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Dive into the research topics where Helen K. Chew is active.

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Featured researches published by Helen K. Chew.


Journal of Clinical Oncology | 2010

Prospective Multicenter Study of the Impact of the 21-Gene Recurrence Score Assay on Medical Oncologist and Patient Adjuvant Breast Cancer Treatment Selection

Shelly S. Lo; Patricia Mumby; John Norton; Karen Rychlik; Jeffrey B. Smerage; Joseph J. Kash; Helen K. Chew; Ellen R. Gaynor; Daniel F. Hayes; Andrew J. Epstein; Kathy S. Albain

PURPOSE The 21-gene Recurrence Score (RS) assay has been validated to quantify the risk of distant recurrence in tamoxifen-treated patients with lymph node-negative, estrogen receptor-positive breast cancer and predict magnitude of chemotherapy benefit. This multicenter study was designed to prospectively examine whether RS affects physician and patient adjuvant treatment selection and satisfaction. PATIENTS AND METHODS Before and after obtaining the 21-gene RS assay, medical oncologists stated their adjuvant treatment recommendation and confidence in it. Patients also indicated their treatment choice pre- and post-RS assay. Patients completed measures for decisional conflict, anxiety, and quality of life. RESULTS Seventeen medical oncologists at one community and three academic practices consecutively enrolled 89 assessable patients. The medical oncologist treatment recommendation changed for 28 patients (31.%). Twenty-four patients (27%) changed their treatment decision. The largest change after the RS results was conversion from the medical oncologists pretest recommendation for chemotherapy plus hormonal therapy (CHT) to post-test recommendation for hormone therapy (HT) in 20 cases (22.5%). Nine patients (10.1%) changed their treatment decision from CHT to HT. RS results increased medical oncologist confidence in their treatment recommendation in 68 cases (76%). Patient anxiety and decisional conflict were significantly lower after RS results. CONCLUSION The results of this study indicate that the RS assay impacts medical oncologist adjuvant treatment recommendations, patient treatment choice, and patient anxiety.


Journal of Clinical Oncology | 2006

Venous Thromboembolism in Patients With Colorectal Cancer: Incidence and Effect on Survival

Allison Alcalay; Ted Wun; Vijay P. Khatri; Helen K. Chew; Danielle Harvey; Hong Zhou; Richard H. White

PURPOSE To describe the incidence and outcomes associated with venous thromboembolism (VTE) among patients with colorectal cancer. METHODS This was a retrospective analysis of all colorectal cancer patients diagnosed in California between 1993 and 1995 and 1997 to 1999. Principal outcomes were incident symptomatic VTE events and death. Associations between specific risk factors and principal outcomes were analyzed using Cox proportional hazards models. RESULTS Among 68,142 colorectal cancer patients, 50% were women, mean age was 70 +/- 15 years, and approximately 70% underwent a major operation. The 2-year cumulative incidence of VTE was 2,100 patients (3.1%), with an incidence rate that decreased significantly over time from 5.0% (events/100 patient-years) in months 0 to 6 to 1.4% during months 7 to 12 to 0.6% during the second year. Significant predictors of VTE included metastatic stage (hazard ratio [HR] = 3.2; 95% CI, 2.8 to 3.8) and three or more comorbid conditions (HR = 2.0; 95% CI, 1.7 to 2.3). The risk of VTE was significantly reduced among Asians/Pacific Islanders (HR = 0.4; 95% CI, 0.3 to 0.5.) and patients who underwent an abdominal operation (HR = 0.4; 95% CI, 0.3 to 0.4). In risk-adjusted models, VTE was a significant predictor of death within 1 year of cancer diagnosis among patients with local- (HR = 1.8; 95% CI, 1.4 to 2.3) or regional-stage disease (HR = 1.5; 95% CI, 1.3 to 1.8) but not among patients with metastatic disease (HR = 1.1; 95% CI, 1.0 to 1.2). CONCLUSION The incidence of VTE among colorectal cancer patients was highest in the first 6 months after diagnosis and decreased rapidly thereafter. Metastatic disease and the number of medical comorbidities were the strongest predictors of VTE. Incident VTE reduced survival among patients with local or regional disease, suggesting that, in these patients, VTE may reflect the presence of a biologically more aggressive cancer.


Journal of Clinical Oncology | 2006

Incidence of Venous Thromboembolism and the Impact on Survival in Breast Cancer Patients

Helen K. Chew; Theodore Wun; Danielle Harvey; Hong Zhou; Richard H. White

PURPOSE The incidence of venous thromboembolism (VTE) and the risk factors associated with development of VTE have not been reported in a large population-based study of breast cancer patients. PATIENTS AND METHODS The California Cancer Registry was merged with the Patient Discharge Data Set, and the number of VTE events determined among patients diagnosed between 1993 and 1999. RESULTS Among 108,255 patients with breast cancer, the 2-year cumulative VTE incidence was 1.2%, with a rate of 1.2 and 0.6 events/100 patient-years during the first and second half-year, respectively. The 1-year incidence of VTE was significantly increased compared with the general population (standardized incidence ratio of VTE, 4.2; 95% CI, 3.9 to 4.4). In a multivariate model, significant predictors of developing VTE within 2 years were: age (hazard ratio [HR], 2.0 if > 75 years v < 45; 95% CI, 1.6 to 2.6), the number of chronic medical comorbidities (HR, 2.9 if 3 v 0; 95% CI, 2.4 to 3.5), and advancing cancer stage (HR, 6.3; 95% CI, 5.3 to 7.5 for metastatic v local disease). In multivariate models, VTE was a significant predictor of decreased 2-year survival (HR, 2.3; 95% CI, 2.1 to 2.6) and when stratified by initial cancer stage, the effect was highest in patients with localized (HR, 5.1; 95% CI, 3.6 to 7.1) or regional stage (HR, 3.5; 95% CI, 2.5 to 4.8) cancer compared with patients with metastatic disease (HR, 1.9; 95% CI, 1.5 to 2.4). CONCLUSION Approximately 1% of breast cancer patients developed VTE within 2 years, with the highest incidence in the first 6 months after diagnosis. Metastatic disease and comorbidities were the strongest predictors. The diagnosis of VTE was associated with a higher risk of death within 2 years.


Molecular & Cellular Proteomics | 2007

A Serum Glycomics Approach to Breast Cancer Biomarkers

Crystal Kirmiz; Bensheng Li; Hyun Joo An; Brian H. Clowers; Helen K. Chew; Kit S. Lam; Anthony Ferrige; Robert Alecio; Alexander D. Borowsky; Shola Sulaimon; Carlito B. Lebrilla; Suzanne Miyamoto

Because the glycosylation of proteins is known to change in tumor cells during the development of breast cancer, a glycomics approach is used here to find relevant biomarkers of breast cancer. These glycosylation changes are known to correlate with increasing tumor burden and poor prognosis. Current antibody-based immunochemical tests for cancer biomarkers of ovarian (CA125), breast (CA27.29 or CA15-3), pancreatic, gastric, colonic, and carcinoma (CA19-9) target highly glycosylated mucin proteins. However, these tests lack the specificity and sensitivity for use in early detection. This glycomics approach to find glycan biomarkers of breast cancer involves chemically cleaving oligosaccharides (glycans) from glycosylated proteins that are shed or secreted by breast cancer tumor cell lines. The resulting free glycan species are analyzed by MALDI-FT-ICR MS. Further structural analysis of the glycans can be performed in FTMS through the use of tandem mass spectrometry with infrared multiphoton dissociation. Glycan profiles were generated for each cell line and compared. These methods were then used to analyze sera obtained from a mouse model of breast cancer and a small number of serum samples obtained from human patients diagnosed with breast cancer or patients with no known history of breast cancer. In addition to the glycosylation changes detected in mice as mouse mammary tumors developed, glycosylation profiles were found to be sufficiently different to distinguish patients with cancer from those without. Although the small number of patient samples analyzed so far is inadequate to make any legitimate claims at this time, these promising but very preliminary results suggest that glycan profiles may contain distinct glycan biomarkers that may correspond to glycan “signatures of cancer.”


Journal of Thrombosis and Haemostasis | 2008

The incidence of venous thromboembolism among patients with primary lung cancer.

Helen K. Chew; Angela M. Davies; Theodore Wun; Danielle Harvey; Hong Zhou; Richard H. White

Background: The incidence of venous thromboembolism (VTE) by lung cancer histology and stage is unknown. Objectives: To determine the incidence of VTE and the risk factors associated with development of VTE in a large population‐based study of patients with non‐small cell and small cell lung cancer. Methods: The California Cancer Registry was merged with the Patient Discharge Data Set to determine the incidence of VTE among lung cancer cases diagnosed between 1993 and 1999. Results: Among 91 933 patients with newly diagnosed lung cancer, the 1‐year and 2‐year cumulative VTE incidences were 3.0% and 3.4%, respectively, with a person‐time rate of 7.2 events/100 patient‐years during the first 6 months. The 1‐year incidence of VTE was significantly increased in comparison to the general population [standardized incidence ratio = 21.2, 95% confidence interval (CI) = 20.4–22.0]. In a multivariate model, significant predictors of developing VTE within 1 year of non‐small cell lung cancer (NSCLC) diagnosis were: younger age, the number of chronic medical comorbidities [hazard ratio (HR) = 2.8 if 3 vs. 0, 95% CI = 2.5–3.1], advancing cancer stage (HR = 4.0 for metastatic vs. local disease, 95% CI = 3.4–4.6) and adenocarcinoma histology (HR = 1.9 vs. squamous cell, 95% CI = 1.7–2.1). In multivariate models, VTE was a significant predictor of death within 2 years for both NSCLC and small cell lung cancer (SCLC), HR = 2.3, 95% CI = 2.2–2.4, and HR = 1.5, 95% CI = 1.3–1.7, respectively. Conclusions: Approximately 3% of lung cancer patients developed VTE within 2 years. The diagnosis of VTE was associated with a higher risk of death within 2 years for NSCLC and SCLC.


Molecular & Cellular Proteomics | 2011

High-mannose glycans are elevated during breast cancer progression

Maria Lorna A. De Leoz; Lawrence J. T. Young; Hyun Joo An; Scott R. Kronewitter; Jae-Han Kim; Suzanne Miyamoto; Alexander D. Borowsky; Helen K. Chew; Carlito B. Lebrilla

Alteration in glycosylation has been observed in cancer. However, monitoring glycosylation changes during breast cancer progression is difficult in humans. In this study, we used a well-characterized transplantable breast tumor mouse model, the mouse mammary tumor virus-polyoma middle T antigen, to observe early changes in glycosylation. We have previously used the said mouse model to look at O-linked glycosylation changes with breast cancer. In this glycan biomarker discovery study, we examined N-linked glycan variations during breast cancer progression of the mouse model but this time doubling the number of mice and blood draw points. N-glycans from total mouse serum glycoproteins were profiled using matrix-assisted laser desorption/ionization Fourier transform-ion cyclotron resonance mass spectrometry at the onset, progression, and removal of mammary tumors. We observed four N-linked glycans, m/z 1339.480 (Hex3HexNAc), 1485.530 (Hex3HexNAc4Fuc), 1809.639 (Hex5HexNAc4Fuc), and 1905.630 (Man9), change in intensity in the cancer group but not in the control group. In a separate study, N-glycans from total human serum glycoproteins of breast cancer patients and controls were also profiled. Analysis of human sera using an internal standard showed the alteration of the low-abundant high-mannose glycans, m/z 1419.475, 1581.528, 1743.581, 1905.634 (Man6–9), in breast cancer patients. A key observation was the elevation of a high-mannose type glycan containing nine mannoses, Man9, m/z 1905.630 in both mouse and human sera in the presence of breast cancer, suggesting an incompletion of the glycosylation process that normally trims back Man9 to produce complex and hybrid type oligosaccharides.


Journal of Clinical Oncology | 2014

Burnout and Career Satisfaction Among US Oncologists

Tait D. Shanafelt; William J. Gradishar; Michael P. Kosty; Daniel Satele; Helen K. Chew; Leora Horn; Ben Clark; Amy Hanley; Quyen D. Chu; John Pippen; Jeff A. Sloan; Marilyn Raymond

PURPOSE To evaluate the personal and professional characteristics associated with career satisfaction and burnout among US oncologists. METHODS Between October 2012 and March 2013, the American Society of Clinical Oncology conducted a survey of US oncologists evaluating burnout and career satisfaction. The survey sample included equal numbers of men and women and represented all career stages. RESULTS Of 2,998 oncologists contacted, 1,490 (49.7%) returned surveys (median age of respondents, 52 years; 49.6% women). Among the 1,117 oncologists (37.3% of overall sample) who completed full-length surveys, 377 (33.8%) were in academic practice (AP) and 482 (43.2%) in private practice (PP), with the remainder in other settings. Oncologists worked an average of 57.6 hours per week (AP, 58.6 hours per week; PP, 62.9 hours per week) and saw a mean of 52 outpatients per week. Overall, 484 oncologists (44.7%) were burned out on the emotional exhaustion and/or depersonalization domain of Maslach Burnout Inventory (AP, 45.9%; PP, 50.5%; P = .18). Hours per week devoted to direct patient care was the dominant professional predictor of burnout for both PP and AP oncologists on univariable and multivariable analyses. Although a majority of oncologists were satisfied with their career (82.5%) and specialty (80.4%) choices, both measures of career satisfaction were lower for those in PP relative to AP (all P < .006). CONCLUSION Overall career satisfaction is high among US oncologists, albeit lower for those in PP relative to AP. Burnout rates among oncologists seem similar to those described in recent studies of US physicians in general. Those oncologists who devote the greatest amount of their professional time to patient care seem to be at greatest risk for burnout.


Blood | 2009

Venous thromboembolism in patients with acute leukemia: incidence, risk factors, and effect on survival

Grace H. Ku; Richard H. White; Helen K. Chew; Danielle Harvey; Hong Zhou; Ted Wun

A population-based cohort was used to determine the incidence and risk factors associated with development of venous thromboembolism (VTE) among Californians diagnosed with acute leukemia between 1993 to 1999. Principal outcomes were deep vein thrombosis in both the lower and upper extremities, pulmonary embolism, and mortality. Among 5394 cases with acute myelogenous leukemia (AML), the 2-year cumulative incidence of VTE was 281 (5.2%). Sixty-four percent of the VTE events occurred within 3 months of AML diagnosis. In AML patients, female sex, older age, number of chronic comorbidities, and presence of a catheter were significant predictors of development of VTE within 1 year. A diagnosis of VTE was not associated with reduced survival in AML patients. Among 2482 cases with acute lymphoblastic leukemia (ALL), the 2-year incidence of VTE in ALL was 4.5%. Risk factors for VTE were presence of a central venous catheter, older age, and number of chronic comorbidities. In the patients with ALL, development of VTE was associated with a 40% increase in the risk of dying within 1 year. The incidence of VTE in acute leukemia is appreciable, and is comparable with the incidence in many solid tumors.


Obstetrics & Gynecology | 2008

Evidence of Poorer Survival in Pregnancy-Associated Breast Cancer

Anne O. Rodriguez; Helen K. Chew; Rosemary D. Cress; Guibo Xing; Sherrie S McElvy; Beate Danielsen; Lloyd H. Smith

OBJECTIVE: To compare stage distribution, tumor characteristics, and survival outcome in pregnancy-associated and non–pregnancy-associated breast cancer, and to evaluate pregnancy as a risk factor for mortality in breast cancer. METHODS: The California Cancer Registry (1991–1999) was linked with the California Patient Discharge Data Set to identify women with breast cancer occurring within 9 months before or 1 year after an obstetric delivery. Age-matched, non–pregnancy-associated breast cancer controls were also identified. Demographics, cancer stage, tumor size, histology, hormone receptor status, type of treatment, and survival were reviewed and compared. Predictive factors for death from breast cancer were identified using proportional hazards modeling. RESULTS: Seven hundred ninety-seven pregnancy-associated breast cancer cases were compared with 4,177 non–pregnancy-associated breast cancer controls. Pregnancy-associated breast cancer cases were significantly more likely to have more advanced stage, larger primary tumor, hormone receptor negative tumor, and mastectomy as a component of their treatment. In survival analysis, pregnancy-associated breast cancer had a higher death rate than non–pregnancy-associated breast cancer (39.2% compared with 33.4%, P=.002). In a multivariable analysis, advancing stage (2.22–10.76 times the risk of death for stages II–IV), race (African Americans had 68% increased risk of death over non-Hispanic whites), hormone receptor–negative tumors (20% increased risk of death over receptor-positive tumors), and pregnancy (14% increased risk of death over nonpregnant women) all were significant predictors of death. CONCLUSION: Pregnancy-associated breast cancer presented with more advanced disease, larger tumors, and increased percentage of hormone receptor–negative tumors. When controlled for stage, race, and hormone receptor status, pregnancy-associated breast cancer cases had a slightly higher risk of death, even when only localized-stage disease was considered. LEVEL OF EVIDENCE: II


Clinical Cancer Research | 2005

High-dose radioimmunotherapy combined with fixed, low-dose paclitaxel in metastatic prostate and breast cancer by using a MUC-1 monoclonal antibody, m170, linked to indium-111/yttrium-90 via a cathepsin cleavable linker with cyclosporine to prevent human anti-mouse antibody.

Carol M. Richman; Sally J. DeNardo; Robert T. O'Donnell; Aina Yuan; Sui Shen; Desiree S. Goldstein; Joseph M. Tuscano; Ted Wun; Helen K. Chew; Primo N. Lara; David L. Kukis; Arutselvan Natarajan; Claude F. Meares; Kathleen R. Lamborn; Gerald L. DeNardo

Purpose: Although radioimmunotherapy alone is effective in lymphoma, its application to solid tumors will likely require a combined modality approach. In these phase I studies, paclitaxel was combined with radioimmunotherapy in patients with metastatic hormone-refractory prostate cancer or advanced breast cancer. Experimental Design: Patients were imaged with indium-111 (111In)-1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid-peptide-m170. One week later, yttrium-90 (90Y)-m170 was infused (12 mCi/m2 for prostate cancer and 22 mCi/m2 for breast cancer). Initial cohorts received radioimmunotherapy alone. Subsequent cohorts received radioimmunotherapy followed 48 hours later by paclitaxel (75 mg/m2). Cyclosporine was given to prevent development of human anti-mouse antibody. Results: Bone and soft tissue metastases were targeted by 111In-m170 in 15 of the 16 patients imaged. Three prostate cancer patients treated with radioimmunotherapy alone had no grade 3 or 4 toxicity. With radioimmunotherapy and paclitaxel, two of three prostate cancer patients developed transient grade 4 neutropenia. Four breast cancer patients treated with radioimmunotherapy alone had grade 3 or 4 myelosuppression. With radioimmunotherapy and paclitaxel, both breast cancer patients developed grade 4 neutropenia. Three breast cancer patients required infusion of previously harvested peripheral blood stem cells because of neutropenic fever or bleeding. One patient in this trial developed human anti-mouse antibody in contrast to 12 of 17 patients in a prior trial using m170-radioimmunotherapy without cyclosporine. Conclusions:111In/90Y-m170 targets prostate and breast cancer and can be combined with paclitaxel with toxicity limited to marrow suppression at the dose levels above. The maximum tolerated dose of radioimmunotherapy and fixed-dose paclitaxel with peripheral blood stem cell support has not been reached. Cyclosporine is effective in preventing human anti-mouse antibody, suggesting the feasibility of multidose, “fractionated” therapy that could enhance clinical response.

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Gabriel N. Hortobagyi

University of Texas MD Anderson Cancer Center

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Kathy S. Albain

Loyola University Chicago

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Hong Zhou

University of California

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William E. Barlow

Fred Hutchinson Cancer Research Center

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Ted Wun

University of California

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Agustin A. Garcia

University of Southern California

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