Pathologic assessment of response to chemotherapy in colorectal cancer liver metastases after hepatic resection: which method to use?

Tumoral and Parenchymal Morphological Assessment in Liver Metastases of Colorectal Carcinoma: Micrometastasis, Peritumoral Lymphocytes, Tumor Budding and Differentiation are Potential Prognostic Factors

Introduction: Various potential prognostic histopathologic factors for colorectal carcinoma liver metastasis have been proposed. However, there is still no consensus on pathological reporting of colorectal carcinoma liver metastasis resection materials. The aim of this study was to investigate the relation between selected tumoral and parenchymal histopathologic features and prognostic factors for better characterization and prognostic prediction of the patients with colorectal carcinoma liver metastasis. Methods: Hematoxylin-eosin stained slides from 100 patients who underwent hepatic resection were evaluated. Pathologic characteristics; including number of tumor nodules, largest tumor size, status of surgical margin, tumor distance to closest margin, tumor necrosis, the presence of tumor capsule, tumor differentiation, perineural and lymphovascular invasion, micrometastasis, tumor budding, peritumoral lymphocytic infiltrate and parenchymal features including steatosis, steatohepatitis, lobular inflammation, confluent necrosis, hepatocyte ballooning, portal inflammation were assessed. For 49 patients who were treated with preoperative chemotherapy, tumor regression grade and chemotherapy-related parenchymal changes such as sinusoidal damage, venous obstruction, nodular regenerative hyperplasia, steatosis and steatohepatitis were also evaluated. Results: The presence of lymphovascular invasion (p < 0.001), micrometastasis (p=0.004), absent or mild peritumoral lymphocytic infiltration (p =0.013), high tumor budding score (p=0.033) and moderate/poor differentiation (p=0.022) were significantly associated with shorter overall survival. Lymphovascular invasion (p < 0.001) was an independent predictor of mortality in multivariate analysis. Conclusions: We conclude that tumor differentiation, lymphovascular invasion, micrometastasis, peritumoral lymphocytic reaction and tumor budding score are potential prognostic histopathological features and candidates for inclusion in pathology reports of colorectal carcinoma liver metastasis resections.

Prognostic significance of pseudocapsule status in patients with metastatic renal cell carcinoma treated with tyrosine kinase inhibitors

Background

We sought to determine whether pseudocapsule (PS) features have prognostic implications in patients with metastatic renal cell carcinoma (mRCC).

Methods

We retrospectively reviewed 231 patients diagnosed with mRCC and treated with tyrosine kinase inhibitors; 188 patients with data available regarding the tumor-parenchyma interfacial PS of the primary tumor were enrolled for analysis. PS status was evaluated as intact (grade 0), merely involved (grade 1), penetrated (grade 2), and absent (grade 3). We applied the Kaplan-Meier method and Cox regression model to assess the survival impact.

Results

Of the 188 patients, 19 (10.1%), 61 (32.4%), 96 (51.1%) and 12 (6.4%) had grade 0, 1, 2 and 3 PS, respectively. PS status was significantly associated with histology (P=0.0206), venous tumor embolus (P=0.0511), microvascular invasion (P=0.0108) and microsatellite formation (P=0.0097). Patients without a PS had the worst overall survival (OS), with a 3-year OS rate of 12.7%, whereas the OS rates for grades 0, 1 and 2 were 78.8%, 50.8% and 43.6%, respectively. Adjusted by other variables, grade 3 and grade 2 PS gave rise to a much higher risk of death across the cohort [hazard ratio (HR) =5.217, P=0.0182; HR =3.765, P=0.0281, respectively]. Sarcomatoid change was also an independent factor for OS (HR =2.932, P=0.0075). In contrast, microsatellite formation was not associated with survival in the cohort.

Conclusions

PS status has prognostic implications for OS in metastatic renal cancer. The absence of the PS and sarcomatoid change are two pathological features related to an extremely poor prognosis.

Ratio of Pathological Response to Preoperative Chemotherapy in Patients Undergoing Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Metastatic Colorectal Cancer Correlates with Survival

BACKGROUND

Pathological response of colorectal peritoneal metastasis (CRPM) may affect prognosis. We investigated the relationship between oncological outcomes and pathological response to chemotherapy of CRPM following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

We conducted a retrospective analysis of a prospectively maintained Peritoneal Surface Malignancies database between 2015 and 2020. Analysis included patients with CRPM who underwent a CRS/HIPEC procedure (n = 178). The cohort was divided into three groups according to the response ratio (ratio of tumor-positive specimens to the total number of specimens resected): Group A, complete response; Group B, high response ratio, and Group C, low response ratio.

RESULTS

The group demographics were similar, but the overall complication rate was higher in Group C (65.2%) compared with Groups A (55%) and B (42.8%) [p = 0.03]. Survival correlated to response ratio; the estimated median disease-free survival of Group C was 9.1 months (5.97-12.23), 14.9 months (4.72-25.08) for Group B, and was not reached in Group A (p = 0.001). The estimated median overall survival in Group C was 35 months (26.69-43.31), and was not reached in Groups A and B (p = 0.001).

CONCLUSIONS

The pathological response ratio to systemic therapy correlates with survival in patients undergoing CRS/HIPEC. This study supports the utilization of preoperative therapy for better patient selection, with a potential impact on survival.

Detection of genes responsible for cetuximab sensitization in colorectal cancer cells using CRISPR-Cas9

Colorectal cancer (CRC) is a common malignant tumor in digestive tract with highly invasive and metastatic capacity. Drug sensitivity remains a significant obstacle to successful chemotherapy in CRC patients. The present study aimed to explore genes related to cetuximab (CTX) sensitivity in CRC by clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9. Celigo image cytometer was used to detect suitable cells and optimal dosage of CTX. Inhibition rate of CTX on Caco-2 cells was evaluated by cell counting kit-8 (CCK-8) method before and after transfection. 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) was performed to explore suitable concentration of puromycin and multiplicity of infection (MOI). CRISPR-Cas9, sequencing data quality analysis and cell viability test were used for the selection of genes related to CTX sensitivity in CRC cells. Finally, the selected genes associated with CTX sensitivity in CRC cells were further validated by colony formation and CCK-8 assays. In the present study, Caco-2 cells had a better prolificacy, and CTX 100 μg/ml exhibited a good inhibition trend on the 7th and 14th days of infection. MTT assay indicated that the minimum lethal concentration of puromycin was 2.5 μg/ml. Forty-six candidate genes were preliminarily screened via sequencing data quality analysis. Subsequently, we found that knockout of any of the four genes (MMP15, MRPL48, CALN1 and HADHB) could enhance CTX sensitivity in Caco-2 cells, which was further confirmed by colony formation assay. In summary, MMP15, MRPL48, CALN1 and HADHB genes are related to the mediation of CTX sensitivity in CRC.

Impact of preoperative chemotherapy on the histological response of patients with peritoneal metastases from colorectal cancer according to peritoneal regression grading score (PRGS) and TRG

BACKGROUND

This study evaluated the histologic response after preoperative systemic therapy (pST) using the Peritoneal Regression Grading Score (PRGS) and tumor regression grade (TRG) classifications for patients with peritoneal metastases (PM) from colorectal cancer (CRC).

METHODS

Twenty-three patients were selected from a prospective database of 196 patients who underwent CRS followed by HIPEC for synchronous PM from CRC. In all study patients, biopsies of the PM obtained before pST (during the first laparoscopy) and after pST (during cytoreductive surgery) were compared.

RESULTS

Complete (PRGS 1), Major (PRGS 2), Minor (PRGS 3) and no histological responses (PRGS 4) were obtained in 17,5%, 52% and 13% and 17,5% of patients, respectively. Major (TRG 1-2), partial (TRG3), and no (TRG4-5) histological tumor regression were observed in 61%, 9% and 30% of patients, respectively. Regardless of the classification applied, median OS was significantly higher in patients with a "complete or major" response than in those with a "minor/partial or no" response (54 vs. 26 months, p < 0.05).

CONCLUSIONS

The PRGS and TRG can be used in clinical practice to evaluate the histological response after pST. This study demonstrated that a complete histologic response of PM from CRC can be obtained after pST.

The impact of circumferential tumour location on the clinical outcome of rectal cancer patients managed with neoadjuvant chemoradiotherapy followed by total mesorectal excision

AIM

To investigate the impact of circumferential tumour location on neoadjuvant chemoradiotherapy (CRT) response and its prognostic value for locally advanced rectal cancer (LARC) patients after CRT and surgery.

METHODS

A retrospective study was performed on 486 patients with LARC who received neoadjuvant CRT and surgical treatment. The rate of pathological complete response (pCR) and survival among patients with anteriorly, laterally, and posteriorly located tumours were compared. Logistic regression was performed to identify pCR predictors.

RESULTS

The anterior tumours exhibited the highest pCR rate of 26.7%, which was slightly higher than the 20.0% and 12.3% for lateral and posterior tumours, respectively (P = 0.006). The 5-year Overall survival (OS) rates after CRT were similar among the anterior, lateral, and posterior groups (anterior vs lateral vs posterior: 81.1% vs 89.9% vs 84.1%, P = 0.6368). Multivariate analysis revealed that the circumferential tumour location, post-CRT serum CEA and post-CRT tumour thickness measured by MRI were independently correlated with achieving pCR.

CONCLUSION

This study is the first, to the best of our knowledge, to show that anterior LARC exhibited the highest pCR rate after neoadjuvant CRT. Patients with anterior rectal cancers do not have different prognoses from those with non-anterior cancers if they undergo neoadjuvant CRT.

Thymidylate synthase expression in primary colorectal cancer as a predictive marker for the response to 5-fluorouracil- and oxaliplatin-based preoperative chemotherapy for liver metastases

In patients with colorectal liver metastases (CRLM), predictive markers for response to preoperative chemotherapy are lacking. The aim of the present study was to evaluate the expression of thymidylate synthase (TS) and excision repair cross-complementation group 1 (ERCC1) as predictive markers in CRLM. A total of 24 patients with CRLM were included in this study. Tumor response was evaluated using the tumor regression grade (TRG) and Response Evaluation Criteria in Solid Tumors (RECIST) methods. TS and ERCC1 expression in paired CRLM and primary lesions were assessed by immunohistochemistry. We analyzed correlations between i) the response to preoperative chemotherapy evaluated by TRG and RECIST, ii) TS and ERCC1 expression and the response evaluated by TRG and RESICT, and iii) TS and ERCC1 expression in matched pairs of primary tumor and CRLM. The preoperative chemotherapy response evaluated by TRG and RECIST was significantly associated (P=0.0005). The response based on RECIST criteria and TRG was significantly associated with TS expression in the primary tumor (P=0.0272, and P=0.0137, respectively). No correlations were detected between marker expression in the primary tumor and in CRLM for either TS or ERCC1 (P=0.371 and P=1.00, respectively). Our data suggested that TS expression in the primary tumor is a predictive marker of preoperative chemotherapy response in CRLM based on both TRG and RECIST methods.

Assessment of pathological response to therapy using lipid mass spectrometry imaging

In many cancers, the establishment of a patient’s future treatment regime often relies on histopathological assessment of tumor tissue specimens in order to determine the extent of the ‘pathological response’ to a given therapy. However, histopathological assessment of pathological response remains subjective. Here we use MALDI mass spectrometry imaging to generate lipid signatures from colorectal cancer liver metastasis specimens resected from patients preoperatively treated with chemotherapy. Using these signatures we obtained a unique pathological response score that correlates with prognosis. In addition, we identify single lipid moieties that are overexpressed in different histopathological features of the tumor, which have potential as new biomarkers for assessing response to therapy. These data show that computational methods, focusing on the lipidome, can be used to determine prognostic markers for response to chemotherapy and may potentially improve risk assessment and patient care.

Study of the Kidney Tumor-Parenchymal Interface after Neoadjuvant Treatment with Axitinib for Locally Advanced Clear Cell Renal Cell Carcinoma: Matched Analysis from a Phase II Trial

PURPOSE

The aim of this study was to evaluate histological changes in the tumor-parenchymal interface in clear cell renal cell carcinoma after neoadjuvant axitinib treatment.

MATERIALS AND METHODS

We obtained clinical and pathology materials from 23 patients with clear cell renal cell carcinoma treated with neoadjuvant axitinib in a phase II clinical trial and from 23 matched patients with clear cell renal cell carcinoma who underwent upfront surgery. Histology of the tumor pseudocapsule and the peritumor kidney parenchymal change was evaluated and compared between the 2 cohorts.

RESULTS

A tumor pseudocapsule was noted in all 23 patients who received neoadjuvant axitinib and in all 23 control patients. Most pseudocapsules were noncontinuous and only partially covered the tumor, including in 17 of 23 axitinib cases (74%) and 19 of 23 controls (83%). In axitinib cases the median thickness of the intrarenal and extrarenal pseudocapsule was 1.4 and 2.4 mm, respectively, which was significantly thicker than in control cases (intrarenal p = 0.0008 and extrarenal p <0.0001). The thickness of the pseudocapsule in axitinib treated cases was more frequently irregular compared to that in controls (16 of 23 or 70% and 9 of 23 or 39%, respectively, p = 0.0746). Inflammation, nephrosclerosis, glomerulosclerosis and arteriosclerosis decreased with increasing distance from the tumor edge in the neoadjuvant axitinib and control groups.

CONCLUSIONS

The tumor pseudocapsule becomes irregularly thick after neoadjuvant axitinib therapy. Although axitinib likely evokes a strong fibrous reaction in the tumor-parenchymal interface, it does not affect the frequency of infiltrative tumor invasion to the outside of the pseudocapsule or the degree of atrophic/inflammatory change in tissue surrounding the tumor. These findings support the notion that partial nephrectomy could be safely done in well selected patients after neoadjuvant axitinib.

Neuron-glial antigen 2 overexpression in hepatocellular carcinoma predicts poor prognosis

AIM: To investigate whether neuron-glial antigen 2 (NG2) could be an effective prognostic marker in hepatocellular carcinoma (HCC).

METHODS: NG2 expression was semi-quantitatively scored from the immunohistochemistry (IHC) data based on the number of positive cells and the staining intensity. A total of 132 HCC specimens and 96 adjacent noncancerous tissue samples were analyzed by IHC for NG2 protein expression. To confirm the NG2 expression levels observed by IHC, we measured NG2 expression in 30 randomly selected tumor and adjacent noncancerous tissue samples by quantitative real-time polymerase chain reaction and Western blot. The correlations between NG2 protein expression and the clinicopathological features of HCC patients were analyzed using the χ² test. To assess the prognostic value of NG2 for HCC, the association between NG2 expression and survival was analyzed using the Kaplan-Meier method with the log-rank test. To further evaluate the prognostic value of NG2 expression, a Cox multivariate proportional hazards regression analysis was performed with all the variables to derive risk estimates related to disease-free and overall survival and to control for confounders.

RESULTS: High NG2 expression was observed in significantly more primary tumor samples (63.6%; 84/132) compared with the adjacent noncancerous tissue samples (28.1%; 27/96) (P < 0.0001). Moreover, high NG2 protein expression was closely associated with tumor differentiation (χ² = 9.436, P = 0.0089), recurrence (χ² = 5.769, P = 0.0163), tumor-node-metastasis (TNM) stage (χ² = 8.976, P = 0.0027), and invasion (χ² = 5.476, P = 0.0193). However, no significant relationship was observed between NG2 protein expression in HCC and other parameters, such as age, sex, tumor size, serum alpha fetoprotein (AFP), tumor number, or tumor capsule. The log-rank test indicated a significant difference in the overall survival of HCC patients with high NG2 expression compared with those with low NG2 expression (29.2% vs 9.5%, P < 0.001). Moreover, NG2 expression in HCC tissue significantly correlated with disease-free survival (15.2% vs 6.7%, P < 0.001). Multivariate analysis showed that NG2 expression (HR = 2.035, P = 0.002), serum AFP (HR = 1.903, P = 0.003), TNM stage (HR = 2.039, P = 0.001), and portal vein invasion (HR = 1.938, P = 0.002) were independent prognostic indicators for OS in HCC patients. Furthermore, NG2 expression (HR = 1.974, P = 0.003), serum AFP (HR = 1.767, P = 0.008), TNM stage (HR = 2.078, P = 0.001), tumor capsule (HR = 0.652, P = 0.045), and portal vein invasion (HR = 1.941, P = 0.002) were independent prognostic indicators for DFS in HCC patients.

CONCLUSION: The up-regulation of NG2 is associated with poor prognosis in HCC. Therefore, NG2 could be useful as an additional prognostic marker to increase the resolution of traditional approaches.

Bevacizumab-based neoadjuvant chemotherapy for colorectal cancer liver metastases: Pitfalls and helpful tricks in a review for clinicians

Bevacizumab added to chemotherapy has shown encouraging efficacy in the neoadjuvant therapy of colorectal cancer liver metastases. In absence of biological predictor factors of efficacy to bevacizumab-based treatment, the assessment of response may be a crucial point to select patients who may benefit the most from surgery. At the same time the pathological response after liver resection could represent a guide for the next therapeutic plan. In the pre-surgical phase, conventional computed tomography and response evaluation with RECIST criteria may underestimate the response to anti-angiogenic drugs. Modified computed tomography criteria of response, morphologic changes as well as novel imaging techniques and metabolic assessment by fluorodeoxyglucose positron emission tomography seem to be promising methods for the assessment of response and for leading the clinical choices. Pathological response at the time of surgery is an important prognostic factor and a surrogate of survival for resected patients. Different classification criteria to assess pathological response have been developed, residual viable tumor, tumor regression grade (TRG), modified TRG and tumor thickness at the tumor-normal interface, but to date a superiority of one approach over the others has not been clearly established. In this review, we evaluate the available data with the aim to help the clinicians in the pre- and post-surgical care of patient with colorectal cancer liver metastases treated with bevacizumab-based neoadjuvant strategy.