Clinical Analysis of Primary Colorectal Signet-Ring Cell Carcinoma

The mutational spectrum of NRAS gene discovers a novel frameshift mutation (E49R) in Saudi colorectal cancer patients

Colorectal cancer (CRC) is a major health problem the world face currently and one of the leading causes of death worldwide. CRC is genetically heterogeneous and multiple genetic aberrations may appear on course of the disease throughout patient's lifetime. Genetic biomarkers such as BRAF, KRAS, and NRAS may provide early precision treatment options that are crucial for patient survival and well-being. The aim of this study was to identify pathogenic mutations in the NRAS gene causing colorectal cancer in the Saudi population. We enrolled 80 CRC tumor tissue samples and performed molecular analyses to establish the mutation spectrum status in the western region of Saudi Arabia. We identified 5 different mutations in 10 patients, 4 of whom were reported previously (G10R, E37K, Q61K, and Q61*) in the literature while we discovered one novel lethal insertion mutation (E49R). A novel identified insertion mutation was present in the third codon of the NRAS gene [c.145 insA (p.Glu49ArgTer85)], causing a frameshift in the amino acid sequence of the protein, and leading to an aberrant and truncated protein of 85 amino acids. Subsequent bioinformatics analysis showed that the mutation was highly deleterious and affected protein function to a greater extent. This identification may further improve the prognosis of CRC and benefit subsequent treatment choices.

Unraveling the complexities of colorectal cancer and its promising therapies - An updated review

Colorectal cancer (CRC) continues to be a global health concern, necessitating further research into its complex biology and innovative treatment approaches. The etiology, pathogenesis, diagnosis, and treatment of colorectal cancer are summarized in this thorough review along with recent developments. The multifactorial nature of colorectal cancer is examined, including genetic predispositions, environmental factors, and lifestyle decisions. The focus is on deciphering the complex interactions between signaling pathways such as Wnt/β-catenin, MAPK, TGF-β as well as PI3K/AKT that participate in the onset, growth, and metastasis of CRC. There is a discussion of various diagnostic modalities that span from traditional colonoscopy to sophisticated molecular techniques like liquid biopsy and radiomics, emphasizing their functions in early identification, prognostication, and treatment stratification. The potential of artificial intelligence as well as machine learning algorithms in improving accuracy as well as efficiency in colorectal cancer diagnosis and management is also explored. Regarding therapy, the review provides a thorough overview of well-known treatments like radiation, chemotherapy, and surgery as well as delves into the newly-emerging areas of targeted therapies as well as immunotherapies. Immune checkpoint inhibitors as well as other molecularly targeted treatments, such as anti-epidermal growth factor receptor (anti-EGFR) as well as anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies, show promise in improving the prognosis of colorectal cancer patients, in particular, those suffering from metastatic disease. This review focuses on giving readers a thorough understanding of colorectal cancer by considering its complexities, the present status of treatment, and potential future paths for therapeutic interventions. Through unraveling the intricate web of this disease, we can develop a more tailored and effective approach to treating CRC.

Incidence, Clinicopathological Features, and Outcomes of Signet Ring Colorectal Carcinoma: A Retrospective Study

Background Signet ring cell carcinoma (SRCC) is a rare subtype of colorectal cancer with significant variations in clinical characteristics and poor prognosis. However, there is limited data available in Pakistan. Therefore, we analyzed to examine the incidence, clinicopathological features, treatments, and outcomes of SRCC in colorectal cancer cases in Pakistan. Methods This study includes 214 primary signet ring cell carcinoma cases in the colon and rectum. All relevant clinical information extracts on demographic details, laboratory results, radiological findings, endoscopy, pathologic diagnoses, surgical interventions, neoadjuvant and adjuvant therapies, and their corresponding outcomes were undertaken from the same online database of hospital and analyzed using SPSS (SPSS Inc., Chicago, IL, USA), Chi-square test, and independent sample Kruskal-Wallis H test. Results The prevalence of SRCC was higher in younger patients (<50 years), 184 (86%). SRCC was more common in advanced stages T3 and T4, with 210 (98%) cases and 106 cases (49.5%) belonging to stage N2. In 27 cases (12.6%), there was already distant metastasis. The most common site of recurrent disease in SRCC patients was the peritoneum in about 50 (51.5%) patients, followed by multi-site metastases involving the lung, liver, bones, and lymph nodes. Conclusion Signet ring cell colorectal cancer (SRCC) manifests in Pakistan at a younger age and is diagnosed at a more advanced stage, often accompanied by peritoneal metastasis with elevated levels of recurrence due to relatively low rates of screening and the absence of national cancer data and guidelines. It is imperative that these issues should be addressed in order to alleviate the burden of this disease in our population.

Systematic review of risk factors, prognosis, and management of colorectal signet-ring cell carcinoma

BACKGROUND

Colorectal signet-ring cell carcinoma (CSRCC) is a rare clinical entity which accounts for approximately 1% of all colorectal cancers. Although multiple studies concerning this specific topic have been published in the past decades, the pathogenesis, associated risk factors, and potential implications on treatment are still poorly understood. Besides the low incidence, historically confusing histological criteria have resulted in confusing data. Nevertheless, the rising incidence of CSRCC along with relatively young age at presentation and associated dismal prognosis, highlight the actual interest to synthesize the known literature regarding CSRCC.

AIM

To provide an updated overview of risk factors, prognosis, and management of CSRCC.

METHODS

A literature search in the MEDLINE/PubMed database was conducted with the following search terms used: 'Signet ring cell carcinoma' and 'colorectal'. Studies in English language, published after January 1980, were included. Studies included in the qualitative synthesis were evaluated for content concerning epidemiology, risk factors, and clinical, diagnostic, histological, and molecular features, as well as metastatic pattern and therapeutic management. If possible, presented data was extracted in order to present a more detailed overview of the literature.

RESULTS

In total, 67 articles were included for qualitative analysis, of which 54 were eligible for detailed data extraction. CSRCC has a reported incidence between 0.1%-2.4% and frequently presents with advanced disease stage at the time of diagnosis. CSRCC is associated with an impaired overall survival (5-year OS: 0%-46%) and a worse stage-corrected outcome compared to mucinous and not otherwise specified adenocarcinoma. The systematic use of exploratory laparoscopy to determine the presence of peritoneal metastases has been advised. Surgery is the mainstay of treatment, although the rates of curative resection in CSRCC (21%-82%) are lower compared to those in other histological types. In case of peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy should only be proposed in selected patients.

CONCLUSION

CSRCC is a rare clinical entity most often characterized by young age and advanced disease at presentation. As such, diagnostic modalities and therapeutic approach should be tailored accordingly.

Prognostic and predictive value of tumor deposits in advanced signet ring cell colorectal cancer: SEER database analysis and multicenter validation

BACKGROUND

Colorectal signet-ring cell carcinoma (SRCC) is a rare cancer with a bleak prognosis. The relationship between its clinicopathological features and survival remains incompletely elucidated. Tumor deposits (TD) have been utilized to guide the N staging in the 8th edition of American Joint Committee on Cancer (AJCC) staging manual, but their prognostic significance remains to be established in colorectal SRCC.

PATIENTS AND METHODS

The subjects of this study were patients with stage III/IV colorectal SRCC who underwent surgical treatment. The research comprised two cohorts: a training cohort and a validation cohort. The training cohort consisted of 631 qualified patients from the SEER database, while the validation cohort included 135 eligible patients from four independent hospitals in China. The study assessed the impact of TD on Cancer-Specific Survival (CSS) and Overall Survival (OS) using Kaplan-Meier survival curves and Cox regression models. Additionally, a prognostic nomogram model was constructed for further evaluation.

RESULTS

In both cohorts, TD-positive patients were typically in the stage IV and exhibited the presence of perineural invasion (PNI) (P < 0.05). Compared to the TD-negative group, the TD-positive group showed significantly poorer CSS (the training cohort: HR, 1.87; 95% CI, 1.52-2.31; the validation cohort: HR, 2.43; 95% CI, 1.55-3.81; all P values < 0.001). This association was significant in stage III but not in stage IV. In the multivariate model, after adjusting for covariates, TD maintained an independent prognostic value (P < 0.05). A nomogram model including TD, N stage, T stage, TNM stage, CEA, and chemotherapy was constructed. Through internal and external validation, the model demonstrated good calibration and accuracy. Further survival curve analysis based on individual scores from the model showed good discrimination.

CONCLUSION

TD positivity is an independent factor of poor prognosis in colorectal SRCC patients, and it is more effective to predict the prognosis of colorectal SRCC by building a model with TD and other clinically related variables.

Signet-ring cell carcinoma of the caecum: A case report

Colorectal cancer (CRC) ranks as the third most prevalent cancer globally, with adenocarcinomas being the most frequent type. Signet ring cell carcinoma (SRCC) is a very rare subtype of adenocarcinoma, it commonly occurs in the stomach. However, other digestive localizations are possible including the colon, rectum, and gallbladder. Herein, we report a rare case of a metastatic caecal SRCC in a young male patient, presented to our department for abdominal diffuse pain and distention evolving for 3 months, associated with remarkable weight loss and asthenia. The clinical examination revealed abundant ascites and abdominal tenderness. Laboratory tests showed an elevated C-reactive protein at 35 mg/l (normal value: <6 mg/l), a microcytic hypochromic anemia at 11.2 g/dl (normal value for a man > 13 g/dl), increased carcinoembryonic antigen (CEA) levels, as well as CA 19-9 and CA-125.The abdominal scan showed irregular and asymmetrical thickening with peripheral speculation of the caecum measuring 2.1 cm *5.8 cm. Additionally, adjacent adenopathies, abundant ascites, and peritoneal carcinomatosis were observed to be associated with suspicious bilateral pulmonary nodules and micronodules. The colonoscopy identified a bulging ulcerative tumor of the ileocecal valve extended to the ileum. Further histologic examination confirmed the presence of signet-ring cell carcinoma. The patient was referred to the medical oncology department to initiate palliative chemotherapy following a multidisciplinary consultation meeting. We can underline that SRCC of the caecum is a rare entity with a bad prognosis. Usually, the diagnosis is made at late stages due to the lack of obvious symptoms earlier.

Comparison of survival outcomes and survival prediction in patients with primary colorectal MANEC and primary colorectal SRCC: a population-based propensity-score matching study

PURPOSE

Primary mixed adeno-neuroendocrine carcinoma (MANEC) and primary signet-ring cell cancer (SRCC) are two rare but highly malignant tumors in colorectal cancer. Therefore, we attempted to compare the tumors' survival outcomes, identify risk factors, and ultimately evaluate the prognosis by developing a nomogram.

METHODS

We identified 755 MANEC and 5836 SRCC patients of colorectal cancer. PSM was used to balance the influence of baseline clinical and pathological differences. Kaplan-Meier method was used to compare the prognosis of different pathological grades and AJCC stages. Cox proportional hazards model was used to identify potential prognostic factors for the two groups. Finally, we developed a nomogram and evaluated the feasibility of the model.

RESULTS

After PSM, the median OS and CSS of MANEC patients were significantly better than those of SRCC patients in stage III-IV (P < 0.001) but similar in stage I-II. The median OS and CSS of MANEC patients in each pathological grade were also greater than those of SRCC patients. Patients with MANEC and SRCC who underwent lymph node dissection in more than four areas had longer survival time. MANEC patients benefited from postoperative chemotherapy and radiotherapy; among SRCC patients, those who received preoperative and postoperative comprehensive chemotherapy and radiotherapy had benefits in OS and CSS.

CONCLUSION

Both MANEC and SRCC are often diagnosed in advanced stages, highlighting the importance of early screening. Despite the better prognosis of MANEC compared to SRCC, both types of patients require the formulation of personalized treatment strategies based on different risk factors combined with column charts.

Clinicopathologic and prognostic factors of patients with T3/T4 colorectal signet ring cell carcinoma: a population-based study

BACKGROUND

To evaluate cancer-specific survival (CSS) and construct a nomogram to predict the CSS of patients with colorectal signet ring cell carcinoma (SRCC).

METHODS

The data for patients with colorectal SRCC from 2000 to 2019 was identified from Surveillance, Epidemiology, and End Results (SEER) database. Propensity Score Matching (PSM) was used to minimize bias between SRCC and adenocarcinoma patients. Kaplan-Meier method and log-rank test were used to estimate the CSS. A nomogram was constructed based on the independent prognostic factors identified by univariate and multivariate Cox proportional hazards regression analyses. The model was evaluated by receiver operating characteristic (ROC) curves and calibration plots.

RESULTS

Poor CSS was more common in patients with colorectal SRCC, especially in patients with T4/N2 stage, tumor size > 80 mm, grade III-IV, and chemotherapy. Age, T/N stage, and tumor size > 80 mm were identified as independent prognostic indicators. And a prognostic nomogram was constructed and validated as an accurate model for the CSS of patients with colorectal SRCC by ROC curves and calibration plots.

CONCLUSION

Patients with colorectal SRCC have a poor prognosis. And the nomogram was expected to be effective in predicting the survival of patients with colorectal SRCC.

Unravelling the Complexity of Colorectal Cancer: Heterogeneity, Clonal Evolution, and Clinical Implications

Colorectal cancer (CRC) is a global health concern and a leading cause of death worldwide. The disease's course and response to treatment are significantly influenced by its heterogeneity, both within a single lesion and between primary and metastatic sites. Biomarkers, such as mutations in KRAS, NRAS, and BRAF, provide valuable guidance for treatment decisions in patients with metastatic CRC. While high concordance exists between mutational status in primary and metastatic lesions, some heterogeneity may be present. Circulating tumor DNA (ctDNA) analysis has proven invaluable in identifying genetic heterogeneity and predicting prognosis in RAS-mutated metastatic CRC patients. Tumor heterogeneity can arise from genetic and non-genetic factors, affecting tumor development and response to therapy. To comprehend and address clonal evolution and intratumoral heterogeneity, comprehensive genomic studies employing techniques such as next-generation sequencing and computational analysis are essential. Liquid biopsy, notably through analysis of ctDNA, enables real-time clonal evolution and treatment response monitoring. However, challenges remain in standardizing procedures and accurately characterizing tumor subpopulations. Various models elucidate the origin of CRC heterogeneity, highlighting the intricate molecular pathways involved. This review focuses on intrapatient cancer heterogeneity and genetic clonal evolution in metastatic CRC, with an emphasis on clinical applications.

Metastatic Breast Signet-Ring Cell Carcinoma from a Colonic Primary: Review of a Rare Case Report

Introduction: Colonic signet-ring cell carcinoma is a distinctive rare subtype of adenocarcinoma with a predilection for early metastasis. Among the rare extramammary metastatic adenocarcinomas to the breast, colonic signet-ring cell carcinomas constitute a small percentage. The distinction of a primary from a secondary breast signet ring cell carcinoma is indispensable since it may result in different therapeutic approaches. Here we presented a rare case of metastatic breast signet-ring cell carcinoma from a rectal origin and review its distinctive histopathologic features. Case Presentation: A 37-year-old woman presented with a breast mass 3 months after undergoing low anterior resection surgery to remove a rectal mass, diagnosed as signet ring cell carcinoma. Histopathologic examination of the core needle breast mass biopsy revealed tumor cells with signet-ring cell cytomorphology. The performed immunohistochemistry confirmed carcinoma of colonic origin. Conclusions: Colorectal signet-ring cell carcinoma is a rare and aggressive tumor. Its metastatic spread is most seen in the intra-abdominal area, with seldom reported cases of breast metastasis. Histologically, it can mimic a primary breast carcinoma, especially if no prior history of colonic origin exists. Accurate diagnosis is important since these 2 entities carry different therapeutic management. Proper immunophenotyping, obtaining a thorough clinical history and imaging studies facilitate a correct diagnosis.

MRI features of signet ring rectal cancer

PURPOSE

Signet Ring Rectal Cancer (SRRC) of rectum is rare high-grade subtype with poor prognosis and characteristic histopathology. We evaluated its imaging appearance and correlated its outcomes.

MATERIALS AND METHODS

We conducted a retrospective review of the rectal MRIs of 97 patients with rectal SRRC, evaluating tumor morphology, T2 signal, length, location, pattern of tumor growth, nodal status and location, EMVI (extramural vascular invasion), site of metastases, and response to chemotherapy. The tumor signal on T2W images was categorized into intermediate, T2 hyperintense, and fluid/mucin bright. Imaging findings were correlated with risk of metastatic/ recurrent disease, disease-free survival, and overall survival.

RESULTS

The median age of patients of SRRC in our study was 35 years and more frequently found in male patients. The common imaging features of SRRC were T2-hyperintense signal (63%), infiltrative growth pattern (76%), positive MR CRM (Circumferential Resection Margin on MRI) (84%), presence of EMVI (51%), and advanced T and N stage (97% and 84%, respectively). Peritoneum and nodes were the most common sites of metastases. Raised serum CEA (Carcino-embryonic Antigen) levels, positive MR CRM status, extramesorectal adenopathy, and advanced N stage had statistically significant predictive value for recurrence or metastases. Elevated serum CEA levels (p = 0.019) and intermediate T2 signal (p = 0.012) demonstrated significant independent association with poor overall survival, while advanced N stage (p = 0.033) demonstrated significant independent association with worse disease-free survival in multivariate analysis.

CONCLUSION

SRRC affected young patients and demonstrated T2-hyperintense signal and subepithelial spread in an infiltrative pattern. Elevated CEA levels and T2-intermediate signal intensity are independent predictors for worse overall survival and advanced nodal stage is independent prognostic factor of poor disease-free survival. MRI rectum can pinpoint the pathology given the distinct MRI morphology and age of presentation.

Clinicopathological and Molecular Characteristics of Colorectal Signet Ring Cell Carcinoma: A Review

Colorectal signet ring cell carcinoma (SRCC) is a rare subtype of colorectal cancer (CRC) with unique characteristics. Due to the limited researches on it, a comprehensive and in-depth understanding of this subtype is still lacking. In this article, we summarize the clinicopathological features and molecular characteristics of colorectal SRCC based on a literature review. Clinically, SRCC has been associated with young age, proximal site preference, advanced tumor stage, high histological grade, high rate of lymph node involvement, frequent peritoneal metastasis, and a significantly poor prognosis. Regarding molecular characteristics, in SRCC, the mutation burden of the classic signaling pathways that include WNT/β-catenin, RAS/RAF/MAPK, and PI3K/AKT/mTOR signaling pathways are generally reduced. In contrast, some genes related to the “epithelial-mesenchymal transition (EMT) process” and the “stem cell properties”, including RNF43, CDH1, and SMAD4, as well as the related TGF-β signaling pathway have been observed more frequently altered in SRCC than in conventional adenocarcinoma (AC). In many studies but not in others, SRCC showed a higher frequency of BRAF mutation, microsatellite instability-high (MSI-H) and CpG island methylator phenotype (CIMP) positive status compared to AC. It has been proposed that colorectal SRCC consists of two subtypes, in which the MSI⁺/CIMP⁺/BRAF⁺/CD3⁺/PD-L1⁺ hypermethylated genotype is more common in the proximal colon, and may represent the potential candidate for immunotherapy. Understanding the special molecular mechanisms related to the aggressive biology of SRCC is of great importance, which may provide a theoretical basis for the development of more targeted and effective treatments for this refractory disease.

Incidence of and Risk Factors for Gastroepiploic Lymph Node Involvement in Patients with Cancer of the Transverse Colon Including the Hepatic Flexure

BACKGROUND

To define the incidence of gastroepiploic lymph node (GLN) metastasis in patients with cancer of the transverse colon, including the hepatic flexure, and to identify the preoperative predictors of GLN involvement in a large-volume center in China.

METHODS

This retrospective monocentric cross-sectional study respected the STROBE statement. Of 3208 consecutive patients who underwent colon cancer resection, a total of 371 patients with cancer of the transverse colon including the hepatic flexure who underwent complete mesocolic excision and GLN resection in our center were retrospectively reviewed between November 2010 and November 2017. Logistic regression was performed to identify predictors of GLN metastasis. Endoscopic obstruction was defined as a luminal obstruction of the colon severe enough to prevent the colonoscope from passing beyond the tumor regardless of the presenting symptoms.

RESULTS

The GLN involvement rate was 4.0 (2.0-6.1)%. Patients who had GLN involvement had a significantly higher rate of endoscopic obstruction (P = 0.030), higher rate of signet ring adenocarcinoma or lymphovascular invasion (P < 0.05), higher preoperative CEA level (P = 0.037), more advanced pN stage (P < 0.001) and more advanced M stage (P = 0.003) than the patients without GLN involvement. ROC curve analyses showed that the cutoff value for CEA was 17.0 ng/ml (46.7% sensitivity, 84.3% specificity, P = 0.037) for the prediction of GLN metastasis. Multivariate analysis showed that endoscopic obstruction, signet ring adenocarcinoma, a CEA level ≥17 ng/ml and M1 stage were independently correlated with the GLN metastasis.

CONCLUSION

The incidence rate of GLN metastasis was low. To the best of our knowledge, the present study was the first to evaluate the preoperative predictors of GLN metastasis. Combinations of predictive factors may be useful for stratifying patients at high risk of GLN metastasis.

Clinical features, treatment, and prognosis of different histological types of primary small bowel adenocarcinoma: A propensity score matching analysis based on the SEER database

PURPOSE

This aim of this study was to provide a comprehensive understanding of the clinical characteristics, treatment, and prognosis of patients with small bowel adenocarcinoma (SBA), mucinous small bowel adenocarcinoma (MSBA), and signet ring cell carcinoma of the small bowel (SRCSB).

METHODS

Information on patients with SBA, MSBA, and SRCSB (2004-2015) was obtained from the Surveillance, Epidemiology and End Results (SEER) database. Cox proportional hazards models and Kaplan-Meier curves were used for the survival analyses. Propensity-score matching (PSM) was implemented to determine the differences among these tumors.

RESULTS

In all, 3697 patients with SBA (n = 3196), MSBA (n = 325) and SRCSB (n = 176) were ultimately eligible for this study. Poor differentiation, local invasion, and lymph node metastasis were more likely to be observed in SRCSB than in SBA and MSBA. Surgery was the most common treatment modality in all groups. The prognosis of SBA was similar to that of MSBA, but better than that of SRCSB in both unmatched and matched cohorts. M stage, surgery, and chemotherapy were identified as independent predictors of survival in all patients. Surgery and chemotherapy could significantly improve outcomes in all groups before and after PSM. Radiotherapy was associated with a survival benefit in patients with SBA, but this trend was not maintained after PSM. Survival advantages of SBA and MSBA were remarkable in the stratified analysis of surgery after PSM.

CONCLUSION

Patients with SRCSB had the worst prognosis among all histological types examined. However, surgery and chemotherapy could improve patients survival, regardless of histological type.

Signet ring cell carcinoma of rectum metastasizing to synchronous renal cell carcinoma: a case report

BACKGROUND

Rectal signet ring cell carcinoma is a rare type of colorectal adenocarcinoma characterized by an aggressive biological behavior and poor prognosis. The co-occurrence of colorectal carcinoma and renal cell carcinoma (RCC) has found in many hundreds of patients, many of whom also have additional malignancies. Cancer to cancer metastasis is rare and an uncommon phenomenon in malignancy, especially at the time of initial diagnosis, suggesting a genetic susceptibility.

CASE PRESENTATION

We present the case of a 66-year-old Macedonian man with synchronous rectal signet ring cell carcinoma and RCC with tumor to tumor metastasis feature. He underwent a left nephrectomy and anterior rectal resection after complaining of constipation for 3-4 months and the appearance of synchronous tumors on the imaging studies. Morphology and immunohistochemical analysis of specimens from the RCC revealed signet ring cells identical to the rectal signet ring cell carcinoma. The next-generation sequencing study revealed mutations in TP53 and ERBB2, and microsatellite stable signet ring cell carcinoma was determined by deoxyribonucleic acid (DNA) sequencing.

CONCLUSIONS

Cancer to cancer metastasis, although rare, needs to be considered in synchronous tumors. RCC, when diagnosed in multiple synchronous tumors, should be examined carefully. The paucity of reported cases indicates the need for advanced research in imaging methods for metastasis and new therapeutic approaches.

Investigation of clinicopathological characters and gene expression features in colorectal signet-ring cell carcinoma utilizing CMS classification

Signet ring cell carcinoma (SRCC) is a rare pathological type of colorectal cancer, of which the clinicopathological features and genetic background have not yet been fully investigated. Previous research has focused on the optimization of colorectal cancer treatment utilizing consensus molecular subtyping (CMS). However, it is not known what type of CMS would be designated to SRCC treatment. In the current study, of 1,350 patients diagnosed with colorectal cancer who underwent surgery, 14 were diagnosed with SRCC. The case-control cohort that fit the clinical background of the SRCC case was constructed. Statistical comparison between the SRCC group and the case-control cohort was performed among clinicopathological variables. SRCC and well to moderately adenocarcinoma case mRNA were submitted to microarray analysis and CMS analysis. Compared with the case-control cohort, the SRCC group was located more in the right-sided colon, the lymphatic invasion was more severe and the peritoneal dissemination was more frequent. The cancer-specific survival and the progression-free survival were significantly worse in the SRCC group compared with the case-control cohort. Microarray and CMS analysis identified that one SRCC case was significantly well assigned in the CMS 4 group and the other case was assigned in the CMS 1 group. Gene set analysis revealed the upregulation of EMT related genes and the downregulation of fatty acid, glycolysis, differentiation, MYC, HNF4A, DNA repair genes. In conclusion, the clinical characteristics of SRCC are severe but there is a possibility of the presence of different phenotypes according to CMS analysis.

Risk of Second Primary Malignancies Based on the Histological Subtypes of Colorectal Cancer

Background: Previous studies have revealed an increased risk of second primary malignancies (SPMs) after colorectal cancer (CRC); however, no previous investigation has quantified differences in the risk of SPMs based on the histological subtypes of first primary CRC.

Methods: Patients diagnosed with first primary CRC between 2000 and 2011 were identified from the Surveillance, Epidemiology, and End Results cancer registries. The patients were divided into three cohorts: classical adenocarcinoma (CA), mucinous adenocarcinoma (MA), and signet-ring cell carcinoma (SRCC). Standardized incidence ratios were calculated to assess the risk of SPMs among the patients.

Results: Overall risk of SPMs was significantly higher among patients with three histological subtypes of CRC than in the general population. The risk of esophagus cancer was significantly increased in SRCC. The risk of small intestine, colon and rectum, and corpus uteri cancers was high in three histological subtypes, with the highest risk observed in SRCC, followed by MA. Increased risks of second stomach, uterus, urinary bladder, kidney, and thyroid cancers were only observed in CA patients, while increased risk of second renal pelvis cancer was limited to MA patients. Furthermore, the high overall risk of SPMs in CA patients persisted regardless of clinicopathological factors. After surgery combined with chemotherapy treatment, CA patients were more prone to developing second small intestine, colon and rectum cancers than those treated with surgery only. A lower second prostate cancer risk was observed in rectal CA patients treated with surgery combined with radiotherapy than in patients treated with surgery only.

Conclusion: The present study revealed that the risk of developing SPMs after CRC varied based on the histological subtypes of the first primary CRC. Although the mechanisms underlying the observed patterns of SPM risk remain unknown, the study provided insights into future cancer surveillance based on the histological subtypes of CRC.

Primary signet ring cell carcinoma with tubular adenoma of the rectum: A case report and a review of the literature

RATIONALE

Among the various forms of colorectal carcinomas, primary signet ring cell carcinoma (SRCC) of rectum is infrequent. Primary SRCC with adenoma is even rarer. Due to its low morbidity and lack of obvious manifestations at early stages, it is difficult to make an early diagnosis and perform surgical intervention in time. Herein, we reported a case of primary SRCC with tubular adenoma of rectum and also performed a review of the literature of such cases, in hopes of expanding the general understanding regarding such cases.

PATIENT CONCERNS

A 61-year-old male patient presented with rectal bleeding for 1 week.

DIAGNOSES

A neoplasm could be palpated through a rectal examination, with a size of 4.0 cm by 3.0 cm, at a distance of 5 cm from the anal edge. Magnetic resonance imaging examination and colonoscopies were performed to confirm the finding, and 4 tissue specimens were obtained for histopathologic biopsy. The result of biopsy was high-grade intraepithelial neoplasia with an adenoma component.

INTERVENTIONS

Surgical resection was performed, and histopathologic and immunohistochemical staining examination of the resection confirmed the diagnosis of SRCC with tubular adenoma.

OUTCOMES

The patient was discharged from hospital 12 days postsurgery, without any complications. Further chemotherapy and supportive treatments were suggested to him and will be followed at a local hospital.

LESSONS

Primary rectal SRCC has a rather low morbidity. Furthermore, a rectal SRCC with adenoma which was presenting in this case is even more rare. Besides lack of clinical characters, delay of diagnosis and treatment frequently occur. So far, a surgical procedure has still been one of the most effective treatments. Considering of metastasis and the poor prognosis, early diagnosis, in-time radical resection, and a comprehensive followed treatment are recommended for a higher 5-year overall survival.

Does signet ring cell carcinoma component signify worse outcomes for patients with colorectal cancer?

AIM

The purpose of this study was to elucidate the differences in clinical pathology and prognosis between signet ring cell carcinoma component and adenocarcinoma in colorectal cancer.

MATERIALS AND METHODS

From April 2007 to December 2016, a total of 4348 patients with colorectal cancer underwent surgery, of which 3283 were included in the study. One patient was diagnosed with signet ring cell carcinoma (SRCC); 16 were diagnosed with signet ring cell carcinoma component (SRCCc); and 3266 patients were diagnosed with adenocarcinoma (ADC). We matched SRCCc and ADC with a propensity score of 1:3 and analyzed overall survival rates (OS) and cancer-specific survival rate (CSS) between the 2 groups before and after matching.

RESULTS

Before matching, patients in the SRCCc group had more advanced cancer (stage III-IV: 87.5% vs 45.6%; P < .001), more perineural invasion (75.0% vs 44.2%; P = .013), and higher lymphatic invasion (87.5% vs 42.4%; P < .001) than those in the ADC group. Consequently, the OS (P < .001) and CSS (P = .049) of the SRCCc group were worse than the ADC group. Peritoneal metastasis was found in 4 (57%) patients with stage IV disease. However, after tumor staging and all background factors were matched, there were no significant differences in prognosis for OS (P = .127) and CSS (P = .932) between the 2 groups.

CONCLUSION

SRCCc is more likely to be associated with lymphatic invasion and perineural infiltration than ADC, leading to significantly poorer survival outcomes. However, when all background factors are matched with ADC, the prognosis of SRCCc is not worse than ADC. Improving the treatment outcomes of peritoneal metastasis may be pivotal in the treatment of SRCCc.

CDH1 gene mutation in early-onset, colorectal signet-ring cell carcinoma

AIM

Colorectal signet-ring cell carcinomas (SRCC) are highly malignant tumours with poor prognosis that disproportionately affect younger patients. There is growing evidence of a unique set of molecular features that separate SRCC from conventional colorectal adenocarcinoma. Identification of these distinct features may have diagnostic and prognostic significance for patients and families. CDH1, which encodes E-cadherin, a cell adhesion protein, is commonly mutated in gastric SRCC and our study aimed to identify whether CDH1 mutation was also a common phenomenon in colorectal SRCC.

METHODS

DNA was extracted from formalin-fixed paraffin embedded tumour tissue, the CDH1 gene was analysed by next generation sequencing and the pathogenicity of mutations assessed in silico. Sections cut from the same blocks were immunostained to identify the presence of the E-cadherin protein.

RESULTS

We found 8 CDH1 mutations that meet our inclusion criteria in seven of 11 samples. Of these, five (from four patients), were likely to be germline mutations. E-cadherin staining was absent or markedly reduced in all of the seven samples with CDH1 mutation.

CONCLUSION

Our finding of CDH1 mutations in a proportion of signet-ring cell carcinomas and associated reduction in E-cadherin in these tumours supports previous findings of a role for mutation of this gene in the development of this disease. In addition, the finding of likely germline mutations suggests that a subset of these tumours may be familial. Loss of E-cadherin staining in the absence of CDH1 mutations however also suggests a role for environmental factors in a subset of these tumours.

Mucinous rectal cancer: concepts and imaging challenges

Rectal adenocarcinoma with mucinous components is an uncommon type of rectal cancer with two distinct histologic subtypes: mucinous adenocarcinoma and signet-ring cell carcinoma. Mucin can also be identified as pattern of response after neoadjuvant treatment. On imaging modalities, mucin typically demonstrates high signal intensity on T2-weighted images, low attenuation on computed tomography, and may be negative on 18-fluorodeoxyglucose positron emission tomography. After neoadjuvant CRT, cellular and acellular mucin share similar imaging features, and differentiating them is currently the main challenge faced by radiologists. Radiologists should be aware of pros, cons, and limitations of each imaging modality in the primary staging and restaging to avoid misinterpretation of the radiological findings.

Mucinous rectal cancer: concepts and imaging challenges

Rectal adenocarcinoma with mucinous components is an uncommon type of rectal cancer with two distinct histologic subtypes: mucinous adenocarcinoma and signet-ring cell carcinoma. Mucin can also be identified as pattern of response after neoadjuvant treatment. On imaging modalities, mucin typically demonstrates high signal intensity on T2-weighted images, low attenuation on computed tomography, and may be negative on 18-fluorodeoxyglucose positron emission tomography. After neoadjuvant CRT, cellular and acellular mucin share similar imaging features, and differentiating them is currently the main challenge faced by radiologists. Radiologists should be aware of pros, cons, and limitations of each imaging modality in the primary staging and restaging to avoid misinterpretation of the radiological findings.

Prognoses of different pathological subtypes of colorectal cancer at different stages: A population-based retrospective cohort study

Background

Whether the prognoses of different pathological subtypes of colorectal cancer (CRC) at different stages are distinct is unclear.

Methods

We extracted data on all cases of CRC from the Surveillance, Epidemiology, and End Results database between 2004 and 2015. The incidence of different pathological subtypes, clinical characteristics, and five-year overall survival (OS) and cause-specific survival (CSS) were analyzed.

Results

A total of 384,996 cases diagnosed as adenocarcinoma (AC), mucinous adenocarcinoma (MAC), and signet ring cell carcinoma (SRCC) were included in this analysis. Compared with AC, MAC and SRCC were more likely to reach T4, N2, M1, stages III and IV, and grades III and IV, and patients were generally of a younger age (P < 0.001). Compared with those with AC, patients with MAC and SRCC showed poorer OS (50.6 and 26.8% vs. 60.2%, P < .001), with corresponding HR values of 1.238 (95% CI, 1.213–1.263, P < .001) and 1.592 (95% CI, 1.558–1.627, P < .001), respectively. The MAC and SRCC groups also showed poorer overall CCS (60.9 and 32.5% vs. 67.8%, P < .001), with corresponding HR values of 1.271 (95% CI, 1.242–1.302, P < .001) and 1.724 (95% CI, 1.685–1.765, P < .001), respectively. Compared with patients with AC, those with MAC showed poor OS at every stage and poor CSS at every stage except stage II (P < .05), while patients with SRCC revealed poor OS and CSS at every stage except stage 0 (P < .05).

Conclusions

Patients of different pathological subtypes minimally differed at early stages. However, patients with AC have significantly better prognoses in advanced CRC (stages III and IV) than those with MAC or SRCC. Distinct treatment strategies should be applied depending on a particular histological subtype in advanced CRC.

Signet ring cell features with peritoneal carcinomatosis in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are associated with poor overall survival

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is effective in select patients with peritoneal carcinomatosis (PC). Signet ring cell (SRC) pathology is associated with poor prognosis. The role of CRS/HIPEC in this population is unclear.

METHODS

Patients diagnosed with PC due to appendiceal (AC), colorectal (CRC), and gastric cancer (GC) undergoing CRS/HIPEC 2007-2016 were included.

RESULTS

A total of 268 patients were referred for CRS/HIPEC. Of the 204 patients who underwent complete CRS/HIPEC, 101 (49.5%) had AC, 85 (41.7%) CRC, and 18 (8.8%) GC. Patients with GC had higher rates of SRC pathology than AC and CRC: 12 (66.7%) vs 16 (15.8%) and 10 (11.7%). The 3-year survival rate after CRS/HIPEC was 5.7% for the SRC group and 66.1% for the non-SRC group (P < 0.001). This was true for both AC and CRC subgroups (P < 0.001 for both). Overall, patients with SRC were more likely to have a peritoneal carcinomatosis index (PCI) score > 15 (P = 0.046). Upon multivariate analysis of the SRC population, PCI > 20 (P = 0.007) and GC (P = 0.008) were found to be independent predictors of poor overall survival.

CONCLUSIONS

Performing CRS/HIPEC for PC from gastrointestinal malignancies presenting SRC features is recommended on patients with select diseases of appendiceal and colorectal origins.

The Amount of Bifidobacterium Genus in Colorectal Carcinoma Tissue in Relation to Tumor Characteristics and Clinical Outcome

Evidence indicates a complex link between microbiota, tumor characteristics, and host immunity in the tumor microenvironment. In experimental studies, bifidobacteria appear to modulate intestinal epithelial cell differentiation. Accumulating evidence suggests that bifidobacteria may enhance the antitumor immunity and efficacy of immunotherapy. We hypothesized that the amount of bifidobacteria in colorectal carcinoma tissue might be associated with tumor differentiation and higher immune response to colorectal cancer. Using a molecular pathologic epidemiology database of 1313 rectal and colon cancers, we measured the amount of Bifidobacterium DNA in carcinoma tissue by a quantitative PCR assay. The multivariable regression model was used to adjust for potential confounders, including microsatellite instability status, CpG island methylator phenotype, long-interspersed nucleotide element-1 methylation, and KRAS, BRAF, and PIK3CA mutations. Intratumor bifidobacteria were detected in 393 cases (30%). The amount of bifidobacteria was associated with the extent of signet ring cells (P = 0.002). Compared with Bifidobacterium-negative cases, multivariable odd ratios for the extent of signet ring cells were 1.29 (95% CI, 0.74-2.24) for Bifidobacterium-low cases and 1.87 (95% CI, 1.16-3.02) for Bifidobacterium-high cases (Ptrend = 0.01). The association between intratumor bifidobacteria and signet ring cells suggests a possible role of bifidobacteria in determining distinct tumor characteristics or as an indicator of dysfunctional mucosal barrier in colorectal cancer.