Tea and coffee consumption and the risk of digestive tract cancers: data from a comparative case-referent study in Japan

OBJECTIVES

The purpose of this study was to examine the hypothesis that tea and coffee consumption have a protective effect against development of digestive tract cancers.

METHODS

A comparative case-referent study was conducted using Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC) data from 1990 to 1995 in Nagoya, Japan. This study comprised 1,706 histologically diagnosed cases of digestive tract cancers (185 esophagus, 893 stomach, 362 colon, 266 rectum) and a total of 21,128 non-cancer outpatients aged 40 years and over. Logistic regression was used to analyze the data, adjusting for gender; age; year and season at hospital-visit; habitual smoking and alcohol drinking; regular physical exercise; fruit, rice, and beef intake; and beverage intake.

RESULTS

The odds ratio (OR) of stomach cancer decreased to 0.69 (95 percent confidence interval [CI] = 0.48-1.00) with high intake of green tea (seven cups or more per day). A decreased risk was also observed for rectal cancer with three cups or more daily intake of coffee (OR = 0.46, CI = 0.26-0.81).

CONCLUSIONS

The results suggest the potential for protective effect against site-specific digestive tract cancer by consumption of green tea and coffee, although most associations are limited only to the upper category of intake and have no clear explanation for site-specificity.

How to ensure data security of an epidemiological follow-up: quality assessment of an anonymous record linkage procedure

A computerised record hash coding and linkage procedure is proposed to allow the chaining of medical information within the framework of epidemiological follow-up. Before their extraction, files are rendered anonymous using a one-way hash coding based on the standard hash algorithm (SHA) function, in order to respect the legislation on data privacy and security. To avoid dictionary attacks. two keys have been added to SHA coding. Once rendered anonymous, the linkage of patient information can be accomplished by means of a statistical model, taking into account several identification variables. Quality assessment of this anonymous record linkage procedure shows a specificity of 100% and a sensitivity of 95%.

[Evaluation of the effectiveness of screening for tumors of the digestive system]

Some features of digestive cancers encourage screening programs, even though no such program has been shown so far effective in reducing mortality rates. The visual inspection of the oral cavity and pharynx, with the addition of flexible endoscopy and, possibly, blue-toluidine staining, can be easily performed by specialists and dentists. The strong association with smoking habits and alcohol consumption favours the organization of screening programs but primary prevention maintains the highest priority. For cancer of the colon-rectum two different screening approaches are under close scrutiny: fecal occult blood testing, on an yearly basis, and once-in-a-life sigmoidoscopy at 55-60 years of age. Only one of five ongoing randomized prospective studies on occult blood testing has reported, so far, a significant reduction, around 33%, of mortality from colorectal cancer, with, however, a large burden of sigmoidoscopies.

[Food consumption in Italy in relation to tumors of the digestive system]

Time trends of consumption of the principal food and nutrients in Italy are evaluated in relation with geographic area, using most of the published data. A progressive enrichment was observed for the Italian diet, with an increasing intake of animal proteins, saturated fats and sugars, and a decreasing intake of bread and pasta. Differences of dietary habits among different geographical areas are also decreasing. The main geographical and temporal patterns of digestive sites cancer are in agreement with the above described trends and with the principal hypothesis on nutritional causation of cancer.

[Incidence and prevalence of digestive system tumors: data from Italian tumor registries]

In incidence data from 10 cancer registries in Italy, cancers of digestive organs make up 20-25% of all cancers. In incidence of oral cavity, pharynx, oesophagus and colorectal cancer is higher in the North. The highest incidence rates for stomach cancer (among the highest in Europe) are in Centre-North. Liver cancer, on the contrary, is one of few cancers with the highest frequency in the South. The first observed prevalence data measured from Italian cancer registries refer to patients with colorectal cancer recorded in Varese province in 1976-87 period and followed up to 1988. Including those cases with less than 12 years from diagnosis, they were about 200 per 100,000: more than 60% aged between 60 and 80 years.

[Incidence and prevalence of digestive system tumors in Italy: estimates from mortality data]

This work presents estimates and middle-term projections of incidence and prevalence levels in Italy for cancers of the oral cavity and pharynx, of the stomach, and of colon and rectum. The estimation procedure was previously validated using incidence data observed by Italian cancer registries operating in limited geographical areas. Projections up to the year 2000 of mortality, incidence, and prevalence rates and estimated cohort effects are reported for stomach and colorectal cancers only. For both cancer sites, cohort effects, rather than period effects, result to be responsible for mortality and incidence dynamics. Incidence levels show a general decreasing trend for stomach cancer and an increasing one for colorectal cancer. Cumulative risk trend tends, however, to level-off for the youngest cohorts. Moreover, the well known geographical differences between the North and the South of the country seem to be progressively reducing.

[Hereditary factors in tumors of the digestive system]

Gastrointestinal tumours are an excellent model for the investigation of hereditary factors in cancer. Epidemiological studies on high risk population (China, Iran) evidenced a strong familiarity for esophageal cancer with up to 60% of the affected patients reporting a positive familiary history. About 10-15% of gastric cancer patients show a positive familiary history for this neoplasm. The proportion is even higher for the "diffuse" hystological type. Gastric cancer belongs to the neoplastic spectrum of hereditary nonpolyposis colorectal cancer, a genetic disease with an autosomal dominant pattern of inheritance. Familial polyposis coli and hereditary nonpolyposis colorectal cancer are the two main hereditary colon cancer syndromes. Familiar aggregation have been observed in about 10% of colorectal cancer cases. As for pancreatic cancer, anedoctal reports and one case control study have shown an increased risk of pancreatic carcinoma in patients with a positive family history both for all cancers (relative risk, RR, 2), and specific for pancreatic cancer (RR: 5).

[Second primary malignant neoplasms in patients treated in the Otolaryngology Clinic AM of Lodz in the years 1981-1989]

The incidence of multiple primary malignant tumours in 913 patients treated during 9 years for malignant neoplasms was investigated. In 24 (2.63%) cases second primary malignant neoplasm was diagnosed, mostly (in 19 cases-2.1%) it was correlated to cancer of larynx. In 18 cases (75% of all multiple tumours) neoplasms were metachronous, in 5-synchronous, and in one case--it was multifocal neoplasm (in both tonsils). In 3 patients three separate primary neoplasms were observed.

Socioeconomic differences in cancer incidence and mortality

This chapter summarizes accumulated data on the presence, magnitude and consistency of socioeconomic differentials in mortality and incidence of all malignant neoplasms and 24 individual types of neoplasms in 37 populations in 21 countries. More or less consistent excess risks in men in lower social strata were observed for all respiratory cancers (nose, larynx and lung) and cancers of the oral cavity and pharynx, oesophagus, stomach, and, with a number of exceptions, liver, as well as for all malignancies taken together. For women, low-class excesses were consistently encountered for cancers of the oesophagus, stomach, cervix uteri and, less consistently, liver. Men in higher social strata displayed excesses of colon and brain cancers and skin melanoma. In the two Latin American populations for which data were available, lung cancer was more frequent in higher social strata. Excesses in high female socioeconomic strata were seen in most populations for cancers of the colon, breast and ovary and for skin melanoma. Longitudinal data from England and Wales suggested widening over time of social class differences in men for all cancers combined and for cancers of the lung, larynx and stomach, and in women for all cancers combined and for cervical cancer.

Retrospective study of 60 cases of feline lymphosarcoma

OBJECTIVE

To characterise epidemiological and clinical findings, and diagnostic procedures undertaken, in cats with lymphosarcoma at a veterinary teaching hospital.

DESIGN

Retrospective case study.

PROCEDURE

Hospital records were reviewed for 7159 cats, sick or healthy, examined during a 10-year period (1984 to 1994). Sixty cats with lymphosarcoma were identified and classified by anatomical location of the tumor. Data on breed, age, sex, clinical signs and diagnostic procedures were collated.

RESULTS

The prevalence of feline lymphosarcoma in the hospital population was 0.84%. Siamese cats appeared predisposed to lymphosarcoma but other purebreds were not. Males were somewhat overrepresented amongst affected cats. Similar numbers of cases (12 to 18) were seen in each of the four anatomic categories (multicentric, mediastinal, alimentary and extranodal). Cats with mediastinal lymphosarcoma were mostly young and Siamese. Clinical signs in affected cats were varied, usually multiple and often nonspecific. Two of 22 cases tested positive for feline leukaemia virus antigen in blood and 6 of 13 were positive for feline immunodeficiency virus antibody.

CONCLUSIONS

Extranodal lymphosarcoma seemed more prevalent in this study than reported elsewhere. Siamese cats in the study population may have had a genetic predisposition to lymphosarcoma. Limited evidence suggested feline leukaemia virus may be less important, and feline immunodeficiency virus more important, in the local population than indicated in overseas reports. Additional studies are needed to investigate breed predisposition and feline leukaemia virus and feline immunodeficiency virus status in Australian cats with lymphosarcoma.

[Prevalence of digestive system cancer patients covered by the Mexican Institute of Social Security of the State of Sinaloa, Mexico]

OBJECTIVE

To determine the frequency of malignant neoplasia of the digestive tract in patients seen at the IMSS concentration hospital in Culiacán, Sinaloa, México.

METHODS

From 32,097 histopathologic studies performed at No. 1 Regional General Hospital Pathology Department in Culiacán, Sinaloa, 406 were identified as digestive tract malignant neoplasia (DTMN); patient's age and gender were analyzed as well as involvement site and histological type. Benign and metastasic neoplasias were excluded.

RESULTS

DTMN prevalence: 1.26%; more affected: 60-69 years; male predominance (66%), p < 0.0001. As a whole, 47.2% of the studies reported stomach cancer; colorectal cancer: 17.5%; gall bladder and bile duct cancer; 8.4%; liver cancer: 8.1%; the remainder were located in other sites. DTMN rate by histologic type were similar to other concentration hospitals of the country.

CONCLUSIONS

DTMN has an outstanding magnitude in IMSS Sinaloa patients if other hospital registrations are considered. There are possible regional factors that may contribute to this behavior.

[Digestive cancers in France. Geographic distribution and estimation of national incidence]

OBJECTIVES

The purpose of this study was to compare the incidence of digestive cancers in 9 French departments and to give an estimate of this incidence for the whole of France, based on this data.

METHODS

This study focused on the 1983-1987 period. The record quality for the 9 included registries (Calvados, Côted'Or, Doubs, Haute-Garonne, Hérault, Isère, Bas-Rhin, Somme, Tarn) has been assessed by the National Committee of Registries. The crude incidence rates and those standardized according to the world population have been worked out per localization and per sex. Incidence and mortality rates per department as well as mortality rates for the whole of France have enabled the assessment of the incidence and number of new digestive cancer cases per year.

RESULTS

Esophagus and liver cancers are distinguished by large incidence disparities, fluctuating in a ratio of 1 to 5, and by a high sex ratio. In other localizations, incidence rates vary in a ratio of 1 to 2. The incidence rates of digestive cancers were especialy high in the Bas-Rhin department. They tended to be higher in Côte-d'Or, Doubs, Calvados and Somme, than in Haute-Garonne. Hérault and Tarn. The estimated number of digestive cancers was 30,071 in males and 19,951 in females: colorectal cancer was particularly frequent, 14,179 cases and 12,228 cases, respectively.

CONCLUSION

There are some geographical variations, from one region to another, in digestive cancer incidence in France more pronounced for esophagus and liver cancers than for other localizations. Because of its frequency, colorectal cancer represents a serious problem for public health.

Trends in the incidence of smoking-associated cancers in Norway, 1954-93

A large proportion of cancer cases have been attributed to tobacco smoking. In Norway, the proportion of smokers was 64% in men and 27% in women in 1960. Since then, the difference in the proportion of smokers between the genders has diminished and the proportion at present is 30-40% in both genders. The aim of the present study was to explore trends in the risk of the most common smoking-associated cancers in Norway based on incidence data from the national population-based cancer registry. The nearly complete registration of cancer cases in the entire country has been carried out for more than 40 years. The types of cancer included in this study were cancers of the lung, urinary bladder, kidney and pancreas, and a group of cancers of the upper digestive and respiratory tract. The incidence of all the cancers studied increased in both genders during 1954-93. The largest relative increase was observed in lung and bladder cancer. In female lung cancer, the risk increased dramatically by successive birth cohorts. Interesting differences were revealed between the trends in males and females. It seemed that the lung-cancer incidence increased more rapidly, relative to the other smoking-associated cancers, in females than in males. This is in accordance with other studies suggesting that females are at higher risk of developing lung cancer than males, given similar smoking exposure.

Smoking habits and risk of cancers other than lung cancer: 28 years' follow-up of 26,000 Norwegian men and women

The impact of tobacco smoking on lung cancer risk has been investigated thoroughly since the 1950s, but other types of cancer also have been associated with smoking. In the present study, the aim was to explore the variation in risk connected with cigarette, cigar, and pipe smoking of suspected smoking-associated cancers other than lung cancer. Data were obtained from a survey of a random sample of the Norwegian population. A self-administered mailed questionnaire, which included questions about smoking habits, was completed by 26,000 men and women in 1965 (response rate: 76 percent). The cohort was followed from 1966 through 1993, including registration of all incident cancer cases. A dose-response relationship of cigarette smoking to the risk of urinary bladder cancer and cancers of the upper digestive and respiratory tract was observed. For the latter forms of cancer, a dose-response relationship of pipe smoking also was observed. In cancer of the pancreas, a stronger association between cigarette smoking and cancer risk was observed when the analysis was confined to histologically confirmed cases only. Current cigarette smokers at baseline had a significantly higher risk of cervical cancer than those who never smoked cigarettes. In cancers of the stomach, colon, rectum, breast, corpus uteri, ovary, and prostate, and in leukemia, no association between smoking and cancer risk was observed.

Twenty to thirty year follow-up after cholecystectomy

BACKGROUND/AIMS

We studied retrospectively the need for re-examinations and re-operations, the development of alimentary tract cancer, and the occurrence of abdominal symptoms 20-30 years after elective cholecystectomy.

MATERIAL AND METHODS

Between 1963 and 1973 296 patients (73 males and 223 females) were treated by cholecystectomy. The indication was biliary colics plus stones in gallbladder. Patients with biliary-enterostomy, sphincteroplasty or synchronous extrabiliary operations were excluded. Retained bile duct stones were excluded by cholangiography. Medical records of all patients, death certificates of the patients who had died during the follow-up (n = 74), and the autopsy findings of autopsied patients (n = 29) were reviewed. The living 220 patients were interviewed by a structured questionnaire a median of 26 years after the operation.

RESULTS

Patients were divided into two groups: Group I (172 patients) underwent cholecystectomy only and Group II (122 patients) underwent cholecystectomy and common duct stone extraction. During the follow-up, 25 patients (9%) underwent examinations for biliary colics and 12 (4%) were re-operated, 10 during 1-5 years after cholecystectomy. Both the examinations and re-operations were more common in Group II than in Group I (p < 0.005). Eight patients developed alimentary tract cancer during the follow-up. Thirty-nine per cent of patients reported abdominal symptoms, 20% having had these already prior to cholecystectomy. Abdominal pain was reported by 21%, distention by 20%, heart burn 16%, obstipation 14%, and diarrhea by 11%. Abdominal pain and diarrhea occurred more frequently in Group I than in Group II.

CONCLUSION

Recurrent biliary colics and stones in the common bile duct are extremely rare later than five years after cholecystectomy and are not expected unless the patients have also initially had common duct stones. One third of patients suffer from other abdominal symptoms.

Cancer mortality among north African migrants in France

BACKGROUND

Data on cancer mortality in North African migrants to France (the largest foreign-born community in the country) are presented, providing useful insights both into cancer patterns in North Africa and their changes following migration.

METHODS

The cancer mortality in migrants from North Africa (Algeria, Morocco, Tunisia and Egypt) resident in France relative to that of the local-born population, is estimated from mortality data for the period 1979-1985, and population data from the 1982 French census. Risks of death from different cancers were adjusted for important confounding factors such as social status and area of residence.

RESULTS

The risks are quite similar for Algerian, Tunisian and Moroccan migrants. Compared to the local-born, those Maghrebian migrants of one or both sexes have higher risks of death from cancer of the nasopharynx, gallbladder and bladder (in Algerians only). Conversely, Maghrebian migrants have lower risks of death from cancer of the oral cavity, other pharynx, oesophagus, stomach, colon, rectum, lung, larynx, melanoma (in Algerians only), kidney and nervous system (except in Tunisians), breast, ovary, and cervix uteri (except in Moroccans). For Egyptian migrants, because of small numbers, few of the estimates are statistically significant. They are at lower risk of death from lung cancer and at higher risk for lymphoma and leukaemia.

CONCLUSION

The findings provide confirmatory evidence of the unusual cancer patterns among North African populations, who have low risks for most cancer sites, and high risks for certain cancers, such as of the nasopharynx and bladder.

Cancer of the digestive system in Circumpolar Inuit

Cancer of the oesophagus, stomach, small intestine, colon, rectum, liver, gallbladder, biliary tract and pancreas was studied in the Inuit populations of Alaska, Canada and Greenland. Indirect standardization to the populations in Canada, Connecticut (USA) and Denmark was used. High risk of oesophageal cancer was observed in both sexes with standardized incidence ratios (SIRs) of up to 7. An increased risk of colon and rectum cancer occurred among Alaskan Inuit compared with the Inuit populations in Canada and Greenland, which had lower rates. Liver and gallbladder cancer rates were high, with SIRs of 1.5 to 4.1, whereas there were no differences in pancreatic cancer in the populations compared. Dietary habits, alcohol and tobacco consumption are believed to play an important role in most of the observed cancer patterns, but for liver cancer hepatitis B virus infection is also believed to have a causal role.

Anthropometric measures and risk of cancers of the upper digestive and respiratory tract

Data from a case-control study on the upper digestive and respiratory tract cancers were analyzed to investigate the relationship with anthropometric measures. The data set included 538 oropharyngeal, 410 esophageal, and 388 laryngeal cancer cases and 2,102 controls in hospital for acute nonneoplastic diseases, unrelated to tobacco or alcohol use, recruited in the same catchment areas as the cases. Lower body weight appeared to be an indicator of oropharyngeal and esophageal cancer and, more moderately, of laryngeal cancer. The multivariate odds ratio (OR) for oropharyngeal cancer was 5.0 for subjects in the lowest compared with the highest quartile of weight. The corresponding ORs were 6.2 for esophageal and 2.2 for laryngeal cancer. When quartiles of body mass index (BMI) were considered, the ORs in the lowest quartile were 4.0 for oropharyngeal, 6.3 for esophageal, and 2.4 for laryngeal cancer. Subjects in the lowest quartile of height had ORs of 2.0 for oropharyngeal, 1.6 for esophageal, and 1.4 for laryngeal cancer. When all the upper digestive and respiratory tract neoplasms were considered together, the OR for subjects with lower BMI who were also current smokers compared with never-smokers with higher BMI was 11.4. The OR was 5.0 for those consuming six or more drinks/day and with low BMI. Although the nature of the association needs to be clarified, these data suggest that leanness may be involved in the process of upper digestive and respiratory tract carcinogenesis.

[Muscular tumors of the digestive tract: an analysis of 53 cases]

We present 53 cases of gastrointestinal smooth tumors (43 leiomyomas and 10 leiomyosarcomas) which have being diagnosed in Virgen del Camino Hospital during a period of 17 years. The aim of the research is to know the incidence of such tumors, their clinical presentation, the usefulness of radiologic and endoscopic studies for their diagnosis, as soon as to make a bibliographic revision of new diagnostic and therapeutic methods. This kind of tumor had an incidence of 3.1 cases per year. The symptomatology because of which the patients consulted depended on the location and the size of the tumors, though 18% of the cases were asymptomatic and were found in surgical operations. Endoscopic biopsy had a diagnostic sensibility of 28%; it didn't obstruct later exeresis. It has to be emphasized that, according to our bibliographic revision, there is a growing importance of endoscopic echography, not only as for diagnosis, but also as for non surgical treatment of this kind of tumor. Endoscopic resection can be a valid alternative for exeresis of small tumors (less than 2 cm according to some authors); haemorrhage is the most frequent complication, though it can be easily controlled.

Alcohol as a cause of cancer

This is a review of the epidemiologic literature on alcohol and risks of various cancers. Alcohol has consistently been related to risks of squamous cell carcinomas of the mouth, oral pharynx, larynx, and esophagus in multiple studies of varying design. The joint effects of alcohol and smoking are greater than additive, and are probably multiplicative, suggesting biological synergism. All major types of alcoholic beverages have been casually implicated in the genesis of these diseases. The influence of alcohol on risks of upper aerodigestive tract cancers may be greater in persons with marginal nutritional status than in better-nourished individuals. Alcohol also has been associated with an increased risk of adenocarcinomas of the esophagus, gastro-esophageal junction, and gastric cardia, but the relationship is not as strong as for squamous cell esophageal carcinomas. Alcohol and tobacco account for over 80% of the squamous carcinomas of the mouth, pharynx, larynx, and esophagus in the United States. Risks of cancers of the distal stomach, pancreas, colon, and rectum have not been consistently related to alcohol, although possible relationships between beer drinking and rectal cancer and between heavy use of alcohol and pancreatic cancer warrant further study. Studies of alcohol and liver cancer, in which the confounding influence of hepatitis B was considered, have yielded inconsistent results and should be replicated. An association between heavy alcohol use and breast cancer has been observed in most studies, even after controlling for known risk factors for breast cancer, and additional investigations of this issue are warranted.

Endoscopic ultrasonography in the study of extramucosal swellings in the upper digestive tract

The authors performed an echoendoscopic examination of 91 patients who, at a previous endoscopy, had presented extramucosal swellings in the upper digestive tract. On this occasion, the images were suggestive of a leiomyoma in 73 cases, a schwannoma in 3, an ectopic pancreas in 1, and a cyst of the gastric wall in 1. There was an extrinsic compression of the tract by an adjacent organ in three cases and by an adenopathy in two others. In six patients the authors were unable to make an echographic identification of the swellings noted upon endoscopy as they noted no echographic alteration. The echoendoscopic examination was considered normal. Given that most of these patients did not undergo surgery, the authors were only able to obtain a histological examination of surgically removed tissue in 11. The diagnosis was confirmed in eight cases. In one patient in which it proved impossible to pass the endoscope through the stenotic area, the histological examination did not confirm the echography: In two others, classified as leiomyomas, the histology showed leiomyosarcomas.

Alcohol as a cause of cancer

This is a review of the epidemiologic literature on alcohol and risks of various cancers. Alcohol has consistently been related to risks of squamous cell carcinomas of the mouth, oral pharynx, larynx, and esophagus in multiple studies of varying design. The joint effects of alcohol and smoking are greater than additive, and are probably multiplicative, suggesting biological synergism. All major types of alcoholic beverages have been casually implicated in the genesis of these diseases. The influence of alcohol on risks of upper aerodigestive tract cancers may be greater in persons with marginal nutritional status than in better-nourished individuals. Alcohol also has been associated with an increased risk of adenocarcinomas of the esophagus, gastro-esophageal junction, and gastric cardia, but the relationship is not as strong as for squamous cell esophageal carcinomas. Alcohol and tobacco account for over 80% of the squamous carcinomas of the mouth, pharynx, larynx, and esophagus in the United States. Risks of cancers of the distal stomach, pancreas, colon, and rectum have not been consistently related to alcohol, although possible relationships between beer drinking and rectal cancer and between heavy use of alcohol and pancreatic cancer warrant further study. Studies of alcohol and liver cancer, in which the confounding influence of hepatitis B was considered, have yielded inconsistent results and should be replicated. An association between heavy alcohol use and breast cancer has been observed in most studies, even after controlling for known risk factors for breast cancer, and additional investigations of this issue are warranted.

Second cancers occurring after cancers of the mouth and pharynx: data from three population-based registries in Australia, Scotland and Slovenia

Data over at least 20 years from three large population-based registries in Europe and Australasia have been used to assess the risk of second primary tumours occurring after a cancer of the mouth or pharynx. These patients have previously been shown in clinical series to be at a particularly high risk of subsequent tumours, while data from cancer registries have shown conflicting results on the magnitude of the risk. In this study, patients were found to have between a 2-fold (Scotland and New South Wales) and 4-fold (Slovenia) increase in risk of a subsequent tumour over that in the population, although the actual risk in each centre was similar (between 2.8 and 3.1 per 100 person years). The risk remained for 10 years after diagnosis of the original tumour and was primarily in the upper aerodigestive tract. The most elevated risks (approximately 10-fold) were for tumours in the oral cavity and oesophagus. These data provide higher estimates of risk than previously reported from European cancer registries for second primary tumours and emphasize the need for close follow-up of patients who may represent an appropriate population in which to assess possible new chemopreventive agents.

Retinoid chemoprevention of aerodigestive cancer: from basic research to the clinic

Epithelial cancers in the lung and head and neck are a devastating group of diseases which account for approximately 35% of cancer deaths in the United States. Chemoprevention is a new strategy to block or reverse the carcinogenic process. Biological concepts including field carcinogenesis and multistep carcinogenesis strongly support the rationale for using chemopreventive approaches. Our group has focused on applications of translational retinoid studies to increase our knowledge of the molecular events in biology and chemoprevention. In this review, we will focus on four issues, biology, retinoids, retinoid clinical trials, and translational research, in the chemoprevention of aerodigestive cancers.

Epidemiology, biology, and chemoprevention of aerodigestive cancer

Cancers of the aerodigestive tract are a major cause of worldwide morbidity and mortality. Long term survival rates for these epithelial cancers have not improved substantially in the past 20 years despite intensive efforts to improve the prevention and therapy of these diseases. Therefore, new approaches are needed. One new investigative approach is chemoprevention, the chemical prevention of cancer. Chemoprevention studies in the upper aerodigestive tract have focused on the reversal of premalignant lesions and the prevention of second primary tumors. These chemoprevention efforts have resulted from an understanding of the multistep nature of epithelial carcinogenesis and the diffuse epithelial injury that results from carcinogen exposure. Ongoing research efforts are attempting to define these processes. The interaction between carcinogen exposure and host susceptibility in the development of cancers of the aerodigestive tract is being evaluated (e.g., with an assay of chromosomal sensitivity to the clastogen bleomycin). This review discusses several new aspects of the epidemiology, biology, and chemoprevention of aerodigestive tract carcinogenesis.

Tomatoes and risk of digestive-tract cancers

In view of the persisting uncertainty concerning possible mechanisms by which high vegetable and fruit intake decreases cancer risk, foods with divergent values for potentially important micronutrients are a priority for investigation. Tomatoes are low in beta-carotene, but high in lycopene, an active antioxidative agent. In order to assess the effect of tomatoes on risk of cancers of the digestive tract, data were analyzed from an integrated series of case-control studies conducted between 1985 and 1991 in northern Italy, where tomato intake is high but, also, heterogeneous. The overall dataset included the following histologically confirmed cancer cases: oral cavity and pharynx, 314; esophagus, 85; stomach, 723; colon, 955; and rectum, 629; and a total of 2,879 controls admitted to hospital for acute non-neoplastic or non-digestive conditions, unrelated to long-term dietary modifications. Multivariate odds ratios (OR) and 95% confidence interval (CI) for subsequent quartiles of intake of raw tomatoes were derived, after allowance for age, sex, study center, education, smoking and drinking level, and tertile of total caloric intake. There was a consistent pattern of protection for all sites (OR in the upper quartile ranging between 0.4 and 0.7), most notably for gastrointestinal neoplasms. All trends in risk were highly significant. The beneficial effect of raw tomatoes in this population may be partly due to the fact that they constitute perhaps the most specific feature of the Mediterranean diet. However, if it is true that tomatoes protect against digestive-tract cancers, this is of interest from both a scientific and a public health viewpoint.

Cancer incidence in migrants to New South Wales (Australia) from the Middle East, 1972-91

The incidence of cancer in migrants to New South Wales (NSW) from Cyprus, Egypt, Iran, Iraq, Israel, Lebanon, Syria, and Turkey has been compared with that in the Australian-born population using data from the NSW Central Cancer Registry for 1972-91. Age-standardized incidence rates showed overall cancer incidence to be less common in migrants from each Middle Eastern country than in the Australian-born. There was a clear pattern of generally low rates for cancers of the mouth and pharynx, esophagus, colon and rectum, lung (men only), ovary, prostate and testis, and melanoma. Cancers which tended to be more common in migrants were nasopharynx, stomach (women only), liver (men only), gallbladder (chiefly in women), bladder (men only), and thyroid. Breast cancer did not show a uniform pattern among migrant groups, rates being high in the Egyptian-born but low in Lebanese-born women. The overall low incidence of cancers related to tobacco and alcohol, and to a 'high fat, low fiber' diet, emphasizes the potential role of preventable lifestyle factors in the burden of cancer in Australia.

Multiple occurrence of carcinoma in the upper aerodigestive tract associated with esophageal cancer: reference to smoking, drinking and family history

Smoking and drinking habits as well as family history were examined in 143 men with esophageal cancer, including 30 who had associated second cancers of the upper aerodigestive tract (UADT) and 113 who did not. The risk of second cancers of UADT associated with the main lesions of the esophagus was evaluated, using odds ratios (ORs). As a result, the ORs of second cancers for current smoking and drinking were 5.3 and 7.6 respectively. The ORs significantly increased to 12.7 and 14.7 in heavy smokers and in heavy drinkers respectively. Furthermore, the risk of second cancer also significantly increased (8-fold) in patients who had close relatives with UADT cancer, compared to those without family history of any cancer. However, there were no differences in smoking or drinking habits regardless of family history. Our data thus suggest that a family history of UADT cancer as well as heavy smoking and drinking are clearly associated with multiple occurrence of UADT cancer. Therefore, careful and frequent examination for appearance of any second lesions are required for patients in these high-risk groups.

Adjuvant therapy for gastrointestinal cancer

Perioperative adjuvant treatment with chemotherapy or radiation therapy has been investigated for colon, rectal, gastric, esophageal, and pancreatic cancers. To date, conclusive benefit had been shown only for colon and rectal cancers. Demonstration that adjuvant therapy can result in reductions in tumor recurrence and cancer death after surgery for large bowel cancer is a major therapeutic advancement, and current clinical trials may yield further incremental improvements. Standard recommendations for adjuvant treatment exist for patients with colorectal cancers who do not take part in these clinical studies. Several factors complicate the assessment of adjuvant therapy for gastric, esophageal, and pancreatic cancers. Some regimens have appeared to offer promise of improved postsurgical outcome, but no adjuvant treatment has established benefit in these sites.

Second cancers following oral and pharyngeal cancers: role of tobacco and alcohol

BACKGROUND

The exceptionally high rate of second primary cancers among patients with oral and pharyngeal cancers is well recognized, yet there has been limited epidemiologic study of risk factors for second tumors.

PURPOSE

To evaluate the relation of smoking and alcohol consumption to the development of second cancers among this high-risk patient group, we conducted a nested case-control study.

METHODS

A total of 1090 patients enrolled in a 1984-1985 population-based, case-control study of oral cancer in four areas of the United States were followed through June 1989 for the occurrence of second primary cancers. Information on tobacco and alcohol consumption was obtained from the original interviews and was updated by follow-up interviews obtained for 80 case patients with second cancers and 189 sex-, study area-, and survival-matched cancer patients free of second cancers (control subjects).

RESULTS

Tobacco smoking and alcohol drinking each contributed to risk of second cancers, with the effects of smoking more pronounced than those of alcohol. The odds ratios (ORs) for smoking (adjusted for alcohol) rose with duration and intensity of smoking and were strongest for tumors of the aerodigestive tract (oral cavity, pharynx, esophagus, larynx, and lungs), with ORs reaching 4.7 (95% confidence interval [CI] = 1.4-16) among smokers of 40 or more cigarettes per day for 20 or more years. Current smokers as of the baseline survey experienced a fourfold increased risk of a second aerodigestive tract cancer relative to nonsmokers and former smokers. No reduction in risk was associated with cessation of smoking or drinking at or after the index diagnosis, although the short median interval (27 months) between tumor diagnoses limited observation of the effects due to recent cessation. Risk was significantly reduced, however, 5 years after smoking cessation. Among drinkers, second cancer risk was greatest for beer intake, with an OR for a second aerodigestive tract cancer of 3.8 (95% CI = 1.2-12) for 15 or more beers per week.

CONCLUSIONS

Oral and pharyngeal cancer patients with the highest intakes of tobacco and alcohol are the ones most prone to develop second primary cancers.

IMPLICATIONS

Avoidance of tobacco smoking and alcohol drinking is the most desirable way not only to prevent primary oral cancers, but also to reduce risk of second cancers of the aerodigestive system.

Assessment of fat intake in retrospective epidemiological studies

The evidence on the positive association between fat intake and the risk of several cancers, including cancer of the breast, digestive tract and female genital tract, is substantial. Further, the interpretation of some null associations is hampered by various difficulties in the evaluation of the fat and cancer link.

[Incidence of digestive system neoplasms. Trends. Soria 1981-1990]

The aim of this study was to evaluate, to compare and to identify the various incidence rate trends in digestive tract malignant tumours in the province of Soria. Tumor sites and histological types, patient's age, sex and town and area residence were studied. All new cases of digestive tract malignant tumours were collected during the 1981-1990 period. 30.4% of all malignant tumours in men (1906 patients) and 29% in women (1,256 patients) came from digestive tract sites. Incidence rates for each site were calculated for the two 1981-1985 and 1986-1990 subperiods. The histology, rates and trends of the tumours were compared with the other national and international cancer registries. Gastric cancer showed the highest adjusted rate for men (35.1 x 10(5) and colo-rectal cancer one for women (14.7 x 10(5). The lowest rates were for men in the gallbladder (0.5) and liver (1.1) sites; and for women in the gallbladder (1.6), whose diminishing trend was significant (2.92/0.75) (p < 0.05) and liver (0.5). Colorectal cancer showed a marked increase between the two subperiods for both sexes (men: 13.1/27.6) (women: 9.8/19.2). Pancreas cancer trends ascended for both sexes (men: 1.22/2.74) (women: 0.13/1.46). Gastric cancer rates in Soria are higher than the rest of the cancer registries in Spain while gallbladder, liver, and colorectal, cancer rates are one of the lowest for both sexes. Trends are significantly increasing in colorectal sites for both sexes (p < 0.01), and for women only in the pancreas (p < 0.05). The other cancer rate sites showed lesser variations and are not statistically significant.

Estimates of the worldwide incidence of eighteen major cancers in 1985

The annual incidence rates (crude and age-standardized) and numbers of new cases of 18 different cancers have been estimated for the year 1985 in 24 areas of the world. The total number of new cancer cases (excluding non-melanoma skin cancer) was 7.6 million, 52% of which occur in developing countries. The most common cancer in the world today is lung cancer, accounting for 17.6% of cancers of men worldwide, and 22% of cancers in men in the developed countries. Stomach cancer is now second in frequency (it was slightly more common than lung cancer in 1980) and breast cancer--by far the most important cancer of women (19.1% of the total)--is third. There are very large differences in the relative importance of the different cancers by world area. The major cancers of developed countries (other than the 3 already named) are cancers of the colon-rectum and prostate, and, in developing countries, cancers of the cervix uteri, mouth and pharynx, liver and oesophagus. The implications of these patterns for cancer control, and specifically prevention, are discussed. Tobacco smoking and chewing are almost certainly the major preventable causes of cancer today.

Joint analysis of site-specific cancer risks for the atomic bomb survivors

Statistical methods are presented for joint analysis of site-specific cancer risks for the atomic bomb survivors. Previous analyses of these data have been made either without regard to cancer type, excluding leukemia, or separately for types or classes of cancers. Clearly, analyses without regard to cancer type are less than satisfactory. The primary advantages of joint, rather than separate, analyses are that: (1) models can be fitted with some parameters common to cancer types and others type-specific; (2) significance tests can be used to compare type-specific risks; and (3) through consideration of more comprehensive models, a clearer understanding may be obtained of the modifying effects of sex, age at exposure, and time since exposure. Joint analysis is straightforward, entailing primarily the incorporation of another factor, cancer type, in the usual cross-tabulation of the data for analysis. The use of these methods is illustrated in an analysis of three classes of cancer studied by the National Research Council's BEIR V Committee: digestive, respiratory, and other solid tumors. Based on this analysis, some criticism is made of the BEIR V preferred models. The proposed methods are applicable to models for either relative or absolute risks, and results using both types of models are given. Although some of the gains from joint analysis are apparent from the results here, it will be important to use these methods with a more suitable choice of cancer classes and for cancer incidence data where the diagnoses are more accurate.

[Evaluation of acquired data on long-term risk of hypolipidemic treatments]

At present, it is very difficult, if not impossible, to draw reliable conclusions about the long-term risks of lipid lowering therapy. Many so-called "long-term" trials only cover a few years of treatment, comparative studies versus placebo are very rare and the notification of acute events in the context of pharmacovigilance does not provide information about the long-term risk. However, analysis of large scale primary or secondary prevention trials, the Lipid Research Clinics study with cholestyramine, the Helsinki cardiological study with gemfibrozil, the Coronary Drug Project with clofibrate and nicotinic acid, has not shown any significant differences between the treatment and control groups, in particular with regards to the prevalence of malignant disease. These reassuring observations contradict those of the WHO study with clofibrate: a significant increase in the incidence of cancer, especially gastrointestinal, is observed in the treatment group. Therefore, despite the absence of confirmed long-term clinical or biological adverse effects of lipid lowering drugs (apart from the WHO clofibrate study), the physician must remain vigilant, especially as the long-term risks are difficult to assess.

Spontaneous neoplasms in aged Sprague-Dawley rats

Incidence of neoplastic lesions in untreated Sprague-Dawley rats (1340 males and 1329 females) used as controls in 17 carcinogenicity studies are tabulated and evaluated. In male rats, the most common neoplasms were benign pheochromocytomas and keratoacanthomas (4.0% in each case) followed by pancreatic islet cell adenomas (3.7%), thyroid parafollicular cell adenomas (3.6%), fibromas and squamous cell papillomas of the skin and hepatocellular adenomas (2.0% in each), malignant lymphoma lymphocytic (1.9%), histiocytic sarcomas (1.4%), and adrenal cortical adenomas (1.2%). In female rats, the most common neoplasms were of mammary gland origin (31.3%: fibroadenoma 19.0%, adenocarcinomas 8.8%, and adenomas 3.5%) followed by thyroid parafollicular cell adenomas (2.9%), uterine endometrial stromal polyps (2.6%), adrenal cortical adenomas (1.9%), malignant lymphoma lymphocytic (1.6%), fibromas in the skin (1.3%), and pancreatic islet cell adenoma (1.1%). Metastases were observed from pheochromocytomas, hepatocellular carcinomas, nephroblastomas, renal pelvis transitional cell carcinoma, interstitial cell tumor and seminoma of the testes, Zymbal's gland adenocarcinomas, and mammary adenocarcinomas.

Digestive cancer in relation to diet in Spain

Dietary factors are widely considered to be largely responsible for the different cancer incidences observed in different populations. In the present study we investigated the possible influence of dietary habits on the incidence of digestive cancer in the provinces of Spain. Data on specific mortality due to digestive cancer corresponding to the period 1975 to 1985 were obtained from the Instituto Nacional de Estadística. Nutritional data on the different provinces were in turn gathered from the Instituto de Nutrición del Consejo Superior de Investigaciones Científicas. The information was processed by the SPSS statistical software package. Lifestyle and socio-cultural factors are found to influence dietary risk factors in digestive cancer, particularly among women. The most significant correlations with the different cancers studied corresponded to total energy intake (responsible for 27.4% of variance), animal fats, and smoked fish and coffee. The latter is related to oral and esophageal cancer in particular (responsible for 15.4% of variance). Consumption of carrots and frozen vegetables is responsible for 6.5% of variance, vs. 4.4% of variance for alcoholic beverages, sugar, and Vitamin D. Differences are noted between both the sexes and their relationship to the different cancers studied.

Cholesterol and cancer in a population of male civil service workers

Cancer incidence and mortality were ascertained in a cohort of 1910 male participants of the Albany Cardiovascular Health Center (CVHC). The New York State Cancer Registry, vital records files, CVHC follow-up records, New York State Retirement System files, and New York State Department of Motor Vehicles driver's license files were used. Serum cholesterol measurements as well as values for other exposure variables were obtained from records of medical examinations which began in 1953-1954. The study cohort was divided into two groups, based on initial serum cholesterol measurement (less than or equal to 190 mg/100 ml and less than or equal to 190 mg/100 ml). For total cancers, both incidence and mortality were similar in these groups. For digestive cancer, both incidence and mortality were slightly lower in the less than or equal to 190 mg/100 ml group. The deficit was not statistically significant. For respiratory cancer, relative risk and rate ratio estimates were in the range of 1.4-1.7 for incidence and mortality. The excess risk in the less than or equal to 190 mg/100 ml group was of borderline statistical significance. The association was concentrated in the lowest cholesterol quintile rather than suggesting a strong dose-response relationship. The estimates were not found to be confounded by cigarette smoking, body mass index, education or age. A reduction in the crude rate ratio estimate from 1.5 to 1.2 was observed when early cases were excluded, suggesting that part of the observed excess may be due to preclinical cancer.