- Email: [email protected]
The use of helicobacter pylori immunohistochemistry
S138
PATHOLOGY 2017 ABSTRACT SUPPLEMENT
cohort, low methylation of the CpG island of PLK1 was detected in CRC tissues and normal mucosa tissues and it is independent of PLK1 expression. Conclusions: In conclusion, overexpression of PLK1 does not appear to be related to intrinsic factors such as mutation or methylation, and it may be the result of dysregulation of upstream proteins. 48. THE USE OF HELICOBACTER PYLORI IMMUNOHISTOCHEMISTRY D. A. Ryan, R. Lourie Mater Pathology Services, South Brisbane, Australia Background: Helicobacter pylori immunohistochemistry (IHC) is an extremely useful and relatively recently introduced adjunct to standard haematoxylin and eosin staining for identification of Helicobacter organisms in tissue sections. It has become the gold standard for H. pylori detection and shows near 100% sensitivity and specificity in some studies. Judicious use of immunohistochemistry is important for prompt reporting time, accuracy of diagnosis and appropriate use of lab resources. Since H. pylori IHC was introduced in our laboratory, we had not followed its use and examined how pathologists were using this test, and the appropriateness of its use. Objectives: We audited H. pylori IHC use in our tertiary hospital laboratory to determine the indications for which pathologists ordered H. pylori IHC, examined variation in ordering between pathologists, and assessed whether pathologists relied upon the positive or negative predictive value of this test in different settings. Methods: Over the course of 2015 all instances of H. pylori IHC were recorded. Each of these cases were reviewed and key information regarding the clinical scenario, histological findings, the result of the stain (positive or negative) and the identity of the reporting pathologist were recorded. Each of the reporting pathologists completed a questionnaire which examined how they thought they used H. pylori IHC in different clinical scenarios and histological settings. The results from the questionnaire were then compared with the extracted data in an attempt to relate pathologists’ attitudes to testing with actual test use. Findings: Distinct differences in the use of Helicobacter pylori immunohistochemistry are present within a group of pathologists reporting similar cases. Conclusions: Pathologist attitudes to, and use of, apparently straightforward diagnostic tests in similar cases vary markedly. This has implications for resource use and allocation and test use within pathology departments. 49. p21 AS A PREDICTOR AND PROGNOSTIC INDICATOR OF CLINICAL OUTCOME IN RECTAL CANCER PATIENTS L. C. Ooi, J. Z. Zhu, S. Lim, A. Sood, D. Lam, A. Hegde, L. P. Chung, A. Abubakar, J. S. Shin, C. S. Lee Discipline of Pathology, Western Sydney University, and Department of Anatomical Pathology, Liverpool Hospital, NSW, Australia
Pathology (2017), 49(S1)
Background: Autophagy and senescence play key complex roles in the development of human cancers. p21 is a potent cyclin-dependent kinase (CDK) inhibitor involved in the promotion of cell cycle arrest and regulation of cellular senescence. Altered p21 expression in rectal cancer cells may affect tumour cells’ resistance to neoadjuvant and adjuvant therapy. Aim: Our study aimed to ascertain the relationship between differential expressions of p21 in rectal cancer cells with survival outcomes. Methods: Using tissue microarrays (TMAs), 266 rectal cancer specimens were immunohistochemically stained for p21. Expression patterns were scored separately in cancer cells retrieved from the centre and the periphery of the tumour; compared with clinicohistopathological data, tumour regression score (TRS), disease-free and overall survival. Results: Negative p21 expression in cancer cells from tumour centre correlated with positive lymph node involvement (p = 0.046) and positive recurrence (p = 0.029). Conversely, negative p21 expression in tumour periphery cells was significantly associated with longer overall survival times (p = 0.001, HR = 1.946). Longer overall survival times also correlated with lower tumour grades (p = 0.011), negative vascular and perineural invasion (p = 0.001; p < 0.005); patients without tumour metastases (p < 0.005) and patients who received adjuvant treatment (p = 0.009). Conclusions: p21 is a predictive and prognostic biomarker for overall survival in rectal cancer patients. Negative p21 expression in tumour periphery cells demonstrated significant association with longer overall survival. Future larger, prospective studies are warranted to investigate the ability of p21 to identify rectal cancer patients who will benefit from neoadjuvant and adjuvant therapy. 50. DIFFERENTIAL EXPRESSION OF AUTOPHAGY MARKER p62 IN RECTAL CANCER J. Z. Zhu, L. C. Ooi, S. Lim, A. Sood, D. Lam, A. Hegde, L. P. Chung, A. Abubakar, J. S. Shin, C. S. Lee Discipline of Pathology, Western Sydney University, and Department of Anatomical Pathology, Liverpool Hospital, NSW, Australia Background: Autophagy plays a complex role in tumourigenesis where it can be involved in both tumour growth and suppression. p62 is an autophagy marker which increases when autophagy is inhibited. Previous studies examined p62 expression as a predictor of prognosis in many cancers but not in rectal cancer. Aims: This study aimed to examine p62 as a marker of prognosis and response to radiotherapy in rectal cancer. Methods: Tissue microarrays (TMAs) were constructed from rectal cancer samples of 271 patients. Paired samples of preneoadjuvant therapy biopsy samples and post-resection specimens were obtained. Samples were immunostained with p62 antigen and graded according to percentage and intensity of cytoplasmic and nuclear expression. Samples were taken from the periphery and centre of the tumour and p62 expression was graded separately to allow comparison. Results: p62 was primarily localised in the cytoplasm with cancerous tissues demonstrating stronger cytoplasmic p62 staining than normal tissue. While both tumour and normal tissue
PATHOLOGY 2017 ABSTRACT SUPPLEMENT
cohort, low methylation of the CpG island of PLK1 was detected in CRC tissues and normal mucosa tissues and it is independent of PLK1 expression. Conclusions: In conclusion, overexpression of PLK1 does not appear to be related to intrinsic factors such as mutation or methylation, and it may be the result of dysregulation of upstream proteins. 48. THE USE OF HELICOBACTER PYLORI IMMUNOHISTOCHEMISTRY D. A. Ryan, R. Lourie Mater Pathology Services, South Brisbane, Australia Background: Helicobacter pylori immunohistochemistry (IHC) is an extremely useful and relatively recently introduced adjunct to standard haematoxylin and eosin staining for identification of Helicobacter organisms in tissue sections. It has become the gold standard for H. pylori detection and shows near 100% sensitivity and specificity in some studies. Judicious use of immunohistochemistry is important for prompt reporting time, accuracy of diagnosis and appropriate use of lab resources. Since H. pylori IHC was introduced in our laboratory, we had not followed its use and examined how pathologists were using this test, and the appropriateness of its use. Objectives: We audited H. pylori IHC use in our tertiary hospital laboratory to determine the indications for which pathologists ordered H. pylori IHC, examined variation in ordering between pathologists, and assessed whether pathologists relied upon the positive or negative predictive value of this test in different settings. Methods: Over the course of 2015 all instances of H. pylori IHC were recorded. Each of these cases were reviewed and key information regarding the clinical scenario, histological findings, the result of the stain (positive or negative) and the identity of the reporting pathologist were recorded. Each of the reporting pathologists completed a questionnaire which examined how they thought they used H. pylori IHC in different clinical scenarios and histological settings. The results from the questionnaire were then compared with the extracted data in an attempt to relate pathologists’ attitudes to testing with actual test use. Findings: Distinct differences in the use of Helicobacter pylori immunohistochemistry are present within a group of pathologists reporting similar cases. Conclusions: Pathologist attitudes to, and use of, apparently straightforward diagnostic tests in similar cases vary markedly. This has implications for resource use and allocation and test use within pathology departments. 49. p21 AS A PREDICTOR AND PROGNOSTIC INDICATOR OF CLINICAL OUTCOME IN RECTAL CANCER PATIENTS L. C. Ooi, J. Z. Zhu, S. Lim, A. Sood, D. Lam, A. Hegde, L. P. Chung, A. Abubakar, J. S. Shin, C. S. Lee Discipline of Pathology, Western Sydney University, and Department of Anatomical Pathology, Liverpool Hospital, NSW, Australia
Pathology (2017), 49(S1)
Background: Autophagy and senescence play key complex roles in the development of human cancers. p21 is a potent cyclin-dependent kinase (CDK) inhibitor involved in the promotion of cell cycle arrest and regulation of cellular senescence. Altered p21 expression in rectal cancer cells may affect tumour cells’ resistance to neoadjuvant and adjuvant therapy. Aim: Our study aimed to ascertain the relationship between differential expressions of p21 in rectal cancer cells with survival outcomes. Methods: Using tissue microarrays (TMAs), 266 rectal cancer specimens were immunohistochemically stained for p21. Expression patterns were scored separately in cancer cells retrieved from the centre and the periphery of the tumour; compared with clinicohistopathological data, tumour regression score (TRS), disease-free and overall survival. Results: Negative p21 expression in cancer cells from tumour centre correlated with positive lymph node involvement (p = 0.046) and positive recurrence (p = 0.029). Conversely, negative p21 expression in tumour periphery cells was significantly associated with longer overall survival times (p = 0.001, HR = 1.946). Longer overall survival times also correlated with lower tumour grades (p = 0.011), negative vascular and perineural invasion (p = 0.001; p < 0.005); patients without tumour metastases (p < 0.005) and patients who received adjuvant treatment (p = 0.009). Conclusions: p21 is a predictive and prognostic biomarker for overall survival in rectal cancer patients. Negative p21 expression in tumour periphery cells demonstrated significant association with longer overall survival. Future larger, prospective studies are warranted to investigate the ability of p21 to identify rectal cancer patients who will benefit from neoadjuvant and adjuvant therapy. 50. DIFFERENTIAL EXPRESSION OF AUTOPHAGY MARKER p62 IN RECTAL CANCER J. Z. Zhu, L. C. Ooi, S. Lim, A. Sood, D. Lam, A. Hegde, L. P. Chung, A. Abubakar, J. S. Shin, C. S. Lee Discipline of Pathology, Western Sydney University, and Department of Anatomical Pathology, Liverpool Hospital, NSW, Australia Background: Autophagy plays a complex role in tumourigenesis where it can be involved in both tumour growth and suppression. p62 is an autophagy marker which increases when autophagy is inhibited. Previous studies examined p62 expression as a predictor of prognosis in many cancers but not in rectal cancer. Aims: This study aimed to examine p62 as a marker of prognosis and response to radiotherapy in rectal cancer. Methods: Tissue microarrays (TMAs) were constructed from rectal cancer samples of 271 patients. Paired samples of preneoadjuvant therapy biopsy samples and post-resection specimens were obtained. Samples were immunostained with p62 antigen and graded according to percentage and intensity of cytoplasmic and nuclear expression. Samples were taken from the periphery and centre of the tumour and p62 expression was graded separately to allow comparison. Results: p62 was primarily localised in the cytoplasm with cancerous tissues demonstrating stronger cytoplasmic p62 staining than normal tissue. While both tumour and normal tissue