Can pathological reports of rectal cancer provide national quality indicators?

A comparison of whole-mount and conventional sections for pathological mesorectal extension and circumferential resection margin assessment after total mesorectal excision

INTRODUCTION

The objective of the study is to compare 2 techniques for histological handling of rectal cancer specimens, namely whole-mount in a large block vs conventional sampling using small blocks, for mesorectal pathological assessment of circumferential resection margin status and depth of tumor invasion into the mesorectal fat.

METHODS

This is a prospective study including 27 total mesorectal excision specimens of rectal cancer from patients treated for primary rectal carcinoma between 2020 and 2022 in a specialized multidisciplinary Colorectal Unit. For each total mesorectal excision specimen, 2 contiguous representative tumoral slices were selected and comparatively analyzed with whole-mount and small blocks macroscopic dissection techniques, enabling comparison between them in the same surgical specimen. The agreement between the 2 techniques to assess the distance of the tumor from the circumferential resection margin as well as the depth of tumor invasion was evaluated with the Student's t-test for paired samples, Pearson's correlation coefficient, and the Bland-Altman method comparison analysis.

RESULTS

Complete mesorectal excision was observed in 8% of cases. Circumferential resection margin involvement was observed in only one case (4 %). The whole-mount and small block techniques obtained similar results when we assessed the distance to the circumferential resection margin (t-test P = 0.8, r = 0.92) and the depth of mesorectal infiltration (t-test P = 0.6, r = 0.95).

CONCLUSIONS

Both gross dissection techniques (whole-mount vs multiple small cassettes) are equivalent and reliable to assess the distance to circumferential resection margin and the depth of mesorectal infiltration in the mesorectal fat in rectal cancer staging.

Pathology reporting of pelvic exenteration specimens for locally recurrent rectal cancer

INTRODUCTION

Reporting of pelvic exenteration specimens for locally recurrent rectal cancer (LRRC) can be challenging for structured pathological analysis and currently, there is a lack of specific guidelines. The aim of this study was to assess the quality of pathology reporting in a cohort of patients who underwent pelvic exenteration for LRRC in a high-volume tertiary unit.

MATERIALS AND METHODS

In a retrospective analysis of histopathology reports of consecutive patients who underwent pelvic exenteration for LRRC from 1996 to 2018, the quality of pathology reporting was assessed using the Structure Reporting Protocol for Colorectal Cancer. The primary endpoint was the completeness of pathology reporting, secondary endpoints were the association between the reporting style (narrative versus synoptic), reporting period (the first half versus the second half), as well as the activity of the pathologists with the completeness of pathology reporting.

RESULTS

221 patients who underwent pelvic exenteration for LRRC were included into the study. There was a high variability in completeness of pathology reporting within the cohort, ranging from 9.5% to 100%. Notably, microscopic clearance was reported in only 92.4% of the reports. Overall, a significantly higher rate of completeness was observed in synoptic reports when compared to narrative reports and in more recent compared to earlier reports. There was no significant association between the activity of pathologists and the completeness of reporting.

CONCLUSIONS

This study shows a significant variability in the quality of reporting in pelvic exenteration for LRRC. The use of synoptic reporting clearly resulted in more complete reports.

Variability in Synoptic Reporting of Colorectal Cancer pT4a Category and Lymphovascular Invasion

CONTEXT.—

Serosal involvement (pT4a category) and lymphovascular invasion have prognostic significance in colorectal carcinoma, but are subject to interobserver variation in assessment.

OBJECTIVES.—

To provide the first large-scale assessment of interobserver variability in pT4a category and lymphovascular invasion reporting in real-world practice and to explore the impact of information from guidelines on variability in reporting these features.

DESIGN.—

Analysis of 1555 consecutive synoptic reports of colorectal carcinoma was performed using multivariate logistic regression. Interobserver variability before and after the presentation of guideline information was assessed using an image-based survey.

RESULTS.—

Significant differences in the odds of reporting pT4a versus pT3 category, detecting lymphovascular invasion of any type, and detecting large vessel invasion were identified among hospital sites and for individual pathologists compared with the median pathologist at the same site. Consistent with these results, interobserver agreement was only moderate in the image-based survey regarding T4a staging and lymphovascular invasion (all κ ≤ 0.57). The provision of information from guidelines did not tend to increase interobserver agreement in the survey, though responses in favor of using an elastic stain increased following recommendations for their use. However, when observers were provided with elastic-stained images, interobserver agreement remained only moderate (κ = 0.55).

CONCLUSIONS.—

Real-world reporting of pT4a category and lymphovascular invasion shows substantial variability at both local and regional levels. Our study underscores the need to address these features in quality initiatives, and provides a novel method through which existing synoptic data can be harnessed to monitor reporting patterns and provide individualized feedback.