Routine elastin staining improves venous invasion detection in colorectal carcinoma

Area of Science:

• Pathology
• Oncology
• Surgical Pathology

Background:

• Colorectal carcinoma is a leading cause of cancer mortality in North America.
• Tumor cell invasion into blood and lymphatic vessels is critical for colorectal carcinoma metastasis.

Purpose of the Study:

• To evaluate the impact of routine elastin staining on venous invasion (VI) detection in colorectal carcinoma (CRC) resection specimens.
• To compare VI detection rates before and after implementing a standardized elastin staining protocol.

Main Methods:

• A before-and-after study design was employed, comparing CRC specimens from 2021 (pre-implementation, n=93) and 2022 (post-implementation, n=61).
• Routine elastin staining was implemented on all feasible tumor-containing blocks in the post-implementation cohort.
• Clinicopathological parameters were collected and analyzed for both cohorts.

Main Results:

• Venous invasion detection increased significantly from 18.6% in the pre-implementation cohort to 50.8% in the post-implementation cohort.
• Elastin staining implementation showed a significant association with increased VI detection (OR=4.5, p<0.001) on univariate analysis and remained independently significant (OR=2.6, p=0.034) on multivariate analysis.
• No significant differences were observed in other clinicopathological parameters between the cohorts.

Conclusions:

• Routine elastin staining on all tumor-containing blocks in colorectal carcinoma resection specimens confirms an increased rate of venous invasion detection.
• This enhanced detection method improves the identification of a key factor in colorectal cancer metastasis.