Comparisons of colon-cancer survival among European countries: The Eurocare Study

Impact of geography on prognostic outcomes of 21,509 patients with metastatic colorectal cancer enrolled in clinical trials: an ARCAD database analysis

BACKGROUND

Benchmarking international cancer survival differences is necessary to evaluate and improve healthcare systems. Our aim was to assess the potential regional differences in outcomes among patients with metastatic colorectal cancer (mCRC) participating in international randomized clinical trials (RCTs).

DESIGN

Countries were grouped into 11 regions according to the World Health Organization and the EUROCARE model. Meta-analyses based on individual patient data were used to synthesize data across studies and regions and to conduct comparisons for outcomes in a two-stage random-effects model after adjusting for age, sex, performance status, and time period. We used mCRC patients enrolled in the first-line RCTs from the ARCAD database, which provided enrolling country information. There were 21,509 patients in 27 RCTs included across the 11 regions.

RESULTS

Main outcomes were overall survival (OS) and progression-free survival (PFS). Compared with other regions, patients from the United Kingdom (UK) and Ireland were proportionaly over-represented, older, with higher performance status, more frequently male, and more commonly not treated with biological therapies. Cohorts from central Europe and the United States (USA) had significantly longer OS compared with those from UK and Ireland (p = 0.0034 and p < 0.001, respectively), with median difference of 3-4 months. The survival deficits in the UK and Ireland cohorts were, at most, 15% at 1 year. No evidence of a regional disparity was observed for PFS. Among those treated without biological therapies, patients from the UK and Ireland had shorter OS than central Europe patients (p < 0.001).

CONCLUSIONS

Significant international disparities in the OS of cohorts of mCRC patients enrolled in RCTs were found. Survival of mCRC patients included in RCTs was consistently lower in the UK and Ireland regions than in central Europe, southern Europe, and the USA, potentially attributed to greater overall population representation, delayed diagnosis, and reduced availability of therapies.

Trends of Colorectal Cancer Incidence and Prevalence in Italian Regions

Incidence and prevalence of tumors of colon and rectum, estimated from mortality and survival data, are presented for Italian regions and for the period 1970-1990. Projected rates to the year 2000 are also given. Age-standardized incidence rates have increased during the considered period. The increase has been higher for southern regions, which had, during the 70's, the lowest incidence and mortality levels. Geographic heterogeneity of colorectal cancer occurrence across Italian regions is therefore decreasing. The phenomenon parallels a tendency towards the homogenization of dietary habits observed in the Italian population. Estimated incidence levels increased less for the younger generation and appear stable for people born after 1940. More than 150,000 prevalent cases were estimated by the year 1990. The number is likely to increase owing to the simultaneous increasing tendency in incidence and survival rates.

Cancer Patient Survival in the Elderly in Italy

Aims and background

Italy, like most western populations, is sharply aging and changing its age structure with a striking increase in the oldest segment of the elderly. Since age is related to an exponential growth of cancer incidence rates and to a worsening of prognosis, the progressive aging of the population will constitute, in the future, an issue increasingly more important for public health. The present study is the first effort to present and analyze survival rates in Italian elderly cancer patients in order to provide a starting point for the development of better clinical strategies addressed to the aged.

Materials and methods

The presented data come from a large data set consisting of survival data relating to 25,798 men and 20,479 women, aged 65–84 years at diagnosis, collected by Italian cancer registries participating in the ITACARE project. Relative survival rates of patients have been calculated by sex, quinquennial age classes and the considered entire age class for overall malignant neoplasms and the 10 most frequent cancer sites in the elderly.

Results

When all Italian data for all cancers in the 65–84 year age group were pooled, survival rates at 5 years from the diagnosis was 27% and 39% in men and women, respectively. As regards specific sites, survival rates below 50% were observed for lung, stomach and ovary cancer at 1 year from diagnosis. At 5 years from diagnosis, the rates were less than 50% for colon, prostate, cervix, multiple myeloma, non-Hodgkin's lymphoma and melanoma (only in men). The best survival at 5 years from diagnosis (above 50%) was in women for melanoma and corpus uteri and breast cancer. For all cancers, the prognosis for women was better in each considered age group even though a dramatic decrease in survival with age was observed in both sexes. In general, a similar decline in survival with increasing age characterized all considered specific sites. However, at closer observation, the patterns of a decrease revealed some differences. The ratio between the survival rates of 55–64 vs 65–84 year age class indicated that the sites with the greatest advantage of survival for younger patients (ratio >1.5) were ovary, lung and melanoma (only in men), whereas the least advantage was observed for colon, corpus uteri, breast and prostate. By calendar periods, excluding non-Hodgkin's lymphoma for women, an increase in survival was observed for all considered sites, improving an encouraging successful trend in diagnostic and therapeutic progresses.

Interpreting Survival Differences and Trends

Since 1990 a concerted action between European population-based cancer registries (the EUROCARE project) has been carried out with the aims of establishing whether there are differences in cancer patient survival in Europe, and the reasons for such differences. Survival differences actually exist for cancer sites for which the stage of disease at diagnosis is the major prognostic factor (such as breast, stomach and colon cancer). However, for most cancer sites, survival increases over time and the survival rates of different countries tend to converge towards higher values. Interpreting survival differences and trends is not an easy task. Longer survival may be achieved by postponing death through better treatment or by anticipating diagnosis. However, an earlier diagnosis may or may not make a treatment more effective in postponing death. The computation of stage-specific or stage-adjusted survival is not sufficient for interpretation of survival differences, because staging procedures change over time and may vary in different hospitals and countries. In addition to an early diagnosis and more effective treatment, a number of factors may bias survival estimates. They may be classified into factors that can be controlled in the analysis (at least partially), such as mortality from other causes, demographic factors, epoch of diagnosis, different statistical methodology, and factors depending on the validity of cancer registry data, such as definition of the illness, exhaustiveness and quality of registration, completeness of follow-up, definition of the date of diagnosis, and definition of disease stage including the diagnostic procedure used to establish stage. To help disentangle the effects of early diagnosis and better treatment, several statistical approaches are being developed: multivariate analysis on relative survival data, new modeling analysis to separately estimate the proportion of cured patients and the length of survival for those patients destined to die, and the standardized collection of information on stage at diagnosis and staging procedures.

Survival in Adult Italian Cancer Patients, 1978–1989

Aims

To present a systematic analysis of population-based cancer patient survival in Italy.

Methods

Population-based survival data have been made available from 10 Italian cancer registries within the ITACARE project. Data, collected and validated using a common protocol, included over 100,000 patients with cancer diagnosed between 1978 and 1989. Multivariate weighted analysis was used to provide relative survival estimates attributable to Italy at national level.

Results

Results are presented, according to a systematic frame, as the main object of the ITACARE study, involving crude and relative survival figures for adult Italian cancer patients, by age, sex, period of diagnosis and registry area. An estimate with reference to Italy as a whole is also presented by cancer site and for all malignant neoplasms combined. Age-standardized relative survival figures are presented to allow comparisons between Italian registries and also to give a basis for international comparisons with countries involved in the EUROCARE study.

Conclusions

For the fist time, population-based survival of cancer patients is made available in Italy on a large scale analysis of data from all the Italian cancer registries in a combined action. Estimates of cancer patient survival at a national level in Italy allow proper international comparisons with European countries and give elements of evaluation and discussion on the performance of the Italian health care system.

State of the Art Reviews: Health Benefits Related to Exercise in Patients With Chronic Low-Grade Systemic Inflammation

Today, there is substantial evidence to suggest that regular exercise has health-promoting effects, which are beyond its effect on weight control. Regular exercise offers protection against all-cause mortality, and there is evidence from randomized intervention studies that physical training is effective as a treatment in patients with chronic heart diseases, type 2 diabetes, and symptoms related with the metabolic syndrome. Chronic diseases such as cardiovascular disease and type 2 diabetes are associated with chronic low-grade systemic inflammation. This review focuses on the anti-inflammatory effects of exercise that are mediated by muscle-derived cytokines (myokines). It is suggested that myokines may be involved in mediating the health-beneficial effects of exercise and that these in particular are involved in the protection against chronic diseases associated with low-grade inflammation.

Probiotics Lactobacillus rhamnosus GG, Lactobacillus acidophilus suppresses DMH-induced procarcinogenic fecal enzymes and preneoplastic aberrant crypt foci in early colon carcinogenesis in Sprague Dawley rats

Diet makes an important contribution to colorectal cancer (CRC) risk implying risks for CRC are potentially reducible. Therefore, the probiotics have been suggested as the prophylactic measure in colon cancer. In this study, different probiotics were used to compare their protective potential against 1,2 dimethylhydrazine dihydrochloride (DMH)-induced chemical colon carcinogenesis in Sprague Dawley rats. Animals belonging to different probiotic groups were fed orally with 1 × 10(9) lactobacilli daily for 1 week, and then a weekly injection of DMH was given intraperitoneally for 6 wks with daily administration of probiotic. Lactobacillus GG and L.acidophilus + DMH-treated animals had maximum percent reduction in ACF counts. A significant decrease (P < 0.05) in fecal nitroreductase activity was observed in L.casei + DMH and L.plantarum + DMH-treated rats whereas β-glucuronidase activity decreased in L.GG + DMH and L.acidophilus + DMH-treated rats. Animals treated with Bifidobacterium bifidum + DMH had significant decreased β-glucosidase activity. However, not much difference was observed in the colon morphology of animals belonging to various probiotic + DMH-treated rats compared with DMH-treated alone. The results indicated that probiotics, L.GG, and L.acidophilus can be used as the better prophylactic agents for experimental colon carcinogenesis.

EURECCA colorectal: multidisciplinary mission statement on better care for patients with colon and rectal cancer in Europe

BACKGROUND

Care for patients with colon and rectal cancer has improved in the last twenty years however still considerable variation exists in cancer management and outcome between European countries. Therefore, EURECCA, which is the acronym of European Registration of cancer care, is aiming at defining core treatment strategies and developing a European audit structure in order to improve the quality of care for all patients with colon and rectal cancer. In December 2012 the first multidisciplinary consensus conference about colon and rectum was held looking for multidisciplinary consensus. The expert panel consisted of representatives of European scientific organisations involved in cancer care of patients with colon and rectal cancer and representatives of national colorectal registries.

METHODS

The expert panel had delegates of the European Society of Surgical Oncology (ESSO), European Society for Radiotherapy & Oncology (ESTRO), European Society of Pathology (ESP), European Society for Medical Oncology (ESMO), European Society of Radiology (ESR), European Society of Coloproctology (ESCP), European CanCer Organisation (ECCO), European Oncology Nursing Society (EONS) and the European Colorectal Cancer Patient Organisation (EuropaColon), as well as delegates from national registries or audits. Experts commented and voted on the two web-based online voting rounds before the meeting (between 4th and 25th October and between the 20th November and 3rd December 2012) as well as one online round after the meeting (4th-20th March 2013) and were invited to lecture on the subjects during the meeting (13th-15th December 2012). The sentences in the consensus document were available during the meeting and a televoting round during the conference by all participants was performed. All sentences that were voted on are available on the EURECCA website www.canceraudit.eu. The consensus document was divided in sections describing evidence based algorithms of diagnostics, pathology, surgery, medical oncology, radiotherapy, and follow-up where applicable for treatment of colon cancer, rectal cancer and stage IV separately. Consensus was achieved using the Delphi method.

RESULTS

The total number of the voted sentences was 465. All chapters were voted on by at least 75% of the experts. Of the 465 sentences, 84% achieved large consensus, 6% achieved moderate consensus, and 7% resulted in minimum consensus. Only 3% was disagreed by more than 50% of the members.

CONCLUSIONS

It is feasible to achieve European Consensus on key diagnostic and treatment issues using the Delphi method. This consensus embodies the expertise of professionals from all disciplines involved in the care for patients with colon and rectal cancer. Diagnostic and treatment algorithms were developed to implement the current evidence and to define core treatment guidance for multidisciplinary team management of colon and rectal cancer throughout Europe.

State of the Art Reviews: Health Benefits Related to Exercise in Patients With Chronic Low-Grade Systemic Inflammation

Today, there is substantial evidence to suggest that regular exercise has health-promoting effects, which are beyond its effect on weight control. Regular exercise offers protection against all-cause mortality, and there is evidence from randomized intervention studies that physical training is effective as a treatment in patients with chronic heart diseases, type 2 diabetes, and symptoms related with the metabolic syndrome. Chronic diseases such as cardiovascular disease and type 2 diabetes are associated with chronic low-grade systemic inflammation. This review focuses on the anti-inflammatory effects of exercise that are mediated by muscle-derived cytokines (myokines). It is suggested that myokines may be involved in mediating the health-beneficial effects of exercise and that these in particular are involved in the protection against chronic diseases associated with low-grade inflammation.

Trends in colorectal cancer survival in northern Denmark: 1985-2004

OBJECTIVE

The prognosis for colorectal cancer (CRC) is less favourable in Denmark than in neighbouring countries. To improve cancer treatment in Denmark, a National Cancer Plan was proposed in 2000. We conducted this population-based study to monitor recent trends in CRC survival and mortality in four Danish counties.

METHOD

We used hospital discharge registry data for the period January 1985-March 2004 in the counties of north Jutland, Ringkjøbing, Viborg and Aarhus. We computed crude survival and used Cox proportional hazards regression analysis to compare mortality over time, adjusted for age and gender. A total of 19,515 CRC patients were identified and linked with the Central Office of Civil Registration to ascertain survival through January 2005.

RESULTS

From 1985 to 2004, 1-year and 5-year survival improved both for patients with colon and rectal cancer. From 1995-1999 to 2000-2004, overall 1-year survival of 65% for colon cancer did not improve, and some age groups experienced a decreasing 1-year survival probability. For rectal cancer, overall 1-year survival increased from 71% in 1995-1999 to 74% in 2000-2004. Using 1985-1989 as reference period, 30-day mortality did not decrease after implementation of the National Cancer Plan in 2000, neither for patients with colon nor rectal cancer. However, 1-year mortality for patients with rectal cancer did decline after its implementation.

CONCLUSION

Survival and mortality from colon and rectal cancer improved before the National Cancer Plan was proposed; after its implementation, however, improvement has been observed for rectal cancer only.

Colorectal cancer survival in the Nordic countries and the United Kingdom: Excess mortality risk analysis of 5 year relative period survival in the period 1999 to 2000

A deficit in colorectal cancer survival in Denmark and in the UK compared to Sweden, Norway and Finland was found in the EUROCARE studies. We set out to explore if these differences still exist. Patients diagnosed with colorectal cancer as their first invasive cancer at age 15-89 in the period 1994-2000 were identified using data from 11 cancer registries in the UK and from four Nordic countries. Five-year relative period survival using deaths in 1999-2000 following cancers diagnosed in 1994-2000 was analysed with excess mortality risk modelling. Follow-up time since diagnosis with age as an effect-modifier in the first half year was the most important factor with the highest excess risk of death immediately after diagnosis and with higher age and decreasing with length of follow-up. Variations between countries were bigger in the first half year following diagnosis than in the interval 0.5-5 years with about 30% higher risk in UK and Denmark. The differences between countries are still substantial and the order has not changed, even if the five year relative survival has improved since the EUROCARE studies. Patient management, diagnostics, and comorbidity likely explain the excess deaths in UK and Denmark during the first 6 months. The effect of stage and quality of management and treatment should be examined in population based studies with detailed patient information. Use of more detailed age-intervals than conventionally applied in survival studies proved to be important in statistical modelling and is recommended for future studies.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

Carbohydrate Digestibility Predicts Colon Carcinogenesis in Azoxymethane-Treated Rats

The purpose of this study was to compare the effect of carbohydrate structure and digestibility on azoxymethane (AOM)-induced colon carcinogenesis. Five groups of male Fischer 344 rats each comprising 30 animals were injected with AOM and fed a high-fat diet with 15% of various carbohydrates. The carbohydrate sources used were sucrose, cornstarch (a linear starch, reference group), potato starch (a branched starch), a short-chained oligofructose (Raftilose), and a long-chained inulin-type fructan (Raftiline). An interim sacrifice was performed after 9 wk to investigate markers of carbohydrate digestibility, including caecal fermentation (caecum weight and pH) and glucose and lipid metabolism [glucose, fructoseamine, HbA1c, triglycerides, and insulin-like growth factor (IGF) 1]. In addition potential early predictors of carcinogenicity [cell proliferation and aberrant crypt foci (ACF)] at 9 wk and their correlation to colon cancer risk after 32 wk were investigated. Tumor incidence was significantly reduced in animals fed oligofructose, and the number of tumors per animal was significantly reduced in animals fed inulin and oligofructose at 32 wk after AOM induction compared to the reference group fed sucrose. Increased caecum weight and decreased caecal pH were seen in groups fed oligofructose, inulin, and potato starch. Plasma triglyceride was decreased in rats fed oligofructose and inulin. Cell proliferation was increased in the proximal colon of rats fed sucrose, oligofructose, and inulin, and the number of cells per crypt decreased in rats fed oligofructose and inulin. The total number of ACF's was unaffected by treatment, and the size and multiplicity of ACF was unrelated to tumor development. It was concluded that less digestible carbohydrates with an early effect on caecum fermentation and plasma triglyceride decreased subsequent tumor incidence and multiplicity. This was unrelated to ACF, cell proliferation, and other markers of glucose and lipid metabolism.

Effective screening for bowel cancer: a United kingdom perspective

Bowel cancer is a major cause of morbidity and death and is a high cost to health care systems. Screening currently offers the best chance of improving outcomes from bowel cancer. When introducing screening, the problems encountered in other cancers need to be avoided to maximize benefits and minimize harms.

Population-based study of short- and long-term survival from colorectal cancer in Denmark, 1977–1999

Background

Survival rates for patients with colorectal cancer have been lower in Denmark than in other European countries. The aim of this study was to examine temporal trends in relative survival from colorectal cancer between 1977 and 1999.

Methods

All patients diagnosed with colorectal cancer between 1977 and 1999 were identified using the nationwide population-based Danish Cancer Registry. Patients were linked with the Danish Central Population Registry to obtain data on survival to December 2002, and to select ten population controls per patient.

Results

A total of 69 562 patients with colorectal cancer were identified, of whom 49·2 per cent were men. Six-month relative survival after diagnosis increased from 69·7 per cent in 1977–1982 to 77·7 per cent in 1995–1999. Five-year relative survival rates increased from 37·8 to 46·8 per cent respectively. Women had slightly higher 5-year relative survival than men throughout the study period. Rectal tumours were associated with better survival than colonic tumours until 2 years after diagnosis, after which tumour location had no impact on survival.

Conclusion

Relative survival of patients with colorectal cancer has improved in Denmark between 1977 and 1999, most probably reflecting better management of the disease.

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.

Adjuvant chemotherapy in curative resected colon carcinoma: 5-fluorouracil/leucovorin versus high-dose 5-fluorouracil 24-h infusion/leucovorin versus high-dose 5-fluorouracil 24-h infusion

BACKGROUND

Adjuvant postoperative treatment with 5-fluorouracil (5-FU) and leucovorin in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrence and improves survival. The impact of continuous 5-FU with and without leucovorin on survival and tumor recurrence was analyzed in this study compared with the effects of bolus 5-FU/leucovorin.

PATIENTS AND METHODS

Patients with a curatively resected UICC stage III colon cancer were stratified according to T, N and G category and randomly assigned to receive one of the three adjuvant treatment schemes: 5-FU 450 mg/m2 and leucovorin 100 mg/m2 x 5 days every 4 weeks; six cycles, arm A; 24-h infusion of high-dose 5-FU/leucovorin 2,600 mg/m2 and 500 mg/m2, two cycles of six applications, arm B; 24-h infusion of high-dose 5-FU 2,600 mg/m2, two cycles of six applications, arm C.

RESULTS

One hundred and forty-five patients enrolled into this study were eligible. To date, 28 patients have died; 9 on arm A, 11 on arm B, and 8 on arm C (P was nonsignificant). After a median follow-up time of 45 months, there was no statistical difference in survival and tumor recurrence between the three treatment arms. Adjuvant treatment in all arms was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities.

CONCLUSION

There is no statistical difference in efficacy and toxicity in patients receiving either high-dose 5-FU with or without leucovorin or the standard 5-FU bolus regime after a curative resection of a stage III colon cancer.

5-Fluorouracil plus leucovorin is an effective adjuvant chemotherapy in curatively resected stage III colon cancer: long-term follow-up results of the adjCCA-01 trial

BACKGROUND

Adjuvant postoperative treatment with 5-fluorouracil (5-FU) and leucovorin in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrences and improves survival. The impact of 5-FU plus leucovorin on survival and tumor recurrence was analyzed in a long-term follow-up study in comparison with the effects of 5-FU plus levamisole in the prospective multicenter trial adjCCA-01.

PATIENTS AND METHODS

Patients with a curatively resected stage III (International Union Against Cancer) colon cancer were stratified according to tumor, node and grading category and randomly assigned to receive one of the two adjuvant treatment schemes: 5-FU 400 mg/m2 body surface area intravenously in the first chemotherapy course, then 450 mg/m2 x 5 days, plus leucovorin 100 mg/m2, 12 cycles (arm A), or 5-FU plus levamisole (Moertel scheme; arm B).

RESULTS

Six hundred and eighty (96.9%) of 702 patients enrolled into this study were eligible. To date, 261 patients have died, 117 on arm A and 144 on arm B (P = 0.007). After a median follow-up time of 82 months, the 5-FU plus leucovorin combination significantly improved disease-free survival [79.8 months in arm A versus 69.3 months in arm B (P = 0.012)] and significantly increased median overall survival (88.9 months in arm A versus 78.6 months in arm B; P = 0.003). Adjuvant treatment with 5-FU plus levamisole as well as 5-FU plus leucovorin was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities.

CONCLUSIONS

After curative resection of a stage III colon cancer, adjuvant treatment with 5-FU plus leucovorin is generally well tolerated. This long-term follow-up study demonstrates that adjuvant treatment with 5-FU plus leucovorin given for 12 cycles is significantly more effective than 5-FU plus levamisole (Moertel scheme) in reducing tumor relapse and improving survival.

Diet and cancer: assessing the risk

Globally, colorectal cancer (CRC) is a leading cause of mortality from malignant disease. Case-control and cohort studies provide strong support for a role of diet in the aetiology of CRC. However to establish causal relationships and to identify more precisely the dietary components involved, intervention studies in human subjects are required. Cancer is an impractical endpoint in terms of numbers, cost, study duration and ethical considerations. Consequently, intermediate biomarkers of the disease are required. This review aims to provide an overview of the intermediate endpoints available for the study of CRC, particularly non-invasive faecal biomarkers. Examples of their use in dietary intervention studies are given.

Lactic acid bacteria and cancer: mechanistic perspective

Colorectal cancer is one of the most important causes of cancer morbidity and mortality in Western countries. While a myriad of healthful effects have been attributed to the probiotic lactic acid bacteria (LAB), perhaps the most controversial remains that of anticancer activity. It should be pointed out that there is no direct experimental evidence for cancer suppression in man as a result of consumption of lactic cultures in fermented or unfermented dairy products. However, there is a wealth of indirect evidence, based largely on laboratory studies, in the literature. The precise mechanisms by which LAB may inhibit colon cancer are presently unknown. However, such mechanisms might include: alteration of the metabolic activities of intestinal microflora; alteration of physico-chemical conditions in the colon; binding and degrading potential carcinogens; quantitative and/or qualitative alterations in the intestinal microflora incriminated in producing putative carcinogen(s) and promoters (e.g. bile acid-metabolising bacteria); production of antitumourigenic or antimutagenic compounds; enhancing the host's immune response; and effects on physiology of the host. These potential mechanisms are addressed in the present paper.

The importance of quality assurance in surgical oncology

AIMS

The aims were to review the existing methods of quality assurance in surgical oncology and to determine a relationship between surgery-related factors and the variety in outcomes in the treatment of solid cancers.

METHODS

The literature was reviewed by searching Medline and Cancerlit databases.

RESULTS

Wide variations were found in virtually all tumour types. Clear evidence was found that an improvement in the quality of the surgical procedure could have major implications for the prognosis and quality of life of cancer patients.

CONCLUSIONS

These findings emphasize the need for strict quality control procedures in surgical oncology and might imply a considerable change in cancer treatment strategies, because the routine use of adjuvant therapies could be questioned.

Treatment outcome studies. pitfalls in current methods and practice

The objective of a treatment outcome study is to investigate the heterogeneity in outcome between patients according to factors other than treatment, such as country, institution or physician. Results of treatment outcome studies have already been extensively presented in the medical literature. However, no clear methodology has emerged to perform treatment outcome studies and various methods have been used. This paper reviews the different types of questions addressed in treatment outcome studies, the different methodologies and the different endpoints used. Statistical techniques are mainly descriptive including tables, estimates of survival curves, but regression models have also been used. Most of the studies use registry data, while only a few use discharge data or data available from clinical trials.

Modelling time-dependent hazard ratios in relative survival: application to colon cancer

The Cox model is widely used in the evaluation of prognostic factors in clinical research. In population-based studies, however, which assess long-term survival of unselected populations, relative survival models are often considered more appropriate. In both approaches, the validity of proportional hazard hypothesis should be evaluated. To explore the validity of the proportional hazard assumption in a population-based study of colon cancer, to propose non-proportional hazard relative survival models and to evaluate their utility. The use of a piecewise proportional hazard relative survival model in colon cancer has shown that the effects of most clinical prognostic factors such as age, period of diagnosis and stage are non-proportional. The non-proportional hazard relative survival models developed in this article have been found to be efficient tools for better understanding the time-dependent aspect of prognostic factors.

Impact of patient and provider characteristics on the treatment and outcomes of colorectal cancer

While the management and prognosis of colorectal cancer are largely dependent on clinical features such as tumor stage, there is considerable variation in treatment and outcome not explained by traditional prognostic factors. To guide efforts by researchers and health-care providers to improve quality of care, we review studies of variation in treatment and outcome by patient and provider characteristics. Surgeon expertise and case volume are associated with improved tumor control, although surgeon and hospital factors are not associated consistently with perioperative mortality or long-term survival. Some studies indicate that patients are less likely to undergo permanent colostomy if they are treated by high-volume surgeons and hospitals. Differences in treatment and outcome of patients managed by health maintenance organizations or fee-for-service providers have not generally been found. Older patients are less likely to receive adjuvant therapy after surgery, even after adjustment for comorbid illness. In the United States, black patients with colorectal cancer receive less aggressive therapy and are more likely to die of this disease than white patients, but cancer-specific survival differences are reduced or eliminated when black patients receive comparable treatment. Patients of low socioeconomic status (SES) have worse survival than those of higher SES, although the reasons for this discrepancy are not well understood. Variations in treatment may arise from inadequate physician knowledge of practice guidelines, treatment decisions based on unmeasured clinical factors, or patient preferences. To improve quality of care for colorectal cancer, a better understanding of mechanisms underlying associations between patient and provider characteristics and outcomes is required.

Fluorouracil plus leucovorin as effective adjuvant chemotherapy in curatively resected stage III colon cancer: results of the trial adjCCA-01

PURPOSE

Adjuvant postoperative treatment with fluorouracil (5-FU) and levamisole in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrence and improves survival. Biochemical modulation of 5-FU with leucovorin has resulted in increased remission rates in metastatic colorectal cancer, thus reflecting an increased tumor-cell kill. The impact of 5-FU plus leucovorin on survival and tumor recurrence was analyzed in comparison with the effects of 5-FU plus levamisole in the prospective multicentric trial adjCCA-01.

PATIENTS AND METHODS

Patients with a curatively resected International Union Against Cancer stage III colon cancer were stratified according to T, N, and G category and randomly assigned to receive one of the two adjuvant treatment schemes: 5-FU 400 mg/m(2) body-surface area intravenously in the first chemotherapy course, then 450 mg/m(2) x 5 days; 12 cycles, plus leucovorin 100 mg/m(2) (arm A), or 5-FU plus levamisole (Moertel scheme; arm B).

RESULTS

Six hundred eighty (96.9%) of 702 patients enrolled onto this study were eligible. After a median follow-up time of 46.5 months, the 5-FU plus leucovorin combination significantly improved disease-free survival (P =.037) and significantly decreased overall mortality (P =.0089) in comparison with 5-FU plus levamisole. In a multivariate proportional hazards model, adjuvant chemotherapy emerged as a significant prognostic factor for survival (P =.0059) and disease-free survival (P =.03). Adjuvant treatment with 5-FU plus levamisole as well as with 5-FU plus leucovorin was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities.

CONCLUSION

After a curative resection of a stage III colon cancer, adjuvant treatment with 5-FU plus leucovorin is generally well tolerated and significantly more effective than 5-FU plus levamisole in reducing tumor relapse and improving survival.

Socioeconomic inequalities in cancer survival in England and Wales

BACKGROUND

Cancer survival often has been reported as lower for the poor than the rich, but, to the authors' knowledge, systematic national estimates of deprivation gradients in survival over long periods of time have not been available.

METHODS

The authors estimated national population-based survival rates for almost 3 million people who were diagnosed with 1 of 58 types of cancers (47 in adults, 11 in children) in England and Wales during the 20-year period 1971-1990 and followed through December 31, 1995. Cancer patients were assigned by their address at diagnosis to 1 of 5 categories (quintiles of the national distribution) of material deprivation by using a standard index derived from census data on unemployment, car ownership, household overcrowding, and social class that was available for all 109,000 census tracts in Great Britain. The authors used relative survival rates: the ratio of observed survival among the cancer patients to the survival that would have been expected if they had had the same background mortality as the general population. Background mortality differed widely among socioeconomic categories, and the authors constructed life tables from raw national mortality data by gender, single year of age, calendar period of death, and socioeconomic category to adjust for it. The authors used variance-weighted least squares regression to estimate both time trends in age standardized survival and socioeconomic gradients in survival. The number of avoidable deaths was estimated from the observed mortality excess compared with the expected mortality in each group of patients.

RESULTS

Survival rose steadily for most cancers over 25 years to 1995 in England and Wales, but inequalities in survival between patients living in rich and poor areas were geographically widespread and persistent over this period of time. These patterns existed for 44 of 47 adult cancers examined but not for 11 childhood cancers. These inequalities in survival represented more than 2500 deaths that would have been avoided each year if all cancer patients had had the same chance of surviving up to 5 years after diagnosis as patients in the most affluent group.

CONCLUSIONS

The largest national cancer survival study has provided strong evidence of systematic disadvantage in outcome among patients who lived in poorer districts compared with those who lived in wealthier districts.

Methodological issues in the use of guidelines and audit to improve clinical effectiveness in breast cancer in one United Kingdom health region

AIMS

To develop a system to improve and monitor clinical performance in the management of breast cancer patients in one United Kingdom health region.

DESIGN

An observational study of the changes brought about by the introduction of new structures to influence clinical practice and monitor change.

SETTING

North Thames (East) Health region, comprising seven purchasing health authorities and 21 acute hospitals treating breast cancer.

SUBJECTS

The multi-disciplinary breast teams in 21 hospitals and an audit sample of 419 (28%) of the breast cancer patients diagnosed in 1992 in the region.

INTERVENTIONS

Evidence-based interventions for changing clinical practice: regional guidelines, senior clinicians acting as <<opinion leaders>>, audit of quality rather than cost of services, ownership of data by clinicians, confidential feed-back to participants and education.

OUTCOME MEASURES

Qualitative measures of organizational and behavioural change. Quantitative measures of clinical outcomes compared to guideline targets and to results from previous studies within this population.

RESULTS

Organizational changes included the involvement, participation of and feedback to 16 specialist surgeons and their multidisciplinary teams in 21 hospitals. Regional clinical guidelines were developed in 6 months and the dataset piloted within 9 months. The audit cycle was completed within 2 years. The pilot study led to prospective audit at the end of 2 years for all breast cancers in the region and a 15-fold increase in high quality clinical information for these patients. Changes in clinical practice between 1990 and 1992 were observed in the use of chemotherapy (up from 17-23%) and axillary surgery (up from 46-76%).

CONCLUSIONS

The approach used facilitated rapid change and found a balance between local involvement (essential for sustainability within a hospital setting) and regional standardization (essential for comparability across hospitals). The principles of the approach are generalized to other cancers and to other parts of the UK and abroad.

Influence of stage at diagnosis on survival differences for rectal cancer in three European populations

Important differences have recently been highlighted between European countries in the survival of colorectal cancer patients. As data on stage at diagnosis were available for rectal cancers in three European population-based registries (Geneva Switzerland; Côte d'Or, France; Mallorca, Spain), we compared relative survival while assessing the effect of stage in a multiple regression model. We analysed 1005 rectal cancer cases diagnosed between 1982 and 1987 and followed up for at least 5 years. In the Mallorca registry, 16% of the patients were diagnosed in the TNM stage I (versus 21% in the Côte d'Or registry and 29% in the Geneva registry, P < 10(-4)) and the 5-year relative survival rate was lower (35%) than in the other two registries (Côte d'Or 47%, Geneva 48%, P = 0.01). In the multivariate analysis, stage was the only independent prognostic factor, whereas the excess death risk did not vary significantly among registries (compared to Geneva, Côte d'Or relative risk was 1.0, Mallorca relative risk 1.11, 95% confidence interval 0.76-1.32 and 0.85-1.44 respectively). Survival differences between the registries were mainly due to stage at diagnosis. Thus, diagnostic conditions appear to be the main determinant of the survival inequalities found in those three European populations.

Improvement of survival over time for colon cancer patients by anatomical sub-sites

The aims of this study are to describe and to evaluate improvement of survival over time for colon cancer patients by anatomical sub-sites. Data on 661 patients newly diagnosed as having colon cancer at Osaka Medical Center for Cancer and Cardiovascular Diseases from 1978 to 1991 were examined in this study. Corrected survival was calculated with the Kaplan-Meier method according to the period of diagnosis: early period (1978-84) and later period (1985-91). Factors concerning the difference in survival between the two periods were examined with the Cox proportional hazards regression model according to sub-site. Five-year corrected survival of the patients with left colon cancer improved significantly (60 to 72%; P < 0.01), probably due to advances in treatment, while that of patients with transverse colon cancer also improved significantly (39 to 67%; P < 0.01), mainly because of progress in diagnosis. The five-year corrected survival of those with right colon cancer did not increase (57 to 46%; P = 0.14), owing to lack of improvement in stage at diagnosis. Among the three sub-sites, the right showed the worst five-year survival in the later period. We concluded that survival of patients with right colon cancer, differing from the other anatomical sub-sites, did not improve, possibly because of lack of symptoms. The screening programs for colon cancer introduced in Japan in 1992 may be expected to improve the survival of patients with colon cancer, including that of the right colon.

Loss of heterozygosity at 18q21 is indicative of recurrence and therefore poor prognosis in a subset of colorectal cancers

Adjuvant therapies are increasingly used in colorectal cancers for the prevention of recurrence. These therapies have side-effects and should, thus, be used only if really beneficial. However, the development of recurrence cannot be predicted reliably at the moment of diagnosis, and targeting of adjuvant therapies is thus based only on the primary stage of the cancer. Loss of heterozygosity (LOH) in the long arm of chromosome 18 is suggested to be related to poor survival and possibly to the development of metastases. We studied the value of LOH at 18q21 as a marker of colorectal cancer prognosis, association with clinicopathological variables, tumour recurrence and survival of the patients. Of the 255 patients studied, 195 were informative as regards LOH status when analysed in primary colorectal cancer specimens using the polymerase chain reaction (PCR) and fragment analysis. LOH at 18q21 was significantly associated with the development of recurrence (P = 0.01) and indicated poor survival in patients of Dukes' classes B and C, in which most recurrences (82%) occurred. An increased rate of tumour recurrence is the reason for poor survival among patients with LOH at 18q21 in primary cancer. These patients are a possible target group for recurrence-preventing adjuvant therapies.

Survival of colorectal cancer patients in Europe during the period 1978-1989. EUROCARE Working Group

This study concerns the survival of European patients diagnosed between 1978 and 1989 with colorectal cancer. Variations in survival in relation to age, country and period of diagnosis were examined. Data from the EUROCARE study were supplied by population-based cancer registries in 17 countries to a common protocol. Five years after diagnosis, relative survival rates were 47 and 43% for cancers of the colon and rectum, respectively. Survival decreased with increasing age: the relative risk of dying for the oldest patients (75+) was 1.39 for rectum and 1.54 for colon compared with the youngest patients (15-44 years). In 1985-1989 survival from colorectal cancer differed significantly between different European countries: the Nordic countries (Denmark excluded), The Netherlands, Switzerland, France and Austria were characterised by high survival, whilst Eastern European countries, the U.K. and Denmark were characterised by low survival. There was a general improvement in survival over the period 1978-1989: from 40 to 48% for colon cancer and 38 to 46% for rectal cancer. For neither cancer site did between-country survival differences narrow over the study period. Intercountry and time differences in survival differences are probably related to stage at diagnosis and postoperative mortality.

The prognostic role of gender in survival of adult cancer patients. EUROCARE Working Group

Many observations indicate that women have a much longer expectancy of life than men. Some population-based studies on cancer patients support the idea of the role of gender in predicting survival. However, the data are somewhat contrasting and inconclusive. The purpose of this paper was to evaluate the prognostic role of gender for cancer patients, making use of the large set of survival data made available by the EUROCARE II project for the period 1985-1989. By applying a multivariate approach the major confounders such as age, geographical area and cancer site were considered in analysing survival data on more than 1 million cancer cases collected by 45 population-based cancer registries in 17 European countries. The results were consistent with the general observation that in the industrialised countries women tend to survive longer than men. The multivariate analysis showed better survival from cancer in women than in men, estimated as an overall 2% lower relative risk of dying. The female advantage was particularly evident in young cases, reduced in patients in middle age groups and in the oldest patients completely reversed so that at this age men had the better prognosis. Longer survival for women was not present immediately after diagnosis, but the major advantage was seen after 3 years of follow-up. The risk of death for women was significantly lower for cancer of the head and neck, oesophagus, stomach, liver and pancreas. For bladder cancer, the risk of death was significantly greater for women. These results can be explained by gender differences in sub-site distributions (head and neck and stomach) and by the differences in the stage at diagnosis (presumably bladder). However, the consistency of the data, evident only when a vast set of data is analysed, suggest that women may be intrinsically more robust than men in coping with cancer.

Conditional survival estimates in 34,963 patients with invasive carcinoma of the colon

PURPOSE

We report colon cancer survival rates that are conditioned on patients having already survived one or more years after diagnosis. These rates have more meaning clinically, because they consider those patients who have already survived a given period of time after treatment.

METHODS

The life table method was used to compute conditional survival rates, using population-based data obtained from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. Patients were diagnosed between 1983 and 1987 and followed up through 1994. Relative and observed survival rates are considered.

RESULTS

Survival rates up to ten years after diagnosis are reported by stage of disease, gender, and race for colon cancer patients who survived from one to five years after diagnosis. Survival rates are also reported by lymph node involvement.

CONCLUSIONS

Five-year and ten-year survival in colon cancer patients having already survived between one and five years after diagnosis continues to be influenced significantly by stage and race.

The cure for colon cancer: results from the EUROCARE study

The interpretation of time trends and geographical differences of population-based survival rates is generally not easy, due to the difficulty in disentangling the effects of observational biases, diagnostic and therapeutic procedures and their interactions. Whereas descriptive analysis of relative survival is generally based on survival levels estimated at fixed time since diagnosis, interpretation issues can take advantage from the analysis of the shape of the considered relative survival. Parametric survival models allowing the estimation of the fraction of cured patients are applied here to analyze and discuss the differences in colon cancer relative survival between European countries, according to age and period of diagnosis. The survival curves of colon cancer patients are described according to 2 parameters: the proportion of cured patients and the mean survival time of fatal cases. These parameters are estimated by least square nonlinear regression of relative survival values derived from the EUROCARE Project publication. Exponential and Weibull survival functions are used to model the relative survival curve for the fraction of fatal cases. The Weibull model gives generally a better fit with respect to the exponential model, thus indicating that the mortality rate for fatal cases is decreasing with time since diagnosis. For the youngest patients, however, the 2 survival functions give practically overlapping estimates. The overall proportion of colon cancer patients in Europe that are estimated to be cured was 38.6%. This proportion increased from 36% to 40% for patients diagnosed in 1978-1980 and in 1983-1985, respectively. Accordingly, mean survival time of fatal cases increased from 1.18 to 1.52 years. According to age, the proportion of cured patients present a marked decrease from young (48.4% at age 15-44 years) to middle-aged patients (38.6% at age 5564 years) and only a mild decrease from these to the oldest patients (34.4% at age 75 or more). The opposite effect was shown by survival time of fatal cases, i.e., 1.71, 1.75 and 0.77 years for the same age classes, respectively. Proportion of cured cases and mean survival time of fatal cases tended to be positively correlated with each other across countries. Our results are consistent with the hypothesis that a real improvement in colon cancer survival took place in Europe during the years 1978-1985 and also suggest that the well-known decrease of relative survival with age at diagnosis could be mostly due to a decreasing efficacy of early diagnosis for patients under 60 years old and to less effective therapies for older patients.

International differences in survival from colon cancer: more effective care versus less complete cancer registration

BACKGROUND

Reporting of a recent international comparison of cancer survival rates has left an impression of inadequate treatment of patients in the UK but failed to address adequately the extent to which differences in survival may reflect variation in the completeness and accuracy of cancer registration. The aim of this study was to quantify the extent to which differences in registration practice may confound comparisons of survival from cancer of the colon.

METHODS

A cohort of incident cases of colon cancer identified from records held by the North Western Regional Cancer Registry was used to simulate the effects on survival of changes in clinical and registration factors. The survival curve produced after each simulation was compared with that for aggregated data from 21 European registries.

RESULTS

The observed survival differences were not explained by more effective primary treatment or by misclassification of in situ cases as malignant disease, whereas the exclusion of cases with only a clinical diagnosis produced estimates close to those of the European cohort.

CONCLUSION

The observed survival differentials may not be due to differences in the quality of care but may reflect the failure of some European registries to register all patients with advanced disease.

Substantial variation in therapy for colorectal cancer across Europe: EUROCARE analysis of cancer registry data for 1987

To provide a quantitative description of the treatments applied to malignant colorectal cancer across Europe, we analysed all cases (11,333) of colorectal cancer registered in 1987 by 15 Cancer Registries in eight European countries. In a third of cancer registries, therapy was known for all cases, in the others 1-15% of registrations lacked treatment information. Eighty per cent of all patients received surgical resection, ranging from 58% (Estonia) to 92% (Tarn). The proportion of resections decreased with advancing age (85-73% for colon cancer; 85-70% for rectal cancer for < 65 years to > 74 years, respectively). Only 4% of colon cancer patients received adjuvant or palliative chemotherapy, range 1-12%. Sixteen per cent of rectal cancer patients received radiotherapy with great inter-registry variability (1-43%). Since the proportion of surgically resected patients correlated positively with the 5-year relative survival probability reported by the recently published EUROCARE study, this may be part of the explanation for the major differences in survival for these cancers among different European populations. The most likely determinant of this correlation is stage at diagnosis, but, quality of, and access to surgery, as well as access to endoscopy, may differ among countries and registry areas, and these may also contribute to inter-country survival differences.