Jacques Estève

Dietary effects on breast-cancer risk in Singapore

It is suspected that diet influences the risk of getting breast cancer. A study of diet and breast cancer was done among 200 Singapore Chinese women with histologically confirmed disease and 420 matched controls. A quantitative food-frequency questionnaire was used to assess intakes of selected nutrients and foods 1 year before interview. Daily intakes were computed and risk analysed after adjustment for concomitant risk factors. In premenopausal women, high intakes of animal proteins and red meat were associated with increased risk. Decreased risk was associated with high intakes of polyunsaturated fatty acids (PUFA), beta-carotene, soya proteins, total soya products, a high PUFA to saturated fatty acid ratio, and a high proportion of soya to total protein. In multiple analysis, the variables which were significant after adjustment for each other were red meat (p less than 0.001) as a predisposing factor, and PUFA (p = 0.02), beta-carotene (p = 0.003), and soya protein (p = 0.02) as protective factors. The analysis of dietary variables in postmenopausal women gave uniformly non-significant results. Our finding that soya products may protect against breast cancer in younger women is of interest since these foods are rich in phyto-oestrogens.

Trends and socioeconomic inequalities in cancer survival in England and Wales up to 2001.

We examined national trends and socioeconomic inequalities in cancer survival in England and Wales during the 1990s, using population-based data on 2.2 million patients who were diagnosed with one of the 20 most common cancers between 1986 and 1999 and followed up to 2001. Patients were assigned to one of five deprivation categories (from ‘affluent’ to ‘deprived’) using characteristics of their electoral ward of residence at diagnosis. We estimated relative survival up to 5 years after diagnosis, adjusting separately in each deprivation category for background mortality by age, sex and calendar period. We estimated trends in survival and in the difference in survival between deprivation categories (‘deprivation gap’) over the periods 1986–90, 1991–95 and 1996–99. We used period analysis to examine likely survival rates in the near future. Survival improved for most cancers in both sexes during the 1990s, and appears likely to continue improving for most cancers in the near future. The deprivation gap in survival between rich and poor was wider for patients diagnosed in the late 1990s than in the late 1980s. Increases in cancer survival in England and Wales during the 1990s are shown to be significantly associated with a widening deprivation gap in survival.

On Estimation in Relative Survival

Estimation of relative survival has become the first and the most basic step when reporting cancer survival statistics. Standard estimators are in routine use by all cancer registries. However, it has been recently noted that these estimators do not provide information on cancer mortality that is independent of the national general population mortality. Thus they are not suitable for comparison between countries. Furthermore, the commonly used interpretation of the relative survival curve is vague and misleading. The present article attempts to remedy these basic problems. The population quantities of the traditional estimators are carefully described and their interpretation discussed. We then propose a new estimator of net survival probability that enables the desired comparability between countries. The new estimator requires no modeling and is accompanied with a straightforward variance estimate. The methods are described on real as well as simulated data.

Sex- and strain-specific induction of renal tumors by ochratoxin A in rats correlates with DNA adduction

Ochratoxin A (OTA), a nephrotoxic and carcinogenic mycotoxin, has been implicated as an etiologic agent in the Balkan endemic nephropathy (BEN), a chronic disease affecting populations in the Balkans. Compared with unaffected individuals, patients suffering from BEN and/or urinary tract tumors were more frequently found to have a capacity for rapid debrisoquine (DB) metabolism, a metabolic reaction related mostly to cytochrome P450 (CYP) 2D in humans. Earlier studies, using female DA and Lewis rats phenotyped as poor or extensive DB metabolizers respectively, revealed a parallelism between DB‐4 hydroxylation and OTA‐4 hydroxylation. To investigate whether genetic polymorphism modifies tumor induction, we have compared both OTA‐induced renal carcinogenicity and DNA adducts in DA and Lewis rats of both sexes. OTA induced renal adenocarcinoma, DA male rats being most responsive, while DA females were resistant. Lewis rats showed an intermediate renal tumor response. OTA also induced malignant transitional cell carcinomas of the bladder in DA male rats only. DNA adducts in the kidney, as judged by the nature of spots and prevalence in OTA‐treated animals, were significantly correlated with renal carcinogenicity of OTA, being highest in DA males and lowest in DA females. A parallelism between karyomegalies and tumors of the kidney was observed. In conclusion, our results classify OTA as a genotoxic carcinogen in rats, with sex‐specific response controlled in part by drug‐metabolizing enzymes that convert OTA into reactive intermediates. Int. J. Cancer 77:70–75, 1998.© 1998 Wiley‐Liss, Inc.

Risk factors for breast cancer by age and menopausal status: a case-control study in Singapore.

A case-control study was conducted among Singapore Chinese women, comprised of 200 histologically confirmed cases of breast cancer and 420 hospital controls. Subjects were interviewed on family history of breast cancer, social and demographic characteristics, reproductive history, and diet one year prior to interview. Differences in risk factors were observed according to menopausal status. In the premenopausal group, the most consistently significant nondietary effect was an increased risk with late age at first birth. In postmenopausal women, the most consistent nondietary effects were increased risks with nulliparity, tall stature, high educational status, and a family history of breast cancer. In premenopausal women, the strongest dietary effects were low risks with high intakes of polyunsaturated fatty acids (PUFA), β-carotene, soya protein as a proportion of all protein, and a high risk with high red-meat intake. No dietary effects were observed in postmenopausal women. Examination of effects by 10-year age groups suggested that the differences in the effects of age at first birth, nulliparity, height, education, β-carotene intake, and PUFA intake between premenopausal and postmenopausal women were at least partly attributable to age-related differences in the baseline distributions of these variables. The variation in the effects of red meat and soya protein appeared to be attributable mainly to menopausal status itself, which is consistent with the hypothesis that these factors operate on risk by way of hormonal mechanisms.

Survival of patients with oesophageal and gastric cancers in Europe

The EUROCARE study is a European Union project to collect survival data from population-based cancer registries and analyse them according to standardised procedures. We investigated and compared oesophageal and gastric cancer survival in 17 countries between 1985 and 1989. Time trends in survival over the 1978-1989 period were also investigated in 13 countries. The overall European 1-year relative survival rates were 33% for oesophageal cancer and 40% for gastric cancer. The corresponding 5-year relative survival rates were 10 and 21%, respectively. Important intercountry survival differences exist within Europe for oesophageal and gastric cancer. Taking the European average as the reference, the relative risk (RR) of death at 5 years was at least 30% higher in Denmark, Poland, Estonia and Slovenia for oesophageal cancer and in Denmark, England, Scotland and Poland for gastric cancer. In the other countries survival figures were close to the European average. Gender had little influence on survival, whilst age at diagnosis was inversely related to prognosis. There was a slight improvement between 1978 and 1989 in 5-year overall relative survival rates for both oesophageal cancer (RR = 0.80, 95% confidence interval (CI) 0.72-0.90) and gastric cancer (RR = 0.88, 95% CI 0.82-0.94). Differences in quality of care and stage at diagnosis can explain in part the differences in survival found in the EUROCARE countries. Significant improvement in prognosis has still to be achieved.

Incidence of gastrointestinal cancers in France

AIM Monitoring cancer incidence and time trends is essential for cancer research and health care planning. The aim of the study was to compare the incidence of gastrointestinal cancers in twelve administrative area in France to estimate the national cancer incidence during 2000 compared with the preceding 20 years. METHODS Incidence data was provided by cancer registries and mortality data by the French national medical research institute (INSERM). The two data sets were modeled separately over the period 1988-1997 using age-cohort models. The incidence/mortality ratio obtained from these models was applied to the mortality rates of an age-cohort model of the entire population. RESULTS The estimated number of new cases of gastrointestinal cancer was 61,465 in 2000. Colorectal cancer was the leading localization with 36,257 cases. The incidence of gastrointestinal cancers was slightly higher in northern than in southern area. Incidence of esophageal cancer was three times that of liver cancer. Variations in incidence were less marked for other localizations. The incidence of gastric and esophageal cancer in the male population decreased between 1980 and 2000, on average by slightly more than 2% per year. Incidence of other cancers increased. The number of new cases of colorectal cancer increased by 50%. The rise in the incidence of liver cancer was particularly striking, with an increase from 2000 incident cases in 1980 to nearly 6000 in 2000. CONCLUSION For most localizations, incidence of gastrointestinal cancers displays few geographical differences in France, but there has been a striking change in incidence trends over the past 20 years.

Diet and cancers of the larynx and hypopharynx: the IARC multi-center study in southwestern Europe

The main causes of cancer of the larynx and hypopharynx are smoking cigarettes and drinking alcohol. However, for these as well as for other cancers of the upper aerodigestive tract, some dietary components, mainly low consumption of fruit and vegetables, have been observed to be associated with increased cancer risk. We report results from a multicenter case-control study carried out in six regions of Europe located in northern Spain, northern Italy, Switzerland, and France. A total of 1,147 males with cancer (cases) and 3,057 population controls were interviewed on usual diet, lifelong drinking and smoking habits, and occupational history. Cancer cases had histologically verified epidermoid carcinomas. The cancers were classified in two anatomic sub-entities: the epilarynx (hypopharynx and upper part of the larynx), which enters into contact with the bolus and the air; and the endolarynx, through which air and tobacco smoke pass, but not the bolus. A previous report from this study found that alcohol drinking presents a greater risk factor for cancer of the epilarynx than for cancer of the endolarynx. The main results regarding diet indicate that high intake of fruit, vegetables, vegetable oil, fish, and low intake of butter and preserved meats were associated with reduced risk of both epilaryngeal and endolaryngeal cancers, after adjustment for alcohol, tobacco, socioeconomic status, and non-alcohol energy intake. Among nutrients, a reduced risk was found for high intake of vitamins C and E and for a high polyunsaturated/saturated fatty acids (P/S) ratio. While these variables are relevant in scoring nutritional behaviour, it remains unresolved whether the biologic properties of these nutrients play a role in the apparent protective effect.

Cancer survival in England and Wales at the end of the 20th century

Survival has risen steadily since the 1970s for most cancers in adults in England and Wales, but persistent inequalities exist between those living in affluent and deprived areas. These differences are not seen for children. For many of the common adult cancers, these inequalities in survival (the ‘deprivation gap’) became more marked in the 1990s. This volume presents extended analyses of survival for adults diagnosed during the 14 years 1986–1999 and followed up to 2001, including trends in overall survival in England and Wales and trends in the deprivation gap in survival. The analyses include individual tumour data for 2.2 million cancer patients. This article outlines the structure of the supplement – an article for each of the 20 most common cancers in adults, followed by an expert commentary from one of the leading UK clinicians specialising in malignancies of that organ or system. The available data, quality control and methods of analysis are described here, rather than repeated in each of the 20 articles. We open the discussion between clinicians and epidemiologists on how to interpret the observed trends and inequalities in cancer survival, and we highlight some of the most important contrasts in these very different points of view. Survival improved substantially for adult cancer patients in England and Wales up to the end of the 20th century. Although socioeconomic inequalities in survival are remarkably persistent, the overall patterns suggest that these inequalities are largely avoidable.

Survival of women with breast cancer in Europe: Variation with age, year of diagnosis and country

Breast cancer is the most frequent malignancy among women in developed countries. Prognosis is better than for other major cancers, and an improvement in survival has been reported for several populations in recent decades. Within the framework of EUROCARE, a population‐based project concerned with the survival and care of cancer patients in Europe, we analysed data from 119,139 women diagnosed with breast cancer between 1978 and 1985 in 12 countries and followed for at least 6 years. Multiple regression models of relative survival, which take mortality from all other causes in each area into account, were used to estimate the effect of age, period of diagnosis and country on survival. For the comparison between countries, survival rates were age‐standardised to the age structure of the entire study population. Women aged 40–49 years at diagnosis had the best prognosis in all countries and throughout the study period. Women younger than 30 years at diagnosis had a worse prognosis than those aged 30–39. The highest relative survival at 5 years was in Finland and Switzerland (about 74%), intermediate levels were found for Italy, France, The Netherlands, Denmark and Germany (about 70%) and the lowest rates were in Spain, the United Kingdom, Estonia and Poland (55–64%). During the 6 months following diagnosis, survival was highly dependent on age and was sharply lower in women older than 49 years. For women surviving more than 6 months after diagnosis, survival was similar for all ages, although women aged 40–49 still had the better prognosis. The average rate of death from breast cancer fell by about 2.5% for each year of diagnosis between 1978 and 1985. This improvement manifested mainly in younger and older women, for whom survival was initially less good. The largest improvement was seen in Poland (−15% death risk per year). We suggest that the better survival of women aged 40–49 at diagnosis is related to lower levels of circulating sex hormones, resulting in reduced stimulation of tumour cell growth. Early diagnosis may also be important in the peri‐menopausal period due to increased diagnostic attention. Low survival in the United Kingdom may be due to inadequate adherence to consensus treatment guidelines and greater variation in treatment. Int. J. Cancer 77:679–683, 1998.© 1998 Wiley‐Liss, Inc.