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Dive into the research topics where Erin S. O'Connor is active.

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Featured researches published by Erin S. O'Connor.


Journal of Clinical Oncology | 2011

Adjuvant Chemotherapy for Stage II Colon Cancer With Poor Prognostic Features

Erin S. O'Connor; David Yu Greenblatt; Noelle K. LoConte; Ronald E. Gangnon; Jinn-Ing Liou; Charles P. Heise; Maureen A. Smith

PURPOSE Adjuvant chemotherapy is typically considered for patients with stage II colon cancer characterized by poor prognostic features, including obstruction, perforation, emergent admission, T4 stage, resection of fewer than 12 lymph nodes, and poor histology. Despite frequent use, the survival advantage conferred on patients with stage II disease by chemotherapy is yet unproven. We sought to determine the overall survival benefit of chemotherapy among patients with stage II colon cancer having poor prognostic features. PATIENTS AND METHODS A total of 43,032 Medicare beneficiaries who underwent colectomy for stage II and III primary colon adenocarcinoma diagnosed from 1992 to 2005 were identified from the Surveillance, Epidemiology, and End Results (SEER) -Medicare database. χ(2) and two-way analysis of variance were used to assess differences in patient- and disease-related characteristics. Five-year overall survival was examined using Kaplan-Meier survival analysis and Cox proportional hazards regression with propensity score weighting. RESULTS Of the 24,847 patients with stage II cancer, 75% had one or more poor prognostic features. Adjuvant chemotherapy was received by 20% of patients with stage II disease and 57% of patients with stage III disease. After adjustment, 5-year survival benefit from chemotherapy was observed only for patients with stage III disease (hazard ratio[HR], 0.64; 95% CI, 0.60 to 0.67). No survival benefit was observed for patients with stage II cancer with no poor prognostic features (HR, 1.02; 95% CI, 0.84 to 1.25) or stage II cancer with any poor prognostic features (HR, 1.03; 95% CI, 0.94 to 1.13). CONCLUSION Among Medicare patients identified with stage II colon cancer, either with or without poor prognostic features, adjuvant chemotherapy did not substantially improve overall survival. This lack of benefit must be considered in treatment decisions for similar older adults with colon cancer.


Annals of Surgery | 2010

Readmission after colectomy for cancer predicts one-year mortality.

David Yu Greenblatt; Sharon M. Weber; Erin S. O'Connor; Noelle K. LoConte; Jinn-Ing Liou; Maureen A. Smith

Objectives:Early hospital readmission is a common and costly problem in the Medicare population. In 2009, the Centers for Medicaid and Medicare Services began mandating hospital reporting of disease-specific readmission rates. We sought to determine the rate and predictors of readmission after colectomy for cancer, as well as the association between readmission and mortality. Methods:Medicare beneficiaries who underwent colectomy for stage I to III colon adenocarcinoma from 1992 to 2002 were identified from the Surveillance, Epidemiology, and End Results-Medicare database. Multivariate logistic regression identified predictors of early readmission and 1-year mortality. Odds ratios were adjusted for multiple factors, including measures of comorbidity, socioeconomic status, and disease severity. Results:Of 42,348 patients who were discharged, 4662 (11.0%) were readmitted within 30 days. The most common causes of rehospitalization were ileus/obstruction and infection. Significant predictors of readmission included male gender, comorbidity, emergent admission, prolonged hospital stay, blood transfusion, ostomy, and discharge to nursing home. Readmission was inversely associated with hospital procedure volume, but not surgeon volume. After adjusting for potential confounding variables, the predicted probability of 1-year mortality was 16% for readmitted patients, compared with 7% for those not readmitted. This difference in mortality was significant for all stages of cancer. Conclusions:Early readmission after colectomy for cancer is common and due in part to modifiable factors. There is a remarkable association between readmission and 1-year mortality. Early readmission is therefore an important quality-of-care indicator for colon cancer surgery. These findings may facilitate the development of targeted interventions that will decrease readmissions and improve patient outcomes.


Journal of Clinical Oncology | 2011

Mortality by Stage for Right- Versus Left-Sided Colon Cancer: Analysis of Surveillance, Epidemiology, and End Results–Medicare Data

Jennifer M. Weiss; Patrick R. Pfau; Erin S. O'Connor; Jonathan King; Noelle K. LoConte; Gregory D. Kennedy; Maureen A. Smith

PURPOSE Recent studies have reported increased mortality for right-sided colon cancers but had limited adjustment for patient characteristics and conflicting results by stage. We examined the relationship between colon cancer location (right- v left-side) and 5-year mortality by stage. PATIENTS AND METHODS We identified Medicare beneficiaries from 1992 to 2005 with American Joint Commission on Cancer stages I to III primary adenocarcinoma of the colon who underwent surgery for curative intent through Surveillance, Epidemiology, and End Results (SEER) -Medicare data. Adjusted hazard ratios (HRs) and 95% CIs for predictors of all-cause 5-year mortality were obtained by using Cox proportional hazards regression. RESULTS Of 53,801 patients, 67% had right-sided colon cancer. Patients with right-sided cancer were more likely to be older, to be women, to be diagnosed with a more advanced stage, and to have more poorly differentiated tumors. Adjusted Cox regression showed no significant difference in mortality between right- and left-sided cancers for all stages combined (HR, 1.01; 95% CI, 0.98 to 1.04; P = .598) or for stage I cancers (HR, 0.95; 95% CI, 0.88 to 1.03; P = .211). Stage II right-sided cancers had lower mortality than left-sided cancers (HR, 0.92; 95% CI, 0.87 to 0.97; P = .001), and stage III right-sided cancers had higher mortality (HR, 1.12; 95% CI, 1.06 to 1.18; P < .001). CONCLUSION When analysis was adjusted for multiple patient, disease, comorbidity, and treatment variables, no overall difference in 5-year mortality was seen between right- and left-sided colon cancers. However, within stage II disease, right-sided cancers had lower mortality; within stage III, right-sided cancers had higher mortality.


Annals of Surgery | 2011

Optimizing Surgical Care of Colon Cancer in the Older Adult Population

Gregory D. Kennedy; Rajamanickam; Erin S. O'Connor; Noelle K. LoConte; Eugene Foley; Glen Leverson; Charles P. Heise

Objective:We have undertaken the current study to evaluate factors that correlate with postoperative complications in older patients undergoing surgery for colon cancer. Patients and Methods:The database of the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) from years 2005 to 2008 was accessed. Patients age 65 and older were included according to Current Procedural Terminology and International Classification of Disease-9 codes. Preoperative and operative variables were examined and postoperative complications assessed using a combination of univariate and multivariate statistical models. Propensity score matching was used to control for nonrandomization of the database. Results:We found that patients undergoing laparoscopic (n = 2113) and open (n = 3801) surgery for the diagnosis of colon cancer were similar in age and gender. However, patients undergoing laparoscopic surgery were generally at lower risk for developing postoperative complications (16.1% vs. 25.4%, P < 0.005). Statistical models controlling for preoperative and operative variables demonstrated patients with elevated body mass index (odds ratio [OR] = 1.26), a history of chronic obstructive pulmonary disease (OR = 1.63), over age 85 (OR = 1.35), a surgery lasting longer than 4 hours (OR = 1.48), or having undergone an open operation (OR = 1.53) to have increased risk for developing postoperative complications. Propensity score match analysis confirmed these results. Conclusions:Identification of preoperative factors that predispose patients to postoperative complications could allow for the institution of protocols that may decrease these events. Furthermore, expanding the role of laparoscopy in the treatment of older patients with colon cancer may decrease rates of postoperative complications.


Gastroenterology | 2011

Mortality Differs by Stage for Right- vs Left-Sided Colon Cancer: Analysis of SEER-Medicare Data

Jennifer M. Weiss; Patrick R. Pfau; Erin S. O'Connor; Jonathan C. King; Noelle K. LoConte; Gregory D. Kennedy; Maureen A. Smith

G A A b st ra ct s (95% CI: 15.3-16.5) in 1993-1997 to 18.3 (95%CI: 17.8-18.9) in 2003-2007. On the other hand, a 32% decrease was observed in ages >50 from 120.0 (95% CI: 119.1-121.8) in 1993-1997 to 90.6 (95% CI: 89.6-91.7) in 2003-2007. Hispanic men had 27% higher CRC rates than Hispanic women, but the age and time trends were similar for men and women. The overall stage distribution was 33% localized, 42% regional, and 25% distant in ages 50. Over time, the proportion of cases with regional and distant disease increased by 37% and 18% in ages 50. The Poisson regression model confirmed the increasing CRC incidence in younger Hispanics during 1993-2007. The 1-year observed and relative survival “improved” in all ages from approximately 86% to 90%, however no significant improvement in 5-year observed or relative survival was observed in patients <50 years. CONCLUSION: The incidence of CRC in Hispanics <50 years is rapidly increasing in the United States. This increase has affected both men and women, many of which are diagnosed with regional or distant disease. Unlike older patients, long-term survival has not improved in younger age groups. This finding may have implications on CRC screening guidelines.


Journal of The American College of Surgeons | 2009

Developing a practice-based learning and improvement curriculum for an academic general surgery residency.

Erin S. O'Connor; David M. Mahvi; Eugene F. Foley; Dennis P. Lund; Robert McDonald


Cancer | 2013

Surgical treatment of colon cancer in patients aged 80 years and older

Heather B. Neuman; Erin S. O'Connor; Jennifer M. Weiss; Noelle K. LoConte; David Yu Greenblatt; Caprice C. Greenberg; Maureen A. Smith


Cancer | 2013

Surgical treatment of colon cancer in patients aged 80 years and older : analysis of 31,574 patients in the SEER-Medicare database.

Heather B. Neuman; Erin S. O'Connor; Jennifer M. Weiss; Noelle K. LoConte; David Yu Greenblatt; Caprice C. Greenberg; Maureen A. Smith


Journal of Clinical Oncology | 2012

Reply to S. Bae et al

Erin S. O'Connor; Jennifer M. Weiss; David Yu Greenblatt; Noelle K. LoConte; Ronald E. Gangnon; Jinn-Ing Liou; Charles P. Heise; Maureen A. Smith


Surgery | 2011

Surrogate decision making: a woman in fulminant liver failure after an acetaminophen overdose.

Erin S. O'Connor; Margaret L. Schwarze; Ira J. Kodner; Jason D. Keune

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Noelle K. LoConte

University of Wisconsin-Madison

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Maureen A. Smith

University of Wisconsin-Madison

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David Yu Greenblatt

University of Wisconsin-Madison

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Jennifer M. Weiss

University of Wisconsin-Madison

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Heather B. Neuman

University of Wisconsin-Madison

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Jinn-Ing Liou

University of Wisconsin-Madison

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Charles P. Heise

University of Wisconsin-Madison

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Gregory D. Kennedy

University of Alabama at Birmingham

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Patrick R. Pfau

University of Wisconsin-Madison

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Sharon M. Weber

University of Wisconsin-Madison

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