Prognostic Value of Venous Invasion Detected by Elastin Stain May Surpass Lymph Node Status in Colon Cancer

Assessing venous invasion in stage II colon cancer: optimal elastin stains and survival analysis

AIMS

Venous invasion (VI) in colorectal carcinoma influences treatment strategies, especially in early stages. Despite elastin staining effectiveness in detecting VI, guidelines for its routine application, including the optimal number of slides for staining, are limited.

METHODS

Elastin staining was performed for VI assessment in patients with colorectal adenocarcinoma. Patients were categorised into two groups: single elastin stain group (SEG, n=248) and multiple elastin stain group (MEG, n=204).

RESULTS

The average number of elastin-stained blocks was 2±1.7, increasing to 3.3±1.9 in MEG. VI detection was significantly higher in patients in MEG (50.5%) compared with SEG (37.0%) (p=0.004). VI detection rate was higher in MEG (63.7%) than in SEG (46.0%) among patients with stage III-IV disease (p=0.011), but did not significantly differ among patients with stage I-II disease. Staining two blocks improved VI detection without additional gains from more stains. Compared with elastin performed on a single block, VI detected by elastin stain on two or more blocks did not significantly impact progression-free or disease-free survival with stage II patients.

CONCLUSIONS

Employing two elastin stains on separate blocks significantly enhances VI detection in colorectal carcinoma without additional benefits from more extensive staining. This study suggests that while increasing sensitivity for VI detection, staining beyond two blocks may not benefit prognostication and could be counterproductive, warranting further research. We emphasise the need for strategic use of the elastin stain and cautious interpretation of the increased detection sensitivity of multiple elastin stains.

Venous invasion detectable only by elastic stain shows weak prognostic value in colon cancer

AIMS

Large venous invasion (VI) is prognostically significant in colon cancer. The increased use of elastic stains by pathologists results in higher VI detection rates compared to routine stains alone. This study assesses the prognostic value of VI detected by elastic versus routine stains.

METHODS AND RESULTS

Colon cancers resected between 2014 and 2017 underwent pathology slide review for VI. Cases without VI on routine stain were stained by elastic trichrome and re-examined. Demographic, clinical, pathological and outcome data were gathered by retrospective review. Kaplan-Meier curves with log-rank tests were performed for survival categorised by VI status. Cox regression was performed for multivariate analysis. Of 277 cases, 97 (35%) showed VI by routine stain alone, with an additional 58 (21%) discovered by subsequent elastic stains. Thus, elastic trichrome increased VI detection by 60%. However, only VI detected by routine stain showed worse overall survival (P < 0.001). VI detected by elastic stain only was not prognostically different from cases without VI (P = 0.428). For stage 2 cancers, VI was not prognostically significant regardless of method of detection. For stage 3 cases, only VI detected by routine stain was prognostic for overall survival (P = 0.002) with a hazard ratio of 4.04 by multivariate regression (P = 0.028).

CONCLUSIONS

VI detectable only by elastic stains do not show prognostic significance for survival in colon cancer. For pathologists with high baseline VI detections rates on routine stain, reflexive use of elastic stain may be of limited value.

Impact of tissue sampling on detection of venous invasion in colorectal cancer: a prospective analysis

AIMS

Venous invasion (VI) is a powerful yet under-reported prognostic factor in colorectal cancer (CRC). Efforts to improve its detection have largely focused upon histological assessment, with less attention paid to tissue-sampling strategies. This study aimed to prospectively determine the number of tumour blocks required to optimise VI detection in CRC resections. In addition, the relationship between linear spiculation (LS) and extramural venous invasion (EMVI) was investigated.

METHODS AND RESULTS

A standardised tissue sampling protocol was developed and applied prospectively to 217 CRC resections [AJCC 8th edition, stage 1 (n = 32); stage 2 (n = 84); stage 3 (n = 87); stage 4 (n = 14); and post-neoadjuvant therapy (n = 46)]. Elastin stains were performed on all tumour blocks. VI was identified in 55% of cases (EMVI = 37%; IMVI alone = 18%). The sensitivity of VI detection increased with increasing numbers of tumour blocks submitted [one block (35%), three blocks (66%), five blocks (84%), six blocks (95%) and seven blocks (97%)]. Similar findings were observed for EMVI [one block (35%), three blocks (73%), five blocks (89%), six blocks (96%) and seven blocks (96%)]. LS was identified macroscopically in 22% of specimens. In cases where no neoadjuvant therapy had been given, EMVI was significantly associated with LS (71% in LS+ cases versus 29% in LS- cases; P < 0.001). In addition, tumour blocks targeting LS were associated with a fivefold higher rate of EMVI compared with blocks that did not (P < 0.001).

CONCLUSIONS

Our findings demonstrate the impact of tissue sampling and quality of gross examination on VI detection and may inform practices in future CRC protocols.

Routine elastin staining improves venous invasion detection in colorectal carcinoma

BACKGROUND

Colorectal carcinoma is the second most common cause of cancer-related deaths in North America. Invasion of tumor cells into lymphatic and blood vessels is an imperative step in the metastatic progression of colorectal carcinoma.

OBJECTIVES

This is a before-and-after study conducted by the Department of Pathology and Laboratory Medicine of Mount Sinai Medical Center of Florida to assess the impact on venous invasion (VI) detection by implementing routine elastin staining on all tumor-containing blocks per case, where feasible, in colorectal carcinoma (CRC) resection specimens.

METHODS

Clinicopathological parameters of CRC specimens were collected from January until December 2021 (n = 93) for the pre-implementation cohort and from January until December 2022 (n = 61) for the post-implementation cohort.

RESULTS

VI detection was significantly increased in the post-implementation cohort at a rate of 50.8 % compared to only 18.6 % in the pre-implementation cohort. The majority of VI identified in the pre-implementation cohort was extramural (61.5 %), whereas in the post-implementation cohort it was intramural (41.9 %). On univariate analysis, implementation of routine elastin stain was associated with strikingly increased VI detection rates (OR = 4.5, p-value < 0.001). On multivariate analysis, after adjusting for other clinicopathologic variables, elastin staining retained its independent statistically significant impact on VI detection (OR = 2.6, p-value = 0.034). Of note, there were no significant differences in the pre- and post-implementation cohorts in the frequency of nodal metastases, tumor extent, histologic grade, perineural invasion, T stage or M stage.

CONCLUSION

Based on our results and what has been published recently, we confirm an increase in the VI detection rate after implementing routine elastin staining on all tumor-containing blocks in CRC resection specimens.

Venous Invasion in Pancreatic Neuroendocrine Tumors Is Independently Associated With Disease-free Survival and Overall Survival

In this study, we evaluated venous invasion and its association with survival in patients with resected pancreatic neuroendocrine tumor (PanNET). Surgical Pathology Archives were searched for pancreatectomies performed for PanNET between October 1, 2005, and December 31, 2019. Hematoxylin and eosin (H&E)-stained slides were evaluated for venous invasion, and Movat's stain was performed in all cases with no venous invasion detected on H&E stains. Pathology reports and electronic medical records were also reviewed. Venous invasion was identified in 23 of 145 (15.9%) cases on H&E stains, and Movat's stain identified additional 34 cases with venous invasion (39.3% overall). Orphan arteries with adjacent well-defined tumor nodules or subtle hyalinizing nodules in hyalinizing tumors are highly specific for venous invasion. In stage I-III cases (n=122), venous invasion was associated with larger tumor size, higher World Health Organization (WHO) tumor grade, perineural invasion, extrapancreatic extension, lymph node metastasis, and liver metastasis ( P <0.05). In univariate analyses, tumor size, WHO grade, venous invasion, perineural invasion, T stage, and lymph node metastasis all correlated with disease-free survival; however, only venous invasion was associated with worse disease-free survival in multivariate analyses ( P <0.01). In all-stage cases, venous invasion was the only attributor associated with worse overall survival in multivariate analyses ( P =0.03). In summary, venous invasion in PanNET can be histologically subtle, and Movat's stain can greatly increase the detection rate. More importantly, enhanced venous invasion by Movat's stain correlates independently with disease-free survival in patients with stage I-III tumors and overall survival in all-stage patients.

Is the oncological impact of vascular invasion more important in right colon cancer?

Vascular invasion is an unfavorable prognostic factor for the recurrence and systemic metastasis of colon cancer. An interesting study in this issue evaluate the difference in the oncological impact of vascular invasion according to tumor side in colon cancer. The authors suggest that the oncological impact of vascular invasion could be worse in nonmetastatic right colon cancer than in nonmetastatic left colon cancer. Herein, hematoxylin-eosin staining was used to detect vascular invasion. In a recent study, elastin staining could detect more venous invasion. It is expected that the molecular pathologic characteristics of colon cancer can be identified precisely and the oncological outcomes of colon cancer can be improved in the future.

Impact of the viability assessment of lateral lymph node metastasis in rectal cancer after neoadjuvant chemoradiotherapy

PURPOSE

Preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) without lateral lymph node (LLN) dissection is widely performed for lower advanced rectal cancer. However, it is unclear whether residual cancer cells in the LLNs undergo apoptosis, disappear, or regrow if unresected.

METHODS

Overall, 293 consecutive patients with T3/4 rectal cancer who underwent CRT followed by radical surgery between September 2003 and December 2018 were retrospectively reviewed. We assessed apoptosis of the residual primary tumor, mesorectum lymph nodes (MLN), and LLN using M30 cytoDEATH immunostaining and evaluated the degree of apoptosis. The difference in the prognosis of the lateral lymph node metastasis positive (LLNM +) and lateral lymph node metastasis negative (LLNM-) groups was assessed.

RESULTS

There were 31 patients (10.6%) who were diagnosed with a complete response by hematoxylin and eosin (HE) staining. The residual cancer cells showed complete apoptosis in the primary lesion in 28 patients, in the metastatic MLN in only two patients, and in the metastatic LLN in one patient. The LLNM + group had a significantly poorer distant recurrence, recurrence-free survival, and overall survival than the LLNM- group.

CONCLUSION

The majority of the residual cancer tissue in LNs observed by HE staining was found to be non-apoptotic. If LLN metastasis is suspected on pretreatment imaging, performing LLN dissection together with TME should be considered.