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Dive into the research topics where Natalie G. Coburn is active.

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Featured researches published by Natalie G. Coburn.


Cancer | 2006

Significant regional variation in adequacy of lymph node assessment and survival in gastric cancer.

Natalie G. Coburn; Carol J. Swallow; Alex Kiss; Calvin Law

Lymph node (LN) status is a major determinant of prognosis and treatment of gastric adenocarcinoma. The 1997 American Joint Commission on Cancer/Union Internationale Contre le Cancer guidelines were revised, requiring examination of ≥15 LN for staging.


Annals of Surgical Oncology | 2008

Surgical Management of Intrahepatic Cholangiocarcinoma - A Population-Based Study

Jensen C. C. Tan; Natalie G. Coburn; Nancy N. Baxter; Alex Kiss; Calvin Law

BackgroundCholangiocarcinoma (CCA) is associated with poor survival and therapeutic nihilism. To date, there has not been an examination of the surgical management of CCA at a population level.MethodsUsing the Surveillance, Epidemiology and End Results (SEER) database, we identified all patients with intrahepatic CCA diagnosed between 1988 and 2003. Tumors categorized as a single, unilobar lesion with no evidence of vascular invasion were defined as localized. It was then determined whether patients received cancer directed surgery (CDS). Multivariable logistic regression was used to evaluate factors associated with CDS in patients with localized disease. The influence of CDS on overall survival (OS) was evaluated using Kaplan–Meier curves and Cox proportional hazards modeling.ResultsOnly 446 (12%) of 3,756 patients with intrahepatic CCA underwent CDS. On multivariable analysis, non-Klatskin tumor (p < 0.01) and younger age (p = 0.02) was associated with CDS. Localized disease was strongly associated with CDS (p < 0.01); however, only 91 (37%) of these 248 patients underwent CDS. Of patients with localized disease, those who had CDS had significantly better survival than those who did not (p < 0.01), with median overall survival (OS) of 44 months versus 8 months, and five-year OS of 42% versus 4%, respectively.ConclusionsPatients with localized CCA who are selected for CDS are strongly associated with improved survival, with rates approaching that found in single institution studies. However, many patients with localized tumors do not receive potentially curative cancer-directed surgery. Further study is warranted to address the barriers to the delivery of appropriate care to these patients.


Gastric Cancer | 2012

How useful is preoperative imaging for tumor, node, metastasis (TNM) staging of gastric cancer? A meta-analysis

Rajini Seevaratnam; Roberta Cardoso; Caitlin Mcgregor; Laércio Gomes Lourenço; Alyson L. Mahar; Rinku Sutradhar; Calvin Law; Lawrence Paszat; Natalie G. Coburn

BackgroundSurgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.MethodsSystematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.ResultsFor pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.ConclusionsThe agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.


Breast Journal | 2008

Treatment Variation by Insurance Status for Breast Cancer Patients

Natalie G. Coburn; John Fulton; Deborah N. Pearlman; Calvin Law; Brenda DiPaolo; Blake Cady

Abstract:  Few studies have examined the relationship of insurance status with the presentation and treatment of breast cancer. Using a state cancer registry, we compared tumor presentation and surgical treatments at presentation by insurance status (private insurance, Medicare, Medicaid, or uninsured). Student’s t‐test, Chi‐square test, and ANOVA were used for comparison. P‐values reflect a comparison to insured patients. From 1996 to 2005, there were 6876 cases of invasive breast cancer with either private (n = 3975), Medicare (n = 2592), Medicaid (n = 193), or no insurance (n = 116). The median age (years) at presentation was 55 for private, 76 for Medicare, 54 for Medicaid and 54 for uninsured. The mean and median tumor size (mm) were 18.5 and 15 for private; 20.9 and 15 for Medicare; 24.2 and 18 for Medicaid; and 29.5 and 17 for uninsured, respectively; (p < 0.001 for all). Fewer women with Medicare and Medicaid presented with node negative breast cancers: private, 73.4% node negative; Medicare, 79.5% (p < 0.001); Medicaid, 60.9% (p < 0.001); and uninsured, 58% (p = 0.005). Significantly more uninsured women had no surgical treatment of their breast cancer: 15.5% versus 4.3% for private (p < 0.001). Among women with non‐metastatic T1/T2 tumors, 71.5% with private insurance underwent breast‐conserving surgery (BCS), compared with 64.2% of Medicare (p < 0.001), 65% of Medicaid (p = 0.097), and 65.4% of uninsured (p = 0.234). The rate of reconstruction following mastectomy was higher for private insurance (36.6%), compared with Medicare (3.8%, p < 0.0001), Medicaid (26.1%, p = 0.31), and uninsured (5.0%, p = 0.0038). The presentation of breast cancer in women with no insurance and Medicaid is significantly worse than those with private insurance. Of concern are the lower proportions of BCS and reconstruction among patients who are uninsured or have Medicaid. Reduction of disparities in breast cancer presentation and treatment may be possible by increasing enrollment of uninsured, program‐eligible women in a state‐supported screening and treatment program.


Journal of The American College of Surgeons | 2008

Surgery for gallbladder cancer: a population-based analysis.

Natalie G. Coburn; Sean P. Cleary; Jensen C. C. Tan; Calvin Law

BACKGROUND Gallbladder cancer is an aggressive neoplasm, and resection is the only curative modality. Single institutional studies report an aggressive surgical approach improves survival. This analysis was performed to examine the components of surgical resection and resultant survival. STUDY DESIGN From 1988 to 2003, patients aged 18 to 85 years, resected of T1-3 M0 gallbladder cancer, were identified from the Surveillance, Epidemiology, and End Results (SEER) registry. Resections were classified as en bloc (cholecystectomy + at least one adjacent organ) or simple (cholecystectomy only); lymphadenectomy was defined as three or more lymph nodes assessed. RESULTS Of the 2,835 resected patients with T1-T3 M0 cancer, only 8.6% underwent an en bloc resection, and 5.3% had a lymphadenectomy. In multivariable analysis, age, year of resection, region, and advanced T-stage were associated with more aggressive resection. In univariate analysis, improved survival was associated with en bloc resection for T1/2 cancers, and lymphadenectomy for T2/3 cancers. In multivariable analysis, the following were associated with improved survival: for T1 cancers, en bloc resection, younger age, lower grade, and recent year of resection; for T2 cancers, Caucasian race (versus African-American), lower grade, and node negative disease, with trends for en bloc resection and lymphadenectomy; and for T3 cancers, female gender, Caucasian race (versus American Indian), lower grade, node negative disease, and recent year of resection, with a strong trend for lymphadenectomy. CONCLUSIONS Very few patients underwent aggressive surgery. En bloc resection and lymphadenectomy may have stage-specific effects on survival. Additional studies should explore the underuse of aggressive operations, verify survival advantages, and define stage-specific resection strategies.


Cancer Control | 2004

Decreased breast cancer tumor size, stage, and mortality in Rhode Island: an example of a well-screened population.

Natalie G. Coburn; Maureen A. Chung; John Fulton; Blake Cady

BACKGROUND Since the 1980s, Rhode Island has achieved one of the highest mammography screening rates in the nation. The objective of this study was to determine the effect of high mammography rates on breast cancer presentation and outcomes. METHODS Using the Rhode Island Cancer Registry, the incidence of DCIS and invasive cancer, tumor size, stage, rate of BCS and mortality from breast cancer were determined from 1987 to 2001. RESULTS Over 80% of Rhode Island women report routine mammography. From 1987 to 2001, there were 1,660 cases of DCIS and 11,301 cases of invasive breast cancer. Although the overall incidence of invasive cancer was stable, the median diameter decreased from 2 cm to 1.5 cm with a significant decrease in the incidence of stage III and IV cancers. There was an increase in BCS for women 50 to 64 years of age with stage I and II disease and for women older than 65 years with stage I disease. Disease-specific mortality decreased by 25%. CONCLUSIONS High mammography rates in Rhode Island are associated with smaller and earlier-stage breast cancers. This largely accounts for the decreased mortality from breast cancer and the increased rate of BCS.


Journal of Surgical Oncology | 2009

Lymph nodes and gastric cancer

Natalie G. Coburn

Worldwide, gastric cancer is one of the top three leading causes of cancer mortality, but incidence and presentation vary geographically. Currently, surgery is the only possible cure. Nodal status is an important prognostic indicator for gastric cancer, and despite results of randomized controlled trials, debate continues over the importance of aggressive lymphadenectomy. J. Surg. Oncol. 2009;99:199–206.


Gastric Cancer | 2012

A meta-analysis of D1 versus D2 lymph node dissection

Rajini Seevaratnam; Alina Bocicariu; Roberta Cardoso; Alyson L. Mahar; Alex Kiss; Lucy Helyer; Calvin Law; Natalie G. Coburn

BackgroundSurgery is the only curative treatment for patients with gastric cancer. However, the extent of lymph node dissection is still debated. Therefore, with the publication of newer trial results, we conducted an updated meta-analysis of D1 versus D2 randomized controlled trials comparing outcomes.MethodsSystematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1985, to December 31, 2010. Meta-analyses were performed using RevMan v5 software. Both short- and long-term outcomes were analyzed. Subgroup analyses of T stage and spleen/pancreas resection versus preservation were performed.ResultsOutcomes of 5 randomized trials involving 1642 patients (845 D1, 797 D2) enrolled from 1982 to 2005 were included. Despite the addition of the more recent trials, overall hospital mortality and reoperation rates were still higher in D2 cases. Subgroup analysis of recent trials and spleen/pancreas preservation revealed no significant difference in hospital mortality between groups. Five-year overall survival was similar between D1 versus D2 trials. Sub-analysis by tumor depth and spleen/pancreas preservation detected trends for improved survival with D2 lymphadenectomy in T3/T4 patients and those with spleen/pancreas preservation.ConclusionEarlier trials show that D2 dissections have higher operative mortality, while recent trials have similar rates. A trend of improved survival exists among D2 patients who did not undergo resection of the spleen or pancreas, as well as for patients with T3/T4 cancers.


Gastric Cancer | 2012

A systematic review of the accuracy and utility of peritoneal cytology in patients with gastric cancer

Pierre-Anthony Leake; Roberta Cardoso; Rajini Seevaratnam; Laércio Gomes Lourenço; Lucy Helyer; Alyson L. Mahar; Corwyn Rowsell; Natalie G. Coburn

BackgroundThere is lack of uniformity in the utilization of peritoneal cytology in gastric cancer management. The identification of intraperitoneal free cancer cells (IFCCs) is believed to confer poor prognosis. However, while some of these patients are palliated, others may undergo more aggressive therapies. In this review, we aimed to identify and synthesize findings on the use of peritoneal cytology in predicting peritoneal recurrence and overall survival in curative gastric cancer patients.MethodsElectronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We determined the accuracy, sensitivity, and specificity of peritoneal cytology in predicting peritoneal recurrence based on four techniques—conventional cytology, immunoassay, immunohistochemistry, and reverse transcriptase-polymerase chain reaction. Recurrence rates and overall survival rates for curative patients were determined, based on positivity or negativity for IFCCs.ResultsTwenty-eight articles were included. All four techniques showed wide variations in accuracy, sensitivity, and specificity in predicting peritoneal recurrence. Recurrence rates for patients positive for IFCCs ranged from 11.1 to 100%, while those negative for IFCCs had recurrence rates of 0–51%. Overall survival was significantly reduced for patients with positive IFCCs. Short follow-up periods and possible duplication of results may limit result interpretation.ConclusionThe presence of IFCCs appears to increase the risk of peritoneal recurrence and is associated with worse overall survival in gastric cancer patients. Further incorporation of peritoneal cytology in clinical decision-making in gastric cancer depends on the development of a consistently accurate and rapid IFCC detection method.


Gastric Cancer | 2012

A systematic review of the accuracy and indications for diagnostic laparoscopy prior to curative-intent resection of gastric cancer

Pierre-Anthony Leake; Roberta Cardoso; Rajini Seevaratnam; Laércio Gomes Lourenço; Lucy Helyer; Alyson L. Mahar; Calvin Law; Natalie G. Coburn

BackgroundDespite improved preoperative imaging techniques, patients with incurable or unresectable gastric cancer are still subjected to non-therapeutic laparotomy. Diagnostic laparoscopy (DL) has been advocated by some to be essential in decision-making in gastric cancer. We aimed to identify and synthesize findings on the value of DL for patients with gastric cancer, in this era of improved preoperative imaging.MethodsElectronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We calculated the change in management and avoidance of laparotomy based on the addition of DL and laparoscopic ultrasound (LUS). The accuracy, agreement (kappa), sensitivity, and specificity of DL in assessing tumor extent, nodal involvement, and the presence of metastases with respect to the gold standard (pathology) were also calculated.ResultsTwenty-one articles were included. DL showed moderate to substantial agreement with final pathology for T stage, but only fair agreement for N stage. For M staging, DL had an overall accuracy, sensitivity, and specificity ranging from 85–98.9%, 64.3–94%, and 80–100%, respectively. The use of DL altered treatment in 8.5–59.6% of cases, avoiding laparotomy in 8.5–43.8% of cases. LUS provided additional benefit in 5.8–7.2% of cases.ConclusionsDespite evolving preoperative imaging techniques, diagnostic laparoscopy continues to be of substantial value in staging patients with gastric cancer and in avoiding unnecessary laparotomy. The current data support DL for all patients with advanced gastric cancer.

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Paul J. Karanicolas

Sunnybrook Health Sciences Centre

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Julie Hallet

Sunnybrook Health Sciences Centre

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Rajini Seevaratnam

Sunnybrook Research Institute

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Roberta Cardoso

Sunnybrook Research Institute

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Craig C. Earle

Sunnybrook Health Sciences Centre

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