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1.
J Gastrointest Surg ; 2024 May 31.
Article in English | MEDLINE | ID: mdl-38824070

ABSTRACT

BACKGROUND: Surgery is essential for gastrointestinal (GI) cancer treatment. Many patients lack access to surgical care that optimizes outcomes. Scarce availability and/or low accessibility of appropriate resources may be the reason for this, especially in economically disadvantaged areas. This study aimed to investigate providers' and survivors' perspectives on barriers and facilitators to the availability and accessibility of surgical care. METHODS: Semistructured interviews informed by surgical disparities and access-to-care conceptual frameworks with purposively selected GI cancer providers and survivors in Alabama and Mississippi were conducted. Survivors were within 3 years of diagnosis of stage I to III esophageal, pancreatic, or colorectal cancer. Transcripts were analyzed using inductive thematic and content analysis techniques. Intercoder agreement was reached at 90 %. RESULTS: The 27 providers included surgeons (n = 11), medical oncologists (n = 2), radiation oncologists (n = 2), a primary care physician (n = 1), nurses (n = 8), and patient navigators (n = 3). This study included 36 survivors with ages ranging from 44 to 87 years. Of the 36 survivors, 21 (58.3 %) were male, and 11 (30.6 %) identified as Black. Responses were grouped into 3 broad categories: (i) transportation/geographic location, (ii) specialized care/testing, and (iii) patient-/provider-related factors. The barriers included lack and cost of transportation, reluctance to travel because of uneasiness with urban centers, low availability of specialized care, overburdened referral centers, provider-related referral biases, and low health literacy. Facilitators included availability of charitable aid, centralizing multidisciplinary care, and efficient appointment scheduling. CONCLUSION: In the Deep South, barriers and facilitators to the availability and accessibility of GI surgical cancer care were identified at the health system, provider, and patient levels, especially for rural residents. Our data suggest targets for improving the use of surgery in GI cancer care.

2.
J Telemed Telecare ; : 1357633X241241357, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38557212

ABSTRACT

BACKGROUND: No-show visits have serious consequences for patients, providers, and healthcare systems as they lead to delays in care, increased costs, and reduced access to services. Telemedicine has emerged as a promising alternative to in-person visits by reducing travel barriers, but risks exacerbating the digital divide. The aim of this study was to assess the impact of telemedicine (video and phone) at a tertiary care academic center on no-show visits compared to in-person visits. METHODS: A retrospective cohort analysis of all weekday clinic visits among in-state adult patients at a single tertiary care center in the southeast from January 2020 to April 2023 was performed. Rates of no-show visits for patients who were seen via phone and video were compared with those who were seen in-person. Demographic and clinical characteristics of these groups were also compared, including age, sex, race/ethnicity, socioeconomic status, and visit type. The primary outcome was the rate of no-show visits for each visit type. RESULTS: Our analysis included 3,105,382 scheduled appointments, of which 81.2% were in-person, 13.4% via video, and 5.4% via phone calls. Compared to in-person visits, phone calls and video visits reduced the odds of no-show visits by 50% (aOR 0.5, CI 0.49-0.51) and 15% (aOR 0.85, CI 0.84-0.86), respectively. Older patients, Black patients, patients furthest from clinic, and patients from counties with the greatest degree of vulnerability and disparities in digital access were more likely to use phone visits. No-shows were more common among non-white, male, and younger patients from counties with lower socioeconomic status. CONCLUSION: Telemedicine effectively reduced no-show visits. However, limiting telemedicine to video-based visits only exacerbated disparities in access. Phone calls allow historically underserved patients from lower socioeconomic backgrounds to access healthcare and should be included within the definition of telemedicine.

3.
Dis Colon Rectum ; 67(4): 566-576, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38084910

ABSTRACT

BACKGROUND: Increasing social vulnerability, measured by the Social Vulnerability Index, has been associated with worse surgical outcomes. However, less is known about the impact of social vulnerability on patients who underwent colorectal surgery under enhanced recovery programs. OBJECTIVE: We hypothesized that increasing social vulnerability is associated with worse outcomes before enhanced recovery implementation, but that after implementation, disparities in outcomes would be reduced. DESIGN: Retrospective cohort study using multivariable logistic regression to identify associations of social vulnerability and enhanced recovery with outcomes. SETTINGS: Institutional American College of Surgeons National Surgical Quality Improvement Program database. PATIENTS: Patients undergoing elective colorectal surgery (2010-2020). Enhanced recovery programs were implemented in 2015. Those adhering to 70% or more of enhanced recovery program components were defined as enhanced recovery and all others as nonenhanced recovery. OUTCOMES: Length of stay, complications, and readmissions. RESULTS: Of 1523 patients, 589 (38.7%) were in the enhanced recovery group, with 625 patients (41%) in the lowest third of the Social Vulnerability Index, 411 (27%) in the highest third. There were no differences in Social Vulnerability Index distribution by the enhanced recovery group. On multivariable modeling, social vulnerability was not associated with increased length of stay, complications, or readmissions in the enhanced recovery group. Black race was associated with increased length of stay in both the nonenhanced recovery (OR 1.2; 95% CI, 1.1-1.3) and enhanced recovery groups (OR 1.2; 95% CI, 1.1-1.4). Enhanced recovery adherence was associated with reductions in racial disparities in complications as the Black race was associated with increased odds of complications in the nonenhanced recovery group (OR 1.9; 95% CI, 1.2-3.0) but not in the enhanced recovery group (OR 0.8; 95% CI, 0.4-1.6). LIMITATIONS: Details of potential factors affecting enhanced recovery program adherence were not assessed and are the subject of current work by this team. CONCLUSION: High social vulnerability was not associated with worse outcomes among both enhanced recovery and nonenhanced recovery colorectal patients. Enhanced recovery program adherence was associated with reductions in racial disparities in complication rates. However, disparities in length of stay remain, and work is needed to understand the underlying mechanisms driving these disparities. See Video Abstract . COMPRENDIENDO EL IMPACTO DE LOS PROGRAMAS DE RECUPERACIN MEJORADA EN LA VULNERABILIDAD SOCIAL, LA RAZA Y LOS RESULTADOS DE LA CIRUGA COLORRECTAL: ANTECEDENTES:El aumento de la vulnerabilidad social medida por el índice de vulnerabilidad social se ha asociado con peores resultados quirúrgicos. Sin embargo, se sabe menos sobre el impacto de la vulnerabilidad social en los pacientes de cirugía colorrectal bajo programas de recuperación mejorados.OBJETIVO:Planteamos la hipótesis de que el aumento de la vulnerabilidad social se asocia con peores resultados antes de la implementación de la recuperación mejorada, pero después de la implementación, las disparidades en los resultados se reducirían.DISEÑO:Estudio de cohorte retrospectivo que utilizó regresión logística multivariable para identificar asociaciones de vulnerabilidad social y recuperación mejorada con los resultados.ESCENARIO:Base de datos institucional del Programa de Mejora Nacional de la Calidad de la Cirugía del American College of Surgeons.PACIENTES:Pacientes sometidos a cirugía colorrectal electiva (2010-2020). Programas de recuperación mejorada implementados en 2015. Aquellos que se adhieren a ≥70% de los componentes del programa de recuperación mejorada definidos como recuperación mejorada y todos los demás como recuperación no mejorada.MEDIDAS DE RESULTADO:Duración de la estancia hospitalaria, complicaciones y reingresos.RESULTADOS:De 1.523 pacientes, 589 (38,7%) estaban en el grupo de recuperación mejorada, con 732 (40,3%) pacientes en el tercio más bajo del índice de vulnerabilidad social, 498 (27,4%) en el tercio más alto, y no hubo diferencias en la distribución del índice vulnerabilidad social por grupo de recuperación mejorada. En el modelo multivariable, la vulnerabilidad social no se asoció con una mayor duración de la estancia hospitalaria, complicaciones o reingresos en ninguno de los grupos de recuperación mejorada. La raza negra se asoció con una mayor duración de la estadía tanto en el grupo de recuperación no mejorada (OR1,2, IC95% 1,1-1,3) como en el grupo de recuperación mejorada (OR1,2, IC95% 1,1-1,4). La adherencia a la recuperación mejorada se asoció con reducciones en las disparidades raciales en las complicaciones, ya que la raza negra se asoció con mayores probabilidades de complicaciones en el grupo de recuperación no mejorada (OR1,9, IC95% 1,2-3,0), pero no en el grupo de recuperación mejorada (OR0,8, IC95% 0,4-1,6).LIMITACIONES:No se evaluaron los detalles de los factores potenciales que afectan la adherencia al programa de recuperación mejorada y son el tema del trabajo actual de este equipo.CONCLUSIÓN:La alta vulnerabilidad social no se asoció con peores resultados entre los pacientes colorrectales con recuperación mejorada y sin recuperación mejorada. Una mayor adherencia al programa de recuperación se asoció con reducciones en las disparidades raciales en las tasas de complicaciones. Sin embargo, persisten disparidades en la duración de la estadía y es necesario trabajar para comprender los mecanismos subyacentes que impulsan estas disparidades. (Traducción-Dr. Felipe Bellolio ).


Subject(s)
Colorectal Surgery , Digestive System Surgical Procedures , Humans , Postoperative Complications/epidemiology , Retrospective Studies , Social Vulnerability , Length of Stay
5.
Surgery ; 175(4): 991-999, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38158309

ABSTRACT

BACKGROUND: Although disparities in surgical outcomes are well-documented, our understanding of how socioecological factors drive these disparities remains limited. Comprehensive and efficient assessment tools are needed. This study's objective was to develop and assess the acceptability and feasibility of a comprehensive tool evaluating socioecological determinants of health in patients requiring colorectal surgery. METHODS: In the first phase, a comprehensive socioecological determinant of health assessment tool was developed. A review of validated socioecological health evaluation instruments was conducted, and a 2-step modified Delphi method addressed the length, clarity, appropriateness, and redundancy of each instrument. A comprehensive tool was then finalized. In the second phase, the tool was tested for acceptability and feasibility in adult patients requiring colorectal surgery using a theory-guided framework at 3 Alabama hospitals. Relationships between survey responses and measures of acceptability and feasibility were evaluated using results from initial pilot tests of the survey. RESULTS: In Phase 1, a modified Delphi process led to the development of a comprehensive tool that included 31 socioecological determinants of health (88 questions). Results of acceptability and feasibility were globally positive (>65%) for all domains. Overall, 83% of participants agreed that others would have no trouble completing the survey, 90.4% of respondents reported the survey was not burdensome, 97.6% of patients reported having enough time to complete the survey, and 80.9% agreed the survey was well-integrated into their appointment. CONCLUSION: An 88-item assessment tool measuring 31 socioecological determinants of health was developed with high acceptability and feasibility for patients who required colorectal surgery. This work aids in the development of research needed to understand and address surgical disparities.


Subject(s)
Surveys and Questionnaires , Adult , Humans , Feasibility Studies
7.
Am J Surg ; 226(2): 227-232, 2023 08.
Article in English | MEDLINE | ID: mdl-37120415

ABSTRACT

INTRODUCTION: Enhanced recovery programs (ERPs) reduce racial disparities in surgical outcomes for general colorectal surgery populations. It is unclear, however, if disparities in IBD populations are impacted by ERPs. METHODS: Retrospective study comparing IBD patients undergoing major elective colorectal operations before (2006-2014) and after (2015-2021) ERP implementation using ACS-NSQIP data. The primary outcome of length of stay (LOS) was analyzed by negative binomial regression, and secondary outcomes (complications and readmissions) by logistic regression. RESULTS: Of 466 IBD patients, 47% were pre-ERP and 53% were ERP patients. In multivariable analysis stratified by ERP period, Black race was associated with increased odds of complications in the pre-ERP (OR 3.6, 95%CI 1.4-9.3) and ERP groups (OR 3.1 95%CI 1.3-7.6). Race was not a predictor of LOS or readmission in either group. High social vulnerability was associated with increased odds of readmission pre-ERP (OR 15.1, 95%CI 2.1-136.3), but this disparity was mitigated under ERPs (OR 1.4, 95%CI 0.4-5.6). CONCLUSION: While ERPs mitigated some disparities by social vulnerability, racial disparities persist in IBD populations even under ERPs. Further work is needed to achieve surgical equity for IBD patients.


Subject(s)
Colorectal Neoplasms , Inflammatory Bowel Diseases , Humans , Retrospective Studies , Postoperative Complications/epidemiology , Inflammatory Bowel Diseases/surgery , Perioperative Care , Length of Stay
8.
Surgery ; 174(1): 36-45, 2023 07.
Article in English | MEDLINE | ID: mdl-37088570

ABSTRACT

BACKGROUND: Although specific social determinants of health have been associated with disparities in surgical outcomes, there exists a gap in knowledge regarding the mechanisms of these associations. Gaining perspectives from multiple socioecological levels can help elucidate these mechanisms. Our study aims to identify social determinants of health that act as barriers or facilitators to surgical care among colorectal surgery stakeholders. METHODS: We recruited participants representing 5 socioecological levels: patients (individual); caregivers/surgeons (interpersonal); and leaders in hospitals (organizational), communities (community), and government (policy). Patients participated in focus groups, and the remaining participants underwent individual interviews. Semistructured interview guides were used to explore barriers and facilitators to surgical care at each socioecological level. Transcripts were analyzed by 3 coders in an inductive thematic approach with content analyses. The intercoder agreement was 93%. RESULTS: Six patient focus groups (total n = 18) and 12 key stakeholder interviews were conducted. The mean age of patients was 54.7 years, 66% were Black, and 61% were female. The most common diseases were colorectal cancer (28%), inflammatory bowel disease (28%), and diverticulitis (22%). Key social determinants of health impacting surgical care emerged at each level: individual (clear communication, mental stress), interpersonal (provider communication and trust, COVID-related visitation restrictions), organizational (multiple forms of contact, quality educational materials, scheduling systems, discrimination), community (community and family support and transportation), and policy (charity care, patient advocacy organizations, insurance coverage). CONCLUSION: Key social determinants of health-impacting care among colorectal surgery patients emerged at each socioecological level and may provide targets for interventions to reduce surgical disparities.


Subject(s)
COVID-19 , Colorectal Surgery , Humans , Female , Middle Aged , Male , Qualitative Research , Focus Groups , Health Services Accessibility
9.
Heart Lung ; 58: 98-103, 2023.
Article in English | MEDLINE | ID: mdl-36446264

ABSTRACT

BACKGROUND: Cardiopulmonary resuscitation (CPR) is widely used in response to cardiac arrest. However, little is known regarding outcomes for those who undergo multiple episodes of cardiac arrest while in the hospital. OBJECTIVES: The purpose of this study was to evaluate the association of multiple cardiac events with in-hospital mortality for patients admitted to our tertiary care hospital who underwent multiple code events. METHODS: We performed a retrospective cohort study on all patients who underwent cardiac arrest from 2012 to 2016. Primary outcome was survival to discharge. Secondary outcomes included post-cardiac-arrest neurologic events (PCANE), non-home discharge, and one-year mortality. RESULTS: There were 622 patients with an overall mortality rate of 78.0%. Patients undergoing CPR for cardiac arrest once during their admission had lower in-hospital mortality rates compared to those that had multiple (68.9% versus 91.3%, p<.01). Subset analysis of those who had multiple episodes of CPR revealed that more than one event within a 24-hour period led to significantly higher in-hospital mortality rates (94.7% versus 74.4%, p<.01). Other variables associated with in-hospital mortality included body mass index, female sex, malignancy, and increased down time per code. Patients that had a non-home discharge were more likely to have sustained a PCANE than those that were discharged home (31.4% versus 3.9%, p<.01). A non-home discharge was associated with higher one-year mortality rates compared to a home discharge (78.4% versus 54.3%, p=.01). CONCLUSION: Multiple codes within a 24-hour period and the average time per code were associated with in-hospital mortality in cardiac arrest patients.


Subject(s)
Cardiopulmonary Resuscitation , Heart Arrest , Out-of-Hospital Cardiac Arrest , Humans , Female , Retrospective Studies , Hospitalization , Patient Discharge , Treatment Outcome , Survival Rate
10.
J Surg Res ; 243: 380-383, 2019 11.
Article in English | MEDLINE | ID: mdl-31277015

ABSTRACT

BACKGROUND: Parathyroidectomy for patients with secondary hyperparathyroidism (sHPT) generally requires a four-gland exploration. Some groups have strongly recommended routine preoperative Tc-99m-sestamibi scans; others practice scanning for only selected patients. To determine the utility of sestamibi scans in this patient population, we reviewed our experience. METHODS: We performed a retrospective review of patients who underwent parathyroidectomy for sHPT by one surgeon between 2000 and 2018. Data reviewed included patient demographics, laboratory results, pathology and radiology reports, and clinical and operative notes. RESULTS: Of the 72 patients in the cohort, mean age was 47.2 ± 15.6, and 50% were female. The preoperative mean calcium and parathyroid hormone levels were 9.6 ± 1.1 mg/dL and 1192.1 ± 914.1 pg/mL, respectively. Sestamibi scans were performed in 21 patients (29%). Of these, 17 were reoperative cases. Of all sHPT patients, 27.8% had ectopic glands. In the sestamibi cohort, only four patients had ectopic glands identified on the scan. Among the 51 patients without preoperative imaging, 16 had ectopic glands (26.2% of nonimaged patients). All these 16 ectopic glands were found by the surgeon at the time of operation without the need for preoperative imaging. All patients in the series were cured with a minimum follow-up of 6 mo. CONCLUSIONS: Ectopic parathyroid glands are commonly seen in patients undergoing parathyroidectomy for sHPT. The majority of ectopic glands were successfully identified during the operation without preoperative sestamibi scan. Therefore, routine preoperative Tc-99m-sestamibi scans are not needed for successful parathyroidectomy for sHPT.


Subject(s)
Hyperparathyroidism, Secondary/diagnostic imaging , Parathyroidectomy , Radionuclide Imaging , Renal Insufficiency/complications , Technetium Tc 99m Sestamibi , Adolescent , Adult , Aged , Choristoma/diagnostic imaging , Female , Humans , Hyperparathyroidism, Secondary/etiology , Hyperparathyroidism, Secondary/surgery , Male , Middle Aged , Retrospective Studies , Unnecessary Procedures , Young Adult
11.
Gynecol Oncol ; 150(3): 487-493, 2018 09.
Article in English | MEDLINE | ID: mdl-30037492

ABSTRACT

OBJECTIVE: Patient reported outcomes (PRO) relating to treatment toxicities have been demonstrated to reliably evaluate adverse events in clinical trials. We assessed the user satisfaction of implementing a focused PRO questionnaire for patients with gynecologic cancers undergoing chemotherapy. METHODS: Patients with gynecologic cancers undergoing chemotherapy were prospectively identified after IRB approval from April 2017 to August 2017. We administered a 24-symptom questionnaire, adapted from the validated PRO version of the Common Terminology Criteria for Adverse Event, to enrolled participants at the beginning of two outpatient visits. Patient and provider satisfaction with use of PRO was assessed afterwards. Descriptive statistics were performed. RESULTS: A total of 44 patients were enrolled. Patients were racially diverse: 52% Caucasian, 18% African-American, 9% Asian, and 20% other; 27% were of Hispanic origin. The majority of patients had ovarian cancer (54%), followed by uterine (29%) and cervical cancer (15%). Ninety-five percent of patient and 97% of provider satisfaction survey responses indicated the PRO questionnaire addressed important symptoms. Nearly all patient and provider responses indicated the PRO questionnaire was easy to use. Sixty-nine percent of patient and 97% of provider responses indicated the questionnaire positively impacted clinical care; 85% of patients wished to use a similar questionnaire throughout treatment. CONCLUSIONS: We have shown that incorporating a focused patient-reported symptom questionnaire into routine outpatient care of gynecological oncology patients undergoing chemotherapy was met with a high degree of patient and provider satisfaction regarding questionnaire content, feasibility, and perception of care improvement.


Subject(s)
Antineoplastic Agents/adverse effects , Attitude of Health Personnel , Genital Neoplasms, Female/drug therapy , Patient Reported Outcome Measures , Patient Satisfaction , Adult , Aged , Aged, 80 and over , Female , Humans , Middle Aged , Pilot Projects , Prospective Studies , Symptom Assessment
12.
Gynecol Oncol ; 150(3): 569-580, 2018 09.
Article in English | MEDLINE | ID: mdl-29843906

ABSTRACT

Endometrial cancer is the most prevalent gynecologic cancer in the United States. Over the last 10 years, death rates from endometrial cancer have been rising about 1.4% per year. Traditionally endometrial cancer treatment has been driven by stage and histology. Recent studies have, however, shown that cancers of the same stage and histology have very distinct molecular and genomic profiles. Translational research is progressing rapidly and endometrial cancer-specific precision medicine is evolving. The first tissue agnostic therapy based on the molecular profile of the tumor was approved by the FDA this year. The approval of immune checkpoint inhibitor, pembrolizumab (anti-PD-1), for all solid tumors with defective DNA mismatch repair, could benefit 20-30% of patients with advanced endometrial cancer. Other genomic changes and molecular markers in endometrial cancer, such as hormone receptor status, could lead to more tailored therapy in the future. Pre-clinical and clinical investigations of targeted therapies suggest efficacy for some agents. Single agent targeted therapies, however, have modest activity. Identifying biomarkers that effectively determine response to targeted therapy remains a challenge. The next generation of clinical trials will focus on novel combinations and how to best utilize the advances that have been made in sequencing technology and bioinformatics. Although there is currently an immense body of data and many options for obtaining genomic characteristics of endometrial cancer, how to interpret and utilize this data is still being explored. This review will summarize the important trials that have led to the treatment options we have for advanced and/or recurrent endometrial cancer and discuss the important studies that have led to a better understanding of the distinctive molecular and genomic profiles within endometrial cancer. We will review the current status of biomarker-driven targeted therapy in endometrial cancer and the rationale behind ongoing clinical trials that are utilizing novel targeted agents.


Subject(s)
Biomarkers, Tumor/genetics , Endometrial Neoplasms/drug therapy , Endometrial Neoplasms/genetics , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Clinical Decision-Making , DNA Mismatch Repair/genetics , Endometrial Neoplasms/pathology , Female , Humans , Neoplasm Staging , Radiotherapy , Randomized Controlled Trials as Topic
13.
Mol Cancer Ther ; 17(3): 591-602, 2018 03.
Article in English | MEDLINE | ID: mdl-29726819

ABSTRACT

Ovarian cancer is the fifth leading cause of cancer-related deaths in females in the United States. There were an estimated 22,440 new cases and 14,080 deaths due to ovarian cancer in 2017. Most patients present with advanced-stage disease, revealing the urgent need for new therapeutic strategies targeting pathways of tumorigenesis and chemotherapy resistance. While multiple genomic changes contribute to the progression of this aggressive disease, it has become increasingly evident that epigenetic events play a pivotal role in ovarian cancer development. One of the well-studied epigenetic modifiers, the histone methyltransferase EZH2, is a member of polycomb repressive complex 2 (PRC2) and is commonly involved in transcriptional repression. EZH2 is the enzymatic catalytic subunit of the PRC2 complex that can alter gene expression by trimethylating lysine 27 on histone 3 (H3K27). In ovarian cancer, EZH2 is commonly overexpressed and therefore potentially serves as an effective therapeutic target. Multiple small-molecule inhibitors are being developed to target EZH2, which are now in clinical trials. Thus, in this review, we highlight the progress made in EZH2-related research in ovarian cancer and discuss the potential utility of targeting EZH2 with available small-molecule inhibitors for ovarian cancer. Mol Cancer Ther; 17(3); 591-602. ©2018 AACR.


Subject(s)
Enhancer of Zeste Homolog 2 Protein/genetics , Gene Expression Regulation, Neoplastic , Histones/genetics , Ovarian Neoplasms/genetics , Enhancer of Zeste Homolog 2 Protein/antagonists & inhibitors , Enhancer of Zeste Homolog 2 Protein/metabolism , Female , Histones/metabolism , Humans , Lysine/genetics , Lysine/metabolism , Methylation , Molecular Targeted Therapy/methods , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Small Molecule Libraries/therapeutic use
14.
Breast Cancer Res ; 19(1): 74, 2017 Jun 30.
Article in English | MEDLINE | ID: mdl-28666462

ABSTRACT

BACKGROUND: The importance of the mTOR complex 2 (mTORC2) signaling complex in tumor progression is becoming increasingly recognized. HER2-amplified breast cancers use Rictor/mTORC2 signaling to drive tumor formation, tumor cell survival and resistance to human epidermal growth factor receptor 2 (HER2)-targeted therapy. Cell motility, a key step in the metastatic process, can be activated by mTORC2 in luminal and triple negative breast cancer cell lines, but its role in promoting metastases from HER2-amplified breast cancers is not yet clear. METHODS: Because Rictor is an obligate cofactor of mTORC2, we genetically engineered Rictor ablation or overexpression in mouse and human HER2-amplified breast cancer models for modulation of mTORC2 activity. Signaling through mTORC2-dependent pathways was also manipulated using pharmacological inhibitors of mTOR, Akt, and Rac. Signaling was assessed by western analysis and biochemical pull-down assays specific for Rac-GTP and for active Rac guanine nucleotide exchange factors (GEFs). Metastases were assessed from spontaneous tumors and from intravenously delivered tumor cells. Motility and invasion of cells was assessed using Matrigel-coated transwell assays. RESULTS: We found that Rictor ablation potently impaired, while Rictor overexpression increased, metastasis in spontaneous and intravenously seeded models of HER2-overexpressing breast cancers. Additionally, migration and invasion of HER2-amplified human breast cancer cells was diminished in the absence of Rictor, or upon pharmacological mTOR kinase inhibition. Active Rac1 was required for Rictor-dependent invasion and motility, which rescued invasion/motility in Rictor depleted cells. Rictor/mTORC2-dependent dampening of the endogenous Rac1 inhibitor RhoGDI2, a factor that correlated directly with increased overall survival in HER2-amplified breast cancer patients, promoted Rac1 activity and tumor cell invasion/migration. The mTORC2 substrate Akt did not affect RhoGDI2 dampening, but partially increased Rac1 activity through the Rac-GEF Tiam1, thus partially rescuing cell invasion/motility. The mTORC2 effector protein kinase C (PKC)α did rescue Rictor-mediated RhoGDI2 downregulation, partially rescuing Rac-guanosine triphosphate (GTP) and migration/motility. CONCLUSION: These findings suggest that mTORC2 uses two coordinated pathways to activate cell invasion/motility, both of which converge on Rac1. Akt signaling activates Rac1 through the Rac-GEF Tiam1, while PKC signaling dampens expression of the endogenous Rac1 inhibitor, RhoGDI2.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Mechanistic Target of Rapamycin Complex 2/metabolism , Signal Transduction , rac1 GTP-Binding Protein/metabolism , Animals , Breast Neoplasms/genetics , Breast Neoplasms/mortality , Cell Line, Tumor , Cell Movement/genetics , Disease Models, Animal , Female , Gene Amplification , Heterografts , Humans , Mice , Mice, Transgenic , Neoplasm Metastasis , Neoplasm Staging , Prognosis , Proto-Oncogene Proteins c-akt/metabolism , Rapamycin-Insensitive Companion of mTOR Protein/genetics , Rapamycin-Insensitive Companion of mTOR Protein/metabolism , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , rho Guanine Nucleotide Dissociation Inhibitor beta/genetics , rho Guanine Nucleotide Dissociation Inhibitor beta/metabolism
15.
Cancer Res ; 76(16): 4752-64, 2016 08 15.
Article in English | MEDLINE | ID: mdl-27197158

ABSTRACT

HER2 overexpression drives Akt signaling and cell survival and HER2-enriched breast tumors have a poor outcome when Akt is upregulated. Akt is activated by phosphorylation at T308 via PI3K and S473 via mTORC2. The importance of PI3K-activated Akt signaling is well documented in HER2-amplified breast cancer models, but the significance of mTORC2-activated Akt signaling in this setting remains uncertain. We report here that the mTORC2 obligate cofactor Rictor is enriched in HER2-amplified samples, correlating with increased phosphorylation at S473 on Akt. In invasive breast cancer specimens, Rictor expression was upregulated significantly compared with nonmalignant tissues. In a HER2/Neu mouse model of breast cancer, genetic ablation of Rictor decreased cell survival and phosphorylation at S473 on Akt, delaying tumor latency, penetrance, and burden. In HER2-amplified cells, exposure to an mTORC1/2 dual kinase inhibitor decreased Akt-dependent cell survival, including in cells resistant to lapatinib, where cytotoxicity could be restored. We replicated these findings by silencing Rictor in breast cancer cell lines, but not silencing the mTORC1 cofactor Raptor (RPTOR). Taken together, our findings establish that Rictor/mTORC2 signaling drives Akt-dependent tumor progression in HER2-amplified breast cancers, rationalizing clinical investigation of dual mTORC1/2 kinase inhibitors and developing mTORC2-specific inhibitors for use in this setting. Cancer Res; 76(16); 4752-64. ©2016 AACR.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carrier Proteins/metabolism , Multiprotein Complexes/metabolism , Receptor, ErbB-2/metabolism , TOR Serine-Threonine Kinases/metabolism , Animals , Blotting, Western , Breast Neoplasms/mortality , Disease Progression , Drug Resistance, Neoplasm , Female , Heterografts , Humans , Kaplan-Meier Estimate , Mechanistic Target of Rapamycin Complex 2 , Mice , Mice, Inbred BALB C , Mice, Nude , Rapamycin-Insensitive Companion of mTOR Protein , Signal Transduction/physiology , Tissue Array Analysis
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