with women diagnosed with Stage 1 BC. These findings offer suggestions about the biology of T1mic and may have implications for counseling these women on risk reducing strategies.

Citation Format: Thomas A, Weigel RJ, Leone JP, Spanheimer PM, Schroeder MC. Increased risk of contralateral breast cancer after diagnosis of microscopically invasive breast cancer: SEER 1998-2012. [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 P1-07-24.

Abstract P1-11-04: Long-term patient satisfaction with cosmetic outcome and psychosocial wellbeing after breast conserving therapy is affected only by lumpectomy volume

Introduction: Breast conserving therapy (BCT) is considered the treatment of choice for early stage breast cancer by National Cancer Institute guidelines. Little data exists on patient-reported satisfaction and quality of life outcomes after lumpectomy with radiation. This study aims to identify factors influencing satisfaction with cosmetic outcome and quality of life in patients receiving BCT using a validated instrument.

Methods: All patients treated with lumpectomy and radiation for breast cancer at our institution from 1997-2012 received a mailed questionnaire containing the BREAST-Q breast conservation module (graciously provided by Dr A. Pusic, Memorial Sloan Kettering Cancer Center), a validated quality of life survey instrument. A retrospective chart review was performed for survey responders for demographic, treatment, and staging information. Scores were calculated for satisfaction with appearance of the breast, adverse effects of radiation, sexual wellbeing, psychosocial wellbeing and physical wellbeing: upper body and arm. Pearson correlation coefficients were obtained. Wilcoxon rank-sum and one-way ANOVA were used to identify associations between patient variables and satisfaction scores. Multivariate regression was used to assess confounding variables.

Results: A total of 110 questionnaires (response rate of 29.5%) fit criteria for analysis. The mean age of respondents was 65.9±11.2 yrs, and mean time since diagnosis was 91.8±53.1 mos. We observed the strongest correlations between satisfaction with breast appearance and sexual wellbeing (r=0.66, p&lt;0.01), breast appearance and psychosocial wellbeing (r=0.62, p&lt;0.01), and fewer effects of radiation and physical wellbeing (r=0.65, p&lt;0.01). Lumpectomy volume was associated with decreased satisfaction with breast appearance (r=-0.32, p &lt;0.01) and psychosocial wellbeing (r=-0.19, p&lt;0.05). There was no correlation between satisfaction with breast appearance and patient age, time since surgery, history of re-excision, stage or localization technique. Patients with older age at diagnosis reported significantly fewer effects of radiation and better psychosocial, physical, and sexual wellbeing (all p&lt;0.05) (Table 1). The incidence of recurrence was 2.7% and did not impact satisfaction scores.

Distribution of Satisfaction/Quality of Life Outcomes by Age at Diagnosis  Satisfaction/Quality of Life*AgeNBreastAdverse Effects of RadiationPsychosocialSexualPhysical&lt;451458±2282±1973±1945±2074±1645-553264±2683±1980±2054±2579±1756-602667±1794±983±2370±1885±1361-651267±2989±2383±2053±2983±17&gt;652670±2391±1288±1663±2588±25All11065±2388±1682±2058±2482±19P 0.1590.0190.0140.0300.002*Rasch scores range from 0-100 where 100 indicates highest satisfaction

Conclusions: In women undergoing BCT, patient satisfaction with appearance of the breast and psychosocial wellbeing at 7.6 years of follow-up correlated with the volume of tissue removed but no other patient or tumor characteristics. Increasing age at diagnosis was associated with greater satisfaction in multiple domains. These results emphasize the importance of precise surgical technique and patient selection in order to achieve long-term patient satisfaction with BCT.

Citation Format: Welsh JL, Fu S, Liao J, Sugg SL, Scott-Conner CE, Weigel RJ, Erdahl LM, Lizarraga IM. Long-term patient satisfaction with cosmetic outcome and psychosocial wellbeing after breast conserving therapy is affected only by lumpectomy volume. [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 P1-11-04.

EGFR Is Regulated by TFAP2C in Luminal Breast Cancer and Is a Target for Vandetanib

Expression of TFAP2C in luminal breast cancer is associated with reduced survival and hormone resistance, partially explained through regulation of RET. TFAP2C also regulates EGFR in HER2 breast cancer. We sought to elucidate the regulation and functional role of EGFR in luminal breast cancer. We used gene knockdown (KD) and treatment with a tyrosine kinase inhibitor (TKI) in cell lines and primary cancer isolates to determine the role of RET and EGFR in regulation of p-ERK and tumorigenesis. KD of TFAP2C decreased expression of EGFR in a panel of luminal breast cancers, and chromatin immunoprecipitation sequencing (ChIP-seq) confirmed that TFAP2C targets the EGFR gene. Stable KD of TFAP2C significantly decreased cell proliferation and tumor growth, mediated in part through EGFR. While KD of RET or EGFR reduced proliferation (31% and 34%, P < 0.01), combined KD reduced proliferation greater than either alone (52% reduction, P < 0.01). The effect of the TKI vandetanib on proliferation and tumor growth response of MCF-7 cells was dependent upon expression of TFAP2C, and dual KD of RET and EGFR eliminated the effects of vandetanib. The response of primary luminal breast cancers to TKIs assessed by ERK activation established a correlation with expression of RET and EGFR. We conclude that TFAP2C regulates EGFR in luminal breast cancer. Response to vandetanib was mediated through the TFAP2C target genes EGFR and RET. Vandetanib may provide a therapeutic effect in luminal breast cancer, and RET and EGFR can serve as molecular markers for response.

Receptor Tyrosine Kinase Expression Predicts Response to Sunitinib in Breast Cancer

BACKGROUND

Preliminary data indicate that tyrosine kinase inhibitors (TKIs) function through rearranged during transfection (RET) in breast cancer. However, TKIs are not specific and can block several receptor tyrosine kinases (RTKs). This study used cell lines and primary breast cancer specimens to determine factors associated with TKI response.

METHODS

Proliferation was assessed after short interfering RNA knockdown with or without sunitinib in breast cancer cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Breast cancer tissue and matched normal breast was obtained from 30 women with invasive breast carcinoma. Gene expression was assessed by reverse transcriptase-polymerase chain reaction. Fresh tissue was treated in vitro with sunitinib or control media for 30 min, and response was assessed by phosphorylation-specific western blot.

RESULTS

The RTKs including epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR1-3), platelet-derived growth factor receptor (PDGFRa/b), and Kit were overexpressed in triple-negative breast tumors relative to HER2- and estrogen receptor-alpha (ERα)-positive tumors and normal breast tissue. Knockdown of EGFR reduced in vitro proliferation in MCF-7 and MDA-MB-231 but not in SKBR-3 or ZR-75-1 breast cancer cells. With the exception of RET, response to sunitinib was independent of RTK expression in all four cell lines. Both ERα-positive and low-EGFR-expressing tumors had an increased in vitro sunitinib response, as determined by alteration of Erk activation. Expression of other RTKs and additional clinical factors were not associated with response.

CONCLUSION

Triple-negative breast cancers overexpress RTKs but have decreased in vitro response to the TKI sunitinib. In addition to RET, TKIs that block EGFR may increase the therapeutic efficacy of TKIs in breast cancer.

Surgical Management of Breast Cancer in 2010-2011 SEER Registries by Hormone and HER2 Receptor Status

BACKGROUND

Although locoregional recurrence is known to affect overall survival for operable breast cancer, the impact of receptor status on locoregional control is debated. Currently, hormone receptor (HR) and human epidermal growth factor receptor-2 (HER2) status are generally not considered relevant to surgical choice. This study examines recent population-level surgical trends with regard to receptor status.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) data to identify stage I-III female breast cancers diagnosed from 2010 to 2011. Patients were categorized by HR and HER2 receptor status. Univariate and multivariate logistic regressions were used to assess factors associated with undergoing mastectomy and the choice of contralateral prophylactic mastectomy (CPM).

RESULTS

The overall mastectomy rate for the 87,504 women diagnosed in 2010-2011 was 43.4 %. On multivariate analysis, the odds of receiving mastectomy was greater for HER2-positive disease with either HR-negative or HR-positive status, than for women with HER2-negative/HR-positive disease (odds ratio 1.73 and 1. 31, respectively; all p values <0.001). Age, stage, marital status, race, and year of diagnosis also correlated with mastectomy. Triple-negative breast cancer (TNBC) was associated with CPM, while HER2 status was not. The mastectomy rate, which increased overall from 2006 to 2010, has continued to increase for stage III disease but has decreased for stage I disease. Mastectomy rates overall were lower in 2011 than 2010 (p = 0.012).

CONCLUSIONS

HER2-positive disease and TNBC were independent predictors of more extensive surgery in this large, recent, population-based cohort. Although mastectomy rates have continued to increase for stage III disease, mastectomy rates overall were lower in 2011 than in previous years.

Training and certification of the surgical oncologist

Surgical Oncology has evolved as a distinct subspecialty of General Surgery with a well-defined curriculum focused on surgical care of the cancer patient, specific areas of clinical and basic science research focus and specialty journals dedicated to the discipline. The Society of Surgical Oncology (SSO), originally formed as the James Ewing Society, has provided leadership in developing training programs in Surgical Oncology and for three decades has been involved in the approval and oversight of Surgical Oncology training programs. Over this time, Surgical Oncology Fellowship training has expanded and in 2013 there were 103 applicants for 56 fellowship positions in 21 programs. The basic tenants of Surgical Oncology training has remained devoted to the core principles of multidisciplinary care, surgical management of cancer patients and a focus on education in research, clinical trials, community outreach, patient advocacy and leadership in oncology. With the maturation of Surgical Oncology as a separate specialty, Surgical Oncology training programs are now accredited by the Accreditation Council on Graduate Medical Education (ACGME) and graduates of the programs will soon be offered subspecialty certification in Complex General Surgical Oncology (CGSO) by the American Board of Surgery, which has created a component Surgical Oncology Board (SOB). Similar expansion has occurred in other specialty areas including an expansion of Breast Fellowships, which are still being approved by the SSO. In the 2013 SSO Breast Oncology Match, there were 67 applicants for 54 positions in 39 Breast Fellowship programs. Continued advances in cancer biology and technology will challenge us to evolve training programs in Surgical Oncology to produce surgeons capable of advancing the multidisciplinary care of cancer patients.

Paracrine WNT5A Signaling Inhibits Expansion of Tumor-Initiating Cells

It is not well understood how paracrine communication between basal and luminal cell populations in the mammary gland affects tumorigenesis. During ErbB2-induced mammary tumorigenesis, enriched mammary stem cells that represent a subpopulation of basal cells exhibit enhanced tumorigenic capacity compared with the corresponding luminal progenitors. Transcript profiling of tumors derived from basal and luminal tumor-initiating cells (TIC) revealed preferential loss of the noncanonical Wnt ligand WNT5A in basal TIC-derived tumors. Heterozygous loss of WNT5A was correlated with shorter survival of breast cancer patients. In a mouse model of ErbB2-induced breast cancer, Wnt5a heterozygosity promoted tumor multiplicity and pulmonary metastasis. As a TGFβ substrate, luminal cell-produced WNT5A induced a feed-forward loop to activate SMAD2 in a RYK and TGFβR1-dependent manner to limit the expansion of basal TIC in a paracrine fashion, a potential explanation for the suppressive effect of WNT5A in mammary tumorigenesis. Our results identify the WNT5A/RYK module as a spatial regulator of the TGFβ-SMAD signaling pathway in the context of mammary gland development and carcinogenesis, offering a new perspective on tumor suppression provided by basal-luminal cross-talk in normal mammary tissue.

Targeting the sumoylation pathway in cancer stem cells

Cancer stem cells (CSCs) represent a subset of tumor cells with tumor-initiating potential. We recently demonstrated that inhibition of the sumoylation pathway cleared the CSC population and repressed the outgrowth of basal breast cancer xenografts. Targeting the sumoylation pathway offers a novel treatment strategy for basal breast cancer.

Regulation of epithelial-mesenchymal transition through SUMOylation of transcription factors

Carcinoma cells can transition from an epithelial-to-mesenchymal differentiation state through a process known as epithelial-mesenchymal transition (EMT). The process of EMT is characterized by alterations in the pattern of gene expression and is associated with a loss of cell polarity, an increase in invasiveness, and an increase in cells expressing cancer stem cell (CSC) markers. The reverse process of mesenchymal-to-epithelial transition (MET) can also occur, though the transitions characterizing EMT and MET can be incomplete. A growing number of transcription factors have been identified that influence the EMT/MET processes. Interestingly, SUMOylation regulates the functional activity of many of the transcription factors governing transitions between epithelial and mesenchymal states. In some cases, the transcription factor is a small ubiquitin-like modifier conjugated directly, thus altering its transcriptional activity or cell trafficking. In other cases, SUMOylation alters transcriptional mechanisms through secondary effects. This review explores the role of SUMOylation in controlling transcriptional mechanisms that regulate EMT/MET in cancer. Developing new drugs that specifically target SUMOylation offers a novel therapeutic approach to block tumor growth and metastasis.

A novel animal model for locally advanced breast cancer

BACKGROUND

Locally advanced breast cancer (LABC) poses complex management issues due to failure of response to chemotherapy and progression to local complications such as skin erosion, superinfection, and lymphedema. Most cell line and animal models are not adequate to study LABC.

METHODS

A patient-derived xenograft (IOWA-1T) from a patient with LABC was characterized for expression profile, short tandem repeat profile, oncogenic mutations, xenograft growth, and response to therapy.

RESULTS

Short tandem repeat profile authenticated the cell line as derived from a human woman. The primary tumor and derived xenografts were weakly estrogen receptor alpha positive (<5%), progesterone receptor negative, and HER2 nonamplified. Expression array profile compared to MCF-7 and BT-549 cell lines indicate that IOWA-1T was more closely related to basal breast cancer. IOWA-1T harbors a homozygous R248Q mutation of the TP53 gene; in vitro invasion assay was comparable to BT-549 and greater than MCF-7. IOWA-1T xenografts developed palpable tumors in 9.6 ± 1.6 days, compared to 49 ± 13 days for parallel experiments with BT-20 cells (p < 0.002). Tumor xenografts became locally advanced, growing to >2 cm in 21.6 ± 2 days, characterized by skin erosion necessitating euthanasia. The SUMO inhibitor anacardic acid inhibited the outgrowth of IOWA-1T xenografts, while doxorubicin had no effect on tumorigenesis.

CONCLUSIONS

IOWA-1T is a novel cell line with an expression pattern consistent with basal breast cancer. Xenografts recapitulated LABC and provide a novel model for testing therapeutic drugs that may be effective in cases resistant to conventional chemotherapy.

Abstract 3914: Tcfap2c regulates growth and oncogenesis in neu-activated breast cancer

TFAP2C and mouse homolog tcfap2c are transcription factors that play a critical role in mammary gland development and in maintaining the luminal breast cancer phenotype. Interestingly, several human HER2-positive breast cancer cell lines display genetic dependency on TFAP2C. However, the role of TFAP2C in carcinogenesis and progression in neu-activated breast cancer remains unknown. We examined the role of tcfap2c in mammary gland carcinogenesis by examining tumor formation in mice expressing an activated rat neu gene using MMTV-neu with and without mammary gland conditional knockout (KO) of tcfap2c using MMTV-Cre. The time until spontaneous palpable tumor formation was measured in mice harboring the neu oncogene with and without tcfap2c. Mice with homozygous conditional deletion of tcfap2c demonstrated a significant delay in tumor formation compared to littermate controls that retained tcfap2c expression (42 vs. 25 weeks, p&lt;0.004). Immunohistochemistry of the tumors demonstrated a luminal phenotype; cytokeratin 8 (CK8), a luminal marker, was more strongly expressed compared to cytokeratin 5 (CK5), a basal marker, in tumors from both control (883 vs. 0.1 cells/HPF, p&lt;0.0005) and KO animals (845 vs. 0, p&lt;0.0005). Cleaved caspase-3 (CC3) showed that apoptosis was increased in tumors from KO compared to control animals (5 vs. 0.3 CC3-positive cells/HPF, p&lt;0.0008). Ki-67 showed that proliferation was decreased in KO compared to control (348 vs. 142 cells/HPF, p&lt;0.009). To validate the effects of tcfap2c, we established a cell line from a tumor obtained from an animal expressing activated neu with homozygous floxed tcfap2c lacking Cre expression. Paired cell lines with differential expression of tcfap2c were established by infecting the cells with Adenovirus-Cre (Ad-Cre) or Adenovirus-Empty (Ad-Empty). Proliferation was assessed by MTT and demonstrated that loss of tcfap2c expression resulted in a 30% decrease in proliferation rate (p&lt;0.006). The difference in proliferation was confirmed in vivo through xenograft experiments of these paired cell lines inoculated into athymic (nude) mice. Mice xenografted with the paired cell lines demonstrated that KO of tcfap2c resulted in a significant delay in tumors reaching a 2 cm threshold requiring euthanasia (27.8 vs. 19.8 days post-inoculation, p&lt;0.003). In order to identify a potential mechanism accounting for the differences in proliferation and delay in carcinogenesis, we identified tcfap2c target genes by comparing the binding sites of tcfap2c by chromatin-immunoprecipitation-sequencing (ChIP-seq) and differential expression by microarray/RT-PCR. We identified erbb3 and egfr as two tcfap2c target genes by ChIP-seq. KO of tcfap2c resulted in a 3-fold and 12-fold reduction in erbb3 and egfr expression, respectively (p&lt;0.05). Taken together, these findings indicate that tcfap2c plays critical roles in oncogenesis and progression of HER2-positive mammary cancer.

Citation Format: Jung M. Park, Tong Wu, George Woodfield, Anthony Cyr, James De Andrade, Weizhou Zhang, Frederick Domann, Ronald J. Weigel. Tcfap2c regulates growth and oncogenesis in neu-activated breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3914. doi:10.1158/1538-7445.AM2014-3914