UPDATEs IN GASTROINTESTINAL PATHOLOGY

1. UPDATEs IN GASTROINTESTINAL PATHOLOGY CHRISTINE RONGEY, MD DANBURY HOSPITAL 4/11/2019

2. WHAT ARE WE GOING TO TALK ABOUT? • Colorectal Liver Metastases A Pathologist’s Guide to Creating an Informative Report and Improving Patient Care. • HER2 Heterogeneity in Gastroesophageal CancerDetected by Testing Biopsy and Resection Specimens. • Cost Effectiveness of Intraoperative Gross Examinationin Colorectal Resections A Retrospective Review of 200 Consecutive Cases.

3. Colorectal Liver MetastasesA Pathologist’s Guide to Creating an Informative Reportand Improving Patient CareMariana Moreno Prats, MD; Eizaburo Sasatomi, MD, PhD; Heather L. Stevenson, MD, PhD Arch Pathol Lab Med. 2019;143:251–257.

4. What to include in the report?

5. DOCUMENT NUMBER OF METS, SIZE AND MARGIN STATUS. • Previously, it was the standard of care to have a 1-cm free margin. • Recently proposed that a 1-mm margin should be considered the standard of care in liver resections and that tumor biology is a more important factor in disease-free survival than surgical margin clearance. • In larger resection specimens, such as from a segmentectomy or lobectomy, the margin status of large portal tracts and vessels is also important to assess.

6. TRG SCORE?

7. NON-NEOPLASTIC LIVER FINDINGS • Liver injury may occur with chemotherapy regimens such as irinotecan, which may cause steatohepatitis, and oxaliplatin, which may cause nodular regenerative hyperplasia. • If a patient has received FOLFOX and the background liver shows sinusoidal dilatation, congestion, nodular regenerative hyperplasia changes, and/or venous obstruction, a diagnosis of chemotherapy-induced sinusoidal injury and/or sinusoidal obstruction syndrome should be diagnosed.

8. HISTOPATHOLOGIC FEATURES OF SINUSOIDAL OBSTRUCTION SYNDROME (SOS)

9. TUMOR BIOLOGY AND MOLECULAR STUDIES • According to the National Comprehensive Cancer Network (NCCN) guidelines (version 2.2017), all patients with metastatic colorectal adenocarcinomas should be tested for RAS (KRAS and NRAS) and BRAF mutations at least once (ie, in the primary tumor or metastasis). • The NCCN also states that all patients with colorectal adenocarcinoma should be tested for MSI or mismatch repair genes, including MLH1, PMS2, MSH2, and MSH6.

10. EXAMPLE OF FINAL REPORT

11. HER2 Heterogeneity in Gastroesophageal CancerDetected by Testing Biopsy and Resection SpecimensLadan Fazlollahi, MD; Helen E. Remotti, MD; Alina Iuga, MD; Hui-Min Yang, MD; Stephen M. Lagana, MD;Antonia R. Sepulveda, MD, PhD. Arch Pathol Lab Med. 2018;142:516–522.

12. GUIDELINES FOR HER-2 TESTING IN ESOPHAGEAL CANCER • National Comprehensive Cancer Network guidelines recommend that assessment for HER2 status should be performed first using IHC following the modified scoring system used in the Trastuzumab for Gastric Cancer trial. • The guidelines recommend trastuzumab with chemotherapy only for patients with IHC 3+ or IHC 2+ with evidence of HER2 (ERBB2) amplification by ISH (HER2 [ERBB2] to CEP17 ratio 2).

13. HER-2 SCORING GUIDELINES

14. 27% OF PAIRED BIOPSY AND RESECTION SHOWED A DIFFERENT HER-2 SCORE

15. CONCLUSION • “A minimum of 5 biopsy fragments were shown to accurately predict HER2 status (sensitivity, 92%; specificity, 97%). • Our data suggest that HER2 testing should be performed on resection specimens when the initial biopsy has a negative HER2 IHC (scores 0, 1+) or equivocal 2+ and amplification-negative results if patients are being considered for anti-HER2 monoclonal antibody–targeted therapies. • Biopsy testing alone may miss potential cases with HER2 positivity because of tumor heterogeneity.”

16. Cost Effectiveness of Intraoperative Gross Examinationin Colorectal ResectionsA Retrospective Review of 200 Consecutive CasesArmen Khararjian, MD, MBA; Prakash Mathew, MD, MBA; Ajuni Choudhary, BS; Alexander Baras, MD, PhD Arch Pathol Lab Med. 2018;142:1403–1406.

17. METHODS • During a 15-month period (March 2014 to May 2015) we reviewed 270 colon resection cases. • In 200 of these (74.1%), an intraoperative gross examination was performed for a variety of 21 distinct diagnoses, with the 3 most-common diagnoses being adenocarcinoma, inflammatory bowel disease, and diverticular disease. • In addition, during the same period frozen section microscopic examination was performed on 26 colon resection cases of adenocarcinoma, with an additional 44 colon resection cases of adenocarcinoma for which no intraoperative examination was requested

18. RESULTS

19. RESULTS

20. RESULTS • Of the 200 cases reviewed with gross examination only, 34 (17%) had additional specimens that had the potential to be the result of the findings from the intraoperative gross examination. • After reviewing the operative notes for those 34 cases, none (0%) of the additional specimens were a result of the gross findings reported to the surgeons.

21. DISCUSSION • The most applicable use of intraoperative gross examinations for colorectal resections is margin status evaluation, and the most recent National Cancer Institute guidelines recommend 5 cm of clearance to minimize anastomotic recurrence. • For rectal tumors, some have deemed less than5 cm of clearance as acceptable. • In our study, extra margins were not received for the cases with less than 5 cm of margin clearance reported during intraoperative gross examination, signifying pathology consultation during surgery for margin status was not crucial for surgical decisions.

22. THANK YOU!