Evaluation of pro-carboxypeptidase A and carboxypeptidase A as serologic markers for adenocarcinoma of the pancreas

Peter Shamamian, Judith D. Goldberg, Xiang Y. Ye, Jonathan D. Stewart, Peter J. White, Charles Gilvarg

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Background: A serological marker for pancreatic cancer may allow for early detection and potentially more effective treatments. Pro-carboxypeptidase A (pro-CPA) is produced exclusively in the pancreas and converted to its active form, CPA, in the intestinal lumen. We hypothesized that alterations in serum pro-CPA and/or CPA may be useful as a diagnostic test for pancreatic cancer. Patients and methods: Serum samples obtained from 34 patients with pancreatic adenocarcinoma prior to surgical intervention and 64 control patients were assayed for pro-CPA and CPA. A variety of statistical methods was used to evaluate the utility of these measurements individually and in combination to classify the samples with respect to the presence or absence of pancreatic adenocarcinoma. Results: Because of positive skewing of the data in some populations, transformation of the data to natural logarithmic scales was used and resulted in normal distributions. All pancreatic cancer patients had ln(CPA) levels within or below the normal range defined as two standard deviations from the control group mean (-2.714±0.413). Ln(pro-CPA) levels in 24 of 34 cancer patients were outside the normal range of the control group (0.306±0.33). Pancreatic cancer patients with ln pro-CPA values within the control range had low ln CPA, advanced stage and/or evidence of pancreatic insufficiency. While each of these individual values (ln pro-CPA or ln CPA) does not adequately separate all control from cancer patients, a bivariate classification rule is presented that uses both ln pro-CPA and ln CPA simultaneously to predict the presence of pancreatic cancer with a sensitivity of 91% and a specificity of 95%. Conclusions: The data presented suggest that abnormalities in serum pro-CPA and CPA levels are associated with the presence of pancreatic cancer.

Original languageEnglish (US)
Pages (from-to)451-457
Number of pages7
JournalHPB
Volume8
Issue number6
DOIs
StatePublished - Dec 2006
Externally publishedYes

Fingerprint

Carboxypeptidases A
Pancreas
Adenocarcinoma
Pancreatic Neoplasms
Reference Values
Serum
Exocrine Pancreatic Insufficiency
Control Groups
Normal Distribution
Routine Diagnostic Tests
Neoplasms

Keywords

  • Pancreatic cancer
  • Pro-carboxypeptidase A
  • Tumor marker

ASJC Scopus subject areas

  • Gastroenterology

Cite this

Evaluation of pro-carboxypeptidase A and carboxypeptidase A as serologic markers for adenocarcinoma of the pancreas. / Shamamian, Peter; Goldberg, Judith D.; Ye, Xiang Y.; Stewart, Jonathan D.; White, Peter J.; Gilvarg, Charles.

In: HPB, Vol. 8, No. 6, 12.2006, p. 451-457.

Research output: Contribution to journalArticle

Shamamian, Peter ; Goldberg, Judith D. ; Ye, Xiang Y. ; Stewart, Jonathan D. ; White, Peter J. ; Gilvarg, Charles. / Evaluation of pro-carboxypeptidase A and carboxypeptidase A as serologic markers for adenocarcinoma of the pancreas. In: HPB. 2006 ; Vol. 8, No. 6. pp. 451-457.
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abstract = "Background: A serological marker for pancreatic cancer may allow for early detection and potentially more effective treatments. Pro-carboxypeptidase A (pro-CPA) is produced exclusively in the pancreas and converted to its active form, CPA, in the intestinal lumen. We hypothesized that alterations in serum pro-CPA and/or CPA may be useful as a diagnostic test for pancreatic cancer. Patients and methods: Serum samples obtained from 34 patients with pancreatic adenocarcinoma prior to surgical intervention and 64 control patients were assayed for pro-CPA and CPA. A variety of statistical methods was used to evaluate the utility of these measurements individually and in combination to classify the samples with respect to the presence or absence of pancreatic adenocarcinoma. Results: Because of positive skewing of the data in some populations, transformation of the data to natural logarithmic scales was used and resulted in normal distributions. All pancreatic cancer patients had ln(CPA) levels within or below the normal range defined as two standard deviations from the control group mean (-2.714±0.413). Ln(pro-CPA) levels in 24 of 34 cancer patients were outside the normal range of the control group (0.306±0.33). Pancreatic cancer patients with ln pro-CPA values within the control range had low ln CPA, advanced stage and/or evidence of pancreatic insufficiency. While each of these individual values (ln pro-CPA or ln CPA) does not adequately separate all control from cancer patients, a bivariate classification rule is presented that uses both ln pro-CPA and ln CPA simultaneously to predict the presence of pancreatic cancer with a sensitivity of 91{\%} and a specificity of 95{\%}. Conclusions: The data presented suggest that abnormalities in serum pro-CPA and CPA levels are associated with the presence of pancreatic cancer.",
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AU - Stewart, Jonathan D.

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AU - Gilvarg, Charles

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N2 - Background: A serological marker for pancreatic cancer may allow for early detection and potentially more effective treatments. Pro-carboxypeptidase A (pro-CPA) is produced exclusively in the pancreas and converted to its active form, CPA, in the intestinal lumen. We hypothesized that alterations in serum pro-CPA and/or CPA may be useful as a diagnostic test for pancreatic cancer. Patients and methods: Serum samples obtained from 34 patients with pancreatic adenocarcinoma prior to surgical intervention and 64 control patients were assayed for pro-CPA and CPA. A variety of statistical methods was used to evaluate the utility of these measurements individually and in combination to classify the samples with respect to the presence or absence of pancreatic adenocarcinoma. Results: Because of positive skewing of the data in some populations, transformation of the data to natural logarithmic scales was used and resulted in normal distributions. All pancreatic cancer patients had ln(CPA) levels within or below the normal range defined as two standard deviations from the control group mean (-2.714±0.413). Ln(pro-CPA) levels in 24 of 34 cancer patients were outside the normal range of the control group (0.306±0.33). Pancreatic cancer patients with ln pro-CPA values within the control range had low ln CPA, advanced stage and/or evidence of pancreatic insufficiency. While each of these individual values (ln pro-CPA or ln CPA) does not adequately separate all control from cancer patients, a bivariate classification rule is presented that uses both ln pro-CPA and ln CPA simultaneously to predict the presence of pancreatic cancer with a sensitivity of 91% and a specificity of 95%. Conclusions: The data presented suggest that abnormalities in serum pro-CPA and CPA levels are associated with the presence of pancreatic cancer.

AB - Background: A serological marker for pancreatic cancer may allow for early detection and potentially more effective treatments. Pro-carboxypeptidase A (pro-CPA) is produced exclusively in the pancreas and converted to its active form, CPA, in the intestinal lumen. We hypothesized that alterations in serum pro-CPA and/or CPA may be useful as a diagnostic test for pancreatic cancer. Patients and methods: Serum samples obtained from 34 patients with pancreatic adenocarcinoma prior to surgical intervention and 64 control patients were assayed for pro-CPA and CPA. A variety of statistical methods was used to evaluate the utility of these measurements individually and in combination to classify the samples with respect to the presence or absence of pancreatic adenocarcinoma. Results: Because of positive skewing of the data in some populations, transformation of the data to natural logarithmic scales was used and resulted in normal distributions. All pancreatic cancer patients had ln(CPA) levels within or below the normal range defined as two standard deviations from the control group mean (-2.714±0.413). Ln(pro-CPA) levels in 24 of 34 cancer patients were outside the normal range of the control group (0.306±0.33). Pancreatic cancer patients with ln pro-CPA values within the control range had low ln CPA, advanced stage and/or evidence of pancreatic insufficiency. While each of these individual values (ln pro-CPA or ln CPA) does not adequately separate all control from cancer patients, a bivariate classification rule is presented that uses both ln pro-CPA and ln CPA simultaneously to predict the presence of pancreatic cancer with a sensitivity of 91% and a specificity of 95%. Conclusions: The data presented suggest that abnormalities in serum pro-CPA and CPA levels are associated with the presence of pancreatic cancer.

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