Epidemiology of large bowel cancer

Surgical Resection for Liver Metastases Developing 10 and 21 Years After Primary Surgery for Mucinous Colon Adenocarcinoma: A Case Report

Optimal management for liver metastases from colorectal mucinous adenocarcinoma is still controversial. Here, we report such a case of liver metastases that developed twice with 10-year intervals after curative resection. An 84-year-old man had undergone a radical left hemicolectomy for descending colon cancer at age 63 years. The histopathologic diagnosis was mucinous adenocarcinoma. Ten years later, he was found to have a cystic tumor in liver and underwent partial hepatectomy of segment 5. Moreover, 10 years after that hepatic resection, computed tomography showed a low-density tumor with calcification in remnant liver, and partial hepatectomy of segment 8 was performed. Histopathologic and immunohistochemical findings of each liver tumor indicated metastasis from primary colon mucinous adenocarcinoma. It is rare for colorectal mucinous adenocarcinoma to recur twice after long intervals of 10 years. However, in a patient with a history of colorectal mucinous adenocarcinoma, possibility of recurrence more than 10 years after curative surgery also must be kept in mind. Long-term clinical follow-up after curative surgery for primary colon cancer or liver metastases may be necessary to detect early signs of recurrence of colorectal mucinous adenocarcinoma.

Mechanism study of 5-alkylresorcinols-induced colon cancer cell apoptosis in vitro

AIM

To investigate the mechanism of 5-alkylresorcinols (5ARs)-induced apoptosis by detecting the effect on BCL2, Bax, PARP1 and Caspase3 expression patterns in colon cancer cell lines.

METHODS

After HT29 and HCT 116 cells were treated with different concentrations of 5ARs, cell morphological changes were observed by phase-contrast microscopy, cell proliferation and apoptosis phenotypes were evaluated by Cell Counting Kit-8 (CCK8) and Annexin V-FITC/PI flow cytometric assays, respectively, and the protein levels of BCL2, Bax, PARP1 and Caspase3 were detected by Western blotting assays.

RESULTS

CCK8 assays indicated that the proliferation of HT29 and HCT 116 cells treated with different concentrations of 5ARs was significantly decreased (P < 0.05), and treatment with 5ARs increased the apoptosis of HT29 and HCT 116 cells. 5ARs suppressed BCL2 expression and elevated the levels of Bax, PARP1, Caspase3 and the ratio of BAX to BCL2 in colon cancer cells.

CONCLUSION

5ARs can induce the apoptosis of HT29 and HCT 116 cells in vitro, possibly by enhancing BAX, PARP1 and Caspase3 expression and elevating the ratio of BAX to BCL2 in colon cancer cells.

Lifestyle and colorectal cancer: A case-control study

A case-control study has been conducted to investigate the relationship between lifestyle and risk of colorectal cancer. Cases are one hundred patients diagnosed with colon and rectal cancer in Tokai University Hospital between 1986 and 1994. Three controls per case were individually matched by age, sex, local areas and date of health checkups at the Automated Multi-phasic Health Testing and Services (AMHTS ) Center of the hospital. The results were analyzed by multi-factorial logistic regression models. Positive history of maternal cancer, large consumption of alcohol, frequent consumption of potato products and white-collar job were predominant risk factors while frequent intake of seaweed was a protective factor. Frequent intakes of dairy foods and lack of exercise showed no significant tendency to increase risk of colorectal cancer. Smoking habits, intakes of meat and egg were shown not to be related to this disease. These findings suggest that family history of cancer and dietary factors play a key role in causation and prevention of colorectal cancer.

The clinicopathological features of colorectal mucinous adenocarcinoma and a therapeutic strategy for the disease

Background

The guidelines established by the National Comprehensive Cancer Network do not describe mucinous histology as a clinical factor that should influence the therapeutic algorithm. However, previous studies show conflicting results regarding the prognosis of colorectal mucinous adenocarcinoma. In this study, we described the clinicopathological features of mucinous adenocarcinoma in Japan, to identify optimal therapeutic strategies.

Methods

144 patients with mucinous and 2673 with non-mucinous adenocarcinomas who underwent primary resection in two major centers in Yokohama, Japan were retrospectively evaluated for clinicopathological features and treatment factors. A multivariate analysis for overall survival followed by the comparison of overall survival using Cox proportional hazard model were performed.

Results

Patients with mucinous adenocarcinoma had larger primary lesions, higher preoperative CEA levels, a deeper depth of invasion, higher rates of nodal and distant metastasis, and more metastatic sites. A multivariate analysis for overall survival revealed a mucinous histology to be an independent prognostic factor. In the subgroup analysis stratified by stage, Patients diagnosed as StageIII and IV disease had a worse survival in mucinous adenocarcinoma than non-mucinous, while survival did not differ significantly in patients diagnosed as Stage0-II disease. In StageIII, local recurrence in rectal cases and peritoneal dissemination were more frequently observed in patients with a mucinous histology.

Conclusions

Our study indentified that mucinous adenocarcinoma was associated with a worse survival compared with non-mucinous in patients with StageIII and IV disease. In rectal StageIII disease with mucinous histology, additional therapy to control local recurrence followed by surgical resection may be a strategical alternative. Further molecular investigations considering genetic features of mucinous histology will lead to drug development and better management of peritoneal metastasis

Adjuvant therapy in colon cancer

Huge advances have been made in the treatment of colon cancer over the last decade. Success has been most noticeable in stage IV disease - where careful selection of patients with small-volume disease for treatment with surgical resection ± perioperative chemotherapy has resulted in an improvement in survival of approximately 5-50%; and stage III - disease where the advent of 5-fluorouracil/oxaliplatin, as adjuvant treatment has also resulted in a significant prolongation in survival. Progression-free survival is now an established surrogate for overall survival, and has resulted in more timely reporting of adjuvant studies and therefore faster integration of promising agents into the clinic. Targeted agents, which have shown promise in the metastatic setting, are currently being examined in the adjuvant setting, although results so far are disappointing. Patients with high-risk stage II cancer remain a challenging group. They have a poorer prognosis than those with stage IIIA disease, and national and international guidance recommend offering chemotherapy after careful discussion of the pros and cons. Despite the fact that we have identified many of the biological features that make stage II disease higher risk, we still struggle to achieve the same improvement in survival for this subgroup compared with others. It may be that these patients required treatment with alternative regimens and predictive biomarkers would be particularly helpful.

Prognosis of mucinous histology for patients with radically resected stage II and III colon cancer

BACKGROUND

Previous studies investigating the prognostic role of mucinous histology of colorectal cancer produced conflicting results. This retrospective analysis was carried out in order to explore whether mucinous adenocarcinoma (MC) is associated with a comparatively worse prognosis than that of nonmucinous adenocarcinoma (NMC) for patients undergoing curative resection for stage II and III colon cancer.

PATIENTS AND METHODS

This study involved 1025 unselected patients who underwent curative surgery for sporadic colon cancer and follow-up procedures at six different oncology departments.

RESULTS

MCs accounted for 17.4% (n=178) of tumours. Patients with MC had 5- and 8-year overall survival rates of 78.6% and 68.8%, respectively, compared with 72.3% and 63.8%, respectively, for patients with nonmucinous tumours. Multivariate analysis using the Cox proportional hazards model showed that the clinically significant prognostic factors were stage of disease and adjuvant chemotherapy. No statistically significant interaction between mucinous histology and adjuvant chemotherapy was found.

CONCLUSIONS

For patients with stage II and III colon cancer who underwent curative surgery, mucinous histology has no significant correlation with prognosis compared with NMC. This retrospective analysis suggests a comparable benefit from adjuvant chemotherapy for MC compared with NMC.

Noninvasive detection of inflammation-associated colon cancer in a mouse model

Helicobacter bilis-infected Smad3(-/-) mice represent an attractive model of inflammation-associated colon cancer. Most infected mice develop mucinous adenocarcinoma (MUC) by 6 weeks post inoculation (PI); however, approximately one third do not progress to MUC. The ability to predict the development of MUC in mice used in therapeutic studies would confer a considerable saving of time and money. In addition, the inadvertent use of mice without MUC may confound therapeutic studies by making treatments seem falsely efficacious. We assessed both magnetic resonance imaging (MRI) and fecal biomarkers in Helicobacter- and sham-inoculated mice as methods of noninvasively detecting MUC before the predicted onset of disease. Non-contrast-enhanced MRI was able to detect lesions in 58% of mice with histologically confirmed MUC; however, serial imaging sessions produced inconsistent results. MRI was also a labor- and time-intensive technique requiring anesthesia. Alternatively, inflammatory biomarkers isolated from feces at early time points were correlated to later histologic lesions. Fecal expression of interleukin 1β, macrophage inflammatory protein 1α, and regulated on activation, normal T-cell expressed, and secreted at 3 weeks PI correlated significantly with lesion severity at 9 weeks PI. For each biomarker, receiver-operator characteristic curves were also generated, and all three biomarkers performed well at 1 to 3 weeks PI, indicating that the development of MUC can be predicted based on the early expression of certain inflammatory mediators in feces.

Azathioprine-induced carcinogenesis in mice according to Msh2 genotype

BACKGROUND

The thiopurine prodrug azathioprine is used extensively in cancer therapy. Exposure to this drug results in the selection of DNA mismatch repair-deficient cell clones in vitro. It has also been suggested that thiopurine drugs might constitute a risk factor for the emergence of human neoplasms displaying microsatellite instability (MSI) because of deficient DNA mismatch repair.

METHODS

Azathioprine was administered via drinking water (6-20 mg/kg body weight per day) to mice that were null (Msh2⁻(/)⁻; n = 27), heterozygous (Msh2(+/)⁻; n = 22), or wild type (Msh2(WT); n = 18) for the DNA mismatch repair gene Msh2. Control mice (45 Msh2⁻(/)⁻, 38 Msh2(+/)⁻, and 12 Msh2(WT)) received drinking water lacking azathioprine. The effect of azathioprine on tumorigenesis and survival of the mice was evaluated by Kaplan-Meier curves using log-rank and Gehan-Breslow-Wilcoxon tests. Mouse tumor samples were characterized by histology and immunophenotyping, and their MSI status was determined by polymerase chain reaction analysis of three noncoding microsatellite markers and by immunohistochemistry. Msh2 status of tumor samples was assessed by loss of heterozygosity analyses and sequencing after reverse transcription-polymerase chain reaction of the entire Msh2 coding sequence. All statistical tests were two-sided.

RESULTS

Most untreated Msh2(WT) and Msh2(+/)⁻ mice remained asymptomatic and alive at 250 days of age, whereas azathioprine-treated Msh2(WT) and Msh2(+/)⁻ mice developed lymphomas and died prematurely (median survival of 71 and 165 days of age, respectively). Azathioprine-treated Msh2(+/)⁻ mice developed diffuse lymphomas lacking Msh2 expression and displaying MSI due to somatic inactivation of the functional Msh2 allele by loss of heterozygosity or mutation. By contrast, azathioprine-treated Msh2(WT) mice displayed no obvious tumor phenotype, but histological examination showed microscopic splenic foci of neoplastic lymphoid cells that retained Msh2 expression and did not display MSI. Both untreated and azathioprine-treated Msh2⁻(/)⁻ mice had a reduced lifespan compared with untreated Msh2(WT) mice (median survival of 127 and 107 days of age, respectively) and developed lymphomas with MSI.

CONCLUSION

Azathioprine-induced carcinogenesis in mice depends on the number of functional copies of the Msh2 gene.

Mucinous adenocarcinomas with intra-abdominal dissemination: a review of current therapy

Peritoneal carcinomatosis has been considered a terminal disease with a median survival time of 5.2-12.6 months. Systemic chemotherapy and cytoreductive surgery (CRS) have long been used to treat macroscopic disease, with limited success. However, a comprehensive treatment approach involving cytroreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) has evolved into a novel approach for peritoneal carcinomatosis. Surgery removes the primary cancer and any dissemination within the peritoneal cavity and adjuvant HIPEC eradicates macroscopic or microscopic tumor residue, thus reducing the risk for recurrence. This approach offers a new potential treatment option for patients with metastatic disease confined to the peritoneum. The present review provides an update of the most recent data on the current therapy for pseudomyxoma peritonei (PMP) and mucinous colorectal adenocarcinoma (MCA) with metastatic disease confined to the peritoneum.

Two subtypes of mucinous adenocarcinoma of the colorectum: clinicopathological and genetic features

BACKGROUND

This work is aimed at comparing mucinous colorectal adenocarcinomas (MUC) and non-mucinous colorectal adenocarcinomas (non-MUC), and at verifying the existence of two different subgroups of MUC, in terms of clinicopathological features, chromosomal alterations, and outcome, in a geographical area where mucinous colorectal cancer resulted as being very frequent.

METHODS

One hundred and fifty-six unselected patients who underwent curative colorectal resection for sporadic colorectal cancer over a 4-year period were evaluated for histological classification as to MUC and non-MUC subtype, for microsatellite instability (MSI) using six microsatellite markers, and for the presence of p27, Fhit, and cyclooxygenase-2 (Cox-2). Molecular data, immunohistochemical results, recurrence frequency, and patient survival were analyzed statistically in relation to histological subtypes.

RESULTS

MUC accounted for 38.5% of all colorectal carcinomas. Compared to non-MUCs, MUCs were more frequently located in the proximal colon (p < 0.001), and more frequently showed MSI phenotype (p < 0.001), altered protein expression of hMlh1 (p = 0.030), Fhit (p <0.001), and p27 (p < 0.001). Compared to MUC with microsatellite-stable (MSS) phenotype, MUC with MSI more frequently resulted as being located in the proximal colon (p = 0.013), and more frequently showed altered expression of hMlh1 (p < 0.001), hMsh2 (p = 0.008), Fhit (p < 0.001), and p27 (p = 0.015). Significantly better survival of patients with proximal MUC (p = 0,012), with MSI MUC (p = 0.017), and with MUC with altered p27 expression (p = 0.02).

CONCLUSION

The results of the present study confirm that MUC represents distinct clinicopathological and genetic features as compared to non-mucinous tumors and support the hypothesis that MUC includes two subtypes with different genetic pathways and behavior.

Unexplained inversion of the incidence ratio of colon and rectal cancer among men in East Germany. A time trend analysis including 147,790 cases

INTRODUCTION

The incidence rate ratio of colon to rectal cancer is usually about 2:1. It has been observed for a while that the incidence of colon cancer among men (as opposed to women) in the Former German Democratic Republic (GDR) is lower than the rate of rectal cancer. Detailed analyses of this phenomenon have not been done so far. The aim was to give insights in this observation by detailed incidence and mortality analyses and to explore the worldwide ratio of colon and rectal cancers based on population-based cancer registry data.

METHODS

We analyzed age-standardized incidence and mortality data of colorectal cancers in East Germany (1961-1989 and 1996-2002; mortality 1980-2002), West Germany, Saarland (1970-2002) and all over the world (1978-82 up to 1993-97).

RESULTS

With the incidence increase of colorectal cancers in the GDR, the ratio of colon to rectal cancer incidence became larger and surpassed the reference value (ratio = 1) during the time of the reunification. Also the mortality data revealed a similar pattern. Estimated annual percentage increases of colon subsite incidences tended to be higher within the distal colon as compared to the proximal colon

CONCLUSIONS

Our analyses of international cancer registries over a period of 20 years show that the colon-rectum cancer ratio is positively associated with the overall incidence of colorectal cancer with a stronger association among women than men. Non-causal factors such as underdetection or registration artefacts are unlikely to explain the unusual colon/rectal rate ratio among men. A gradual decrease of the job-related physical activity among men may have contributed to the findings.

Changing patterns of colorectal cancer in China over a period of 20 years

AIM: To determine whether any changes have occurred on the patterns of colorectal cancer in China.

METHODS: Data from 21 Chinese articles published from 1980 to 1999, were used to analyze the time trend of colorectal cancer according to the patients’ age at diagnosis, sex, the site of the tumor, stage, and the pathology.

RESULTS: From 1980s to 1990s, the mean age of the colorectal cancer patients has increased. The percentage of the female patients rose. The distribution of colorectal carcinoma shows a predominance of rectal cancer. However, the proportion of proximal colon cancer (including transverse and ascending colon) increased significantly accompanied by a decline in the percentage of rectal cancer. Similarity in the percentage of distal colon cancer between two decades was revealed. In the 1990s, statistically more Stage B patients were found than those in 1980s. In addition, databases show a significant decrease in the Stage D cases. The proportion of adenocarcinoma increased, but the mucinous adenocarcinoma decreased during two decades.

CONCLUSION: These findings indicate that the pattern of colorectal cancer in China has been changing. Especially, a proximal shift due to the increasing proportion of ascending and transverse colon cancer has occurred in China.

The changing distribution and survival of colorectal carcinoma: an epidemiological study in an area of northern Italy

OBJECTIVE

This study analyses the inter-relations of anatomical tumour location, gender, age and incidence rates for colorectal cancer from 1978 to 1999 in an area of northern Italy: the Parma district.

METHODS

Data were obtained from the Parma Cancer Registry. Age-adjusted incidence rates were analysed by gender, age and colorectal cancer subsites. In addition, 5 year observed survival rates were determined.

RESULTS

In the Parma area, the incidence of colorectal cancer is rising. We have observed a true increase in the rate of the age standardized incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. The frequency of right-sided colon cancer was higher in aged patients, and in women. Age-standardized relative survival of patients after diagnosis of colorectal cancer between 1992 and 1996 was found to be significantly higher than age-standardized relative survival after diagnosis between 1978 and 1982.

CONCLUSIONS

In the Parma area there has been an increased incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. We feel that this shift, whatever the reason for it, has important implications for the choice of screening techniques.

Primary colorectal carcinomas and their intrapulmonary metastases: clinical, glyco-, immuno- and lectin histochemical, nuclear and syntactic structure analysis with emphasis on correlation with period of occurrence of metastases and survival

BACKGROUND

The aim of the study was to correlate clinical factors (disease-free interval/survival) with growth pattern in terms of structural entropy of patients with primary colorectal carcinomas and secondary lung lesions.

METHODS

Proliferation and apoptosis markers as well as determinants involved in information transfer by protein-carbohydrate interactions were monitored. The clinical history, surgical and histopathological reports, tumor load, survival of the patients with a maximum follow-up of 14 years, and sections of paraffin blocks of 60 colorectal carcinoma specimens and their pulmonary metastases were examined. Measurements of the staining intensities after processing sections of primary and secondary carcinomas with the marker panel and calculations of syntactic structure and stereological parameters were performed.

RESULTS

The majority of primary tumors (80%, 49/60) were surgically treated at advanced tumor stages (pT3/pT4), with detectable lymph node involvement (34/60). Lung metastases were resected after a median disease-free interval of 30.5 months, an average of 3.0 metastases adding up to a mean intrapulmonary tumor load of 9.98 ccm. The median survival was calculated to be 82 months after resection of the colon/rectal carcinomas and 40 months after that of intrapulmonary metastases. It was correlated with certain structural and vascular features such as vascular circumference. The proliferation index and several textural features were strongly associated with vascularization in primary and secondary tumors.

CONCLUSIONS

Despite intra- and interindividual variations, vascularization properties and features such as bcl-2 positivity and CEA- and galectin-3-associated structural entropy in primary tumors or metastases are described as independent prognostic features. Absence of lymph node involvement or limited tumor stages of colon/rectal carcinomas should not exclude patients from thorough postsurgical scrutiny to detect lung metastases.

Long-term follow-up after surgery for advanced colorectal carcinoma involving the urogenital tract

OBJECTIVES

Advanced colorectal carcinomas frequently involve the urogenital tract. In the following we evaluate the long-term survival after radical surgical extirpation and the prognostic significance of involvement of specific urological organs.

METHODS

Between January 1985 and April 1996, 101 patients underwent interdisciplinary tumour extirpation of an advanced colorectal carcinoma involving the urogenital tract.

RESULTS

Of 68 men and 33 women, 40 presented with primary and 61 with recurrent carcinoma. As far as urological organs are concerned, the ureter was removed in 82 patients, followed by bladder (n=52), seminal vesicles (n=25), prostate (n=22), kidney, testicle and penis. Histology revealed cancerous infiltration in 52% of the organs resected. A negative surgical margin was obtained in 54% of the patients, 43% showed positive lymph nodes. There was a 41% peri-operative complication with a mortality rate of 5%. Five year overall survival was 24.4% (median 23 months) with prognostic factors being type of tumour (primary versus recurrent), surgical margin and lymph node status. Stratification according to these factors showed removal of bladder and prostate to be a favourable and ureteral removal to be an omnious factor.

CONCLUSION

We conclude that multivisceral extirpation of advanced colorectal carcinomas involving the urogenital tract should be recommended in selected patients. Our data showed it to be a safe surgical procedure, which is associated with favourable long-term outcome in non-metastatic patients in whom complete surgical resection could be achieved.

Rarity of colon cancer in Africans is associated with low animal product consumption, not fiber

OBJECTIVE

To investigate whether the rarity of colon cancer in black Africans (prevalence, < 1:100,000) can be accounted for by dietary factors considered to reduce risk, and by differences in colonic bacterial fermentation.

METHODS

Samples of the adult black South African population were drawn from several rural and urban regions. Food consumption was assessed by home visits, food frequency questionnaires, computerized analysis of 72-h dietary recall, and blood sampling. Colonic fermentation was measured by breath H2 and CH4 response to a traditional meal, and to 10-g of lactulose. Cancer risk was estimated by measurement of epithelial proliferation indices (Ki-67 and BrdU) in rectal mucosal biopsies. Results were evaluated by comparison to measurements in high-risk white South Africans (prevalence, 17:100,000).

RESULTS

Epithelial proliferation was significantly lower in rural and urban blacks than whites. The diets of all the black subgroups were characterized by a low animal product and high boiled maize-meal content, whereas whites consumed more fresh animal products, cheese, and wheat products. Blacks consumed below RDA quantities of fiber (43% of RDA), vitamin A (78%), C (62%), folic acid (80%) and calcium (67%), whereas whites consumed more animal protein (177% of RDA) and fat (153%). Fasting and food-induced breath methane production was two to three times higher in blacks.

CONCLUSIONS

The low prevalence of colon cancer in black Africans cannot be explained by dietary "protective" factors, such as, fiber, calcium, vitamins A, C and folic acid, but may be influenced by the absence of "aggressive" factors, such as excess animal protein and fat, and by differences in colonic bacterial fermentation.

Prolonged hypergastrinemia does not increase the frequency of colonic neoplasia in patients with Zollinger-Ellison syndrome

Whereas considerable experimental evidence suggests chronic hypergastrinemia can increase the occurrence of colonic neoplasia, the risks in man remain unclear. Zollinger-Ellison syndrome (ZES) is associated with marked plasma elevation of all forms of gastrin and, because of its prolonged course, has been shown to be an excellent model disease to study the effects of chronic hypergastrinemia in man. To determine whether profound chronic hypergastrinemia affects the occurrence of colonic dysplasia and neoplasia, 97 consecutive patients with ZES were studied. All patients underwent colonoscopic examination to the cecum, and the location, size, and type of polyps/tumors were determined. The patients had a mean fasting gastrin level 31 times above normal and a mean disease duration of 10 years; 17/97 (18%) had adenomatous polyps, 67/97 (69%) no adenomatous polyps, and 2/97 (2%) had colonoscopy and/or autopsy studies fo asymptomatic controls. Stratification by age or gender, presence of MEN-I, tumor extent, and duration of degree of hypergastrinemia did not increase prevalence. This study shows that despite prolonged, profound hypergastrinemia, no increased rate of colonic neoplasia (polyps or cancer) was noted. These data suggest that the development of hypergastrinemia secondary to continuous use of H+,K+-ATPase inhibitors for as long as 10 years is unlikely to cause an increased risk of developing colonic neoplasia in man.

Sensitivity of monoclonal antibodies to carcinoembryonic antigen, tissue polypeptide antigen, alpha-fetoprotein, carbohydrate antigen 50, and carbohydrate antigen 19-9 in the diagnosis of colorectal adenocarcinoma

PURPOSE

This study was designed to establish the sensitivity of monoclonal antibodies to carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), tissue polypeptide antigen (TPA), carbohydrate antigen 50 (CA 50), and carbohydrate antigen 19-9 (CA 19-9) and the efficacy of the joint determination of several tumor markers, as well as the dynamics of postoperative normalization of each marker in the absence of recurrence.

MATERIALS AND METHODS

A prospective study was carried out in 100 patients subjected to surgical resection of colon adenocarcinoma. Serum concentrations of these markers were determined the day before surgery and seven days, two months, and six months after surgery.

RESULTS

The results demonstrate that sensitivity increased as the disease spread and that CA 19-9 was the most sensitive tumor marker. The rate of false negatives was 40 percent for Dukes Stage A lesions, 19 percent for Dukes Stage B, 7 percent for Dukes Stage C, and 0 percent for Dukes Stage D. Determination of two markers (CA 19-9 and CEA) provided the greatest sensitivity in Stages A and D tumors (60 percent and 100 percent, respectively); the incidence did not change when measurements of other antigens were associated. For Stages B and C, determination of at least three markers was necessary, the association of CEA, TPA, and CA 19-9 being that which showed the greatest sensitivity, 78 percent and 91 percent, respectively.

CONCLUSIONS

It would be advisable to include monoclonal antibody determination of CEA, TPA, and CA 19-9 in the diagnosis of adenocarcinoma, despite the fact that ultimate sensitivity will depend on the degree of tumor extension or on the presence of metastasis.

Dietary habits and colorectal cancer in a low-risk area. Results from a population-based case-control study in southern Italy

Many epidemiological studies have focused on the relationships between diet and colorectal cancer, but only a few have been conducted in the Mediterranean area. A population-based case-control study was carried out from July 1987 to June 1989 in a low-risk area in Southern Italy. By means of an "ad hoc" tumor registry, 132 diagnosed colorectal cancers were detected during the two years of study. One hundred nineteen of these 132 colorectal cancer cases were interviewed about their personal dietary habits with use of a questionnaire concerning the frequency of consumption of 70 foods or beverages. An equal number of controls was randomly selected from the lists of general practitioners of the area during the same period and interviewed with the same food frequency questionnaire. In a multivariate analysis, the relative risks (RRs) of developing colorectal cancer were estimated according to the different levels of consumption of food groups and selected food items. All RRs were adjusted for age, sex, education, smoking status, and modifications in diet in the previous 10 years. The risk of colorectal cancer increased nearly threefold for the highest level of consumption of foods with a high content of refined sugar [RR = 2.75, 95% confidence interval (CI) 1.26-5.97] and for the consumption of wine (> 1 l/day) (RR = 3.22, 95% CI 1.05-9.88). An inverse relationship was revealed for the highest consumption of raw and cooked vegetables (RR = 0.51, 95% CI 0.25-1.04) and diary products (RR = 0.46, 95% CI 0.22-0.98) and for the consumption of more than two cups of coffee per day (RR = 0.38, 95% CI 0.16-0.89). In this Mediterranean area, the main source of calories, cereals, did not show a significant relationship with colorectal cancer. These findings support the hypothesis that the local Mediterranean dietary pattern could explain the low risk of colorectal cancer.

Aging, genomic entropy and carcinogenesis: implications derived from longitudinal age-specific colon cancer mortality rate dynamics

Many types of cancer are intrinsically linked to the process of aging. Aging, from the perspective of the second law of thermodynamics, can be viewed as associated with the inevitable and natural increase in informational entropy of the genome. The molecular biologic basis of increasing genetic informational entropy is the inherent and variable instability of different regions of genome. Colon cancer cells have been shown to have characteristic acquired genetic abnormalities, most commonly, deletions in presumed tumor suppressor genes. Age-specific colon cancer mortality rates in the US from 1958 to 1988 were subjected to longitudinal Gompertzian analysis, a method that may identify and distinguish among genetic, environmental and competitive influences upon mortality. The Strehler-Mildvan modification of the Gompertz relationship between aging and mortality can be used to determine a relative measure of the rate of increase in informational entropy (a reflection of genetic instability) for those genetic factors that are involved in the pathogenesis of colon cancer.

The permissive role of oxygen-derived free radicals in the development of colonic cancer in the rat. A new theory for carcinogenesis

The colonic carcinogen 1,2-dimethylhydrazine (DMH) was given to male rats at 10 weeks of age in the form of weekly s.c. injections for 28 weeks. The results obtained show that the incidence of colonic cancer is directly dependent on dietary fat intake and that carcinogens which produce colonic cancer in the presence of a high-fat diet are rendered harmless when a low-fat diet is consumed. These results suggest that dietary fat is permissive for colonic carcinogenesis. Administration of the radical scavengers allopurinol and dimethyl sulfoxide afforded dose-dependent protection against this permissive role.