A 10-year outcomes evaluation of mucinous and signet-ring cell carcinoma of the colon and rectum

Prognostic comparison between mucinous and nonmucinous adenocarcinoma in colorectal cancer

Mucinous adenocarcinoma (MAC) is a histological subtype of colorectal cancer. The oncologic behavior of MAC differs from nonmucinous adenocarcinoma (non-MAC). Our aim in this study was to characterize patients with colorectal MAC through evaluation of a large, institutional-based cohort with long-term follow-up. A total of 6475 patients with stages I to III colorectal cancer who underwent radical surgery were enrolled from January 2000 to December 2010. Prognostic comparison between MAC (n = 274, 4.2%) and non-MAC was performed. The median follow-up period was 48.0 months. Patients with MAC were younger than those without MAC (P = 0.012) and had larger tumor size (P < 0.001), higher preoperative carcinoembryonic antigen (P < 0.001), higher pathologic T stage (P < 0.001), more right-sided colon cancer (49.3%, P < 0.001), and more frequent high-frequency microsatellite instability (10.2%, P < 0.001). Five-year disease-free survival (DFS) was 76.5% in the MAC group and 83.2% in the non-MAC group (P = 0.008), and 5-year overall survival was 81.4% versus 87.4%, respectively (P = 0.005). Mucinous histology (MAC vs non-MAC) in the entire cohort was not an independent prognostic factor of DFS but had a statistical tendency (P = 0.071). In subgroup analysis of colon cancer without rectal cancer, mucinous histology was an independent prognostic factor (P = 0.026). MAC was found at more advanced stage, located mainly at the right side and was an independent factor of survival in colon cancer. Because of the unique biological behavior of MAC, patients with MAC require special consideration during follow-up.

Prognostic significance and molecular features of signet-ring cell and mucinous components in colorectal carcinoma

BACKGROUND

Colorectal carcinoma (CRC) represents a group of histopathologically and molecularly heterogeneous diseases, which may contain signet-ring cell component and/or mucinous component to a varying extent under pathology assessment. However, little is known about the prognostic significance of those components, independent of various tumor molecular features.

METHODS

Utilizing a molecular pathological epidemiology database of 1,336 rectal and colon cancers in the Nurses' Health Study and the Health Professionals Follow-up Study, we examined patient survival according to the proportion of signet-ring cell and mucinous components in CRCs. Cox proportional hazards models were used to compute hazard ratio (HR) for mortality, adjusting for potential confounders including stage, microsatellite instability, CpG island methylator phenotype, LINE-1 methylation, and KRAS, BRAF, and PIK3CA mutations.

RESULTS

Compared to CRC without signet-ring cell component, 1-50 % signet-ring cell component was associated with multivariate CRC-specific mortality HR of 1.40 [95 % confidence interval (CI) 1.02-1.93], and >50 % signet-ring cell component was associated with multivariate CRC-specific mortality HR of 4.53 (95 % CI 2.53-8.12) (P trend < 0.0001). Compared to CRC without mucinous component, neither 1-50 % mucinous component (multivariate HR 1.04; 95 % CI 0.81-1.33) nor >50 % mucinous component (multivariate HR 0.82; 95 % CI 0.54-1.23) was significantly associated with CRC-specific mortality (P trend < 0.57).

CONCLUSIONS

Even a minor (50 % or less) signet-ring cell component in CRC was associated with higher patient mortality, independent of various tumor molecular and other clinicopathological features. In contrast, mucinous component was not associated with mortality in CRC patients.

Significance of the mucinous component in the histopathological classification of colon cancer

PURPOSE

Mucinous carcinoma is often independently classified as a histological type of colon cancer, but there are currently no established diagnostic criteria. The relationship between the proportions of mucinous components to the oncological outcomes was examined to determine whether mucinous carcinoma should be classified as an independent histological type.

METHODS

The study group comprised 1,038 patients with colon cancer. The relationships between the survival rates and recurrence patterns with the mucinous component area ratio (MC area ratio) and clinical variables were evaluated.

RESULTS

Tumors were classified into three groups: Group 1 (MC area ratio, 0 %), Group 2 (1-49 %), and Group 3 (≥50 %). Of the 1038 tumors studied, 877 (84 %) were classified as Group 1, 123 (12 %) as Group 2, and 38 (4 %) as Group 3. The tumor size was significantly larger in Group 3, and an increased MC area ratio was significantly related to a higher proportion of right-sided tumors. Among patients with stage II or III disease, stage III disease, poorly differentiated adenocarcinoma, and no adjuvant chemotherapy were poor prognostic factors. There was no relationship between the MC area ratio and the survival or recurrence pattern.

CONCLUSION

Mucinous carcinoma does not need to be classified as a separate histological type from ordinary differentiated adenocarcinoma.

A minor (<50%) signet-ring cell component associated with poor prognosis in colorectal cancer patients: a 26-year retrospective study in China

Background

We performed a retrospective study to determine the cancer-specific survival of colorectal cancer patients with a component of signet-ring cells or mucin comprising < 50% of the tumor mass.

Methods

A total of 2454 patients seen in our hospital from 1985 to 2011 were retrospectively studied. The patients were divided into five groups according to type of cancer: signet-ring cell carcinoma (with > 50% signet-ring cell, n = 36), partial signet-ring cell carcinoma (with < 50% signet-ring cell, n = 28), mucinous adenocarcinoma (with > 50% mucin lacking signet-ring cell, n = 267), partial mucinous adenocarcinoma (with < 50% mucin lacking signet-ring cell, n = 145), and classic adenocarcinoma (with absence of either mucin or signet-ring cell, n = 1978).

Results

Patients with > 50% or < 50% signet-ring cell had the lowest 5-year survival rates (35.5% and 29.7%, respectively), followed by patients with > 50% mucin (48.8%). Patients who had partial mucinous adenocarcinoma with < 50% mucin and classic adenocarcinoma patients had the highest 5-year survival rates (64.8% and 65.3%, respectively). Stratified and multivariate analysis showed that signet-ring cell carcinoma, partial signet-ring cell carcinoma and mucinous adenocarcinoma were independent predictors of decreased survival (hazard ratio 1.699, P = 0.016; hazard ratio 2.182, P = 0.005; hazard ratio 1.532, P < 0.001; respectively), and partial mucinous adenocarcinoma was not (hazard ratio 1.137, P = 0.431).

Conclusions

Patients with a component of signet-ring cells, regardless of the extent, had poor prognoses. Patients with mucinous adenocarcinoma containing >50% mucin had poor prognoses as well, whereas those with < 50% mucin had survival rates similar to those of classic adenocarcinoma patients. Therefore, in clinical practice, patients with a component of signet-ring cells, regardless of the extent, should be given significant clinical attention.

Clinicopathological features of colon adenocarcinoma in Qazvin, Iran: a 16 year study

BACKGROUND

Colorectal cancer (CRC) was the fourth most commonly diagnosed cancer in Iran between 2000 and 2009, with adenocarcinoma (AC) as the most common histological type. Demographic, topographic and histological variables are important in the epidemiology and biology of cancer. The aim of this study was to investigate clinicopathological features of colon adenocarcinomas in Qazvin, Iran.

MATERIALS AND METHODS

With a retrospective design, patient records of two pathology wards from March 1997 to March 2013 were studied with regard to anatomical location and histological classification. A broader anatomical grouping was also used including distal vs proximal regions and right sided vs left sided tumors. Data were analyzed using T-test and chi-square test.

RESULTS

118 (50.9%) male and 114 (49.1%) female patients were included in the study. Mean age was 57.3±14.7 years, with 29.2% under 50 years. There was no significant gender difference for age at diagnosis. The rectum (56%) and sigmoid colon (25%) were the most frequent anatomical locations. Proximal cases accounted for 18.6% in males and 8.8% in females (p=0.02). AC was more prevalent than other usual types in younger patients. The proportion of proximal cancer was 1.7% in first eight years of the study period vs 12.1% in the second one (p=0.005). A similar trend was also seen in right sided colon cancers (p=0.018).

CONCLUSIONS

Young people are also at risk for the cancer with poor prognosis. Screening programs and weight loss in obese individuals can reduce incidence and complications of CRC.

Rectal versus non-rectal primary signet ring cell carcinoma of the colorectum: a retrospective survival analysis controlled for confounders

PURPOSE

Our objective was to compare the outcomes of rectal and non-rectal primary signet ring cell adenocarcinoma of the colorectum.

METHODS

A retrospective survival analysis was performed using the Surveillance, Epidemiology, and End Results Program database between 2004 and 2009 on subjects who were diagnosed as having a primary signet ring cell carcinoma of the colorectum. Cox proportional hazard regression analysis controlled for confounders was used to assess overall survival comparing rectal and non-rectal cancers.

RESULTS

Our population was composed of 1,484 patients: 200 affected by rectal cancer and 1,284 by non-rectal cancer. Unadjusted survival curves resulted to be almost superimposable (P = 0.916). After controlling for age, gender, race, tumor stage, grade, and size, tumor location demonstrated a statistically significant impact on overall survival (P = 0.032; 95% confidence interval 0.640-0.980; hazard ratio 0.792).

CONCLUSION

On the basis of analysis of information from the SEER database, the signet ring cell carcinoma of the rectum was associated to a worse prognosis as compared to non-rectal cancer.

Liver resection for colorectal metastases: results and prognostic factors with 10-year follow-up

PURPOSE

Actual 5-year survival rates after resection of colorectal liver metastases (CLM) are 25-45%, whereas 10-year survival rates are extrapolated from survival curves. Few studies have reported long-term survivors with 10 years of actual follow-up. Therefore, no recurrences occurring after 10-plus years have been reported. The aim of our study was to analyze actual 10-year survival rates and prognostic factors.

METHODS

Clinical data of patients with CLM who had undergone first liver resection in our center between January 1990 and December 2000 were retrospectively analyzed.

RESULTS

Eighty-nine patients of mean age 64 years were studied. Three patients were excluded from the study: one because of postoperative death, and two from being lost to follow-up. All other subjects had a potential 10-year follow-up. Only 33% patients received perioperative chemotherapy. The actual 10-year overall and disease-free survival rate were 22 and 19%, respectively. Poor prognostic factors were disease-free interval less than 1 year, wedge liver resection, clinical risk score>2, segment 1 CLM location, and peritumoral lymphangitis. Good prognostic factors were tumors having mucinous components in primary tumor and CLM located in the right lobe.

CONCLUSIONS

With actual long-term follow-up for 10 years, disease-free survival rate is 19% and mainly depends on surgical management. Recurrence continues to occur more than 5 years after liver resection for CLM; cure cannot be assumed at this time. Clinical risk score is a good predictor of cure and should be taken into account when choosing perioperative treatment.

Inverse effect of mucinous component on survival in stage III colorectal cancer

BACKGROUND

Although mucinous adenocarcinoma (MAC) is has been recognized as a separate entity in colorectal cancer (CRC), adenocarcinoma with a mucinous component (ACM) remains poorly understood.

METHODS

The association of MAC and ACM with disease-free survival (DFS) and overall survival (OS) was examined using the Cox proportional hazard model in 425 consecutive stage III CRCs.

RESULTS

Compared with conventional adenocarcinoma (CAC), patients with MAC exhibited independently worse DFS (hazard ratio [HR], 2.64; 95% CI, 1.21-5.80; P = 0.014) and OS (HR, 3.56; 95% CI, 1.53-8.30; P = 0.003). Unexpectedly, ACM was significantly associated with worse OS than CAC (P = 0.002), despite having a similar DFS to CAC. Further, ACM patients after recurrence exhibited significantly worse OS than CAC patients (P < 0.001), similar to MAC.

CONCLUSIONS

Although ACM is similar to CAC with regard to estimated risk of recurrence, the outcome is extremely poor once recurrence occurs and is identical to MAC; one of the most aggressive phenotypes of stage III CRC. Thus, both MAC and ACM are adverse prognostic factors for OS.

Diagnostic and prognostic significance of different mucin expression, preoperative CEA, and CA-125 in colorectal carcinoma: A clinicopathological study

Background:

Colorectal carcinoma (CRC) is the fourth most commonly diagnosed malignant disease worldwide, with over 1 million new cases and approximately 5,00,000 deaths each year.

Aims and Objectives:

This prospective observational study was done to study the clinicopathological characteristics of CRC including mucin stains and correlate the preoperative serum carcinoembryonic antigen (CEA) and cancer antigen (CA)-125 levels with the prognosis.

Materials and Methods:

A total of 90 CRCs were included from December 2010 to June 2013. Detailed history and relevant clinical/radiological findings were noted in all clinically and/or radiologically suspected cases of CRC. Preoperative blood samples were collected for serum CEA and CA-125 level estimation. The mucin expression was evaluated with special stains.

Results:

The combined Alcian blue-periodic acid Schiff (PAS) staining was positive for both stains in 68.88% cases indicating that both neutral and acidic mucins are increased in CRC. High preoperative serum CEA levels were seen in 82.22% cases, whereas preoperative serum CA-125 levels showed an increase in 20% cases. Higher levels of these tumor markers corresponded with higher TNM stage.

Conclusions:

Mucin evaluation in CRCs remains one of the valuable methods as mucinous variants correlate with worse prognosis. Preoperative serum CEA level assessment is an indispensible adjunct to the diagnosis and prognosis of CRC. However, preoperative serum CA-125 level measurement is not an efficient tool for prognostication in CRC and should not be recommended for routine use.

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.

Overall survival is improved in mucinous adenocarcinoma of the colon

INTRODUCTION

Debate persists regarding the relationship between mucin expression and outcome in colon cancer. This arises due to discrepancy in the definition of mucinous adenocarcinoma and the combination of both colon and rectal cancers in analyses. This study examines the relationship between increased mucin production and outcomes in colon cancer.

METHODS

Cases were classified according to the World Health Organization classification of mucinous adenocarcinoma of the colon. Accordingly, tumors were categorized as either (a) mucinous adenocarcinoma of the colon (greater than 50% of the extracellular matrix occupied by mucin) or (b) non-mucinous adenocarcinoma of the colon. Overall survival and disease-free survival were calculated. A stepwise Cox proportional hazards regression model was employed to determine the risk of death/disease recurrence. Kaplan-Meier estimates of overall survival and disease-free survival were plotted for each group and compared using a log-rank test.

RESULTS

On univariate analysis, mucinous adenocarcinoma was associated with reduced risk of death (P = 0.01). On multivariate analysis, mucinous adenocarcinoma was also associated with reduced risk of death (hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.14-0.79, P = 0.01). Kaplan-Meier estimates confirmed improved rate of survival in the mucinous vs. non-mucinous group (P = 0.01). Mucinous adenocarcinoma did not affect disease-free survival (HR 0.75, 95% CI 0.46-1.21, P = 0.22). A comparison of Kaplan-Meier estimates for systemic recurrence demonstrated significant increases in systemic recurrence in the group with no mucin production (P = 0.04) but not for locoregional recurrence (P = 0.24).

CONCLUSIONS

Histopathological evidence of mucinous adenocarcinoma in colon cancer is associated with improved outcomes.

Insight into mucinous colorectal carcinoma: clues from etiology

The prognostic impact of mucinous carcinoma (MC) in colorectal cancer (CRC) has been subject to debate ever since the introduction of the classification of tumors according to their histological differentiation. MC is a distinct clinical and pathological entity within the spectrum of CRC and accounts for approximately 10-15 % of cases. Factors involved in MC development have not been completely understood, but clinical observations may lead to a better insight into the etiology of MC. In this article, we provide an in-depth review of the literature regarding etiological aspects of MC. We show that there are worldwide differences in the prevalence of MC, with low rates in Asian countries and higher rates in the western world. Moreover, MC is more commonly diagnosed in patients suffering from inflammatory bowel diseases or Lynch syndrome and an increased rate of MC is observed in patients with radiotherapy-induced CRCs. These findings are suggestive of a different oncogenic development. Identification of conditions that are associated with MC generates insight into the etiological pathways leading to the development of this special subtype.

Primary colonic signet ring cell carcinoma in a young patient

A 28-year-old woman presented with colicky abdominal pain for 3 months. Pain was associated with episodes of vomiting, abdominal distension and constipation. She also had loss of weight for this duration. General physical examination was unremarkable and the abdomen was soft, with no palpable organomegaly. A CT of the abdomen showed small bowel and ascending colon dilation with multiple air fluid levels. There was also a short segment of circumferential bowel wall thickening and luminal narrowing in the hepatic flexure with sudden transition of bowel diameter. She underwent a right hemicolectomy after necessary preoperative investigations. Histopathology revealed signet ring cell carcinoma (SRCC). This case highlights the importance of detecting such a lesion in a young, otherwise fit woman. The challenge lies in early diagnosis and awareness of general practitioners about this aggressive form of colonic tumours.

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

BACKGROUND

Signet ring cell carcinoma (SRCC) accounts for less than 1% of all colon cancers. We examined the clinicopathological features and prognosis of signet ring cell and mucinous adenocarcinoma (MCC) of colon.

METHODS

A total of 206 patients diagnosed with SRCC from 1995 to 2009 were identified from the VA Central Cancer Registry (VACCR) database. Age, race, histology, grade, lymph node status, stage and type of treatment received data were collected.

RESULTS

Out of 206 patients, 173 (84%) were white, 31 (15%) were black, and 2 patients were listed as unknown. Median age of diagnosis was 67 years as compared to 70 years for both mucinous cell (MCC) and non-mucinous adenocarcinoma (NMCC) of colon. Pathological T-stages were as follows: T1 =3%, T2 =5%, T3 =34%, T4 =26%, and unknown 32%. Of the total, 22.3% were located in cecum, 7.7% in appendix, 21.8% in ascending colon, 7.7% in hepatic flexure of colon, 11% in transverse colon, 2.9% in splenic flexure 4.4% in descending colon, and 15.5% in sigmoid colon. 46.5% were lymph node positive, 21% were lymph node negative, and 32.5% were unknown. SRCC were in general poorly differentiated tumors (57%), small proportion of patients included were well-differentiated tumors with focal signet ring cell pathology (10%) and in 33% grade was unknown. Among stage 3 patients, 34% patients received only surgery while 64% received surgery with adjuvant chemotherapy and 2% received chemotherapy alone. The stage specific 5-year survivals for SRCC, MCC and NMCC were--Stage I: 100%, 61%, and 41% respectively (P<0.0001); Stage II: 42%, 58% and 32% respectively (P<0.0001); Stage III: 19%, 41% and 47% respectively (P=0.0002); Stage IV: 1.5%, 7% and 31% respectively (P<0.0001). Median survival of SRCC compared to NMCC was 18.6 vs. 46 months (P<0.0001) and mucinous cell adenocarcinoma versus NMCC was 47.8 and 46 months (P=0.63) respectively.

CONCLUSIONS

SRCC of colon has poor survival rates compared to other histological subtypes. SRCC presents at an earlier age, has higher tumor grade and advanced stage at diagnosis when compared to mucinous and NMCC of colon. Due to rarity of this disease further prospective multi-institute studies are required for in-depth understanding of this disease.

Mucinous and signet-ring cell colorectal cancers differ from classical adenocarcinomas in tumor biology and prognosis

Mucinous adenocarcinomas are uncommon and signet-ring cell carcinomas are rare histological subtypes of colorectal cancer, which differ from classical adenocarcinomas in clinicopathology and prognosis. In particular, signet-ring cell carcinomas could be taken into account for individual risk estimation because of their clearly different behavior.

Objectives:

To define the prognostic value of different histological subtypes of colorectal cancer.

Background:

Most colorectal cancers are classical adenocarcinomas (AC). Less frequent subtypes include mucinous adenocarcinomas (MAC) and signet-ring cell carcinomas (SC). In contrast to established prognostic factors such as TNM and grading, the histological subtype has no therapeutical consequences so far, although it may reflect different biological behavior.

Methods:

Between 1982 and 2012, a total of 3479 consecutive patients underwent surgery for primary colorectal cancer (AC, MAC, or SC). Clinical, histopathological, and survival data were analyzed.

Results:

Of all 3479 patients, histological subtype was AC in 3074 cases (88%), MAC in 375 cases (11%), and SC in 30 cases (0.9%). MAC (51%, P < 0.001) and SC (50%, P = 0.029) occurred more frequently in right-sided tumors than AC (28%). Compared with AC, tumor stages and histological grading were higher in MAC and SC (P < 0.001 for each). Rates of angioinvasion were lower in MAC than in AC (5% vs 9%, P = 0.011). Rates of lymphatic invasion were higher in SC than in AC (67% vs 25%, P < 0.001). Five-year cause-specific survival was 67 ± 1% for AC, 61 ± 3% for MAC, and 21 ± 8% for SC (P < 0.001 for difference between the groups). In multivariable analysis, survival did not differ significantly between AC and MAC after correction for tumor stage. However, SC remained an independent prognostic factor associated with worse survival (hazard ratio = 2.5, 95% confidence interval = 1.6–3.8, P < 0.001).

Conclusions:

MAC and SC are histological subtypes of colorectal cancer with different characteristics than classical AC. Both are diagnosed in more advanced tumor stages, but the dismal prognosis of SC seems to be caused by its intrinsic tumor biology.

Colorectal cancer: Histopathologic differences in tumor characteristics between patients with and without diabetes

BACKGROUND

Current literature suggests that diabetes is a possible predictor of risk and worse outcome in colorectal cancer (CRC). The objective of this study was to explore if there are histopathologic differences in CRC between populations with and without diabetes.

PATIENTS AND METHODS

Retrospective analysis was done on 534 patients with CRC. Patients were divided into diabetic and nondiabetic subgroups. Data were collected for lymphovascular invasion, tumor location, depth invasion, staging, level of differentiation, histologic type, and presence of tumor components (mucinous, signet ring, or neuroendocrine).

RESULTS

Univariately, patients with diabetes had deeper tumor invasion, greater lymphovascular invasion, and higher TNM staging (OR and 95% CI, 2.06 [1.37, 3.10], 2.52 [1.74, 3.63], and 2.45 [1.70, 3.52], respectively; P < .001). Covariate adjustment retained the significant effect of diabetes on tumor characteristics (P < .005). Multivariable adjustment significantly linked diabetes with signet ring cell carcinoma (log odds, 11.40 ± 5.28; P = .03) and tumor components (log odds, 0.58 ± 0.25; P = .02). Patients with diabetes with hyperlipidemia had more well-differentiated tumors (log odds, -0.96 ± 0.47; P = .04). Transverse tumors were more common in patients with diabetes (log odds, 1.74 ± 0.72; P = .02).

CONCLUSION

Patients with diabetes had worse histopathologic CRC features. Hyperinsulinemia, insulinlike growth factor receptor activation, and hyperglycemia in diabetes can activate mitogenic pathways stimulating proliferation, invasion, angiogenesis, and metastasis. Future research is needed to identify responsible pathways for targeted therapy and to examine the role of better glycemic control and treatment in patients with CRC and diabetes.

Adjuvant chemotherapy improves overall survival after TME surgery in mucinous carcinoma of the rectum

INTRODUCTION

Mucinous tumours of the rectum are characterised by an abundance of extracellular mucin within the tumour complex. They are known to have a poor prognosis compared to non-mucinous adenocarcinomas. The effect of adjuvant chemotherapy on the survival outcomes of patients with mucinous cancer remains unclear. This study evaluated the 5-year overall survival of patients with mucinous rectal cancer following optimal TME surgery to determine whether adjuvant chemotherapy conferred a survival benefit.

METHODS

An analysis of a prospectively-maintained database was conducted of patients presenting with mucinous rectal cancer between 2000 and 2010. Patients with mucinous tumours were identified from final pathology reports of the surgical resection specimens. The primary outcome was 5-year overall survival; univariate and multivariate analysis was performed using Cox proportional hazards regression models.

RESULTS

A total of 191 patients were included for analysis with mean age of presentation 64.6 years (36-88 ± 11). On the fully adjusted multivariate model, EMVI status (HR 1.853, 95% CI 1.081-3.175) and not being given adjuvant chemotherapy (HR 2.888, 95% CI 1.801-4.633) were significant for disease recurrence. The 5-year overall survival for patients that had undergone adjuvant chemotherapy was 66.1% compared with 35.2% (Mantel Cox log-rank test - p < 0.0001).

CONCLUSION

This study demonstrates that adjuvant chemotherapy is an independent factor for improvement in overall survival in patients with mucinous adenocarcinoma. Therefore, patients who have undergone TME surgery for mucinous carcinoma of the rectum should be offered adjuvant chemotherapy even in the absence of other high-risk features for poor outcomes.

Impact of aggressive histology and location of primary tumor on the efficacy of surgical therapy for peritoneal carcinomatosis of colorectal origin

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) for peritoneal carcinomatosis (PC) of colorectal origin increases survival (OS) compared to systemic chemotherapy alone. Signet ring histology demonstrates aggressive behavior with poor survival. We sought to determine whether CRS/HIPEC increases survival in this subset of patients.

METHODS

We reviewed 67 patients with PC of appendiceal (AP, n = 37) or colorectal origin (CRC, n = 30) with signet cell histology from a prospective database between May 2001 and August 2011. Survival analysis and multivariate Cox regression were used to determine prognostic factors for survival.

RESULTS

Complete CRS (CC-0/1) was achieved in 77 % (CRC) and 73 % (AP) of patients. Progression-free survival (PFS) and OS were 9 and 12 months in CRC and 12 and 21 months in AP patients. In the CRC group, univariate predictors of poor survival included female gender, age, American Society of Anesthesiologists score, preoperative albumin, completeness of cytoreduction, and morbidity. In a multivariate Cox regression model, incomplete cytoreduction (CC-2/3) and female gender were joint significant predictors of poor survival. In the AP group, significant univariate predictors of poor survival included higher EBL and PCI score. In a multivariate Cox regression model, blood loss of >500 ml and a body mass index of <25 kg/m(2) were joint significant predictors of poor survival.

CONCLUSIONS

AP signet cell tumors demonstrate a more favorable outcome than CRC signet cell tumors after CRC/HIPEC for carcinomatosis, suggesting an underlying difference in biology. CRS/HIPEC does not confer survival benefit in colorectal signet ring carcinomatosis unless complete cytoreduction can be achieved, whereas appendiceal signet ring carcinomatosis may benefit, regardless of resectability.

Prognosis and value of adjuvant chemotherapy in stage III mucinous colorectal carcinoma

BACKGROUND

Colorectal mucinous adenocarcinoma (MC) has been associated with impaired prognosis compared with nonmucinous adenocarcinoma (NMC). Response to palliative chemotherapy is poor in metastatic disease, but the benefit of adjuvant chemotherapeutic treatment has never been assessed in large patient groups. This study analyses overall survival and efficacy of adjuvant chemotherapy in terms of survival in patients following radical resection for MC.

PATIENTS AND METHODS

This population-based study involved 27 251 unselected patients diagnosed with colorectal carcinoma between 1990 and 2010 and recorded in a prospective pathology-based registry. Kaplan-Meier analysis and log-rank testing were used to estimate survival. Cox proportional hazard model was used to calculate multivariate hazard ratios for death.

RESULTS

MC was found in 12.3% (N = 3052) of colorectal tumors with a different distribution compared with NMC, with 24.4% located in the rectum and 54.3% in the proximal colon (versus 38.0% and 30.6%), P < 0.0001. NMC was more often classified as stage I disease than MC (20.5% versus 10.9%), P < 0.0001. After adjustments for covariates, MC was associated with a higher risk of death only when located in the rectum [hazard ratio 1.22; 95% confidence interval (CI) 1.11-1.34]. Multivariate regression analysis showed a similar survival after adjuvant chemotherapy for stage III MC and NMC patients.

CONCLUSIONS

The poor prognosis for MC is only present in rectal cancer. In the adjuvant setting, there is no difference in the efficacy of chemotherapy between MC and NMC; therefore, current adjuvant treatment recommendations should not take histology into account.

Does the prognosis of colorectal mucinous carcinoma depend upon the primary tumour site? Results from two independent databases

AIMS

Mucinous adenocarcinoma (MUC) is a commonly studied histological subtype of colorectal adenocarcinoma. However, the prognostic value of MUC remains unclear, particularly in patients stratified by the primary tumour site. We aimed to analyse the prognostic value of MUC in colorectal cancer.

METHODS AND RESULTS

We utilized two independent data sets in this study: (i) the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) data set, and (ii) the data set from a single Chinese institution (the Department of Surgical Oncology at the First Hospital of China Medical University). Patient survival was analysed using Kaplan-Meier survival curves, and comparisons were performed using the log-rank test. MUC occurred more frequently in patients who exhibited higher pT category, higher pN category, higher TNM stage, left-sided colon cancer and higher histological grade. Based on the SEER data set, MUC was an independent negative survival indicator in rectal cancer (HR 1.125, 1.056-1.199; P < 0.001). While there was no significant association in left-sided colon cancer (P > 1.000), MUC was an independent protective survival indicator in right-sided colon cancer (HR 0.925, 0.888-0.962; P < 0.001).

CONCLUSIONS

MUC was associated independently with poorer outcome for rectal cancer and was an independent protective survival indicator in right-sided colon cancer. MUC exhibited a different outcome depending on tumour position for patients with colorectal cancer.

Prognostic value of mucinous histology depends on microsatellite instability status in patients with stage III colon cancer treated with adjuvant FOLFOX chemotherapy: a retrospective cohort study

BACKGROUND

The close association between mucinous histology and microsatellite instability (MSI) may have hindered the evaluation of prognostic significance of mucinous histology. The aim of this retrospective study was to investigate whether mucinous histology was associated with a worse prognosis, independent of MSI status, compared to nonmucinous histology in patients with stage III colon cancer.

METHODS

This study enrolled 394 consecutive patients with stage III colorectal cancer treated with adjuvant FOLFOX after curative resection (R0). Clinicopathological information was retrospectively reviewed. Tumors were analyzed for MSI by polymerase chain reaction to determine MSI status. Kaplan-Meier method, log-rank test, and Cox proportional hazard regression models were used.

RESULTS

The estimated rate of 3-year disease-free survival (DFS) in patients with nonmucinous adenocarcinoma (NMA 79.2 %) was significantly greater than that in patients with mucinous adenocarcinoma (MA) and adenocarcinoma with mucinous component (MC) (56.9 %; log-rank, P = 0.002). In univariate analysis, histology (NMA vs. MA/MC), American Joint Committee on Cancer stage (IIIA, IIIB, and IIIC), and lymphovascular invasion (present vs. absent) were significantly associated with DFS. In multivariate analysis, mucinous histology (MA/MC) was associated with decreased DFS in all patients (hazard ratio 1.82, 95 % confidence interval 1.03-3.23, P = 0.0403). In patients with MA/MC, no difference in DFS was observed between MSI and microsatellite stability (log-rank, P = 0.732).

CONCLUSIONS

Mucinous histology is an independent poor prognostic factor for DFS in patients with stage III colon cancer after adjuvant FOLFOX chemotherapy.

Escalated radiation dose alone vs. concurrent chemoradiation for locally advanced and unresectable rectal cancers: results from phase II randomized study

PURPOSE

This trial was undertaken to compare the rates of resectability between patients treated with neoadjuvant concurrent chemoradiation vs. boosted radiotherapy alone.

MATERIALS AND METHODS

Patients with clinically unresectable rectal cancer were randomized to receive external beam radiation therapy (EBRT) to pelvis (45 Gy) with concurrent oral Capecitabine (CRT group; Arm 1) or EBRT to pelvis (45 Gy) alone followed by 20 Gy dose of localized radiotherapy boost to the primary tumor site (RT with boost group, Arm 2). All patients were assessed for resectability after 6 weeks by clinical examination and by CT scan and those deemed resectable underwent surgery.

RESULTS

A total of 90 patients were randomized, 46 to Arm 1 and 44 to Arm 2. Eighty seven patients (44 in Arm 1 and 41 in Arm 2) completed the prescribed treatment protocol. Overall resectability rate was low in both the groups; R0 resection was achieved in 20 (43 %) patients in Arm 1 vs. 15 (34 %) in Arm 2. Adverse factors that significantly affected the resectability rate in both the groups were extension of tumor to pelvic bones and signet ring cell pathology. Complete pathological response was seen in 7 and 11 %, respectively. There was greater morbidity such as wound infection and delayed wound healing in Arm 2 (16 vs. 40 %; p = 0.03).

CONCLUSION

Escalated radiation dose without chemotherapy does not achieve higher complete (R0) tumor resectability in locally advanced inoperable rectal cancers, compared to concurrent chemoradiation.

TNM stages and prognostic features of colorectal mucinous adenocarcinomas: a meta analysis

AIM

The significance of the mucinous adenocarcinoma in TNM staging and prognosis for colorectal tumor patients is still controversial. The aim was to provide a meta-analysis for TNM staging and prognostic features of colorectal tumors.

METHODS

30 individual case-control studies were finally included into this meta-analysis, involving a total of 444,489 cancer cases and 45,050 mucinous adenocarcinomas, of relations with TNM staging and prognostic features.

RESULTS

Compared to non-mucinous adenocarcinoma patients, the TNM IV stage accounted for a larger percentage of mucinous adenocarcinomas (OR=1.48, 95%CI 1.28-1.71, POR<0.001) and the prognosis was significantly poor (HR=1.06, 95%CI 1.04-1.08, P<0.001). After heterogeneity testing, the results was similar to the holistic approach outcome (HR=1.48, 95%CI 1.35-1.62, P<0.001).

CONCLUSION

Compared to patients with non-mucinous adenocarcinomas, mucinous adenocarcinoma patients with later TNM staging make up a big percentage, and mucinous adenocarcinoma is an independent risk factor for poor prognosis.

Prognostic implication of mucinous histology in colorectal cancer patients treated with adjuvant FOLFOX chemotherapy

Background:

There have been controversies in prognostic impact of mucinous histology on colorectal cancer, and its implication in patients treated with adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) is unclear.

Methods:

Stage II and III colorectal cancer patients who underwent curative resection followed by adjuvant FOLFOX were included. Patients were grouped according to the mucinous content: >50%, mucinous adenocarcinoma (MAC); <50%, adenocarcinoma with intermediated mucinous component (AIM); and without any mucinous component, non-MAC (NMA). Clinicopathological features and disease-free survival (DFS) were compared.

Results:

Among a total of 521 patients, 27 patients (5.2%) had MAC, 41 patients (7.9%) had AIM, and 453 patients (86.9%) had NMA. Mucinous adenocarcinoma and AIM had higher frequency of proximal location and microsatellite instability, but lower frequency of angiolymphatic invasion. Disease-free survival was significantly worse in the MAC compared with NMA (3-year DFS 57% and 86%, respectively; P<0.001) and AIM (3-year DFS 87%, P=0.01 vs MAC). Multivariate analysis revealed MAC as an independent negative prognostic factor of DFS (adjusted hazard ratio 7.96, 95% confidence interval 3.76–16.8).

Conclusion:

Adenocarcinoma with intermediated mucinous component and MAC have distinct clinicopathological features compared with NMA. Mucinous adenocarcinoma has an adverse prognostic impact on stage II or III colorectal cancer treated with adjuvant FOLFOX.

Colorectal carcinoma: Pathologic aspects

Colorectal carcinoma is one of the most common cancers and one of the leading causes of cancer-related death in the United States. Pathologic examination of biopsy, polypectomy and resection specimens is crucial to appropriate patient managemnt, prognosis assessment and family counseling. Molecular testing plays an increasingly important role in the era of personalized medicine. This review article focuses on the histopathology and molecular pathology of colorectal carcinoma and its precursor lesions, with an emphasis on their clinical relevance.

Colorectal carcinoma: Pathologic aspects

Colorectal carcinoma is one of the most common cancers and one of the leading causes of cancer-related death in the United States. Pathologic examination of biopsy, polypectomy and resection specimens is crucial to appropriate patient managemnt, prognosis assessment and family counseling. Molecular testing plays an increasingly important role in the era of personalized medicine. This review article focuses on the histopathology and molecular pathology of colorectal carcinoma and its precursor lesions, with an emphasis on their clinical relevance.

BRAF-mutated, microsatellite-stable adenocarcinoma of the proximal colon: an aggressive adenocarcinoma with poor survival, mucinous differentiation, and adverse morphologic features

The association of BRAF V600E mutation and the presence of the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) often confound analysis of BRAF mutation status and survival in colorectal carcinoma. We evaluated a consecutive series of proximal colonic adenocarcinomas for mismatch repair protein abnormalities/MSI, BRAF V600E mutation, and KRAS mutations in an attempt to determine the prognostic significance of these abnormalities and to correlate histopathologic features with molecular alterations. Of the 259 proximal colon adenocarcinomas analyzed for mismatch repair protein abnormalities and/or MSI, 181 proximal colonic adenocarcinomas demonstrated proficient DNA mismatch repair using either MSI PCR (n=78), mismatch repair protein immunohistochemistry (n=91), or both MSI PCR and mismatch repair immunohistochemistry (n=12); these were tested for the BRAF V600E mutation and KRAS mutations. Compared with BRAF wild-type adenocarcinomas, BRAF-mutated adenocarcinomas more frequently demonstrated adverse histologic features such as lymphatic invasion (16/20, 80% vs. 75/161, 47%; P=0.008), mean number of lymph node metastases (4.5 vs. 2.2; P=0.01), perineural invasion (8/20, 40% vs. 13/161, 8%; P=0.0004), and high tumor budding (16/20, 80% vs. 83/161, 52%; P=0.02). BRAF-mutated adenocarcinomas frequently contained areas with mucinous histology (P=0.0002) and signet ring histology (P=0.03), compared with KRAS-mutated and KRAS/BRAF wild-type adenocarcinomas. Clinical follow-up data were available for 173 proximal colonic adenocarcinomas with proficient DNA mismatch repair. Patients with BRAF-mutated adenocarcinomas had a median survival of 12.3 months with a 1-year probability of survival of 54% and a 1-year disease-free survival of 56%. Patients with KRAS-mutated and KRAS/BRAF wild-type adenocarcinomas had significantly improved overall survival (unadjusted log-rank P=0.03 and unadjusted log-rank P=0.0002, respectively) and disease-free survival (unadjusted log-rank P=0.02 and unadjusted log-rank P=0.02, respectively) compared with patients with BRAF-mutated adenocarcinomas. When adjusting for tumor stage, survival analysis demonstrated that patients with BRAF-mutated adenocarcinoma had a significantly poor overall survival and disease-free survival (hazard ratios 6.63, 95% CI, 2.60-16.94; and 6.08, 95% CI, 2.11-17.56, respectively) compared with patients with KRAS/BRAF wild-type adenocarcinomas. No significant difference in overall or disease-free survival was identified between patients with KRAS-mutated and KRAS/BRAF wild-type adenocarcinomas. Our results demonstrate that BRAF-mutated proximal colon adenocarcinomas with proficient DNA mismatch repair have a dismal prognosis with an aggressive clinical course and often display mucinous differentiation, focal signet ring histology, and other adverse histologic features such as lymphatic and perineural invasion and high tumor budding.

Loss of heterozygosity, aberrant methylation, BRAF mutation and KRAS mutation in colorectal signet ring cell carcinoma

The relationship of molecular abnormalities with clinicopathologic features and survival in colorectal signet ring cell carcinoma, and its comparison with mucinous and conventional adenocarcinomas, has not been well studied. High-level microsatellite instability, loss of heterozygosity (LOH) at four loci, CpG island methylation phenotype based on seven loci, BRAF V600E mutation and KRAS mutation in signet ring cell carcinoma were compared with mucinous and conventional adenocarcinomas. The relationship of these molecular features in signet ring cell carcinoma with clinicopathologic features and survival was examined. LOH was observed in 93% of signet ring cell carcinomas compared with 62 and 70% of mucinous and conventional adenocarcinomas. Also, 80% of signet ring cell carcinomas with high-level microsatellite instability showed LOH compared with 14% each of mucinous and conventional adenocarcinomas. High-level microsatellite instability, CpG island methylation phenotype-positive status and BRAF V600E mutation were more often seen in signet ring cell carcinoma and mucinous adenocarcinoma compared with conventional adenocarcinoma. BRAF V600E mutation was significantly associated with CpG island methylation phenotype-positive status. Stage and BRAF V600E mutation in microsatellite-stable cases were the only variables with an affect on survival. In conclusion, chromosomal instability manifested by LOH is nearly a universal finding in signet ring cell carcinoma, including cases with high-level microsatellite instability. This may explain the aggressive behavior of signet ring cell carcinoma irrespective of high-level microsatellite-instability status. BRAF V600E mutation and CpG island methylation phenotype-positive status are similar in signet ring cell carcinoma and mucinous adenocarcinoma but more frequent when compared with conventional adenocarcinoma. In signet ring cell carcinoma, BRAF V600E mutation adversely affects survival in microsatellite-stable tumors, but not in high-level microsatellite-unstable tumors. The high frequency of methylation and BRAF V600E mutation suggests that many signet ring cell carcinomas may be related to the serrated pathway of carcinogenesis.

Clinicopathology and outcomes for mucinous and signet ring colorectal adenocarcinoma: analysis from the National Cancer Data Base

PURPOSE

We evaluated clinical features and survival outcomes among patients with signet ring and mucinous histologies of colorectal adenocarcinoma by using data from the National Cancer Data Base (NCDB).

METHODS

Patients aged 18-90 years with colorectal adenocarcinoma diagnosed between 1998 and 2002 were identified from the NCDB. Site-stratified (colon vs. rectum) survival analysis was performed by multivariate relative survival adjusted for multiple clinicopathologic and treatment variables.

RESULTS

The study included 244,794 patients: 25,546 (10%) with mucinous, 2,260 (1%) with signet ring, and 216,988 (89%) with nonmucinous, non-signet ring adenocarcinoma. Mucinous and signet ring cancers were more frequently right-sided (60% and 62%, respectively) than were nonmucinous, non-signet ring adenocarcinomas (42%, P < 0.001). Signet ring histology was associated with a higher stage (P < 0.001), and 77.2% of signet ring tumors were high-grade lesions, compared with 20% of mucinous and 17% of non-signet ring, nonmucinous adenocarcinomas (P < 0.001). After adjustment for covariates, signet ring histology was independently associated with higher risk of death [hazard ratio (HR) 1.42, 95% confidence interval (CI) 1.33-1.51, and HR 1.57, CI 1.38-1.77, for tumors located in the colon and rectum, respectively]. Mucinous tumors of the rectum (HR 1.22, CI 1.16-1.29), but not the colon (HR 1.03, CI 1.00-1.06), were associated with increased risk of death.

CONCLUSIONS

Signet ring cell adenocarcinomas of the colon and rectum and mucinous adenocarcinomas of the rectum are associated with poorer survival. These aggressive histologic variants of colorectal adenocarcinoma should be targeted for research initiatives to improve outcomes.

Mucinous differentiation in colorectal cancer--indicator of poor prognosis?

AIMS

  To analyse the prognostic impact of mucinous differentiation in colorectal mucinous adenocarcinomas and adenocarcinomas with a mucinous component.

METHODS AND RESULTS

  A total of 381 tumours were reviewed for mucinous differentiation by two independent pathologists. Mismatch repair status was assessed by immunohistochemistry. Prognostic significance was assessed by univariate and multivariate analyses. Eighty-one (21%) tumours were Union Internationale Contre le Cancer (UICC) Stage I, 120 (31%) Stage II, 126 (33%) Stage III and 54 (14%) Stage IV. Mucinous adenocarcinomas accounted for 12% and adenocarcinomas with a mucinous component for 19% of tumours. Mucinous differentiation was associated significantly with mismatch repair protein deficiency. The presence of extracellular mucin, regardless of extent, did not affect patients' outcome, while tumour grade, vascular and perineural invasion, tumour border configuration and budding were associated significantly with outcome. Cox analysis proved venous invasion to be an independent predictor of outcome in mucinous adenocarcinomas and both venous invasion and tumour budding as independent predictors of outcome in adenocarcinomas with any amount of mucin.

CONCLUSIONS

  Mucinous adenocarcinomas and/or adenocarcinomas with mucinous component do not differ from conventional adenocarcinomas with respect to prognosis and histological predictors of outcome. Hence, recording of mucinous differentiation may be used as an indicator of mismatch repair deficiency, but not for prognostic stratification.

Suppression of mucin 2 enhances the proliferation and invasion of LS174T human colorectal cancer cells

Altered expression of MUC2 (mucin 2) is related to tumour development in colorectal cancer. Colorectal mucinous carcinomas are positive for MUC2 expression, whereas MUC2 is down-regulated in non-mucinous adenocarcinomas. In the present study, we down-regulated MUC2 expression by RNAi (RNA interference) and investigated the in vitro and in vivo effects on the proliferation and invasion/migration potential of the LS174T human colorectal cancer cells. The LS174T cell line is a goblet-cell-like colorectal cancer cell line that continuously produces high levels of MUC2. Inhibition of MUC2 expression in vitro by transfection of LS174T cells with the recombinant plasmid pcDNA6.2-GW/EmGFP-miR-MUC2 led to the production of a stably transfected MUC2-RNAi LS174T cell line. The proliferation and invasion/migration of MUC2-RNAi cells in vitro were significantly higher than those in control cells, as assessed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide], colony formation and transwell assays. Subcutaneous injection of MUC2-RNAi LS174T cells into nude mice resulted in the development of subcutaneous tumours visible to the naked eye after 1 week. The growth rate of tumours derived from MUC2-RNAi LS174T cells was greater than that of tumours derived from control cells. Ki67 and matrix metalloproteinase-9 proteins were detected by immunohistochemistry in the xenografts. The expression levels of these proteins were higher in the MUC2-RNAi-derived xenografts than in xenografts derived from control cells. Although the role of MUC2 in colorectal tumorigenesis is not fully understood, these results strongly suggest a relationship between the proliferation and invasion of LS174T cells and the expression of MUC2.

Colorectal carcinoma in different age groups : a histopathological analysis

PURPOSE

Although colorectal cancer is typical in the older population, tumor onset before age 40 is not infrequent. However, the behavior, characteristics, and prognosis of this disease in young patients are unclear when compared to the older population. It is believed that young patients have a poor prognosis. We hypothesized that young patients have a poor prognosis because they have advanced-stage cancer with more aggressive pathologic features.

METHODS

Using a university hospital database, we analyzed the histopathological features of three groups of patients with a diagnosis of colorectal cancer: young age group (patients 40 years and younger), intermediate age group (patients 41-80 years old), and old age group (patients 81 years and older).

RESULTS

A total of 653 cases of colorectal cancer were analyzed. The young age group comprised 48 patients (7.4%), the intermediate age group comprised 538 patients (82.4%) and the old age group consisted of 67 patients (10.3%).The gender distribution was similar between the groups. The mean age of the young, intermediate, and old age groups were 34.5 (±5.0), 61.7 (±11.1) and 85.1 (±4.6) years old, respectively. The pathological features analyzed such as lymph node involvement, tumor histological classification and grade, venous, neural and lymphatic invasion, T and N classification of the TNM System, and Astler-Coller classification were similar between the age groups.

CONCLUSIONS

The colorectal histopathological features in young patients are similar to older patients. More aggressive characteristics or more advanced stage are not seen in younger patients.

Diffusion-weighted imaging findings of mucinous carcinoma arising in the ano-rectal region: comparison of apparent diffusion coefficient with that of tubular adenocarcinoma

PURPOSE

To determine the diffusion-weighted imaging (DWI) characteristics of ano-rectal mucinous carcinoma. Apparent diffusion coefficient (ADC) and DWI findings for mucinous and tubular adenocarcinomas were retrospectively compared.

MATERIALS AND METHODS

Eight-one consecutive surgically resected ano-rectal adenocarcinomas were evaluated. The patient group consisted of 15 mucinous and 66 tubular adenocarcinomas. The DWI signal intensity (SI) pattern of each tumor was visually classified into one of three groups. Differences in the proportions in each group were statistically compared for the two types of tumor. The ADCs of each tumor, calculated from two different b-factors (0 and 1500 s/mm(2)) were compared statistically.

RESULTS

Visual evaluation revealed ten mucinous carcinomas as predominantly hypointense lesions, and the remaining five as mixed SI lesions. Sixty-one of 66 tubular adenocarcinomas had hyperintensities; the remaining five had mixed SI. The different proportions in each group were statistically significant. The mean ADC for mucinous carcinomas was 1.49 ± 0.34 × 10(-3) mm(2)/s whereas that for tubular adenocarcinomas was 0.80 ± 0.15 × 10(-3) mm(2)/s. The difference between those figures was statistically significant.

CONCLUSION

In DWI, mucinous carcinomas had higher ADCs and lower SI than tubular adenocarcinomas. DWI and ADC measurements were useful for differentiating these two tumors.

Perspectives on current tumor-node-metastasis (TNM) staging of cancers of the colon and rectum

Improvements in classifications of cancers based on discovery and validation of important histopathological parameters and new molecular markers continue unabated. Though still not perfect, recent updates of classification schemes in gastrointestinal oncology by the American Joint Commission on Cancer (tumor-node-metastasis [TNM] staging) and the World Health Organization further stratify patients and guide optimization of treatment strategies and better predict patient outcomes. These updates recognize the heterogeneity of patient populations with significant subgrouping of each tumor stage and use of tumor deposits to significantly "up-stage" some cancers; change staging parameters for subsets of IIIB and IIIC cancers; and introduce of several new subtypes of colon carcinomas. By the nature of the process, recent discoveries that are important to improving even routine standards of patient care, especially new advances in molecular medicine, are not incorporated into these systems. Nonetheless, these classifications significantly advance clinical standards and are welcome enhancements to our current methods of cancer reporting.

Mucinous carcinomas of the ovary and colorectum: different organ, same dilemma

Mucinous carcinomas are uncommon histological types that affect several organ sites. Primary mucinous carcinomas of the ovary are distinct from other ovarian carcinoma types, but they can pose a particular challenge for correct diagnosis from metastases, which most usually originate from the colorectum. Correct diagnosis is the mainstay of treatment, because standard practice states that protocols are tailored to the primary organ site. Little is known of mutational alterations in primary and metastatic mucinous carcinomas of the ovary, and few markers exist that can discriminate between them. We reviewed commonalities between ovarian and colorectal mucinous carcinomas with respect to aetiology, molecular alterations, differential diagnosis, and implications for treatment. Although primary mucinous carcinomas of the ovary and colorectum share similar mutational patterns and unfavourable outcomes at advanced stage, compared with their non-mucinous counterparts, important differences exist with respect to mucin localisation and specific molecular alterations. Technologies--eg, next-generation sequencing--could aid identification of additional driver molecular changes that will help clarify the relation between mucinous carcinomas from different organ sites. Perhaps, then, we can consider moving towards testing and adoption of therapeutic approaches tailored to molecular characteristics of mucinous carcinomas, irrespective of organ site, so patients' survival can be optimised.

Surgical cytoreduction and survival in appendiceal cancer peritoneal carcinomatosis: an evaluation of 46 consecutive patients

BACKGROUND

Surgical cytoreduction and intraperitoneal chemotherapy is increasingly accepted as an effective treatment modality for mucinous appendiceal neoplasm. For the majority of patients with low-grade histology, outcomes have been encouraging. The survival of patients with neoplasms of malignant character is protracted and this study was designed to evaluate the effectiveness of this surgical strategy on outcomes.

METHODS

Forty-six consecutive patients with mucinous and nonmucinous appendiceal cancer with peritoneal dissemination were studied. Clinicopathological and treatment related factors were obtained from a prospective database. The study's end points of disease-free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method.

RESULTS

The median DFS and OS after cytoreduction were 20.5 and 56.4 months respectively. Five-year overall survival rate was 45%. Five independent factors associated with DFS and OS were identified through a multivariate analysis: age (DFS p = 0.001, OS p = 0.002), completeness of cytoreduction (DFS p = 0.001, OS p = 0.003), previous chemotherapy treatment (DFS p = 0.021), CA 199 levels (DFS p = 0.013), and tumor grade (OS p = 0.005).

CONCLUSIONS

Cytoreductive surgery and intraperitoneal chemotherapy may achieve long-term survival in appendiceal malignancies with peritoneal dissemination for which the predictors of outcomes identified through this study may tailor the disease management to commit patients early toward this successful surgical strategy.

Mucinous colorectal adenocarcinoma with signet-ring cells: immunohistochemical and ultrastructural study

A primary mucinous colorectal adenocarcinoma tissue with signet-ring cells, as revealed after histological evaluation, was examined ultrastructurally. The authors also analyzed the immunohistochemical data of the tissue for serotonin, vasoactive intestinal polypeptide (VIP), bombesin, somatostatin, and glucagon, using the peroxidase anti-peroxidase (PAP) method and the immunogold labeling method for light and electron microscope, respectively. Electron microscopically mucinous adenocarcinoma was characterized by the formation of small lumen. Adenocarcinoma cells were full of mucous granules of varying electron density, providing a good environment for the tumor cells to grow. They also exhibited a significant loss of microvilli and intracytoplasmic junctions, which could allow the cells to disseminate. Signet-ring cells were located in the basal site of the ducts or in the lamina propria and appeared neoplastic, with mucin accumulation intracellularly and an eccentric crescent-shaped nucleus. The cytoplasmic organelles were decreased and at the periphery of the cell. The PAP method demonstrated that these cells were strongly positive for bombesin and also positive for vasointestinal polypeptide (VIP). The immunogold method detected bombesin immunoreactivity in the vacuoles as well as in other cytoplasmic membranes, whereas VIP was localized mainly in the plasma membrane. The location of signet-ring cells combined with the immunoreactivity for bombesin and VIP indicated that signet-ring cells were of neuroendocrine origin and probably dedifferentiated enterochromaffin-like endocrine cells. These findings have implications for understanding the biological behavior of these composite malignant tumors and could help in the knowledge of the origin of signet-ring cells.

Signet-ring cell carcinoma of colorectum--current perspectives and molecular biology

PURPOSE

Colorectal signet-ring cell carcinoma (SRCC) is rare, and very little detailed information on the molecular biology of the disease is available.

METHODS

The literature on the clinical, pathological and, in particular, the molecular biology of this rare entity was critically reviewed. The reviewed articles take into account a total of 1,817 cases of SRCC, but only 143 cases have molecular data available. The characteristics of two patients with colorectal SRCC were also discussed.

RESULTS

Colorectal SRCC mostly occurs in younger patients, is larger and has different site predilection compared with conventional colorectal adenocarcinoma. It can occur as one of the synchronous cancers in the colorectum. The cancer is usually diagnosed at advanced stages because of the late manifestation of symptoms, and aggressive treatment strategy is required. Limited reports in the literature have shown that the variant of colorectal cancer demonstrated a different pattern of genetic alterations of common growth kinase-related oncogenes (K-ras, BRAF), tumour suppressor genes (p53, p16), gene methylation and cell adhesion-related genes related to the Wingless signalling pathway (E-cadherin and beta-catenin) from conventional colorectal adenocarcinoma. Colorectal SRCC also showed high expression of mucin-related genes and genes related to the gastrointestinal system. There was also a higher prevalence of microsatellite instability-high tumours and low Cox-2 expression in colorectal SRCC as opposed to conventional adenocarcinoma.

CONCLUSIONS

Colorectal SRCC has unique molecular pathological features. The unique molecular profiles in SRCC may provide molecular-based improvements to patient management in colorectal SRCC.

Colon cancer in Iceland--a nationwide comparative study on various pathology parameters with respect to right and left tumor location and patients age

Increasing evidence suggests genetic, biological and demographical difference between right and left colon cancer. Studies have also indicated age differences in the pathology of colon cancer. There is a scarcity of large-scale studies that closely examine the pathological differences regarding age and tumor location. The aim of our study was to do an extensive comparison of right- and left- sided colon cancers as well as comparing patients <50 years with older patients. A retrospective, population-based study was carried out on all patients with colon cancer in Iceland between 1955 and 2004. A total of 2293 cases were analyzed (1148 men, 1145 women). All histopathology material was re-evaluated. Differences in tumor characteristics between right and left location and younger (<50) and older (≥50) patients was evaluated in particular. Higher TNM-stage, larger tumors, vessel invasion, mucinous type, high grade and expanding tumor border occurred more frequently in right- versus left-sided lesions while annular and polypoid tumors were more common in left-sided tumors (p < 0.05). Young patients had more frequent lymph node metastases, vessel invasion, nonpolypoid lesions and infiltrating tumor border (p < 0.05). Right-sided lesions show more aggressive features, reflected in morphology and stage. Younger patients present more frequently with adverse features than do older patients. Frequency of right- and left-sided colon cancer differs by age with pronounced age-location differences in females. This supports the assumption of differences in etiology and carcinogenesis of right- and left-sided colon cancer, and between young and old patients.

Critical analysis of mucin and signet ring cell as prognostic factors in an Asian population of 2,764 sporadic colorectal cancers

INTRODUCTION

Conflicting data on the clinicopathological characteristics as well as prognosis and survival of signet ring cell (SRC) and mucinous adenocarcinomas (MA) of the colorectum persist.

METHODS

Consecutive patients (2,764) with sporadic colorectal cancer from 1999 to 2005 were evaluated. The clinicopathological characteristics of these patients were reviewed. Univariate analysis was performed, and survival curves were constructed using the Kaplan-Meier method. Multivariate analysis assessed independent prognostic factors.

RESULTS

The incidence of MA and SRC is 6% and 1.1%, respectively. MA and SRC tend to occur in patients aged <or=50 years (SRC 33%, MA 22%, ordinary adenocarcinomas (OA) 14%, p = 0.001) and are more commonly right-sided (MA 30%, SRC 27%, OA 19%, p = 0.001) than OA. SRC tend to be poorly differentiated (SRC 77%, MA 26%, OA 6%, p < 0.0001) and have a higher risk of recurrence (SRC 40%, MA 26%, OA 6%, p < 0.0001). SRC and MA are more likely to have locally advanced lesions (T3/T4; SRC 100%, MA 90%, OA 83%, p = 0.002) and lymph node metastases (SRC 89%, MA 61%, OA 52%, p < 0.0001) and present with an advanced stage at diagnosis (stage III/IV SRC 94%, MA 67%, OA 56%, p < 0.0001). SRC has poorer 5-year cancer-specific survival (CSS; 11.1%, 95% confidence interval (CI) 0-22.9%) compared with MA (46.8%, 95% CI 38.6-55.0%) and OA (58.7%, 95% CI 56.5-60.9%, p < 0.001). In a multivariate analysis, SRC is an independent poor prognostic factor (HR 1.9, 95% CI 1.1-3.0) but MA is not.

CONCLUSION

SRC and MA demonstrate clinicopathologic characteristics suggestive of a different biology compared with OA. In our dataset, SRC has a significantly poorer CSS whereas survival rates for MA are similar to OA. These characteristics are similar in both Asian and Western studies reported. Asian reports however suggest a lower incidence of MA.

The pathologist's role in rectal cancer patient assessments

Since Cuthbert Dukes fundamental work linking cancer stage to prognosis, the pathologist has had an ever-expanding role in the multidisciplinary management of rectal cancer. Gross dissection techniques and histologic evaluation are reviewed. The evolving tumor size, node status, metastasis classification (TNM) staging system is outlined. The pathologist's critical role in correctly assessing circumferential margins and establishing resection adequacy and staging accuracy via lymph node assessment is emphasized.