Aberrant Expression of Calretinin, D2-40 and Mesothelin in Mucinous and Non-Mucinous Colorectal Carcinomas and Relation to Clinicopathological Features and Prognosis

Prevalence of mesothelin expression in peritoneal disease from colorectal and appendiceal cancers

BACKGROUND

Mesothelin is a cell surface glycoprotein overexpressed in 28%-58% of colorectal cancer (CRC). We hypothesized that CRC mesothelin expression contributes to peritoneal spread and that it is selectively overexpressed in those with peritoneal metastasis versus distant metastasis.

METHODS

This case-controlled study involved mesothelin immunohistochemistry staining of tumor specimens from patients with metastatic CRC/appendiceal cancers between 2017 and 2019. Staining reactivity was graded from trace to 4+ (low ≤1+; high >1+). Staining patterns were characterized on global (focal/patchy/diffuse) and cellular (apical/cytoplasmic) levels. Immunostaining of normal mesothelial cells served as internal control.

RESULTS

Thirty-one patients were identified: 11 peritoneal (study) and 20 distant metastasis (control). The control group did not include appendiceal cancers. The study group had greater proportion of high staining reactivity (55% vs. 5%; odds ratio [OR] = 20.4, 95% confidence interval [CI] 1.96-211.8). The study group had more diffuse (36% vs. 0%; OR = 22.2, 95% CI 1.1-465.3) and cytoplasmic staining patterns (73% vs. 28%; OR = 6.9, 95% CI 1.3-37.2).

CONCLUSION

Mesothelin expression is higher in CRC/appendiceal cancers with peritoneal metastasis than those with distant metastasis. Immunohistochemistry staining patterns suggestive of propensity towards peritoneal metastasis include diffuse and cytoplasmic staining. Mesothelin may be a potential target for novel treatments of CRC/appendiceal carcinoma with peritoneal involvement.

Mesothelin Expression in Human Tumors: A Tissue Microarray Study on 12,679 Tumors

Mesothelin (MSLN) represents an attractive molecule for targeted cancer therapies. To identify tumors that might benefit from such therapies, tissue microarrays including 15,050 tumors from 122 different tumor types and 76 healthy organs were analyzed for MSLN expression by immunohistochemistry. Sixty-six (54%) tumor types showed at least occasional weak staining, including 50 (41%) tumor types with at least one strongly positive sample. Highest prevalence of MSLN positivity had ovarian carcinomas (serous 97%, clear cell 83%, endometrioid 77%, mucinous 71%, carcinosarcoma 65%), pancreatic adenocarcinoma (ductal 75%, ampullary 81%), endometrial carcinomas (clear cell 71%, serous 57%, carcinosarcoma 50%, endometrioid 45%), malignant mesothelioma (69%), and adenocarcinoma of the lung (55%). MSLN was rare in cancers of the breast (7% of 1138), kidney (7% of 807), thyroid gland (1% of 638), soft tissues (0.3% of 931), and prostate (0 of 481). High expression was linked to advanced pathological tumor (pT) stage (p < 0.0001) and metastasis (p < 0.0001) in 1619 colorectal adenocarcinomas, but unrelated to parameters of malignancy in 1072 breast-, 386 ovarian-, 174 lung-, 757 kidney-, 171 endometrial-, 373 gastric-, and 925 bladder carcinomas. In summary, numerous important cancer types with high-level MSLN expression might benefit from future anti-MSLN therapies, but MSLN’s prognostic relevance appears to be limited.

CD31 and D2-40 Contribute to Peritoneal Metastasis of Colorectal Cancer by Promoting Epithelial-Mesenchymal Transition

Background/Aims

Colorectal cancer (CRC) patients often exhibit peritoneal metastasis, which negatively impacts their prognosis. CD31 and D2-40 have recently been suggested to be predictors of breast cancer prognosis, but their role in colorectal peritoneal metastasis (CRPM) remains unknown.

Methods

The expression profiles of CD31 and D2-40 were analyzed in CRC patients with or without CRPM and in CRC cell lines with increasing metastatic potential. Overexpression and short hairpin RNA knockdown assays were performed in CRC cells, and the effects of these alterations on epithelial-mesenchymal transition (EMT) in vitro, growth of xenograft tumors in vivo, and peritoneal metastasis potential in a mouse model of CRPM were examined.

Results

The expressions of CD31 and D2-40 were upregulated in CRC tumor tissues and was elevated further in tumor tissues from patients with CRPM. CD31 and D2-40 expression levels exhibited increasing trends parallel to the EMT potential of CRC cells. CD31 and D2-40 are essential for CRC cell EMT in vitro as well as for xenograft tumor growth and peritoneal metastasis in vivo.

Conclusions

CD31 and D2-40 contribute to CRPM by promoting EMT and may serve as prognostic markers and therapeutic targets for CRC, particularly in patients with peritoneal metastasis.

Expression of Calretinin, Marker of Mesothelial Differentiation, in Pancreatic Ductal Adenocarcinoma: A Potential Diagnostic Pitfall

OBJECTIVE

Pancreatic ductal adenocarcinoma is one of the most common causes of "peritoneal carcinomatosis" and has an insidious growth pattern. Thus, it falls into the differential diagnosis of other peritoneal malignancies including malignant mesothelioma. Recently, we have encountered an undifferentiated pancreatic carcinoma presenting with peritoneal disease and exhibiting immunoreactivity to calretinin, mimicking mesothelioma. In this study, we explored the incidence of calretinin expression in pancreatic ductal adenocarcinoma.

MATERIALS AND METHODS

Calretinin immunohistochemical staining was performed on the tissue microarrays (TMAs), which were created using three 0.6 mm diameter punches per tumor (n=113). Distribution and intensity of expression were evaluated.

RESULTS

The TMAs contained 86 well/moderately differentiated and 27 poorly differentiated/undifferentiated carcinomas. Calretinin was positive in nine tumors (8%); six with diffuse and strong staining, three with focal and/or weak staining. The incidence of calretinin expression was 15% in poorly differentiated/undifferentiated carcinomas (vs. 6% in well/moderately differentiated carcinomas, p=0.03).

CONCLUSIONS

Pancreatic ductal adenocarcinomas, especially when poorly differentiated/undifferentiated, may be diffusely and strongly positive for calretinin creating a potential diagnostic challenge with malignant mesothelioma. Therefore, caution should be exercised when using this marker to explore a diagnosis of malignant mesothelioma. Tumors expressing calretinin without other mesothelial markers should prompt a careful evaluation of the morphologic and immunohistochemical features to exclude other malignancies. If the diagnosis of pancreatic ductal adenocarcinoma is considered, ductal differentiation can be demonstrated by using additional immunohistochemical markers such as mucin-related glycoproteins (MUC1, MUC5AC) and/or oncoproteins (CEA, B72.3, CA125).

Predictive Impact of Mucinous Tumors on the Clinical Outcome in Patients with Poorly Differentiated, Stage II Colon Cancer: A TOSCA Subgroup Analysis

BACKGROUND

Although American Society of Clinical Oncology and European Society for Medical Oncology guidelines have identified the negative prognostic factors that clinicians have to consider when treating their patients with stage II colon cancer (CC), the role of histological subtype is controversial.

SUBJECTS, MATERIALS, AND METHODS

The randomized, multicenter, phase III TOSCA trial compared 3 versus 6 months of fluoropyrimidine-oxaliplatin adjuvant chemotherapy in 3,759 patients with high-risk stage II or stage III CC. The objective of this substudy was to evaluate the influence of histological subtypes on the impact of the treatment duration of adjuvant chemotherapy in terms of relapse-free survival (RFS) and overall survival (OS) in 85 mucinous adenocarcinoma (MUC) and 389 nonmucinous adenocarcinoma (NMUC) patients with high-risk stage II, grade 3 CC.

RESULTS

A significant interaction between treatment duration and histology was observed in both RFS (p = .027) and OS (p = .017). In the subgroup of patients with MUC, worse RFS (adjusted hazard ratio [HR], 3.95; 95% confidence interval [CI], 1.03-15.17; p = .045) and OS (HR, 9.56; 95% CI, 1.14-79.98; p = .037) were detected for patients treated in the 3-month arm. No statistically significant differences were found in the subgroup of patients with NMUC.

CONCLUSION

Patients with MUC, grade 3, stage II CC require special attention and may need 6 months of oxaliplatin-based chemotherapy. Larger studies are required to assess the combined use of histology and other prognostic/predictive factors to define the administration of chemotherapy in patients with stage II CC and to improve their prognosis.

IMPLICATIONS FOR PRACTICE

Although ASCO and ESMO guidelines define the prognostic factors for patients with stage II colon cancer to establish the use of adjuvant chemotherapy, the influence of histological subtypes is controversial in this population. This study underscores that patients with grade 3 mucinous adenocarcinomas may need adjuvant chemotherapy with oxaliplatin and fluoropyrimidines for a duration of 6 months rather than 3 months.

Targeted multiplex proteomics for molecular prescreening and biomarker discovery in metastatic colorectal cancer

Protein biomarkers are widely used in cancer diagnosis, prognosis, and prediction of treatment response. Here we introduce the use of targeted multiplex proteomics (TMP) as a tool to simultaneously measure a panel of 54 proteins involved in oncogenic, tumour suppression, drug metabolism and resistance, in patients with metastatic colorectal cancer (mCRC). TMP provided valuable diagnostic information by unmasking an occult neuroendocrine differentiation and identifying a misclassified case based on abnormal proteins phenotype. No significant differences in protein levels between unpaired primary and metastatic samples were observed. Four proteins were found differentially expressed in KRAS-mutant as compared to wild-type tumours (overexpressed in mutant: KRAS, EGFR; overexpressed in wild-type: TOPO1, TOP2A). Survival analyses revealed the association between mesothelin expression and poor overall survival, whereas lack of PTEN protein expression associated with lower progression-free survival with anti-EGFR-based therapy in the first-line setting for patients with RAS wild-type tumour. Finally, outlier analysis identified putative targetable proteins in 65% of patients lacking a targetable genomic alteration. Our data show that TMP constitutes a promising, novel molecular prescreening tool in mCRC to identify protein expression alterations that may impact on patient outcomes and more precisely guide patient eligibility to clinical trials with novel targeted experimental therapies.

Clinical Signatures of Mucinous and Poorly Differentiated Subtypes of Colorectal Adenocarcinomas by a Propensity Score Analysis of an Independent Patient Database from Three Phase III Trials

BACKGROUND

Although colorectal cancer comprises several histological subtypes, the influences of histological subtypes on disease progression and treatment responses remain controversial.

OBJECTIVE

We sought to evaluate the prognostic relevance of mucinous and poorly differentiated histological subtypes of colorectal cancer by the propensity score weighting analysis of prospectively collected data from multi-institute phase III trials.

DESIGN

Independent patient data analysis of a pooled database from 3 phase III trials was performed.

SETTINGS

An integrated database of 3 multicenter prospective clinical trials (the Japanese Foundation for Multidisciplinary Treatment of Cancer 7, 15, and 33) was the source of study data.

INTERVENTIONS

Surgery alone or postoperative adjuvant chemotherapy was offered in patients with resectable colorectal cancer.

MAIN OUTCOME MEASURES

To balance essential variables more strictly for the comparison analyses, propensity score weighting was conducted with the use of a multinomial logistic regression model. We evaluated the clinical signatures of mucinous and poorly differentiated subtypes with regard to postoperative survival, recurrence, and chemosensitivity.

RESULTS

Of 5489 patients, 136 (2.5%) and 155 (2.8%) were pathologically diagnosed with poorly differentiated and mucinous subtypes. The poorly differentiated subtypes were associated with a poorer prognosis than the "others" group (HR, 1.69; 95% CI, 1.00-2.87; p = 0.051), particularly in the patient subgroup of adjuvant chemotherapy (HR, 2.16). Although the mucinous subtype had a marginal prognostic impact among patients with stage I to III colorectal cancer (HR, 1.33; 95% CI, 0.90-1.96), it was found to be an independent prognostic factor in the subpopulation of patients with stage II disease, being associated with a higher prevalence of peritoneal recurrence.

LIMITATIONS

The treatment regimens of postoperative chemotherapy are now somewhat outdated.

CONCLUSIONS

Both mucinous and poorly differentiated subtypes have distinct clinical characteristics. Patients with the mucinous subtype require special attention during follow-up, even for stage II disease, because of the risk of peritoneal or local recurrence. See Video Abstract at http://links.lww.com/DCR/A531.