Re: hemooccult testing in office

[Guest guest]

This is from the discussion about a year ago.. Re: Fecal Occult Blood Testing - which flavor of card? Friday, February 25, 2011 12:08 AM

, The USPSTF also has this:Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detection—colonoscopy, flexible sigmoidoscopy, and fecal tests—can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests ≤ Hemoccult SENSA ≈ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests ≈ Hemoccult II < flexible sigmoidoscopy = colonoscopyfrom: http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd

they only recommend "high sensitivity fecal occult blood tests" meaning

the FIT or the equivalent of the Hemocult II or SENSA.To: practiceimprovement1 < >; Practice Management Issues

; Clinical Procedures Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Recnetly, there was discussion on the list about fecal occult blood testing.

I think the issue crosses clinical list and practice mgt lists - see below.

Several issues were brought up.

1. Which is "best"? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

2. The issue of the cards outdating before being used up was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.Others mentioning getting free cards through Quest Labs, but then having to send them in through quest.

At first blush, it sounds like the Fecal immunochemical tests are becoming the standard, but there are several brands.

Is one cheaper than another?

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Here are the various testing techniques...

I know some aren't a fan of the wiki, but...

http://en.wikipedia.org/wiki/Fecal_occult_blood

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like

effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4]

There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal

clinical performance of the stool

guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin.

For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7]

high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9]

This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample

and of the sample

after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard;

the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14]

test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT)

sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two

teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts,

sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more

specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive

due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat

and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are

underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated

genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33]

and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because

CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree

of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on: Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a

FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

Reply to: Reply to Send To: practiceimprovement1 < > Sent: Monday, March 5, 2012 9:04 PM Subject: hemooccult testing in office

Any thoughts if the newer more sensitive and more expensive ones hemoccult are worth it and why? Should I just stick with the standard cheaper one. What others using in their offices?-- M.D.

www.elainemd.comOffice: Go in the directions of your dreams and live the life you've imagined.This email transmission may contain protected and privileged, highly confidential medical, Personal and Health Information (PHI) and/or legal information. The information is intended only for the use of the individual or entity named above.

If you are not the intended recipient of this material, you may not use, publish, discuss, disseminate or otherwise distribute it. If you are not the intended recipient, or if you have received this transmission in error, please notify the sender immediately and confidentially destroy the information that email in error.

[Guest guest]

Since I have switched to the iFOB, what I can tell you is I have a higher rate of success getting the test completed by the patient. It does not require any special diet before hand, and only 1 sample. With the traditional hemoccult, all I ever got was excuses. So it’s much easier for the patient. It also only detects lower GI blood or colonic blood. Kathy Saradarian, MDBranchville, NJwww.qualityfamilypractice.comSolo 4/03, Practicing since 9/90Practice Partner 5/03Low staffing From: [mailto: ] On Behalf Of Sent: Monday, March 05, 2012 11:05 PMTo: practiceimprovement1Subject: hemooccult testing in office Any thoughts if the newer more sensitive and more expensive ones hemoccult are worth it and why? Should I just stick with the standard cheaper one. What others using in their offices?-- M.D.www.elainemd.comOffice: Go in the directions of your dreams and live the life you've imagined.This email transmission may contain protected and privileged, highly confidential medical, Personal and Health Information (PHI) and/or legal information. The information is intended only for the use of the individual or entity named above. If you are not the intended recipient of this material, you may not use, publish, discuss, disseminate or otherwise distribute it. If you are not the intended recipient, or if you have received this transmission in error, please notify the sender immediately and confidentially destroy the information that email in error.

[Guest guest]

Thanks Carla for this. Since I need the cards in office just to detect blood, usually to r/o upper gi bleeding, not cancer, then I don't really need the expensive cards. The pt can pick those up at the lab

 

This is from the discussion about a year ago.. Re: Fecal Occult Blood Testing - which flavor of card?

Friday, February 25, 2011 12:08 AM

, The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detection—colonoscopy, flexible sigmoidoscopy, and fecal tests—can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests ≤ Hemoccult SENSA ≈ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests ≈ Hemoccult II < flexible sigmoidoscopy = colonoscopyfrom:  http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

And

they only recommend " high sensitivity fecal occult blood tests " meaning

the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues

; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

 

Recnetly, there was discussion on the list about fecal occult blood testing.

 

I think the issue crosses clinical list and practice mgt lists - see below.

 

Several issues were brought up.

 

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

 

2. The issue of the cards outdating before being used up  was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

 

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.Others mentioning getting free cards through Quest Labs, but then having to send them in through quest.

 

At first blush, it sounds like the Fecal immunochemical tests  are becoming the standard, but there are several brands.

Is one cheaper than another?

 

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

 

Here are the various testing techniques...

 

I know some aren't a fan of the wiki, but...

 

http://en.wikipedia.org/wiki/Fecal_occult_blood

 

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like

effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4]

There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal

clinical performance of the stool

guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin.

For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7]

high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9]

This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample

and of the sample

after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard;

the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14]

test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT)

sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two

teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts,

sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more

specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive

due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat

and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are

underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated

genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33]

and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because

CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree

of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on: Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a

FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

Reply to: Reply to Send

To: practiceimprovement1 < > Sent: Monday, March 5, 2012 9:04 PM

Subject: hemooccult testing in office

 

Any thoughts if the newer more sensitive and more expensive ones hemoccult are worth it and why? Should I just stick with the standard  cheaper one. What others using in their offices?--

M.D.

www.elainemd.comOffice: Go in the directions of your dreams and live the life you've imagined.

This email transmission may contain protected and privileged, highly confidential medical, Personal and Health Information (PHI) and/or legal information. The information is intended only for the use of the individual or entity named above.

 If you are not the intended recipient of this material, you may not use, publish, discuss, disseminate or otherwise distribute it. If you are not the intended recipient, or if you have received this transmission in error, please notify the sender immediately and confidentially destroy the information that email in error.

-- M.D.www.elainemd.comOffice: Go in the directions of your dreams and live the life you've imagined.

This email transmission may contain protected and privileged, highly confidential medical, Personal and Health Information (PHI) and/or legal information. The information is intended only for the use of the individual or entity named above.

 If you are not the intended recipient of this material, you may not use, publish, discuss, disseminate or otherwise distribute it. If you are not the intended recipient, or if you have received this transmission in error, please notify the sender immediately and confidentially destroy the information that email in error.