Clinicopathological features and survival outcomes of primary signet ring cell and mucinous adenocarcinoma of colon: retrospective analysis of VACCR database

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.

Histological transformation to signet-ring cell carcinoma in a patient with clinically aggressive poorly differentiated adenocarcinoma of the ascending colon after response to chemotherapy plus cetuximab: a case report

BACKGROUND

Alteration of chemosensitivity or tumor aggressiveness in response to chemotherapy has been reported, and liquid biopsy assessment during chemotherapy for colorectal cancers has confirmed the acquisition of mutations in various oncogenes. However, the occurrence of histological transformation seems to be extremely rare in colorectal cancers, and the few existing case reports of this transformation are from lung cancer and breast cancer. In this report, we describe the histological transformation of clinically aggressive scirrhous-type poorly differentiated adenocarcinoma of the ascending colon to signet-ring cell carcinoma in almost all recurrent tumors that were confirmed by autopsy after response to chemotherapy plus cetuximab.

CASE PRESENTATION

A 59-year-old woman visited our hospital with whole abdominal pain and body weight loss and was diagnosed with scirrhous-type poorly differentiated adenocarcinoma of the ascending colon with aggressive lymph node metastases. The intrinsic chemosensitivity of the tumors was evident upon initiation of mFOLFOX6 plus cetuximab therapy, and right hemicolectomy was performed, and the tumor obviously remained in the peripancreatic area, paraaortic region, or other retroperitoneal areas. The ascending colon tumors mainly consisted of poorly differentiated adenocarcinoma and were not associated with signet-ring cell components except for minute clusters in a few lymphatic emboli in the main tumor. Chemotherapy was continued, and metastases were eliminated at 8 months after the operation; this response was maintained for an additional 4 months. Discontinuation of chemotherapy plus cetuximab resulted in immediate tumor recurrence and rapid expansion, and the patient died of the recurrent tumor 1 year and 2 months after the operation. Autopsy specimens revealed that almost all of the recurrent tumors exhibited transformation and consisted of signet-ring cell histology.

CONCLUSION

This case might suggest that various oncogene mutations or epigenetic changes resulting from chemotherapy, especially regimens that include cetuximab, contribute to the transformation of non-signet-ring cell colorectal carcinoma to signet-ring cell carcinoma histology and can promote the aggressive clinical progression characteristic of signet-ring cell carcinoma.

A Retrospective Study of the Prognostic Patterns in Colorectal Cancer Patients

Introduction  Colorectal cancer (CRC) management has advanced globally, leading to a steady decline in mortality rates. However, recent studies have shown that the prognosis of CRC varies based on the anatomical site of the primary tumor, histopathological grading, and type of mutation. With an increase in the incidence of CRC globally and in Bahrain, there is a need for a recent descriptive study to improve overall management. This study aims to investigate the anatomical, histopathological, and molecular prognostic factors in CRC patients presenting to the Salmaniya Medical Complex (SMC). Methods  The study was conducted retrospectively using ISEHA electronic database over two years (January 2019 to December 2020). A total of 101 patients with primary CRC registered in the General Surgery Department were included in this study. The sample size was further stratified and analyzed using descriptive statistics based on the available data of measured outcomes. Results  Anatomical data showed that 65% of CRC patients had a tumor on the left side of the colon, 27.7% on the right side, and 7% in the transverse colon. Overall, 16.8% of all patients had rectal involvement. Histopathological data showed that 86% of the patients had a low-grade CRC adenocarcinoma. The most diagnosed tumor stage was pT3N0M0 (22.8%). In addition, there were ten metastatic cases (10 to the liver, of which three had concomitant lung involvement and two had concurrent brain metastases). The average tumor diameter was 46.2 mm, where 63% ranged between 30 mm to 69 mm. Most mutations involved the TP53 (27.7%) and the KRAS (29%) genes.  Conclusion  The study found that majority of CRC patients at SMC in Bahrain had relatively good overall anatomical, tumor staging and grading prognostic factors but somewhat poorer molecular prognostics.

Characteristics of primary signet ring cell carcinoma of colon and rectum: a case control study

Background

Primary signet ring cell carcinoma of the colon and rectum (PSRCCR) is rare, usually diagnosed at advanced stage with poor outcomes. We aimed to find possible diagnostic clues in order to help diagnosis.

Methods

A retrospective study of PSRCCR patients from 1993 to 2018 was reviewed at a single tertiary center. Colorectal adenocarcinoma patients as control group with 1:4 ratio was also enrolled.

Results

18 patients with PSRCCR were identified. The prevalence rate was 0.16% (18 of 11,515). The mean age was 50.2 years-old in PSRCCR group and 63 years-old in non-SRCC colorectal cancer patients (p < 0.001). Diagnosis tool depends on colonoscopy were much less in PSRCCR group than control group (44.4% vs 93%, p < 0.001). SRCC patients had higher level of CEA (68.3 vs 17.7 ng/mL, p = 0.004) and lower level of Albumin (3.4 vs 4.3 g/dL, p < 0.001). The majority of PSRCCR tumor configuration was ulcerative and infiltrative. More PSRCCR pathology presented as high-grade carcinoma (66.7 vs 1.4%, p < 0.001) and lymphovascular invasion (77.8 vs 44.4%, p = 0.011) than control group. More PSRCCR patients were diagnosed at advanced stage (88.8 vs 40.3%, p = 0.001). Higher mortality was also noticed in PSRCCR group than control group (72.2 vs 20.8%, p < 0.001).

Conclusion

For young patients with long segment colonic stenosis and ulcerative/ infiltrative mucosa but endoscopic biopsy failed to identify malignant cells, earlier operation or non-colon site biopsy is suggested for diagnosing the PSRCCR.

Clinical significance of mucinous component in colorectal adenocarcinoma: a propensity score-matched study

Background

This study aims to investigate the clinical significance and prognostic value of mucinous component (MC) in colorectal adenocarcinoma (AC).

Methods

Patients with colorectal AC and AC with MC (ACMC) (1–100%) underwent surgical resection between January 2007 and February 2018 were retrospectively reviewed. Propensity score matching (PSM) was performed according to a 1:1 ratio. Receiver-operating characteristic (ROC) curve was used to identify the optimal cut-off value of MC ratio for prognostic prediction. The clinicopathological features and 3-year overall survival (OS) of AC patients, mucinous adenocarcinoma (MAC) (MC > 50%) patients, and ACMC (1–50%) patients were compared before and after matching. Multivariable analysis was used for analyzing independent risk factors related to prognosis.

Results

A total of 532 patients were enrolled in this study. Patients with AC, MAC, and ACMC (1–50%) exhibited different clinicopathological features. However, their 3-year OS rates were similar (82.00% vs. 74.11% vs. 81.48%, P = 0.38). After matching, ROC curve determined 70% as the optimal cut-off value. And patients with ACMC > 70% had a much poorer 3-year OS compared with ACMC (1–70%) patients and AC patients (47.37% vs. 86.15% vs. 79.76%, P < 0.001). In addition, ACMC > 70% was revealed as a risk factor for poor survival in univariate analysis (HR = 1.643, 95%CI = 1.025–2.635, P = 0.039), though not an independent risk factor in multivariable analysis (HR = 1.550, 95%CI = 0.958–2.507, P = 0.074).

Conclusions

MAC is usually diagnosed at an advanced stage. MAC has a similar survival with AC and ACMC (1–50%) patients before and after matching. Patients with ACMC > 70% exhibited a much poorer OS, and should be given more clinical attention.

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.

Trends in the Incidence and Survival Rates of Colorectal Signet-Ring Cell Carcinoma in the South Korean Population: Analysis of the Korea Central Cancer Registry Database

Objective: Signet-ring cell carcinoma (SRCC) is a rare histopathological subtype of colorectal cancer (CRC) constituting approximately 1% of CRC cases. This study analyzed the incidence and survival rates of colorectal SRCC. Methods: We analyzed the incidence and survival rates of colorectal SRCCs based on patients’ data of the Korea Central Cancer Registry. Results: The age-standardized incidence rates of colon and rectum SRCC in 2017 were 0.17 and 0.07 individuals per 100,000, respectively. Between 1993 and 2017, the 1-, 2-, 3-, 4-, and 5-year relative survival rates of patients with colon SRCC were 65.6%, 49.0%, 38.9%, 34.9%, and 33.0%, respectively, while those of patients with rectum SRCC were 69.6%, 47.8%, 38.5%, 32.8%, and 29.4%, respectively. According to the Surveillance, Epidemiology, and End Results summary stages, the 5-year relative survival rates of colon SRCC between 1993 and 2017 were 70.4% for the localized stage, 41.0% for the regional stage, and 7.0% for the distant stage, while those for rectum SRCC were 60.7%, 34.4, and 3.3%, respectively. Conclusions: Although the incidence of colorectal SRCC is extremely low in South Korea, it has been increasing in recent decades. As the prognosis of colorectal SRCC is extremely poor; clinicians should be aware of the differential diagnosis of SRCC in colorectal cancer cases.

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.

Clinicopathological Features and Survival of Signet-Ring Cell Carcinoma and Mucinous Adenocarcinoma of Right Colon, Left Colon, and Rectum

Histological subtype plays an important role in the different clinical characteristics and survival outcomes of patients with colorectal carcinoma (CRC). However, in previous studies, the influences of tumor locations and tumor stages have not been strictly controlled. This study focused on the assessment of the prognostic value of each histological subtype in different tumor locations and tumor stages of CRC. We used the Surveillance, Epidemiology, and End Results (SEER) database (1973-2011) to analyze 818,229 CRC patients with different clinical and pathological features, and analyzed the prognostic value of each histological subtype. Under the condition of stratification by tumor stage, signet-ring cell carcinoma (SRCC) presented the worst survival in each stage of right colon cancer (stage I, log-rank, p = 0.002, stages II, III, and IV, log-rank, p < 0.001), rectal cancer (RC) (log-rank, p < 0.001), and in stages II, III, and IV of left colon cancer (log-rank, p < 0.001). Multivariate survival analysis suggested SRCC subtype, male gender, age ≥ 70 years, tumor size ≥ 5 cm, stage progression, and poor differentiation were all significant factors worsening survival in CRC (p < 0.001, respectively). Mucinous adenocarcinoma (MC) histological subtype proved to be an independent protective factor for the prognosis of right colon cancer (p = 0.003). Overall, in our study, the results suggested SRCC had the worst survival among the three histological subtypes of CRC. MC was associated with favorable prognosis in right colon cancer but not with other tumor locations.

Construction and validation a nomogram to predict overall survival for colorectal signet ring cell carcinoma

To construct and validate a nomogram to predict the overall survival (OS) of colorectal signet ring cell carcinoma (SRCC). The potentially eligible cases were obtained against the SEER database from 2004 to 2015. Log-rank test and Cox analysis were conducted to identify the independent prognostic factors for predicting OS. The identified prognostic factors were later integrated for the construction of an OS prediction nomogram. Altogether 2904 eligible cases were identified, and the median survival time was 18 (range: 0–155) months. As suggested by multivariate analysis, age, primary site, grade, tumor size, T stage, N stage, M stage, surgery, lymph node dissection and chemotherapy were identified as the independent factors for predicting OS. Afterwards, the above variables were incorporated into the nomogram. The C-index indicated better discriminatory ability of the nomogram than AJCC 8th TNM staging and SEER summary stage systems (both P < 0.001). Calibration plots further showed good consistency between the nomogram prediction and actual observation. The time independent area under the curves (tAUCs) for 3-year and 5-year OS in nomogram were larger than AJCC and SEER summary stage system. The constructed nomogram could potentially predict the survival of colorectal SRCC individuals.

Marital status and survival of patients with colorectal signet ring cell carcinoma: a population-based study

The prognostic role of marital status on colorectal signet ring cell carcinoma (SRCC) has not been studied. In this study, the correlation of marital status with prognosis of colorectal SRCC was analyzed. Eligible subjects were extracted from the Surveillance, Epidemiology, and End Results (SEER) dataset from 2004 to 2015, followed by comparison of cancer-specific survival (CSS) and overall survival (OS) between married and unmarried group. 3152 patients were identified including 1777 married patients (56.38%). Married populations tended to be more patients aged < 65, male, receiving chemotherapy, and less black race and large tumor size compared to unmarried group (all P < 0.05).Moreover, 5-year CSS (30.04% vs. 28.19%, P = 0.0013) and OS rates (26.68% vs. 22.94%, P < 0.0001) were superior in married population. Multivariate analysis revealed that marital status was an independent favorable prognostic indicator, and married population had better CSS (HR: 0.898; 95% CI: 0.822–0.980; P = 0.016) and OS (HR: 0.898; 95%CI: 0.827–0.975; P = 0.011).In addition, CSS as well as OS were superior in married populations than unmarried ones in most subgroups. Marital status was an independent prognostic factor for survival in patients with colorectal SRCC. Additionally, married patients obtained better survival advantages.

Superior survival in right-sided versus left-sided colon signet ring cell carcinoma

This study aimed to explore the association of tumor sidedness with the prognosis of patients with colon signet ring cell carcinoma (SRCC). Eligible patients were retrieved from the Surveillance, Epidemiology, and End Results database between 2004 and 2015. Cancer-specific survival (CSS) and overall survival (OS) were compared between patients with left-sided colon SRCC and those with right-sided lesions. A total of 2660 patients were included, among them, 1983 (74.5%) had right-sided colon SRCC. Compared to patients with left-sided colon SRCC, those who had the right-sided colon SRCC showed higher proportion of white race, female, aged ≥ 65 years, receiving total colectomy and ≥ 4 regional lymph node dissection; while had lower proportion of advanced AJCC stage. Besides, right-sided patients exhibited superior 5-year CSS (32.74% vs. 25.89%, P = 0.001) and OS (27.38% vs. 23.02%, P = 0.024) rates compared with left-sided ones. Multivariate analysis revealed that tumor sidedness was an independent prognostic factor. To be specific, patients with right-sided colon SRCC showed better CSS (HR: 0.873; 95% CI 0.777–0.981; P = 0.023) and OS (HR: 0.838; 95% CI 0.753–0.965; P = 0.002). Moreover, subgroup analysis demonstrated superior CSS and OS for right-sided patients in most subgroups. Tumor sidedness was an independent prognostic indicator for colon SRCC. Besides, patients with right-sided colon SRCC have superior prognosis than those with left-sided lesions.

Clinicopathological characteristics and survival in colorectal signet ring cell carcinoma: a population-based study

We aimed to reveal clinicopathological features and explore survival-related factors of colorectal signet ring cell carcinoma (SRCC). A population-based study was carried out to investigate colorectal SRCC by using data extracted from the surveillance, epidemiology and end results (SEER) database between 2004 and 2015. In total, 3,278 patients with colorectal SRCC were identified, with a median age of 63 (12–103) years old. The lesions of most patients (60.49%) were located in the cecum–transverse colon. In addition, 81.27% patients had advanced clinical stage (stage III/IV), and 76.69% patients had high pathological grade. The 3–, 5–year cancer‐specific survival and overall survival rate was 35.76%, 29.32% and 32.32%, 25.14%. Multivariate analysis revealed that primary site in cecum–transverse colon, married, received surgery, lymph node dissections ≥ 4 regional lymph nodes were independent favorable prognostic. Meanwhile, aged ≥ 65 years, higher grade, tumor size ˃5 cm and advanced AJCC stage were associated with poor prognosis. Patient age, tumor grade, marital status, tumor size, primary tumor location, AJCC stage, surgery and number of dissected lymph node had significant correlation with prognosis of colorectal SRCC.

Histotype influences emergency presentation and prognosis in colon cancer surgery

AIM

To investigate whether differences in histotype in colon cancer correlate with clinical presentation and if they might influence oncological outcomes and survival.

METHODS

Data regarding colon cancer patients operated both electively or in emergency between 2009 and 2014 were retrospectively collected from a prospectively maintained database and analyzed for the purpose of this study. Rectal cancer was excluded from this analysis. Statistical univariate and multivariate analyses were performed to investigate possible significant variables influencing clinical presentation, as well as oncological outcomes and survival.

RESULTS

Data from 219 patients undergoing colorectal resection for cancer of the colon only were retrieved. One hundred seventy-four patients had an elective procedure and forty-five had an emergency colectomy. Emergency presentation was more likely to occur in mucinous (p < 0.05) and signet ring cell (p < 0.01) tumors. No definitive differences in 5-year overall (44.7% vs. 60.6%, p = 0.078) and disease-free (51.2% vs. 64.4%, p = 0.09) survival were found between the two groups as a whole, but the T3 emergency patients showed worse prognosis than the elective (p < 0.03). Lymph node invasion, laparoscopy, histology, and blood transfusions were independent variables found to influence survival. Distribution assessed for pTNM stage showed T3 cancers were more common in emergency (p < 0.01).

CONCLUSIONS AND DISCUSSION

Mucinous and signet ring cell tumors are related to emergency presentation, pT3 stage, poorest outcomes, and survival. Disease-free survival in patients who had emergency surgery for T3 colon cancer seems related to the histotype.

Molecular Characterization of Colorectal Signet-Ring Cell Carcinoma Using Whole-Exome and RNA Sequencing

BACKGROUND: Signet-ring cell carcinoma (SRCC) is a very rare subtype of colorectal adenocarcinoma (COAD) with a poor clinical prognosis. Although understanding key mechanisms of tumor progression in SRCCs is critical for precise treatment, a comprehensive view of genomic alterations is lacking. MATERIALS AND METHODS: We performed whole-exome sequencing of tumors and matched normal blood as well as RNA sequencing of tumors and matched normal colonic tissues from five patients with SRCC. RESULTS: We identified major somatic alterations and characterized transcriptional changes at the gene and pathway level. Based on high-throughput sequencing, the pattern of mutations and copy number variations was overall similar to that of COAD. Transcriptome analysis revealed that major transcription factors, such as SRF, HNF4A, ZEB1, and RUNX1, with potential regulatory roles in key pathways, including focal adhesion, the PI3K-Akt signaling pathway, and the MAPK signaling pathway, may play a role in the tumorigenesis of SRCC. Furthermore, significantly upregulated genes in SRCCs were enriched for epithelial-mesenchymal transition genes, and accumulation of mucin in intracytoplasm was associated with the overexpression of MUC2. CONCLUSION: The results indicate that the molecular basis of colorectal SRCC exhibits key differences from that of consensus COAD. Our findings clarify important genetic features of particular abnormalities in SRCCs.

Characteristics and prognostic factors of colorectal mucinous adenocarcinoma with signet ring cells

Background

Colorectal signet ring cell (SRC) carcinoma occurs rarely with a poor prognosis. The present study assessed the prognostic factors and predictive value of SRC ratio in colorectal mucinous adenocarcinoma (MAC) with SRCs (MAC-SRC).

Patients and methods

A total of 95 consecutive colorectal MAC-SRC patients, confirmed pathologically from February 1987 to December 2015, were analyzed retrospectively in our institute. Clinical characteristics, pathological grade, TNM staging, and SRC ratio were assessed to identify the prognostic factors related to progression-free survival (PFS) and overall survival (OS). SPSS 22.0 was used for statistical analyses.

Results

The median follow-up time was 29.7 months (range 0.8–165). Meanwhile, 5-year PFS and OS rates were 25.6% (95% confidence interval [CI] 16.192–35.008%) and 40.5% (95% CI 29.524–51.476%), respectively. Among the 81 patients who underwent surgery, 78 (96.3%) were diagnosed as stage T3 or T4; 74 (91.4%) showed lymph node involvement, and 27 (29.3%) presented distant metastasis. Metastases of the peritoneal cavity and ovaries were observed commonly in colorectal MAC-SRC. In the multivariate Cox regression model, SRC ratio ≥35%, absence of preoperative radiotherapy, and distant metastasis were independent predictors of PFS. Furthermore, SRC ratio ≥35%, absence of preoperative chemotherapy (pre-CT), and distant metastasis were independent risk factors for poor prognosis.

Conclusion

A long-term follow-up of colorectal MAC-SRC reveals that it is a rare subtype of colorectal MAC with a dismal prognosis. Furthermore, SRC ratio, pre-CT, and M stage seem to affect OS independently.

Prognostic Significance of Mucinous Histologic Subtype on Oncologic Outcomes in Patients With Colorectal Cancer

Purpose

Mucinous adenocarcinomas account for about 10% of all colorectal cancers. This study aimed to investigate the prognostic impact of mucinous histologic subtype on oncologic outcomes in patients with colorectal cancer.

Methods

This retrospective study was performed at two large tertiary university hospitals. We analyzed the characteristics, prognostic factors, and survival of patients with colorectal cancer who were treated and followed up between 2000 and 2013.

Results

Totally, 144 of 1,268 patients with a colorectal adenocarcinoma (11.4%) had mucinous histologic subtype. Statistically significant results found in this research are as follows: Mucinous histologic subtype tended to present in younger patients and to have larger tumor size, higher histologic grade, higher node stage, larger number of positive nodes, and higher rate of perineural invasion compared to nonmucinous histologic subtype. On the univariate analysis, mucinous subtype was a prognostic factor for disease-free and overall survival. On the multivariate analysis, primary tumor location, node stage and lymphatic-vascular invasion were independent prognostic factors for the local control rate. Rectal tumor location, higher disease stage, tumor grade II, and presence of lymphatic-vascular invasion had negative influences on disease-free survival, as did rectal tumor location, higher disease stage and presence of lymphatic-vascular invasion on overall survival.

Conclusion

Mucinous histologic subtype was associated with some adverse pathologic features in patients with colorectal cancer; however, it was not an independent prognostic factor for oncologic outcome.

Prognosis and value of preoperative radiotherapy in locally advanced rectal signet-ring cell carcinoma

As well known, signet-ring cell carcinoma (SRCC) is a rare histological subtype of colorectal adenocarcinoma, which has been associated with poor prognosis and resistant to non-surgery therapy compared with common adenocarcinoma. In this study, we assessed the effect of preoperative radiotherapy (PRT) for locally advanced rectal SRCC in a large patient group from the Surveillance, Epidemiology, and End Results program (SEER, 1988–2011) database. SRCC was found in 0.9% (n = 622) rectal cancer (RC) patients in our study. In the PRT setting, SRCC had significantly worse cancer-specific survival than mucinous adenocarcinoma and nonmucinous adenocarcinoma patients (log-rank, P < 0.001). In terms of SRCC, stage III RC patients benefited from PRT (log-rank, P < 0.001) while stage II did not (P = 0.095). The multivariate Cox proportional hazard model showed that PRT was an independent benefit factor in stage III rectal SRCC patients (HR, 0.611; 95% CI, 0.407–0.919; P = 0.018). In conclusion, SRCC was an independent predictor of poor prognosis in stage III RC patients, but not in stage II. In the PRT setting of locally advanced RC, SRCC patients had significantly worse prognosis. PRT was an independent prognostic factor associated with improved survival in stage III rectal SRCC.

Comparison of 627 patients with right- and left-sided colon cancer in China: Differences in clinicopathology, recurrence, and survival

Objective

Recent studies have reported increased mortality for right-sided colon cancers; however, the results are conflicting for different stage tumors. We examined the differences in clinicopathology between right- and left-sided colon cancers and the relationships between colon cancer location (right- and left-side) and 5-year disease-free survival (DFS) and overall survival (OS).

Methods

We identified patients from 2005 to 2008 with stage II/III colon cancer who underwent surgery for curative intent. We explored the impact of the tumor location on the postoperative DFS and OS using univariate and multivariate analyses.

Results

Of 627 patients, 50.6% (317/627) had right-sided colon cancer. These patients were more likely to have weight loss, second primary tumor, elevated preoperative carbohydrate antigen 19-9 (CA19-9), increased incidence of non-adenocarcinoma, more poorly differentiated tumors, vascular invasion, defective mismatch repair, and a lighter smoking history (P < 0.05). Right-sided colon cancer had a higher recurrence incidence compared with left-sided cancer (30.6% vs. 23.2%, P = 0.037), particularly with multiple metastatic sites in the first recurrence (17.5% vs. 5.6%, P = 0.020). Kaplan–Meier survival curves demonstrated a significant difference in the 5-year DFS rate between right- and left-sided cancers across all stages (68.1% vs. 75.2%, P = 0.043). However, there was no significant difference in the 5-year OS rate between the two groups (73.8% vs. 79.0%, P = 0.103). Subgroup analysis demonstrated that patients with left-sided colon cancer had a significantly better 5-year DFS and OS rates compared with those with right-sided disease at stage III (64.3% vs. 46.8%, P = 0.002; 69.5% vs. 53.5%, P = 0.006, respectively); there were no significant differences in the 5-year DFS and OS rates at stage II (85.2% vs. 85.9%, P = 0.819; 89.8% vs. 88.5%, P = 0.803, respectively). Adjusted Cox regression analysis showed no significant differences in the 5-year OS and DFS rates for stage II [hazard ratio (HR) = 1.203, 95% confidence interval (CI): 0.605–2.391, P = 0.598; HR = 0.980, 95% CI: 0.542–1.774, P = 0.948, respectively] or all stages combined (HR = 0.867, 95% CI: 0.613–1.227, P = 0.421; HR = 0.832, 95% CI: 0.606–1.142, P = 0.255, respectively). However, stage III left-sided cancer had higher 5-year OS and DFS rates (HR = 0.626, 95% CI: 0.414–0.948, P = 0.027; HR = 0.630, 95% CI: 0.428–0.926, P = 0.019, respectively).

Conclusion

We found that right- and left-sided colon cancers had significantly different clinicopathological characteristics. Right-sided colon cancer had a higher incidence of recurrence than left-sided disease. Patients with stage III right-sided colon cancer had a worse prognosis compared with those with stage III left-sided colon cancer.

The Characteristics and Prognostic Effect of E-Cadherin Expression in Colorectal Signet Ring Cell Carcinoma

Purpose

Signet ring cell carcinoma (SRCC) is rare. The aim of this study is to understand the clinicopathological features and identify the possible prognostic factors in colorectal SRCC.

Methods

Patients with SRCC who underwent primary lesion resection at Fudan University Shanghai Cancer Center from September 2008 to July 2014 were retrospectively analyzed. Patient’s gender, age, tumor location, depth of invasion, lymph node metastasis, synchronous distant metastasis, perineural invasion, lymphovascular invasion, and E-cadherin expression were studied with prognosis, and the correlation between E-cadherin expression and clinicopathological features were analyzed. All clinicopathological and molecular factors were put into multivariate analysis using Cox proportional hazards model for detecting independent prognostic factors.

Results

59 patients accounting for 0.89% of total colorectal cancer patients met the criteria and were enrolled in the study. The median survival time is 28.9 months, and the 3-year survival rate is 62.7%. SRCC were seen more common in young male patients. Advanced stage was more common in SRCC, 58 (98.3%) patients had T3/T4 lesions, 52 (88.1%) patients had lymph node metastasis, and 14 (23.7%) patients had distant metastasis. Distant metastases were seen more common in peritoneal cavity. Distant metastasis (HR = 4.194, 95% CI: 1.297–13.567), lymphovascular invasion (HR = 2.888, 95% CI: 1.115–7.483), and E-cadherin expression (HR = 0.272, 95% CI: 0.096–0.768) were independent predictors for survival.

Conclusions

SRCC is a rare subtype of colorectal cancer with poor prognosis. Distant metastasis, lymphovascular invasion, and E-cadherin expression can predict prognosis of colorectal SRCCs independently. More precise therapy and more close surveillance are needed for these patients.

Prognostic Impact of Microsatellite Instability in Colorectal Cancer Presenting With Mucinous, Signet-Ring, and Poorly Differentiated Cells

Purpose

Mucinous cells (MUCs), signet-ring cells (SRCs), and poorly differentiated cells (PDCs) are uncommon histologic types and have been associated with advanced tumor stage and poor prognosis. However, MUCs, SRCs, and PDCs are commonly observed in cancers with high microsatellite instability (MSI), which have favorable outcomes compared with cancers with microsatellite stability (MSS). The purpose of this study was to evaluate the prognostic impact of high-MSI in patients with sporadic colorectal cancer presenting with MUCs, SRCs, and/or PDCs.

Methods

Between January 2006 and December 2012, 176 with proven microsatellite status who also presented with MUCs, SRCs, and PDCs were selected for this study and were divided into 2 groups, high-MSI and MSS; their outcomes were analyzed.

Results

Of the 176 patients, 56 and 120, respectively, had high-MSI and MSS cancers. High-MSI cancers had larger tumors, proximal tumor location, and a lower TNM stage. The recurrence rate was lower in the high-MSI group (13.7% vs. 35.4%, P = 0.006). Common patterns of distant metastasis for MUC, SRC, PDC cancers were peritoneal spread (46.9%) and hematogenous metastasis (46.4%). The 5-year CSS rates were 88.2% and 61.2% for patients with high-MSI and MSS cancers, respectively (P < 0.0001). In the multivariate analysis, except for stage-IV cancer, MSI status was an independent risk factor for cancer-specific survival (MSS: hazard ratio, 4.34; 95% confidence interval, 1.68-11.21).

Conclusion

In patients with colorectal cancer presenting with MUCs, SRCs, and/or PDCs, those with high-MSI cancers had better outcomes.

Clinicopathological features and expression of hMLH1 and hMSH2 in Uygur and Han patients with colorectal carcinoma

AIM: To compare the differences in clinicopathological features and expression of hMLH1 and hMSH2 between Uygur and Han patients with colorectal carcinoma.

METHODS: The clinical data for 133 Uygur and 151 Han patients with colorectal carcinoma were analyzed retrospectively. The expression of hMLH1 and hMSH2 proteins was detected in 207 colorectal carcinoma samples, including 98 from Uygur and 109 from Han patients, by immunohistochemical staining.

RESULTS: There were significant differences in onset age, tumor size, pathological differentiation, lymphatic metastasis and tumor stage between the Uygur group and Han group (P < 0.05). In Uygur patients, the loss rate of hMLH1 expression was 9.2% (9/98) in colorectal cancer tissue, and the loss rate of hMSH2 expression was 3.3% (3/98). The loss rate of hMLH1 expression in patients with tumor size > 5 cm was significantly higher than that in patients with tumor size ≤ 5 cm (17.1% vs 3.5%, P < 0.05). The loss rate of hMLH1 expression in patients with lymph node metastasis was 15.1%, significantly higher than that (2.2%) in patients without lymph node metastasis (P < 0.05). The loss rate of hMSH2 in colorectal cancer tissue of Uygur patients (3.1%) was significantly lower than that (10.1%) in Han patients (P < 0.05).

CONCLUSION: There are differences in clinicopathologic features and expression of hMSH2 between Uygur and Han patients with colorectal carcinoma in Xinjiang.

Descending colo-colonic intussusception secondary to signet ring cell carcinoma: A case report

The incidence of intussusception is low in adults, particularly in the descending colon, due to the anatomical attachment of the descending colon to the retroperitoneum. Signet ring cell histology represents ~1% of colon adenocarcinomas and is associated with young patients and a poor clinical outcome. The present study describes a case of descending colo-colonic intussusception caused by signet ring cell carcinoma in a 27-year-old male. The patient presented with a history of intermittent left upper-quadrant abdominal pain for more than six months without any evident etiology. A computed tomography scan of the abdomen revealed left-sided colo-colonic intussusception. Upon laparotomy, a left hemicolectomy was performed according to intraoperative frozen-section pathology. Post-operative pathological evaluation revealed signet ring cell carcinoma invasion of the serosa, and 31.8% (7/22) of the regional lymph nodes were positive for cancerous cells. The post-operative course was uneventful and the patient was discharged on the tenth post-operative day.

Prognostic stratification of colorectal cancer patients: current perspectives

Tumor staging according to the American Joint Committee on Cancer/Union for International Cancer Control tumor, node, metastasis (TNM) system is currently regarded as the standard for staging of patients with colorectal cancer. This system provides the strongest prognostic information for patients with early stage disease and those with advanced disease. For patients with intermediate levels of disease, it is less able to predict disease outcome. Therefore, additional prognostic markers are needed to improve the management of affected patients. Ideal markers are readily assessable on hematoxylin and eosin-stained tumor slides, and in this way are easily applicable worldwide. This review summarizes the histological features of colorectal cancer that can be used for prognostic stratification. Specifically, we refer to the different histological variants of colorectal cancer that have been identified, each of these variants carrying distinct prognostic significance. Established markers of adverse outcomes are lymphatic and venous invasion, as well as perineural invasion, but underreporting still occurs in the routine setting. Tumor budding and tumor necrosis are recent advances that may help to identify patients at high risk for recurrence. The prognostic significance of the antitumor inflammatory response has been known for quite a long time, but a lack of standardization prevented its application in routine pathology. However, scales to assess intra- and peritumoral inflammation have recently emerged, and can be expected to strengthen the prognostic significance of the pathology report.