PRAGATHEESHWAR THIRUNAVUKARASU | Roswell Park Cancer Institute (original) (raw)

Papers by PRAGATHEESHWAR THIRUNAVUKARASU

Research paper thumbnail of Methods of Investigation of Cancer

Research paper thumbnail of External vs. internal motivators: against increasing requirements

Research paper thumbnail of Aberrant Partial Chromosomal Instability With Chemotherapeutically Resistant Metachronous Colorectal Cancer Following a Synchronous Primary Colorectal Cancer: A Case Report

Research paper thumbnail of Is Emergency Appendicectomy Better Than Elective Appendicectomy for the Treatment of Appendiceal Phlegmon?: A Review

Research paper thumbnail of Comparison of the Efficacy of the Various Treatment Modalities in the Management of Perianal Crohn’s Fistula: A Review

Research paper thumbnail of Abstract 4214: Characteristics of carcinoembryonic antigen-producing colorectal cancers: A population based study

Research paper thumbnail of Predicting individualized post-operative survival for colorectal cancer using a new mobile application derived from the National Cancer Database

Journal of Clinical Oncology

Prediction calculators estimate postoperative survival and assist the decision-making process for... more Prediction calculators estimate postoperative survival and assist the decision-making process for adjuvant treatment. The objective of this study was to create a postoperative overall survival (OS) calculator for patients with stage II/III colon cancer. Factors that influence OS, including comorbidity and postoperative variables, were included. The National Cancer Data Base was queried for patients with stage II/III colon cancer, diagnosed between 2004 and 2006, who had surgical resection. Patients were randomly divided to a testing (nt) cohort comprising 80% of the dataset and a validation (nv) cohort comprising 20%. Multivariable Cox proportional hazards regression of nt was performed to identify factors associated with 5-year OS. These were used to build a prediction model. The performance was assessed using the nv cohort and translated into mobile software. A total of 129,040 patients had surgery. After exclusion of patients with carcinoma in situ, nonadenocarcinoma histology, more than 1 malignancy, stage I or IV disease, or missing data, 34,176 patients were used in the development of the calculator. Independent predictors of OS included patient-specific characteristics, pathologic factors, and treatment options, including type of surgery and adjuvant therapy. Length of postoperative stay and unplanned readmission rates were also incorporated as surrogates for postoperative complications (1-day increase in postoperative stay, hazard ratio [HR] 1.019, 95% CI 1.018 to 1.021, p < 0.001; unplanned readmission vs no readmission HR 1.35, 95% CI 1.25 to 1.45, p < 0.001). Predicted and actual 5-year OS rates were compared in the nv cohort with 5-year area under the curve of 0.77. An individualized, postoperative OS calculator application was developed for patients with stage II/III colon cancer. This prediction model uses nationwide data, culminating in a highly comprehensive, clinically useful tool.

Research paper thumbnail of Outcomes of neoadjuvant chemotherapy versus chemoradiation among patients with resected pancreatic head adenocarcinoma

Journal of Clinical Oncology

398 Background: Increasing use of neoadjuvant therapy in pancreatic cancer has been reported. We ... more 398 Background: Increasing use of neoadjuvant therapy in pancreatic cancer has been reported. We compared patterns of practice and outcomes of neoadjuvant chemotherapy (nCHT) versus chemoradiation (nCRT) among pancreatic cancer pts receiving pancreaticoduodenectomy. Methods: National Cancer Data Base pancreatic head adenocarcinoma patients (pts) diagnosed between 2003 and 2011 treated by nCHT or nCRT followed by pancreaticoduodenectomy. Backward elimination logistic and Cox regression models were used. Primary outcome measures were 30-day and 90-day postsurgical mortality and overall survival; adjusted odds (aOR) & hazard ratios (aHR) and 95% confidence intervals (CI) are reported. Results: In all 1,432 pts received neoadjuvant treatment with nCHT (n = 523) or nCRT (n = 909). Odds of 30-day mortality were influenced by age (aOR 1.03, CI 0.99-1.06,p = 0.077), average annual resection volume of facility (aOR 0.98, CI 0.97-1.00, p = 0.135), and household income quartile (aOR 1.94, CI 0...

Research paper thumbnail of National Disparities in Surgical Approach to T1 Rectal Cancer and Impact on Outcomes

The American surgeon, 2016

This study investigated disparities between patients who had local excision versus radical resect... more This study investigated disparities between patients who had local excision versus radical resection for T1 rectal cancer. A retrospective analysis was performed using the National Cancer Data Base, 2004 to 2011. Inclusion criteria consisted of patients with T1, N0 rectal adenocarcinoma that were <3 cm, well or moderately differentiated without perineural invasion. Patients were stratified based on local excision and radical surgery. The primary outcome was overall survival (OS). Secondary outcomes included 30-day mortality, unplanned readmission rates, and postoperative length of stay. A total of 2235 patients were identified; 1335 (59.7%) underwent local excision and 900 (40.3%) had radical surgery. Overall, radical surgery was associated with an improved 5-year OS rate compared to local excision (0.86 vs 0.78, P = 0.009), increased unplanned readmission (6.5% vs 2.7%, P < 0.001), and longer postoperative length of stay (6.9 days vs 3.1 days, P < 0.001). For patients who ...

Research paper thumbnail of National disparities in minimally invasive surgery for pancreatic tumors

Surgical Endoscopy, 2016

For patients with pancreatic tumors, several disparities have been shown to impact access to care... more For patients with pancreatic tumors, several disparities have been shown to impact access to care, including surgery, and subsequently adversely affect long-term oncologic outcomes. The aim of this study was to investigate national disparities in minimally invasive surgery (MIS) across different demographics for pancreatic tumors. We utilized the American College of Surgeons (ACS) National Cancer Data Base (NCDB) to identify patients with pancreatic tumors from 2010 to 2011 who had undergone surgery through either an open or MIS approach. Multivariable analysis was performed to investigate differences in patient characteristics in relation to surgical approach and conversion to open. A total of 2809 patients were identified. The initial surgical approach included 86.5 % open (2430) and 13.5 % MIS (87.6 % were laparoscopic, and 12.4 % were robotic). Tumor histology was significantly associated with MIS, whereby patients with neuroendocrine tumors were more than twice as likely to have an MIS approach compared to adenocarcinoma. Tumor location within the pancreas was also associated with MIS, with tumors in the tail being three times more likely to be removed through MIS compared to tumors in the head. For patients with disease in the body or tail of the pancreas, ethnicity was independently associated with MIS whereby patients of Hispanic origin were less likely to have MIS. The conversion rate to open was 27.7 %, and geographic location was associated with conversion rates. MIS procedures comprise approximately 13.5 % of surgical procedures for pancreatic tumors. In addition to tumor histology, differences in surgical approach were identified with respect to ethnicity for patients with tumors in the body/tail of the pancreas.

Research paper thumbnail of Preoperative Assessment and Optimization of the Future Liver Remnant

Surgical Clinics of North America, 2016

Liver resection of benign, primary, and metastatic tumors is challenging and places patients at r... more Liver resection of benign, primary, and metastatic tumors is challenging and places patients at risk for postoperative liver insufficiency. The magnitude of this risk largely depends on the volume and function of the future liver remnant (FLR). It is, therefore, critical that hepatobiliary surgeons are well versed in measurement of liver volume and function as well as various techniques for preoperative liver volume augmentation. The absolute volume of FLR required to avoid postoperative liver insufficiency depends on patient, disease, and anatomic factors. Rapid expansion of the FLR can safely be achieved with portal venous embolization of the contralateral liver segments.

Research paper thumbnail of Predicting Individualized Postoperative Survival for Stage II/III Colon Cancer Using a Mobile Application Derived from the National Cancer Data Base

Journal of the American College of Surgeons, 2015

Prediction calculators estimate postoperative survival and assist the decision-making process for... more Prediction calculators estimate postoperative survival and assist the decision-making process for adjuvant treatment. The objective of this study was to create a postoperative overall survival (OS) calculator for patients with stage II/III colon cancer. Factors that influence OS, including comorbidity and postoperative variables, were included. The National Cancer Data Base was queried for patients with stage II/III colon cancer, diagnosed between 2004 and 2006, who had surgical resection. Patients were randomly divided to a testing (nt) cohort comprising 80% of the dataset and a validation (nv) cohort comprising 20%. Multivariable Cox proportional hazards regression of nt was performed to identify factors associated with 5-year OS. These were used to build a prediction model. The performance was assessed using the nv cohort and translated into mobile software. A total of 129,040 patients had surgery. After exclusion of patients with carcinoma in situ, nonadenocarcinoma histology, more than 1 malignancy, stage I or IV disease, or missing data, 34,176 patients were used in the development of the calculator. Independent predictors of OS included patient-specific characteristics, pathologic factors, and treatment options, including type of surgery and adjuvant therapy. Length of postoperative stay and unplanned readmission rates were also incorporated as surrogates for postoperative complications (1-day increase in postoperative stay, hazard ratio [HR] 1.019, 95% CI 1.018 to 1.021, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001; unplanned readmission vs no readmission HR 1.35, 95% CI 1.25 to 1.45, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Predicted and actual 5-year OS rates were compared in the nv cohort with 5-year area under the curve of 0.77. An individualized, postoperative OS calculator application was developed for patients with stage II/III colon cancer. This prediction model uses nationwide data, culminating in a highly comprehensive, clinically useful tool.

Research paper thumbnail of Nationwide Analysis of Short-term Surgical Outcomes Of Minimally Invasive Esophagectomy for Malignancy

International Journal of Surgery, 2015

Minimally invasive esophagectomy (MIE) is being increasingly utilized for esophageal cancer. It i... more Minimally invasive esophagectomy (MIE) is being increasingly utilized for esophageal cancer. It is unclear if MIE if being safely performed with satisfactory outcomes across the USA. We aimed to analyze the short-term surgical outcomes of MIE as compared to open esophagectomy (OE) METHODS: The American College of Surgeons National Cancer Database (NCDB) was queried for patients who underwent MIE or OE for esophageal malignancy between 2010 and 2011. Margin positivity, lymph node retrieval, 30-day mortality, 30-day unplanned readmission rate and hospital length of stay. A total of 4,047 patients were identified; 3,050 (75.4%) underwent OE, and 997 (24.6%) underwent MIE. The proportion of MIE increased from 21.9% in 2010 to 27.4% in 2011 (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). The conversion rate was 13.7%. There were no differences in-patient or tumor characteristics between the two cohorts. OE and MIE were comparable in terms of margin positive resection rate (7.4% vs. 8.1%, p = 0.48), 30-day unplanned readmission rate (7.6% vs. 7.2%, p = 0.64) and 30-day mortality rate (4.3% vs. 3.3%, p = 0.71). Compared to OE, MIE was associated with higher node retrieval (median 12 vs 14, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), and shorter hospital stay (median 11.0 vs 10.0 days, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Logistic regression analysis showed that surgical approach (OE vs MIE) was not associated with 30-day mortality rate. In an ANCOVA analysis, MIE was independently associated with a shorter hospital stay compared to OE (estimated mean difference 1.57 ± 0.53 days, p = 0.003). MIE patients who underwent conversion had a longer hospital stay compared to those who did not (11.0 vs 10.0 days, p = 0.02). MIE is being offered more frequently to patients with esophageal cancer, and maybe accompanied with better short-term outcomes including shorter hospital stay when compared to open esophagectomy.

Research paper thumbnail of National disparities in minimally invasive surgery for rectal cancer

Surgical Endoscopy, 2015

Social and racial disparities have been identified as factors contributing to differences in acce... more Social and racial disparities have been identified as factors contributing to differences in access to care and oncologic outcomes in patients with colorectal cancer. The aim of this study was to investigate national disparities in minimally invasive surgery (MIS), both laparoscopic and robotic, across different racial, socioeconomic and geographic populations of patients with rectal cancer. We utilized the American College of Surgeons National Cancer Database to identify patients with rectal cancer from 2004 to 2011 who had undergone definitive surgical procedures through either an open, laparoscopic or robotic approach. Inclusion criteria included only one malignancy and no adjuvant therapy. Multivariate analysis was performed to investigate differences in age, gender, race, income, education, insurance coverage, geographic setting and hospital type in relation to the surgical approach. A total of 8633 patients were identified. The initial surgical approach included 46.5 % open (4016), 50.9 % laparoscopic (4393) and 2.6 % robotic (224). In evaluating type of insurance coverage, patients with private insurance were most likely to undergo laparoscopic surgery [OR (odds ratio) 1.637, 95 % CI 1.178-2.275], although there was a less statistically significant association with robotic surgery (OR 2.167, 95 % CI 0.663-7.087). Patients who had incomes greater than $46,000 and received treatment at an academic center were more likely to undergo MIS (either laparoscopic or robotic). Race, education and geographic setting were not statistically significant characteristics for surgical approach in patients with rectal cancer. Minimally invasive approaches for rectal cancer comprise approximately 53 % of surgical procedures in patients not treated with adjuvant therapy. Robotics is associated with patients who have higher incomes and private insurance and undergo surgery in academic centers.

Research paper thumbnail of Pre-operative unintentional weight loss as a risk factor for surgical outcomes after elective surgery in patients with disseminated cancer

International journal of surgery (London, England), Jan 10, 2015

With improvement in survival, elective surgical procedures are being increasingly performed on pa... more With improvement in survival, elective surgical procedures are being increasingly performed on patients with metastatic disease. We aimed to study the association of pre-operative unintentional weight loss (UWL) with operative outcomes in this patient population. We extracted data on all patients with disseminated cancer undergoing elective surgeries between 2005 and 2011 from the National Surgical Quality Improvement Program (NSQIP), along with the Current Procedure Terminology (CPT) codes. Based on the presence of unintentional weight loss of >10% body weight in the 6-month period preceding surgery, patients were divided into 2 cohorts - (1) patients with UWL ('UWL' cohort) and (2) patients without UWL ('No UWL') cohort. Differences in patient characteristics, co-morbid conditions and outcomes were compared. There were 30,669 surgeries recorded under 1,638 CPT codes, with 8,436 surgeries involving the eight most common CPT codes. UWL was present in 11.5% of all ...

Research paper thumbnail of External vs. internal motivators: against increasing requirements

Bulletin of the American College of Surgeons, 2011

Research paper thumbnail of Comparison of radioactive seed localization to wire localization for nonpalpable breast lesions

Journal of the American College of Surgeons, 2014

Research paper thumbnail of The use of wearable technology in the operating room

Journal of the American College of Surgeons, 2014

Research paper thumbnail of A Rationally Designed A34R Mutant Oncolytic Poxvirus: Improved Efficacy in Peritoneal Carcinomatosis

Research paper thumbnail of CXCL11 improves safety of oncolytic vaccinia virus therapy

Journal of the American College of Surgeons, 2011

Journal of the American College of Surgeons, Volume 213, Issue 3, Pages S138, September 2011, Aut... more Journal of the American College of Surgeons, Volume 213, Issue 3, Pages S138, September 2011, Authors:Pragatheeshwar Thirunavukarasu, MD; Magesh Sathaiah, MB BS; Roshni Ravindranathan, MS; Frances Austin, MD; Mark O'Malley, BSc; Zong Sheng Guo, PhD; Stephen ...

Research paper thumbnail of Methods of Investigation of Cancer

Research paper thumbnail of External vs. internal motivators: against increasing requirements

Research paper thumbnail of Aberrant Partial Chromosomal Instability With Chemotherapeutically Resistant Metachronous Colorectal Cancer Following a Synchronous Primary Colorectal Cancer: A Case Report

Research paper thumbnail of Is Emergency Appendicectomy Better Than Elective Appendicectomy for the Treatment of Appendiceal Phlegmon?: A Review

Research paper thumbnail of Comparison of the Efficacy of the Various Treatment Modalities in the Management of Perianal Crohn’s Fistula: A Review

Research paper thumbnail of Abstract 4214: Characteristics of carcinoembryonic antigen-producing colorectal cancers: A population based study

Research paper thumbnail of Predicting individualized post-operative survival for colorectal cancer using a new mobile application derived from the National Cancer Database

Journal of Clinical Oncology

Prediction calculators estimate postoperative survival and assist the decision-making process for... more Prediction calculators estimate postoperative survival and assist the decision-making process for adjuvant treatment. The objective of this study was to create a postoperative overall survival (OS) calculator for patients with stage II/III colon cancer. Factors that influence OS, including comorbidity and postoperative variables, were included. The National Cancer Data Base was queried for patients with stage II/III colon cancer, diagnosed between 2004 and 2006, who had surgical resection. Patients were randomly divided to a testing (nt) cohort comprising 80% of the dataset and a validation (nv) cohort comprising 20%. Multivariable Cox proportional hazards regression of nt was performed to identify factors associated with 5-year OS. These were used to build a prediction model. The performance was assessed using the nv cohort and translated into mobile software. A total of 129,040 patients had surgery. After exclusion of patients with carcinoma in situ, nonadenocarcinoma histology, more than 1 malignancy, stage I or IV disease, or missing data, 34,176 patients were used in the development of the calculator. Independent predictors of OS included patient-specific characteristics, pathologic factors, and treatment options, including type of surgery and adjuvant therapy. Length of postoperative stay and unplanned readmission rates were also incorporated as surrogates for postoperative complications (1-day increase in postoperative stay, hazard ratio [HR] 1.019, 95% CI 1.018 to 1.021, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001; unplanned readmission vs no readmission HR 1.35, 95% CI 1.25 to 1.45, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Predicted and actual 5-year OS rates were compared in the nv cohort with 5-year area under the curve of 0.77. An individualized, postoperative OS calculator application was developed for patients with stage II/III colon cancer. This prediction model uses nationwide data, culminating in a highly comprehensive, clinically useful tool.

Research paper thumbnail of Outcomes of neoadjuvant chemotherapy versus chemoradiation among patients with resected pancreatic head adenocarcinoma

Journal of Clinical Oncology

398 Background: Increasing use of neoadjuvant therapy in pancreatic cancer has been reported. We ... more 398 Background: Increasing use of neoadjuvant therapy in pancreatic cancer has been reported. We compared patterns of practice and outcomes of neoadjuvant chemotherapy (nCHT) versus chemoradiation (nCRT) among pancreatic cancer pts receiving pancreaticoduodenectomy. Methods: National Cancer Data Base pancreatic head adenocarcinoma patients (pts) diagnosed between 2003 and 2011 treated by nCHT or nCRT followed by pancreaticoduodenectomy. Backward elimination logistic and Cox regression models were used. Primary outcome measures were 30-day and 90-day postsurgical mortality and overall survival; adjusted odds (aOR) & hazard ratios (aHR) and 95% confidence intervals (CI) are reported. Results: In all 1,432 pts received neoadjuvant treatment with nCHT (n = 523) or nCRT (n = 909). Odds of 30-day mortality were influenced by age (aOR 1.03, CI 0.99-1.06,p = 0.077), average annual resection volume of facility (aOR 0.98, CI 0.97-1.00, p = 0.135), and household income quartile (aOR 1.94, CI 0...

Research paper thumbnail of National Disparities in Surgical Approach to T1 Rectal Cancer and Impact on Outcomes

The American surgeon, 2016

This study investigated disparities between patients who had local excision versus radical resect... more This study investigated disparities between patients who had local excision versus radical resection for T1 rectal cancer. A retrospective analysis was performed using the National Cancer Data Base, 2004 to 2011. Inclusion criteria consisted of patients with T1, N0 rectal adenocarcinoma that were <3 cm, well or moderately differentiated without perineural invasion. Patients were stratified based on local excision and radical surgery. The primary outcome was overall survival (OS). Secondary outcomes included 30-day mortality, unplanned readmission rates, and postoperative length of stay. A total of 2235 patients were identified; 1335 (59.7%) underwent local excision and 900 (40.3%) had radical surgery. Overall, radical surgery was associated with an improved 5-year OS rate compared to local excision (0.86 vs 0.78, P = 0.009), increased unplanned readmission (6.5% vs 2.7%, P < 0.001), and longer postoperative length of stay (6.9 days vs 3.1 days, P < 0.001). For patients who ...

Research paper thumbnail of National disparities in minimally invasive surgery for pancreatic tumors

Surgical Endoscopy, 2016

For patients with pancreatic tumors, several disparities have been shown to impact access to care... more For patients with pancreatic tumors, several disparities have been shown to impact access to care, including surgery, and subsequently adversely affect long-term oncologic outcomes. The aim of this study was to investigate national disparities in minimally invasive surgery (MIS) across different demographics for pancreatic tumors. We utilized the American College of Surgeons (ACS) National Cancer Data Base (NCDB) to identify patients with pancreatic tumors from 2010 to 2011 who had undergone surgery through either an open or MIS approach. Multivariable analysis was performed to investigate differences in patient characteristics in relation to surgical approach and conversion to open. A total of 2809 patients were identified. The initial surgical approach included 86.5 % open (2430) and 13.5 % MIS (87.6 % were laparoscopic, and 12.4 % were robotic). Tumor histology was significantly associated with MIS, whereby patients with neuroendocrine tumors were more than twice as likely to have an MIS approach compared to adenocarcinoma. Tumor location within the pancreas was also associated with MIS, with tumors in the tail being three times more likely to be removed through MIS compared to tumors in the head. For patients with disease in the body or tail of the pancreas, ethnicity was independently associated with MIS whereby patients of Hispanic origin were less likely to have MIS. The conversion rate to open was 27.7 %, and geographic location was associated with conversion rates. MIS procedures comprise approximately 13.5 % of surgical procedures for pancreatic tumors. In addition to tumor histology, differences in surgical approach were identified with respect to ethnicity for patients with tumors in the body/tail of the pancreas.

Research paper thumbnail of Preoperative Assessment and Optimization of the Future Liver Remnant

Surgical Clinics of North America, 2016

Liver resection of benign, primary, and metastatic tumors is challenging and places patients at r... more Liver resection of benign, primary, and metastatic tumors is challenging and places patients at risk for postoperative liver insufficiency. The magnitude of this risk largely depends on the volume and function of the future liver remnant (FLR). It is, therefore, critical that hepatobiliary surgeons are well versed in measurement of liver volume and function as well as various techniques for preoperative liver volume augmentation. The absolute volume of FLR required to avoid postoperative liver insufficiency depends on patient, disease, and anatomic factors. Rapid expansion of the FLR can safely be achieved with portal venous embolization of the contralateral liver segments.

Research paper thumbnail of Predicting Individualized Postoperative Survival for Stage II/III Colon Cancer Using a Mobile Application Derived from the National Cancer Data Base

Journal of the American College of Surgeons, 2015

Prediction calculators estimate postoperative survival and assist the decision-making process for... more Prediction calculators estimate postoperative survival and assist the decision-making process for adjuvant treatment. The objective of this study was to create a postoperative overall survival (OS) calculator for patients with stage II/III colon cancer. Factors that influence OS, including comorbidity and postoperative variables, were included. The National Cancer Data Base was queried for patients with stage II/III colon cancer, diagnosed between 2004 and 2006, who had surgical resection. Patients were randomly divided to a testing (nt) cohort comprising 80% of the dataset and a validation (nv) cohort comprising 20%. Multivariable Cox proportional hazards regression of nt was performed to identify factors associated with 5-year OS. These were used to build a prediction model. The performance was assessed using the nv cohort and translated into mobile software. A total of 129,040 patients had surgery. After exclusion of patients with carcinoma in situ, nonadenocarcinoma histology, more than 1 malignancy, stage I or IV disease, or missing data, 34,176 patients were used in the development of the calculator. Independent predictors of OS included patient-specific characteristics, pathologic factors, and treatment options, including type of surgery and adjuvant therapy. Length of postoperative stay and unplanned readmission rates were also incorporated as surrogates for postoperative complications (1-day increase in postoperative stay, hazard ratio [HR] 1.019, 95% CI 1.018 to 1.021, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001; unplanned readmission vs no readmission HR 1.35, 95% CI 1.25 to 1.45, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Predicted and actual 5-year OS rates were compared in the nv cohort with 5-year area under the curve of 0.77. An individualized, postoperative OS calculator application was developed for patients with stage II/III colon cancer. This prediction model uses nationwide data, culminating in a highly comprehensive, clinically useful tool.

Research paper thumbnail of Nationwide Analysis of Short-term Surgical Outcomes Of Minimally Invasive Esophagectomy for Malignancy

International Journal of Surgery, 2015

Minimally invasive esophagectomy (MIE) is being increasingly utilized for esophageal cancer. It i... more Minimally invasive esophagectomy (MIE) is being increasingly utilized for esophageal cancer. It is unclear if MIE if being safely performed with satisfactory outcomes across the USA. We aimed to analyze the short-term surgical outcomes of MIE as compared to open esophagectomy (OE) METHODS: The American College of Surgeons National Cancer Database (NCDB) was queried for patients who underwent MIE or OE for esophageal malignancy between 2010 and 2011. Margin positivity, lymph node retrieval, 30-day mortality, 30-day unplanned readmission rate and hospital length of stay. A total of 4,047 patients were identified; 3,050 (75.4%) underwent OE, and 997 (24.6%) underwent MIE. The proportion of MIE increased from 21.9% in 2010 to 27.4% in 2011 (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). The conversion rate was 13.7%. There were no differences in-patient or tumor characteristics between the two cohorts. OE and MIE were comparable in terms of margin positive resection rate (7.4% vs. 8.1%, p = 0.48), 30-day unplanned readmission rate (7.6% vs. 7.2%, p = 0.64) and 30-day mortality rate (4.3% vs. 3.3%, p = 0.71). Compared to OE, MIE was associated with higher node retrieval (median 12 vs 14, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), and shorter hospital stay (median 11.0 vs 10.0 days, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Logistic regression analysis showed that surgical approach (OE vs MIE) was not associated with 30-day mortality rate. In an ANCOVA analysis, MIE was independently associated with a shorter hospital stay compared to OE (estimated mean difference 1.57 ± 0.53 days, p = 0.003). MIE patients who underwent conversion had a longer hospital stay compared to those who did not (11.0 vs 10.0 days, p = 0.02). MIE is being offered more frequently to patients with esophageal cancer, and maybe accompanied with better short-term outcomes including shorter hospital stay when compared to open esophagectomy.

Research paper thumbnail of National disparities in minimally invasive surgery for rectal cancer

Surgical Endoscopy, 2015

Social and racial disparities have been identified as factors contributing to differences in acce... more Social and racial disparities have been identified as factors contributing to differences in access to care and oncologic outcomes in patients with colorectal cancer. The aim of this study was to investigate national disparities in minimally invasive surgery (MIS), both laparoscopic and robotic, across different racial, socioeconomic and geographic populations of patients with rectal cancer. We utilized the American College of Surgeons National Cancer Database to identify patients with rectal cancer from 2004 to 2011 who had undergone definitive surgical procedures through either an open, laparoscopic or robotic approach. Inclusion criteria included only one malignancy and no adjuvant therapy. Multivariate analysis was performed to investigate differences in age, gender, race, income, education, insurance coverage, geographic setting and hospital type in relation to the surgical approach. A total of 8633 patients were identified. The initial surgical approach included 46.5 % open (4016), 50.9 % laparoscopic (4393) and 2.6 % robotic (224). In evaluating type of insurance coverage, patients with private insurance were most likely to undergo laparoscopic surgery [OR (odds ratio) 1.637, 95 % CI 1.178-2.275], although there was a less statistically significant association with robotic surgery (OR 2.167, 95 % CI 0.663-7.087). Patients who had incomes greater than $46,000 and received treatment at an academic center were more likely to undergo MIS (either laparoscopic or robotic). Race, education and geographic setting were not statistically significant characteristics for surgical approach in patients with rectal cancer. Minimally invasive approaches for rectal cancer comprise approximately 53 % of surgical procedures in patients not treated with adjuvant therapy. Robotics is associated with patients who have higher incomes and private insurance and undergo surgery in academic centers.

Research paper thumbnail of Pre-operative unintentional weight loss as a risk factor for surgical outcomes after elective surgery in patients with disseminated cancer

International journal of surgery (London, England), Jan 10, 2015

With improvement in survival, elective surgical procedures are being increasingly performed on pa... more With improvement in survival, elective surgical procedures are being increasingly performed on patients with metastatic disease. We aimed to study the association of pre-operative unintentional weight loss (UWL) with operative outcomes in this patient population. We extracted data on all patients with disseminated cancer undergoing elective surgeries between 2005 and 2011 from the National Surgical Quality Improvement Program (NSQIP), along with the Current Procedure Terminology (CPT) codes. Based on the presence of unintentional weight loss of >10% body weight in the 6-month period preceding surgery, patients were divided into 2 cohorts - (1) patients with UWL ('UWL' cohort) and (2) patients without UWL ('No UWL') cohort. Differences in patient characteristics, co-morbid conditions and outcomes were compared. There were 30,669 surgeries recorded under 1,638 CPT codes, with 8,436 surgeries involving the eight most common CPT codes. UWL was present in 11.5% of all ...

Research paper thumbnail of External vs. internal motivators: against increasing requirements

Bulletin of the American College of Surgeons, 2011

Research paper thumbnail of Comparison of radioactive seed localization to wire localization for nonpalpable breast lesions

Journal of the American College of Surgeons, 2014

Research paper thumbnail of The use of wearable technology in the operating room

Journal of the American College of Surgeons, 2014

Research paper thumbnail of A Rationally Designed A34R Mutant Oncolytic Poxvirus: Improved Efficacy in Peritoneal Carcinomatosis

Research paper thumbnail of CXCL11 improves safety of oncolytic vaccinia virus therapy

Journal of the American College of Surgeons, 2011

Journal of the American College of Surgeons, Volume 213, Issue 3, Pages S138, September 2011, Aut... more Journal of the American College of Surgeons, Volume 213, Issue 3, Pages S138, September 2011, Authors:Pragatheeshwar Thirunavukarasu, MD; Magesh Sathaiah, MB BS; Roshni Ravindranathan, MS; Frances Austin, MD; Mark O'Malley, BSc; Zong Sheng Guo, PhD; Stephen ...