Colorectal cancer in Jordan and Nova Scotia: a comparative epidemiologic and histopathologic study

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.

Colorectal Cancer Prognosis: The Impact of Signet Ring Cell

Background

The prognosis for patients with colorectal cancer shows variation. The characteristics of colorectal cancer patients with signet-ring cell carcinoma (SRCC) are still not clear.

Materials and Methods

A retrospective comparison was made of the data of signet-ring cell colorectal carcinoma patients operated on between 2009 and 2018 in respect of clinicopathological and operative results, morbidity, mortality, and long-term survival.

Results

The study included a total of 34 patients comprising 26 (76%) males and 8 (24%) females with a mean age of 58 ± 11.7 years. Incidence of SRCC was determined as 1.8%. Lymphovascular invasion was determined in 22 (64%) patients. Tumors were determined as stage T2 in 8 (32%) patients, stage T3 in 9 (36%), and stage T4 in 8 (32%). According to the TNM classification, 5 (14.7%) patients were diagnosed with stage 1, 7 (20.6%) with stage 2, 15 (44.1%) with stage 3, and 7 (20.6%) with stage 4. The mean follow-up period was 40.6 ± 30.4 months, and mean disease-free follow-up was determined as 33.1 ± 36.1 months. Fifteen (44.1%) patients died because of the disease.

Conclusion

Although SRCC is a poor prognostic factor, it should be kept in mind when determining adjuvant therapies and prognosis of patients determined with advanced-stage SRCC.

Measuring quality of Life among Colorectal Cancer Patients in Jordan

Quality of life among colorectal cancer (CRC) patients was evaluated using the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) C30 and EORTC QLQ-CR29. We interviewed 74 CRC patients, and our results indicated lower anxiety functional scores and higher abdominal pain and embarrassment symptom scores among patients aged 55 and under. Patients with disease metastasis showed significantly lower global health scores and higher fatigue, loss of appetite, hair loss, and change in taste symptom scores. Scores for emotional functioning were significantly lower among patients with stage IV disease. Fatigue, nausea and vomiting, loss of appetite, abdominal pain, and change in taste symptom scores were significantly higher in patients treated with a combination of surgery and chemotherapy compared to surgery alone. Age, disease metastasis, late disease stage, and combined treatment modalities were associated with lower scores on health-related quality-of-life scales; patients likely to have low scores on these measures should receive special attention from healthcare providers and be targeted by supportive care strategies.

Nous avons évalué la qualité de vie de patients atteints du cancer colorectal à l'aide du Questionnaire C30 et EORTC QLQ-CR29 de l'Organisation européenne pour la recherche et le traitement du cancer. Nous avons interviewé 74 patients et nos résultats indiquent que les patients agés de 55 ans et moins éprouvent un moindre niveau d'anxiété alors que le niveau de douleurs abdominales et du sentiment de gêne est élevé. Les patients atteints de métastases ont démontré lors des tests que leur état général de santé était plutôt mauvais et qu'ils souffraient de fatigue accrue, de perte de cheveux et de la perte du goût L'état émotionel était à son plus bas chez les patients au stade IV de la maladie. La fatigue, la nausée, le vomissement, la perte d'appétit, les douleurs abdominales, et la perte de goût étaient significativement plus élevés chez les patients ayant été traités par chirurgie et chimiothérapie comparativement à ceux qui n'avaient subi que la chirurgie. L'âge, les métastases et le stade avancé de la maladie combinés à divers traitements médicaux sont les facteurs ayant contribué aux scores plus bas observés sur l'échelle de qualité de vie. Les patients susceptibles de démontrer de faibles résultats devraient recevoir une attention spéciale de la part des soignants et être la cible de soins de soutien appropriés à leur état.

Clinical Analysis of Primary Colorectal Signet-Ring Cell Carcinoma

The objective of the study was to investigate the clinicopathological features of primary colorectal signet-ring cell carcinoma. We retrospectively analyzed the clinical and survival data of 37 patients with primary colorectal signet-ring cell carcinoma. The mean survival time of patients in stage II, III, and IV were estimated using Student t test and the cumulative survival rates were estimated according to the method of Kaplan-Meier. The significance of the differences in survival rates were calculated using the log rank test. The incidence of primary colorectal signet-ring cell carcinoma was 1.40%, the median age of 37 patients was 50 years, the male to female ratio was 1.47:1, and 21 patients (56.8%) received a radical resection. Most patients 33 (89.2%) had an advanced tumor stage at the time of diagnosis (17 patients 45.9% stage III and 16 patients 43.2% stage IV), 34 (94.5%) patients showed a tumor depth of >T3, lymph node involvement occurred in 26 patients (70.3%), patients had a high incidence of peritoneal metastasis (16 patients 43.2% at presentation, 30 patients 81.1% at presentation and recurrence) and a low incidence of liver metastases (1 patients 2.7% at presentation, 5 patients 13.5% at presentation and recurrence). The 5-year survival rate after the initial surgery was 10.8%, the mean survival time of 37 patients was 27.1 ± 3.3 months, the mean survival time of patients in stage II, III, and IV were 47.0 ± 12.8 months, 37.1 ± 3.9 months, and 10.5 ± 1.4 months, respectively (P < .000). Colorectal signet-ring cell carcinoma is a rare neoplasm with a predominance in men. Its characteristic features were the advanced stage at the time of diagnosis, a high incidence of peritoneal metastases, a low incidence of liver metastasis, and a poor prognosis.

Direct medical cost associated with colorectal cancer in north of Jordan

Colorectal cancer (CRC) is mainly characterized as the malignant and impaired growth of rectal cells in the intestinal region. Direct medical cost is related to resources, which are directly used in treating the patient, that mainly includes the cost of drugs, diagnostic, treatment, follow-up, rehabilitation, and hospital admission. The objective of this study is to estimate and analyze direct medical costs attributable to CRC in Jordan. A retrospective analysis of a cohort patients treated for CRC data has been performed to determine direct medical costs attributable to CRC in Jordan. The prevalence-based approach has been used in addition to the "bottom up" approach to accumulate 1-year time costs of CRC. Demographic, clinical, and economic data have been collected and analyzed using SPSS for windows. Costs were estimated by a bottom-up approach, in which each service component was identified and valued at the most detailed level, to provide greater transparency and reliability in economic evaluation of health care services. This study quantified the economic burden associated with CRC by Jordanian patients in King Abdullah University Hospital from the perspective of health care providers (public sector). Total CRC cost in the year 2014 was estimated to JD 695,608, and the most expensive stage for all sites was stage 4 reaching a cost of JD 5147. Advanced disease stages were associated with an increase in total cost and chemotherapy costs. In conclusion, results of this study propose that direct medical costs associated with CRC are considerable. Most of the cost was devoted for medications, primarily chemotherapy. Advanced stages were associated with higher cost and largest number of patients.

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.

Novel KRAS gene mutations in sporadic colorectal cancer

Introduction

In this article, we report 7 novel KRAS gene mutations discovered while retrospectively studying the prevalence and pattern of KRAS mutations in cancerous tissue obtained from 56 Saudi sporadic colorectal cancer patients from the Eastern Province.

Methods

Genomic DNA was extracted from formalin-fixed, paraffin-embedded cancerous and noncancerous colorectal tissues. Successful and specific PCR products were then bi-directionally sequenced to detect exon 4 mutations while Mutector II Detection Kits were used for identifying mutations in codons 12, 13 and 61. The functional impact of the novel mutations was assessed using bioinformatics tools and molecular modeling.

Results

KRAS gene mutations were detected in the cancer tissue of 24 cases (42.85%). Of these, 11 had exon 4 mutations (19.64%). They harbored 8 different mutations all of which except two altered the KRAS protein amino acid sequence and all except one were novel as revealed by COSMIC database. The detected novel mutations were found to be somatic. One mutation is predicted to be benign. The remaining mutations are predicted to cause substantial changes in the protein structure. Of these, the Q150X nonsense mutation is the second truncating mutation to be reported in colorectal cancer in the literature.

Conclusions

Our discovery of novel exon 4 KRAS mutations that are, so far, unique to Saudi colorectal cancer patients may be attributed to environmental factors and/or racial/ethnic variations due to genetic differences. Alternatively, it may be related to paucity of clinical studies on mutations other than those in codons 12, 13, 61 and 146. Further KRAS testing on a large number of patients of various ethnicities, particularly beyond the most common hotspot alleles in exons 2 and 3 is needed to assess the prevalence and explore the exact prognostic and predictive significance of the discovered novel mutations as well as their possible role in colorectal carcinogenesis.

Distinct genetic and epigenetic signatures of colorectal cancers according to ethnic origin

BACKGROUND

The outcome of colorectal cancer varies depending on ethnic origin. Egyptian colorectal carcinoma is surprisingly young-age disease with high proportion of rectal and advanced stage cancers.

METHODS

We characterized 69 sporadic Egyptian colorectal cancers for promoter methylation at 24 tumor suppressor genes, microsatellite instability, and expression of mismatch repair, p53, and β-catenin proteins. Data were compared with 80 Western colorectal carcinoma of sporadic and familial origin from Finland.

RESULTS

Egyptian colorectal carcinomas showed significantly higher methylation of the microsatellite stable (MSS) tumors as reflected by the average number of methylated genes per case (P = 0.00002) and tumor suppressor gene methylator phenotype (TSGMP), defined here as methylation of ≥ 5 genes, (P = 0.0001) compared with the sporadic Western cancers. The TSGMP was associated with advanced stage in the Egyptian cancers (P = 0.0016). Four genes were differentially methylated between Egyptian and Western cases, of which the association of CDKN2B/p15 methylation with Egyptian origin was outstanding (P = 4.83 E-10). Egyptian carcinoma also showed significantly lower frequency of nuclear β-catenin localization than the sporadic Western cancers (P = 0.00006) but similar to that of the familial Western subset designated as familial colorectal cancer type X.

CONCLUSIONS

We show novel pathway in colon carcinogenesis marked by high methylation of MSS cancers, remarkable CDKN2B/p15 methylation, and low frequency of Wnt signaling activation.

IMPACT

Our findings highlight the possible effect of environmental exposures in carcinogenesis through DNA methylation and should have applications in prevention, molecular diagnosis, prognosis, and treatment.

Gene methylation of SFRP2, P16, DAPK1, HIC1, and MGMT and KRAS mutations in sporadic colorectal cancer

The aim of this study was to investigate the methylation of the SFRP2, P16, DAPK1, HIC1, and MGMT genes, as well as the mutation of amino acid codons 12 and 13 of the KRAS gene in normal and tumor tissue DNA of patients diagnosed with sporadic colorectal cancer (SCRC). The methylation of gene regions and the KRAS mutations of normal (N) and tumor tissue (T) DNA obtained from 17 patients diagnosed with SCRC and 20 healthy controls were investigated using the polymerase chain reaction and reverse-hybridization methods. There was an Asp mutation in four patients, an Asp and Ser mutations in one patient in codon 12 of the KRAS gene, and an Asp mutation in codon 13 in eight patients. Overall promoter methylation (OPM) in the SFRP2 gene was observed in one N and four T, whereas partial promoter methylation (PPM) was observed in two N and five T. OPM in the P16 gene was present in one T. In the DAPK1 gene, OPM existed in seven T and five N, while PPM was present in two N. In the HIC1 gene, OPM was demonstrated in three T, while PPM was noted in two N; however, no methylation existed in N. In the MGMT gene, OPM occurred in five T and two N, and PPM was present in one T. KRAS mutations in Turkish patients with SCRC are similar to those of other population groups. Methylations in the genes, which underwent methylation analysis, were higher in T in comparison with N, and it has been suggested that significant results would be obtained by making a study with a larger population.

Differing DNA methylation patterns and gene mutation frequencies in colorectal carcinomas from Middle Eastern countries

PURPOSE

The epidemiology of colorectal carcinoma is well known to differ among countries but the molecular characteristics are usually assumed to be similar. International differences in molecular pathology have not been studied extensively but have implications for the management of patients in different countries and of immigrant patients.

EXPERIMENTAL DESIGN

We evaluated the CpG island methylator phenotype pathway characterized by concordant methylation of gene promoters that often silences transcription of the genes, the microsatellite instability pathway, and K-ras and p53 gene status in 247 colorectal carcinomas from the three selected Middle Eastern countries of Egypt, Jordan, and Turkey.

RESULTS

Colorectal carcinoma from Egypt had the lowest frequencies of methylation. In multinomial logistic regression analysis, Jordanian colorectal carcinoma more frequently had methylation involving the p16 tumor suppressor gene (odds ratio, 3.5; 95% confidence interval, 1.2-10.6; P = 0.023) and MINT31 locus (odds ratio, 2.3; 95% confidence interval, 1.0-5.1; P = 0.041). The K-ras proto-oncogene was more frequently mutated in colorectal carcinoma from Turkey (odds ratio, 2.9; 95% confidence interval, 1.2-6.7; P = 0.016), but p53 overexpression was more common in both Jordanian and Turkish colorectal carcinoma than in Egyptian cases (odds ratio, 2.5; 95% confidence interval, 1.2-5.5; P = 0.019; and odds ratio, 3.6; 95% confidence interval, 1.8-7.1; P = 0.0003, respectively). The findings in Turkish colorectal carcinoma were most similar to those reported for Western cases.

CONCLUSIONS

Colorectal carcinoma from Middle Eastern countries have differing gene methylation patterns and mutation frequencies that indicate dissimilar molecular pathogenesis, probably reflecting different environmental exposures. These molecular differences could affect prevention strategies, therapeutic efficacy, and transferability of clinical trial results.

Colorectal cancer in Egypt

PURPOSE

The aim of this study was to review the age distribution and pathology features of colorectal cancer in Egypt.

METHODS

A seven-year review (retrospective in first six years, prospective in the seventh) of all colorectal adenocarcinoma patients (N = 177; 104 males; mean age, 46; range, 19-74 years) presented to the Department of Surgery, Ain Shams University, was performed. Data from three other major hospitals throughout the country were retrieved and compared with Ain Shams data. Retrospective data were retrieved from patients' files and surgery and pathology records. Family history of colorectal cancer and other characteristic hereditary nonpolyposis colorectal cancer tumors was obtained prospectively in all patients.

RESULTS

According to Ain Shams data, the disease had no predilection to a specific age group. Thirty-eight percent of the tumors occurred in patients aged less than 40 years, and only 15 percent of patients were aged above 60 years. None of the young patients fulfilled the Amsterdam criteria for hereditary nonpolyposis colorectal cancer. Seventy-five percent of tumors occurred in the left side, 3 percent were Dukes A, and 58 percent were Dukes C. Synchronous and metachronous tumors occurred in 2.8 and 4.5 percent of patients, respectively. Adenomas were present in 5.6 percent of patients and bilharziasis in 3.4 percent of resection specimens. Data from different centers were remarkably similar to Ain Shams results.

CONCLUSION

Colorectal cancer in Egypt has no age predilection and more than one-third of tumors affects a young population. The high prevalence in young people can neither be explained on a hereditary basis nor can it be attributed to bilharziasis. The disease usually presents at an advanced stage, and predisposing adenomas are rare. Similarity of the data from different centers suggests that this is the picture of colorectal cancer typical of Egypt.

Primary colorectal signet-ring cell carcinoma in Singapore

BACKGROUND

Primary colorectal signet-ring cell carcinoma is a rare but distinctive tumour of the colon and rectum. The clinicopathological features are still controversial. The aim of this study is to review the clinicopathological features and management of this type of tumour in our hospital.

METHODS

The clinicopathological features and survival data of all cases of primary colorectal signet-ring cell carcinoma were reviewed retrospectively.

RESULTS

There were nine cases of primary colorectal signet-ring cell carcinoma in 3000 consecutive colorectal carcinoma patients seen from 1989 to 1999. There were seven male and two female patients with a mean age of 54.7 years. Three patients were younger than 40 years. The common presenting symptoms were rectal bleeding (33%) and small bowel obstruction (33%). Two (22%) patients required emergency surgery due to acute small bowel obstruction. The most common tumour location was the right colon (44%) followed by the rectum (33%). All nine patients presented at a very late stage of disease. A majority (77%) had Dukes' C disease while two (22%) had Dukes' D disease with distant dissemination. Peritoneal spread (33%) was the most frequent way of dissemination. There was no patient with liver metastases at the time of diagnosis and initial presentation. The mean survival time was 30 (range 5-108) months. The 5-year survival rate was 12%.

CONCLUSIONS

Primary colorectal signet-ring cell carcinoma is frequently diagnosed late with a very poor prognosis. A high incidence of peritoneal seeding and low incidence of liver metastases appears to be a characteristic of signet-ring cell carcinoma of the colon and rectum.

Ordinary colorectal adenocarcinoma vs. primary colorectal signet-ring cell carcinoma: study matched for age, gender, grade, and stage

PURPOSE

This study contributes to the characterization of primary colorectal signet-ring cell cancer in contrast to ordinary colorectal carcinoma. Primary colorectal signet-ring cell cancer is a rare but distinctive primary neoplasm of the large bowel with still-controversial clinicopathologic features.

METHODS

Clinicopathologic features and survival data are evaluated in comparison with those of the ordinary colorectal adenocarcinoma (non-signet colorectal carcinoma) in a retrospective study matched for age, gender, grade, and stage.

RESULTS

In a series of 1,600 consecutive colorectal cancer patients since 1979, 14 patients (0.88 percent) with a signet-ring cell cancer were identified. Gender ratio was balanced, and mean age was 67.5 years. The majority of patients had an advanced tumor stage at the time of diagnosis (57.1 percent Stage IV and 35.7 percent Stage III). Median survival time was only 16 months. In a study matched for age, gender, grade, and stage, a lower survival rate was found for patients with signet-ring cell cancer, but the difference did not reach statistical significance. In contrast to non-signet colorectal carcinoma, signet-ring cell cancer was characterized by a significantly higher incidence of peritoneal tumor spread (64.3 percent) and a lower incidence of hepatic metastases (14.3 percent).

CONCLUSIONS

Signet-ring cell cancer represents a rare but distinctive primary neoplasm of the large bowel. It is frequently diagnosed in an advanced tumor stage, thus showing an overall poorer prognosis than nonsignet colorectal carcinoma. Usually only palliative surgery is possible. A high incidence of peritoneal seeding and a low incidence of hepatic metastasis is characteristic of signet-ring cell cancer.

Focus of signet ring cell carcinoma in an adenoma of the sigmoid colon

A case of a pedunculated adenomatous polyp of the sigmoid colon was found to have a primary focus of signet ring cell carcinoma. Histologic examination of the medium-sized polyp was consistent with an adenoma to carcinoma sequence for signet ring cell carcinoma of the colon, similar to that for the common adenocarcinomas.

Signet-ring cell carcinoma of the colon and rectum: a matched control study

PURPOSE

There is little information comparing signet-ring cell carcinoma to common non-signet-ring cell colon and rectal cancers. The aim of this study was to better define the clinicopathologic differences between these two distinct entities.

METHODS

Using a prospective database of 5,350 surgical patients with rectal cancers operated on at Memorial Sloan-Kettering Cancer Center between 1986 and 1997, 46 patients with signet-ring cell carcinoma were identified. Signet-ring cell carcinoma lesions were those in which signet-ring cells constituted more then 50 percent of the tumor. Six patients who presented with recurrent disease were excluded from the study. Control patients were matched for age, gender, TNM stage, primary site, procedure, and adjuvant therapy. Age, primary site of the tumor, stage at presentation, and survival times of patients with signet-ring cell carcinoma were also compared with 3,371 patients with primary non-signet-ring cell rectal cancers. Survival was calculated using Kaplan-Meier survival estimates.

RESULTS

Mean age of the signet-ring cell carcinoma group was 59 +/- 12 years and median age was 61 (range, 20-91) years. Male-to-female ratio was 1.1:1. Lymphatic and peritoneal spread was more common among the signet-ring cell carcinoma group. Approximately one-third of signet-ring cell carcinoma patients presented with metastatic disease. Mean survival time of the signet-ring cell carcinoma group was 45.4 months (95 percent confidence interval, 26.9-63.8) compared with 78.5 months (95 percent confidence interval, 62.0-94.9) for the control patients group; P = 0.02 by the log-rank test. The cumulative survival curve of patients with signet-ring cell carcinoma resembles that of patients with poorly differentiated rectal cancers.

CONCLUSIONS

Patients with signet-ring cell carcinoma of the colon and rectum have a worse prognosis compared with matched controls with the same stage of disease.

Characteristics in primary signet-ring cell carcinoma of the colorectum, from clinicopathological observations

BACKGROUND

The biological behavior of signet-ring cell carcinomas in colorectum tends to be worse than that of mucinous carcinomas. However, in previous studies, clinicopathological features of this disease have been somewhat ill-defined because various histological criteria of this disease were adopted.

METHODS

We selected 11 cases of signet-ring cell carcinomas and 29 cases of mucinous carcinomas among 1595 consecutive colorectal carcinomas on defined criteria and compared clinicopathological and molecular biological features between these two types of carcinomas.

RESULTS

Clinical staging of signet-ring cell carcinomas were far advanced and their prognosis tended to be worse than that of mucinous carcinomas. Furthermore, the incidence of K-ras mutations in signet-ring cell and mucinous carcinomas showed no difference between these two types of carcinomas. However, the incidence of K-ras mutation in these diseases was slightly lower than that in 30 ordinary colorectal carcinomas examined as a comparison.

CONCLUSIONS

These results suggest that the carcinogenesis of signet-ring cell and mucinous carcinomas are different from that of ordinary colorectal carcinomas and that there may exist other genes related to malignancy of signet-ring cell carcinomas.

Colorectal adenocarcinoma in a defined Jordanian population from 1990 to 1995

PURPOSE

This study aims to evaluate cancer of the large bowel as it occurred in a defined Jordanian population, with special reference to its epidemiologic aspects. Second, this study was undertaken to compare these results with those of other countries and those previously reported from Jordan.

METHODS

Records of patients diagnosed as having colorectal adenocarcinoma during a six-year period in Irbid province, Jordan, were reviewed. The material was analyzed retrospectively with respect to various epidemiologic features, and the results were compared with those of other countries and those previously published about the Jordanian population.

RESULTS

Between January 1990 and December 1995, 109 new patients with colorectal adenocarcinoma were managed, an incidence of 3.8/100,000/year. Male to female ratio was 1:1.05 for colonic cancer and 1.36:1 for rectal cancer. The maximum incidence was seen in the sixth and seventh decades. A total of 12.8 percent of the patients were younger than 40 years of age. The rectum was the most common site involved in 30.3 percent of the patients, followed by the sigmoid, right colon, and the rest of the colon. When compared with previous Jordanian figures, a shift toward the western figures was noted. The delay in diagnosis was noted from the 8.2 months of delay before diagnosis and the advanced stage of the disease at the time of diagnosis. A total of 49.5 percent of the cases were in Dukes B stage, 30.3 percent in Dukes C, and 19.3 percent in Dukes D. Only one patient was in Dukes A stage. A total of 13.8 percent of the cases were mucinous adenocarcinoma. A total of 26.5 percent of the patients presented with complications.

CONCLUSIONS

As for colorectal adenocarcinoma, we still share the epidemiologic characteristics of developing countries, but there is a shift toward those of western communities. Flexible sigmoidoscopy is encouraged for evaluation of lower gastrointestinal symptoms, and education of the public and medical staff about colorectal diseases is needed to improve the outcome.

Clinicopathological study of colorectal mucinous carcinoma in Taiwan: a multivariate analysis

The clinicopathological significance of colorectal mucinous carcinoma is controversial, although some authors feel mucinous carcinoma has a worse prognosis than that of non-mucinous carcinoma. To clarify the significance of this type of carcinoma in Taiwan, a retrospective review of patients with colorectal carcinoma treated at Chang Gung Memorial Hospital between 1984 and 1988 was undertaken. During this period, 53 mucinous carcinomas and 401 non-mucinous carcinomas fulfilling the inclusion criteria were analysed. Mucinous carcinomas were more common in patients 39 years of age or under (P < 0.005). Most mucinous carcinomas were located in the rectum/rectosigmoid, followed by the right colon; however, the right colon had a higher relative incidence (38 vs 8%, respectively; P < 0.005). Mucinous carcinomas presented at a significantly more advanced stage (23 vs 8%, respectively, stage D disease; P < 0.005) and had a markedly lower curative resection rate (68 vs 84%, respectively; P < 0.05). Following curative resection, mucinous carcinomas tended to have an increased incidence of subsequent distant metastasis (27.8 vs 18.8%, respectively; P < 0.005). The overall survival rate of patients with mucinous carcinoma was worse than that of non-mucinous carcinoma (P < 0.005). Multivariate analysis showed that clinically important predictive factors were stage of disease on diagnosis and subsequent distant metastasis. The mucinous histological type itself was not an independent prognostic factor in colorectal cancer.

Is mucinous carcinoma of the colorectum a distinct genetic entity?

Mucinous carcinomas are defined on the basis of the amount of the mucus component in the tumour mass. Apart from this quantitative criterion, a number of clinicopathological parameters (such as localisation, prevalence in different countries and age groups, association with HNPCC and inflammatory processes) and genetic alterations (e.g. frequency of mutation in Ki-ras and p53 genes, level of MUC2 expression) differentiate these tumours from the non-mucinous ones. Since a different set of genetic lesions implies different inducing agents, these observations suggest that there may be a 'mucinous pathway of carcinogenesis'. Further identification of genetic changes characteristic of the mucinous phenotype will help to understand the aetiology of these tumours and possibly establish markers for detection of the high-risk group.

Primary signet-ring cell carcinoma of the colon and rectum

PURPOSE

Colorectal signet-ring cell carcinoma (SRCC) is uncommon; discordant data have been previously reported about clinicopathologic features. Thirty-four cases of primary colorectal SRCC were retrospectively reviewed to clarify controversies.

METHODS

Primary colorectal SRCC was diagnosed when the following criteria were satisfied: 1) the tumor was primary; 2) histologic material was adequate; 3) signet-ring cell represented more than 50 percent of the cancer.

RESULTS

We identified 34 cases (1.1 percent) of 2,995 consecutive large bowel cancers collected at the Institute of Anatomic Pathology of Florence between 1985 and 1993. Patients ranged in age from 31 to 89 (mean, 63.5; median, 65) years; 19 were male, and 15 were female (male:female = 1.3:1). Fifteen tumors were located in the proximal colon, 11 in the rectum, and 8 in the distal colon. The gross shape was infiltrative in 24 cases and exophytic in 10; only 6 cases (17.6 percent) showed features of linitis plastica. Most cancers (61.8 percent) were Stage C, 29.4 percent were Stage B, and distant metastases were present in only three cases (8.8 percent). No Stage A case was found. Prognosis was extremely poor, and overall five-year survival rate was 9.1 percent. Survival was influenced significantly by tumor stage (P < 0.01).

CONCLUSIONS

Comparison of our data with the literature showed many differences that could be related to different applied diagnostic criteria. We underlined the importance of histology as reproducible criterion for diagnosis of primary colorectal SRCC.

Trends in colorectal cancer incidence and histologic findings in Maori and Polynesian residents of New Zealand

BACKGROUND

The aim of this study was to combine an epidemiologic survey of colorectal cancer among Maori, Polynesian, and white inhabitants of New Zealand with a detailed analysis of tumor subsite and histopathology.

METHODS

Data were obtained from the New Zealand National Cancer Registry and included all registrants from 1970 to 1984. Sections of histologic specimens of colorectal cancer of Maori and non-Maori were retrieved from three Auckland hospitals.

RESULTS

The annual age-adjusted incidence rates of large intestinal cancer among male and female Maoris and male and female Polynesians were 40%, 40%, 39%, and 29%, respectively, of the total population incidence. Time-trend analysis showed the incidence of large intestinal cancer to be increasing among all racial groups. The relative proportion of rectal cancers was higher in male and female Maoris and female Polynesians than in the general population, whereas male Polynesians had a relatively high proportion of right colonic cancers. High-grade carcinoma and mucinous carcinoma occurred more frequently in young individuals regardless of race. Carcinomas were diagnosed at a more advanced stage in Maoris.

CONCLUSION

Given the similar environmental characteristics of the three racial groups, the findings indicate the presence of powerful protective factors in Maoris and Polynesians. These could be constitutional or mediated by unrecognized dietary constituents.

Clinicopathologic impact of colloid in colorectal carcinoma

The overall incidence of colloid (mucinous) carcinoma in patients with colorectal cancer is 17 percent, and its influence on patterns of failure and survival in patients with colorectal cancer varies throughout the literature. The presence of colloid carcinoma may have a real but small impact on the patterns of failure or survival in colorectal cancer. The data are conflicting and, furthermore, by proportional hazards analysis, colloid carcinoma is not an independent prognostic factor for survival. Therefore, despite it being common clinical practice, a change in treatment recommendations based solely on the presence or absence of colloid cancer is not recommended. Treatment recommendations should be based primarily on the tumor stage and site. However, given the trend toward increased failure and decreased survival compared with adenocarcinoma, colloid carcinoma should be reported separate from other histological patterns to better understand its natural history.

Colloid carcinoma of the colon and rectum

To determine the clinicopathologic significance of colloid carcinoma in carcinoma of the colon and rectosigmoid/rectum, a retrospective review of 462 patients who underwent potentially curative surgery at the New England Deaconess Hospital was performed. Seventy-seven patients (17%) were identified who had tumors with some component of colloid present. Colloid carcinoma occurred in 49 (11%). The remaining 28 (6%) had adenocarcinoma with colloid features. Compared to patients with pure adenocarcinoma, the 5-year actuarial survival of patients with colloid carcinoma was lower in the colon, rectosigmoid/rectum, and colorectum. Patterns of failure, expressed as the actuarial incidence of failure at 5 years, were examined by histologic condition and stage. Patients with Dukes' Stage B colloid carcinoma had a higher incidence of total failure, and patients with Dukes' Stage C colloid carcinoma had a higher incidence of local, abdominal, and total failure. None of the differences reached statistical significance. The presence of colloid carcinoma may have a real but small impact on the patterns of failure and survival in colorectal cancer.

Colorectal adenocarcinoma in young Lebanese adults. The American University of Beirut-Medical Center experience with 32 patients

Colorectal adenocarcinoma is uncommon in Lebanon. The low frequency and the low average age at the time of diagnosis, 53.7 years, is similar to that observed in other developing countries. Over a period of 40 years (1945-1985), 32 patients (5.8%) developed colorectal adenocarcinoma before age 30 years. Seventeen and 15 patients were males and females, respectively (age range, 14-29 years). The most common presenting symptoms were blood per rectum (27 patients) and abdominal pain (23 patients). The average interval from the first symptom to histologic diagnosis was 5.7 months. The only significant predisposing factors were the presence of a positive family history for colorectal carcinoma in one patient and bladder exstrophy with ureteral diversion in another. Twenty-four patients had surgery with curative intent. Colloid and signet ring adenocarcinoma were present in 22 patients (68.7%). Classification by Duke's staging system demonstrated Stage C in 15 and Stage D in 5 patients. These findings show a definite increase in carcinoma with high histologic grade and advanced stage at presentation in young Lebanese patients.

Peculiarities of mucinous colorectal carcinoma

The clinical and pathological features of 54 mucinous carcinomas of the large intestine were compared with those of 576 non-mucinous carcinomas. Tumours were only categorized as mucinous if they contained at least 60 per cent of mucin by volume. Those with a moderate mucin content (60-80 per cent) were indistinguishable in behaviour from 'non-mucinous' tumours. By contrast, those with a high mucin content (greater than 80 per cent) showed several differences from non-mucinous cancers: they had a more proximal distribution through the large intestine, they comprised a greater fraction of cancers in the under 50 age group (24 versus 7 per cent: P less than 0.01), they were more likely to be Dukes' stage 'D' (58 versus 31 per cent: P less than 0.01) and local fixity was commoner (70 versus 37 per cent: P less than 0.001). Consequently the overall resection rate was reduced from 90 to 73 per cent (P less than 0.01), the curative resection rate from 69 to 42 per cent (P less than 0.01) and the 5-year survival rate from 37 to 18 per cent (P less than 0.05). Colorectal carcinomas of high mucin content require wide excision, tend to recur locally and carry a poor prognosis.

Colorectal juvenile polyps: an epidemiological and histopathological study of 144 cases in Jordanians

The minimal incidence rate of colorectal juvenile polyps in Jordanians was 1.4 per 100 000 in the general population and 2.8 per 100 000 in children under 10 years of age. Out of 144 cases, nine had two to seven polyps and one juvenile polyposis coli. There was male preponderance and a mean age of 8 years: 96.5% of the polyps were in the rectum. Characteristically, stromal oedema, inflammation, ulceration with granulation tissue cap formation and gland regeneration were present. Epithelial hyperplasia was not uncommon and focal dysplastic change was occasionally noted, being always accompanied by hyperplastic change. Focal severe dysplasia was seen in one solitary juvenile polyp. It is concluded that varying degrees of focal epithelial atypia can occasionally develop in solitary juvenile polyps, rarely reaching severe dysplastic change. Malignant transformation in the commonly seen form of juvenile polyp (solitary type) is probably a rare phenomenon, but its frequency needs further evaluation.

The presence of oncofoetal antigens in large bowel carcinoma

This paper is an immunohistological study of the occurrence of the oncofoetal antigens, (carcinoembryonic antigen (CEA), small intestine mucin antigen (SIMA), and normal large bowel mucin antigen (LIMA) in 60 surgically resected colons: 10 non-malignant specimens and 50 colorectal carcinomas. SIMA is a new oncofoetal antigen found in mucinous carcinoma of the large bowel. In the adult it is normally present only in the duodenum and jejunum. Of the 50 carcinoma specimens, 13 were mucinous, 17 non-mucinous and 20 mixed mucinous and non-mucinous. LIMA was the only antigen detected in the mucosa of non-malignant specimens. In mucinous carcinomas only SIMA was present, whilst in the non-mucinous specimens CEA was always found and to a lesser extent LIMA. The same relationship was observed in mixed tumours: SIMA in mucinous and CEA-LIMA in the non-mucinous parts. In the mucosa adjacent to the cancer in all 50 cases there was evidence of an increase or decrease in LIMA. In 42 cases (84%) both oncofoetal antigens (CEA and SIMA) could also be detected in this transitional or perineoplastic epithelium at varying distances from the tumour. These results provide evidence to suggest that the majority of large bowel carcinomas occur in areas of metaplastic change.