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Papers by Birgir Gudjonsson
Journal of Clinical Gastroenterology, Aug 1, 2002
Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 repo... more Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 reported. A number of authors claim a 5-year survival rate of 30% to 58%. Review of the literature reveals only about 1,200 5-year survivors; however, 10 times as many individual resected survivors have been reported (in various countries), and nonresected survivors are overlooked. This high survival percentage is obtained by reducing the subset on which calculations are based and by using methods such as the Kaplan-Meier method, which produces higher figures as increasing numbers of patients are lost to follow-up. After adjustments, hardly more than 350 resected survivors could be found. Revision of statistical methods is urgently needed.
Journal of the American College of Surgeons, 1995
The incidence of carcinoma of the pancreas is increasing in Western societies at great cost. Panc... more The incidence of carcinoma of the pancreas is increasing in Western societies at great cost. Pancreatic resections have been performed for 60 years and there are hundreds of papers written on the subject, but there is no agreement on the efficacy of resections. Authors have reported on different groups and subsets of patients and have used different statistical methods. Most authors are unable to report a single five-year survivor; others claim a five-year survival rate of 30 to 55 percent. I have standardized and compared the results reported in 340 papers that deal with survival rates and where there is apparently adequate confirmation of disease. Survivors who have been resected may be reported up to six times even from different countries, whereas survivors who were not resected are frequently overlooked. Actuarial statistical methods exaggerate results when data are lost. After corrections for repetitions, approximately 300 survivors were found, of whom 10 percent had not under...
Clinics in oncology, Sep 8, 2017
Archives of Surgery, 1979
Intra-abdominal abscesses after colon surgery usually appear within eight weeks. Over the past fe... more Intra-abdominal abscesses after colon surgery usually appear within eight weeks. Over the past few years, we have observed nine patients who underwent colectomy for inflammatory bowel disease in whom large and relatively asymptomatic abscesses developed, requiring surgical drainage as long as three to five years after the operation. In five patients, there was no report of intraoperative complications such as perforation or fecal spillage. At the time of discharge from the hospital, all patients were afebrile. In three of these patients, abscesses were discovered when they were readmitted to the hospital for elective abdominal procedures; most of the others had localized abdominal pain.
European Journal of Gastroenterology & Hepatology, 2009
Resections for pancreatic ductal adenocarcinoma have now been carried out systematically for over... more Resections for pancreatic ductal adenocarcinoma have now been carried out systematically for over 70 years. However, opinions still differ as to the results. Some consider it unresectable, whereas others claim a high survival percentage and recommend resections. The literature on this surgery has been scrutinized from the onset, and 790 studies have been found that deal with resections and reveal survival information. Review reveals that the percentage of survivals is exaggerated with life-table methods when there is censoring of the data. Duplication of reporting survivors is rampant. After adjusting for calculations and duplications, the total number of 5-year survivors can hardly be more than 700-800.
The American Journal of Surgery, 2006
Regarding the article by Martignoni et al To the Editor: I read with interest the paper by Martig... more Regarding the article by Martignoni et al To the Editor: I read with interest the paper by Martignoni and colleagues [1]. They reported on preoperative biliary drainage surgical outcome after pancreatoduodenectomy for more than 17 different diseases. Then they used a Kaplan-Meier graph to show the survival for pancreatic and ampullary carcinoma together, which are known to have very different prognosis. Would the authors kindly inform the readers as to how many were the survivors with pancreatic carcinoma?
The American Journal of Medicine, 1978
J Clin Gastroenterol, 1981
Journal of clinical gastroenterology, 2002
Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 repo... more Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 reported. A number of authors claim a 5-year survival rate of 30% to 58%. Review of the literature reveals only about 1,200 5-year survivors; however, 10 times as many individual resected survivors have been reported (in various countries), and nonresected survivors are overlooked. This high survival percentage is obtained by reducing the subset on which calculations are based and by using methods such as the Kaplan-Meier method, which produces higher figures as increasing numbers of patients are lost to follow-up. After adjustments, hardly more than 350 resected survivors could be found. Revision of statistical methods is urgently needed.
HPB Surgery, 2016
Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and pro... more Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and projected to become the second and third leading causes of cancer-related deaths by 2030. The mean costs in 2015 may be assumed to be 79,800perpatientandforeachresection79,800 per patient and for each resection 79,800perpatientandforeachresection164,100. Attempt is made to evaluate the results over the last 80 years, the number of survivors, and the overall survival percentage.Methods. Altogether 1230 papers have been found which deal with resections and reveal survival information. Only 621 of these report 5-year survivors. Reservation about surgery was first expressed in 1964 and five-year survival of nonresected survivors is well documented.Results. The survival percentage depends not only on the number of survivors but also on the subset from which it is calculated. Since the 1980s the papers have mainly reported the number of resections and survival as actuarial percentages, with or without the actual number of survivors being reported. The actuarial p...
HPB Surgery, 2016
Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and pro... more Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and projected to become the second and third leading causes of cancer-related deaths by 2030. The mean costs in 2015 may be assumed to be 79,800perpatientandforeachresection79,800 per patient and for each resection 79,800perpatientandforeachresection164,100. Attempt is made to evaluate the results over the last 80 years, the number of survivors, and the overall survival percentage.Methods. Altogether 1230 papers have been found which deal with resections and reveal survival information. Only 621 of these report 5-year survivors. Reservation about surgery was first expressed in 1964 and five-year survival of nonresected survivors is well documented.Results. The survival percentage depends not only on the number of survivors but also on the subset from which it is calculated. Since the 1980s the papers have mainly reported the number of resections and survival as actuarial percentages, with or without the actual number of survivors being reported. The actuarial p...
Journal of Clinical Gastroenterology, 1996
Pancreatic Cancer - Clinical Management, 2012
Journal of Clinical Gastroenterology, Aug 1, 2002
Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 repo... more Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 reported. A number of authors claim a 5-year survival rate of 30% to 58%. Review of the literature reveals only about 1,200 5-year survivors; however, 10 times as many individual resected survivors have been reported (in various countries), and nonresected survivors are overlooked. This high survival percentage is obtained by reducing the subset on which calculations are based and by using methods such as the Kaplan-Meier method, which produces higher figures as increasing numbers of patients are lost to follow-up. After adjustments, hardly more than 350 resected survivors could be found. Revision of statistical methods is urgently needed.
Journal of the American College of Surgeons, 1995
The incidence of carcinoma of the pancreas is increasing in Western societies at great cost. Panc... more The incidence of carcinoma of the pancreas is increasing in Western societies at great cost. Pancreatic resections have been performed for 60 years and there are hundreds of papers written on the subject, but there is no agreement on the efficacy of resections. Authors have reported on different groups and subsets of patients and have used different statistical methods. Most authors are unable to report a single five-year survivor; others claim a five-year survival rate of 30 to 55 percent. I have standardized and compared the results reported in 340 papers that deal with survival rates and where there is apparently adequate confirmation of disease. Survivors who have been resected may be reported up to six times even from different countries, whereas survivors who were not resected are frequently overlooked. Actuarial statistical methods exaggerate results when data are lost. After corrections for repetitions, approximately 300 survivors were found, of whom 10 percent had not under...
Clinics in oncology, Sep 8, 2017
Archives of Surgery, 1979
Intra-abdominal abscesses after colon surgery usually appear within eight weeks. Over the past fe... more Intra-abdominal abscesses after colon surgery usually appear within eight weeks. Over the past few years, we have observed nine patients who underwent colectomy for inflammatory bowel disease in whom large and relatively asymptomatic abscesses developed, requiring surgical drainage as long as three to five years after the operation. In five patients, there was no report of intraoperative complications such as perforation or fecal spillage. At the time of discharge from the hospital, all patients were afebrile. In three of these patients, abscesses were discovered when they were readmitted to the hospital for elective abdominal procedures; most of the others had localized abdominal pain.
European Journal of Gastroenterology & Hepatology, 2009
Resections for pancreatic ductal adenocarcinoma have now been carried out systematically for over... more Resections for pancreatic ductal adenocarcinoma have now been carried out systematically for over 70 years. However, opinions still differ as to the results. Some consider it unresectable, whereas others claim a high survival percentage and recommend resections. The literature on this surgery has been scrutinized from the onset, and 790 studies have been found that deal with resections and reveal survival information. Review reveals that the percentage of survivals is exaggerated with life-table methods when there is censoring of the data. Duplication of reporting survivors is rampant. After adjusting for calculations and duplications, the total number of 5-year survivors can hardly be more than 700-800.
The American Journal of Surgery, 2006
Regarding the article by Martignoni et al To the Editor: I read with interest the paper by Martig... more Regarding the article by Martignoni et al To the Editor: I read with interest the paper by Martignoni and colleagues [1]. They reported on preoperative biliary drainage surgical outcome after pancreatoduodenectomy for more than 17 different diseases. Then they used a Kaplan-Meier graph to show the survival for pancreatic and ampullary carcinoma together, which are known to have very different prognosis. Would the authors kindly inform the readers as to how many were the survivors with pancreatic carcinoma?
The American Journal of Medicine, 1978
J Clin Gastroenterol, 1981
Journal of clinical gastroenterology, 2002
Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 repo... more Resections for pancreatic cancer have been performed for 65 years, with approximately 20,000 reported. A number of authors claim a 5-year survival rate of 30% to 58%. Review of the literature reveals only about 1,200 5-year survivors; however, 10 times as many individual resected survivors have been reported (in various countries), and nonresected survivors are overlooked. This high survival percentage is obtained by reducing the subset on which calculations are based and by using methods such as the Kaplan-Meier method, which produces higher figures as increasing numbers of patients are lost to follow-up. After adjustments, hardly more than 350 resected survivors could be found. Revision of statistical methods is urgently needed.
HPB Surgery, 2016
Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and pro... more Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and projected to become the second and third leading causes of cancer-related deaths by 2030. The mean costs in 2015 may be assumed to be 79,800perpatientandforeachresection79,800 per patient and for each resection 79,800perpatientandforeachresection164,100. Attempt is made to evaluate the results over the last 80 years, the number of survivors, and the overall survival percentage.Methods. Altogether 1230 papers have been found which deal with resections and reveal survival information. Only 621 of these report 5-year survivors. Reservation about surgery was first expressed in 1964 and five-year survival of nonresected survivors is well documented.Results. The survival percentage depends not only on the number of survivors but also on the subset from which it is calculated. Since the 1980s the papers have mainly reported the number of resections and survival as actuarial percentages, with or without the actual number of survivors being reported. The actuarial p...
HPB Surgery, 2016
Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and pro... more Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and projected to become the second and third leading causes of cancer-related deaths by 2030. The mean costs in 2015 may be assumed to be 79,800perpatientandforeachresection79,800 per patient and for each resection 79,800perpatientandforeachresection164,100. Attempt is made to evaluate the results over the last 80 years, the number of survivors, and the overall survival percentage.Methods. Altogether 1230 papers have been found which deal with resections and reveal survival information. Only 621 of these report 5-year survivors. Reservation about surgery was first expressed in 1964 and five-year survival of nonresected survivors is well documented.Results. The survival percentage depends not only on the number of survivors but also on the subset from which it is calculated. Since the 1980s the papers have mainly reported the number of resections and survival as actuarial percentages, with or without the actual number of survivors being reported. The actuarial p...
Journal of Clinical Gastroenterology, 1996
Pancreatic Cancer - Clinical Management, 2012