[Alcohol and oropharyngolaryngeal and digestive tract cancer]

Epidemiology has demonstrated that alcoholic beverages are causally related to oropharyngolaryngeal, esophageal, liver, colorectal, and female breast cancer. Among Japanese male alcoholics screened by endoscopy combined with esophageal iodine staining and immunofecal occult blood tests, 4.2% had esophageal squamous cell carcinoma (SCC); 1.2%, oropharyngolaryngeal SCC; 1.4%, stomach adenocarcinoma; 1.9%, colorectal adenocarcinoma. The inactive form of aldehyde dehydrogenase-2 (ALDH2), encoded by the gene ALDH2*1/2*2, which is prevalent in Asians, exposes them to higher levels of acetaldehyde after drinking and was a strong risk factor for these cancers among Japanese heavy drinkers. Inactive ALDH2 was also associated with synchronous and metachronous multiple esophageal cancers. These results suggest a general role of acetaldehyde, an established animal carcinogen, in carcinogenesis of the human alimentary tract. The oropharyngolarynx and esophagus lack ALDH2 activity, suggesting that after exposure to acetaldehyde derived from systemic, mucosal, salivary, or bacterial production or alcoholic beverages, these organs' inefficient degradation of acetaldehyde enhances the chances for local acetaldehyde-associated carcinogenesis. The normal alcohol dehydrogenase-2 (ADH2), encoded by ADH2*1/2*1, is another risk factor for oropharyngolaryngeal and esophageal cancer in Japanese alcoholics. For patients with both normal ADH2 and inactive ALDH2, the risks for oropharyngolaryngeal and esophageal cancer are enhanced in a multiplicative fashion. The responses to a simple questionnaire about both current and past facial flushing after drinking a glass of beer can indicate an individual's ALDH2 phenotype fairly well. Use of this questionnaire to obtain information on ALDH2-associated cancer susceptibility could contribute to the prevention of alcohol-related cancer in Asians.

Upper aerodigestive tract cancers in former employees at an iron and steel works

Local concern about numbers of laryngeal cancer cases led to an investigation of the incidence of upper aerodigestive tract (UAT) cancer in an industrial cohort. Males (n = 11 470) who had been directly employed at an iron and steel works in northern England at any time between January 1960 and site closure in September 1983 were followed up for UAT cancers until December 1998. The incidence of UAT and laryngeal cancer was compared to the general population of the region via indirect standardization. Fifty-two members of the cohort developed a UAT cancer during 1960-1998. There were no more UAT cancers than expected [standardized incidence ratio = 97, 95% confidence interval (CI) = 72-127], but slightly more laryngeal cancers than expected (standardized incidence ratio = 118, 95% CI = 78-171), although this estimate was less precise. The lack of complete work histories meant that relationships between cancer incidence and length of service or job categories could not be explored.

A prospective study of green tea consumption and cancer incidence, Hiroshima and Nagasaki (Japan)

OBJECTIVES

Laboratory and animal studies have shown a protective effect of green tea on cancer of different sites, but epidemiological evidence is limited and inconclusive. This prospective study in Japan examined the association between green tea consumption and cancer incidence.

METHODS

Subjects were 38,540 people (14,873 men, mean age 52.8 years; 23,667 women, mean age 56.8 years) who responded to a mail survey carried out between 1979 and 1981. A self-administered questionnaire ascertained consumption frequency of green tea using precoded answers (never, once per day, twice to four times per day, and five or more times per day). Follow-up continued until 31 December 1994. The study analyzed solid cancers (n = 3881); hematopoietic cancers (188); cancers of all sites combined (4069); and cancer of specific sites with more than 100 cases, i.e. stomach (901), colon (432), rectum (193), liver (418), gallbladder (122), pancreas (122), lung (436), breast (281), and bladder (122). Poisson regression was used to allow for city, gender, age, radiation exposure, smoking status, alcohol drinking, body-mass index, education level, and calendar time.

RESULTS

Green tea consumption was virtually unrelated to incidence of cancers under study. The relative risks of all cancers for those consuming green tea twice to four times per day and five or more times per day were 1.0 (95% confidence interval 0.91-1.1) and 0.98 (0.88-1.1), respectively, as compared with those consuming green tea once per day or less.

CONCLUSION

Our findings do not provide evidence that regular green tea consumption is related to reduced cancer risks.

Digestive neuroendocrine tumours: diagnosis and treatment in Italy. A survey by the Oncology Study Section of the Italian Society of Gastroenterology (SIGE)

BACKGROUND

New insights in the diagnosis and treatment of digestive neuroendocrine tumours have prompted a renewed interest in these rare and complex diseases.

AIM

To establish how many new cases of digestive neuroendocrine tumours were diagnosed, and how they were treated, at gastroenterological centres across Italy during a two-year period (1997-1998).

METHODS

The 12 centres taking part filled in a data collection form reporting type of tumour, methods of diagnosis and therapeutic strategies adopted in each case. Data were collected and analysed by the authors of the present report.

RESULTS

Data refer to 98 patients, 22 with functioning and 76 with non-functioning digestive neuroendocrine tumours [50 carcinoids, 48 pancreatic endocrine tumour syndromes]. Primary tumours were localised in 96% (38% with metastases) of non-functioning and 81% (50% with metastases) of functioning tumours. These were surgically removed in >80% of patients in both groups. Somatostatin analogue treatment, with or without interferon, was administered in 35% of patients, while chemotherapy was used in 9% and 23% of functioning and non-functioning tumours, respectively. The imaging study always included a computed tomography scan (20% helical computed tomography). Magnetic resonance and somatostatin receptor scintigraphy were also performed, the former in 41% and 21% of the two (functioning and non-functioning tumour) groups, the latter in 45% and 30%.

CONCLUSIONS

The number of functioning digestive neuroendocrine tumours reported was lower than expected. Surgery plays a major role in the treatment of these tumours in all centres. Overall, in only a small number of patients was a multidisciplinary approach applied.

Changing socioeconomic correlates for cancers of the upper digestive tract

BACKGROUND

Cancers of the upper digestive tract have long been associated with low socio-economic levels. It has however been suggested that in recent times the social gradient for these cancers is leveling off.

PATIENTS AND METHODS

Data from three case-control studies on oral, pharyngeal and oesophageal cancer conducted in Northern Italy during the periods 1984-1992 and 1992-1997 were combined and re-analyzed. Cases were subjects admitted to the major teaching and general hospitals in the areas under study with incident, histologically confirmed cancer of the oral cavity and pharynx (n = 1126) and oesophagus (n = 714). Controls were subjects admitted to the same hospitals for a wide spectrum of acute, non-neoplastic conditions, not related to smoking or alcohol consumption (n = 4642).

RESULTS

In the 1980s a significant association was observed with low education and social class level. The multivariate odds ratios for oral, pharyngeal and oesophageal cancers combined was 1.78 for the lowest versus the highest educational level, and 1.75 for the lowest versus the highest social class. No consistent pattern of risk was observed with any of the socio-economic indicators considered in the studies conducted in the 1990s.

CONCLUSIONS

The present study indicates that the socio-economic correlates of cancers of the upper digestive tract have changed over the last few years in Italy, with a disappearance of the social gradient.

Risk of testicular cancer in men with abnormal semen characteristics: cohort study

OBJECTIVE

To explore the associations between semen characteristics and subsequent risk of testicular cancer.

DESIGN

Cohort study.

PARTICIPANTS

32 442 men who had a semen analysis done at the Sperm Analysis Laboratory in Copenhagen during 1963-95.

MAIN OUTCOME MEASURE

Standardised incidence ratios of testicular cancer compared with total population of Danish men.

RESULTS

Men in couples with fertility problems were more likely to develop testicular cancer than other men (89 cases, standardised incidence ratio 1.6; 95% confidence interval 1.3 to 1.9). The risk was relatively constant with increasing time between semen analysis and cancer diagnosis. Analysis according to specific semen characteristics showed that low semen concentration (standardised incidence ratio 2.3), poor motility of the spermatozoa (2.5), and high proportion of morphologically abnormal spermatozoa (3.0) were all associated with an increased risk of testicular cancer. The only other cancer group that showed increased incidence was "peritoneum and other digestive organs" (six cases; 3.7, 1.3 to 8.0). Of these, two cases were probably and two cases were possibly extragonadal germ cell tumours.

CONCLUSIONS

The results point towards the existence of common aetiological factors for low semen quality and testicular cancer. Low semen quality may also be associated with increased incidence of extragonadal germ cell tumours.

Natural history of neuroendocrine enteropancreatic tumors

Neuroendocrine enteropancreatic tumors (NEEPTs) include tumors developing from the pancreatic islets and the duodenal loop, and those developing from gut serotonin-secreting cells (mid-gut carcinoids). When functioning, they are rare tumors with frequently inconsistant clinical and biological characteristics. Provocative dynamic tests are very useful. Their natural history, with the exception of insulinomas and mid-gut carcinoids, is still incompletely known due to their rarity, relatively recent description, slow evolution and the absence of definitive reliable markers for prognosis. The following factors affect the natural history of NEEPTs. (1) Inclusion or not within the spectrum of multiple endocrine neoplasia type-1 (MEN1), such an integration often dramatically modifies the management strategy. In patients with MEN1, NEEPTs are often multiple, diffusely spread in the duodenopancreatic area and of small size. Definite cure by surgery is then very scarce. Mid-gut carcinoid tumors are the most protean NEEPTs. In contrast to appendiceal carcinoids, usually with a benign course, mid-gut carcinoids have a more malignant course and are very common indeed: local transmural invasion, early metastasis to lymph nodes and/or liver, and symptoms from hormone oversecretion. Carcinoid syndrome is usually well controlled by long-acting somatostatin analogs. (2) Disease spreading, i.e. liver and bone metastases, are the major causes of death in patients with NEEPTs. Liver metastases (LMs) are synchronous in about 75% of the patients with LMs but may develop during follow-up (about 25% of the patients with LMs were without LMs at the initial evaluation). Development of bone metastases has a very poor prognosis accompanying LM progression.

[Incidence of digestive tumors in the health district of Leon, Spain in 1993-1997: high incidence of colorectal carcinoma]

AIM

To determine the incidence of various digestive tumors in the health district of Leon.

PATIENTS AND METHODS

All digestive tumors registered in the Hospital Tumor Registry in Leon from 1993-1997 were included. Unadjusted and adjusted incidence rates of each kind of tumor, using the ICD-9 classification, were calculated.

RESULTS

A total of 9,913 cancer cases were included. Diagnosis was confirmed by the Department of Pathology in 93.4%. Of these, 25.38% originated primarily in the digestive system, which represents an unadjusted incidence of 151.73 new cases per 100,000 inhabitants/year. A total of 58.07% were male and 41.93% female. Colon cancer was the most frequent (31.5%), followed by gastric cancer (25.7%) and rectal cancer (20.3%). The highest incidence, both unadjusted and adjusted, was in colon cancer (52.8 and 25.9) followed by gastric cancer (47.4 and 24.3) and rectal cancer (36.1 and 18.3, all they 10(5)/year.

CONCLUSIONS

Incidence of digestive cancer in Leon is very high and that of colorectal cancer is higher than in any other region in Spain. This is only partly due to the marked aging of our population.

Multiple primary neoplasms at a single institution: differences between synchronous and metachronous neoplasms

During the 10-year period (1987-1996) of our study, 26,255 patients with cancer were admitted to our clinic and, of these, 271 (1%) patients had multiple primary malignant tumors. Ninety-two (34%) patients had synchronous tumors (synchronous group), and 179 (66%) patients had metachronous tumors (metachronous group). The mean age at first diagnosis was higher in the former group. The ratio of men to women was 1.36 in the synchronous group and 0.74 in the metachronous group (p = 0.018). Smokers and drinkers were more common in the synchronous group. Breast cancer and lung cancer were most prevalent, and associations between head/neck and lung cancer and between breast and breast cancer were the most frequent associations in both the synchronous and the metachronous group. The frequency of aerodigestive tumors was higher and that of mesenchymal tumors was lower in the synchronous group than in the metachronous group. Localization in the medial region and in the head/neck was more frequent in the synchronous group than in the case of metachronous secondary tumors.

Cancer of the upper gastrointestinal tract among patients with pernicious anemia: a case-cohort study

BACKGROUND

An association between pernicious anemia and stomach cancer has been established in several studies. An increased risk of pancreatic and esophageal cancers has also been reported among pernicious anemia patients. The aim of this case-cohort study was to identify additional risk factors for cancer of the esophagus, stomach, and pancreas among patients with pernicious anemia.

METHODS

A population-based cohort of 4586 patients with pernicious anemia was linked to the Swedish Cancer Registry to identify patients who subsequently developed cancers of the esophagus, stomach, or pancreas using a case-cohort design. A subcohort consisting of 4% of the cohort was randomly selected to serve as the comparison group. Information on medical history, smoking habits, and alcohol use was retrieved from medical charts and analyzed for cancer patients and subcohort members.

RESULTS

We could not identify any risk factors other than pernicious anemia for stomach cancer. For pancreatic and esophageal cancer, younger age at diagnosis of pernicious anemia was associated with an increased risk. A prior gastric resection, smoking and alcohol abuse were more frequent among esophageal cancer cases than in the subcohort.

CONCLUSIONS

We conclude that a causal relationship between pernicious anemia and subsequent development of esophageal or pancreatic cancers still remains unproven. For esophageal cancer, confounding by smoking and alcohol use is the likely explanation of earlier reports of an association. In the case of stomach cancer, both the inflammatory process, secondary to the pernicious anemia, and pernicious anemia per se may be factors leading to malignant transformation.

Cancer incidences in the digestive tube: is cobalamin a small intestine cytoprotector?

Malignancies are common in the digestive tube, although with unequal distribution among segments. The aim of this paper was to compare available interpretations of the low cancer incidence in the small bowel and high in the large bowel. Supposed mechanisms include relatively small bacterial population, large secretion of liquid and rapid transit in the small bowel. Small bowel mucosa is the main absorptive part of the digestive tube with absorption rates for various nutrients so high that they can even be considered as clearances from the intestinal content. Consequently, these nutrients are not present in the large bowel. An alternative explanation is that an absorbable protective substance from the intraluminal content, might protect the mucosa from malignant transformations. It can be speculated that if there are any cytoprotective substances in the digested food their effect would be expressed mostly in the absorptive small intestine, leaving the large bowel mucosa unprotected. Vitamin B12 might be a possible candidate for this role. Cobalamin molecules are initially bound to haptocorrin (Hc) in the stomach, but in the small intestine B12 is transferred to intrinsic factor (IF) after the action of pancreatic trypsin on Hc. Cobalamin-IF complexes are absorbed in the terminal ileum leaving only a small fraction of B12 to enter the large bowel. We have tried to summarize available data regarding cancer incidences in digestive tube, segmental length and transit times of tube content. Cancer density is calculated as incidence per length and transit speed as length per transit time. Cancer incidences for seven intestinal segments were considered low if they were below one case per 100 000 inhabitants annually, while the low cancer density meant less than six cases per 100 000 inhabitants per metre. For instance, transverse colon was considered as a high cancer incidence place (2.15 cases), with low cancer density (4.3 cases/m). Transit speed more than 0.3 metre/hour was associated with low cancer incidences (accuracy 0.85) and low cancer density segments (accuracy 1.00). Cobalamin availability showed similar distribution, available in low incidence segments and unavailable in high incidence segments. Experimental studies are needed to quantify B12 availability in the large bowel and to determine whether small amounts of B12-IF or, perhaps, B12-haptocorrin complexes are absorbed by the small bowel mucosa. Without that, no cytoprotective effects of B12 in the digestive tube can be expected.

Epidemiology and course of acute upper gastro-intestinal haemorrhage in four French geographical areas

OBJECTIVE

To compare incidence rates and epidemiological characteristics of acute upper gastrointestinal haemorrhage (AUGIH) in France with those of other European studies.

DESIGN

Population-based multi-centre prospective survey.

SETTING

29 public hospitals and 96 private specialists in gastroenterology in four administrative areas in France during 1996.

SUBJECTS

A total of 2133 AUGIH patients 18 years and over were included in the six-month study.

OUTCOME MEASURES

Incidence and mortality.

RESULTS

The overall incidence in France was 143 cases per 100000 persons per year, classified as out-patients (16%), emergency admissions (59%) and in-patients (25%). The incidence rates increased with age except for in-patients, and were higher in males. Peptic ulcer (36.6%), varices (13.7%) and erosive disease (12.3%) were the most frequent diagnoses. In 677 patients (31.7%), aspirin, antiinflammatory drugs or corticosteroids were taken on the 7 days before bleeding. The overall mortality (out-patients excluded) was 14.3% (10.7% for emergency patients and 23% for in-patients). Mortality was associated with comorbidities (especially malignancies, cirrhosis, asthma or respiratory deficiency), was lower in emergency patients using non-steroid anti-inflammatory drugs, and higher in in-patients using corticosteroids.

CONCLUSIONS

In France, patients with AUGIH are frequently managed as out-patients. Gastrotoxic drug use is frequently associated with AUGIH and constitutes a strategic opportunity for preventive treatment. Discrepancies between countries are not clearly explained either by demographic factors or by drug use, but this may be related to the emphasis on AUGIH in in-patients.

Socioeconomic status, social mobility and cancer occurrence during working life: a case-control study among French electricity and gas workers

OBJECTIVES

A case-control study within a cohort of the workers employed by Electricité de France and Gaz de France between 1988 and 1992 was carried out to investigate relationships between cancers and socioeconomic status, including the effects of social mobility, by studying three professional career points.

METHODS

All the incident cases of breast cancer in women and all the incident cases of upper respiratory and digestive tract cancer (comprising cancers of the larynx, pharynx, buccal cavity and esophagus), lung cancer, hematopoietic system cancers and colon cancer in men were extracted from the Cancer Register of the Social Security Department. The controls were matched for age (men) and for age and length of employment in the company (women). Socioeconomic status was measured at three professional career points (beginning, midpoint (about 35), and time of diagnosis (about 48)) by two types of socio-professional variables: employee category (low, medium, high) and a variable based on the French socioeconomic status classification system. An estimation of social mobility was done between career beginning and midpoint. Cases and controls were compared for socioeconomic status at the three career points. They were also compared for social mobility.

RESULTS

The differences between the social categories were larger at the start than later in the career for breast cancer in women. The category of operations staff was used as a reference, and this analysis shows a difference between the risks associated with supervisors (OR = 2.0) and managers and specialist professions (OR = 1.5). There were large differences according to the type of cancer in men. A socioeconomic gradient in the incidence of cancers of the upper respiratory and digestive tract was observed at every career stage. The gradient was largest at the moment of diagnosis. The odds ratio was 3.4 for supervisors, 7.8 for operations staff and 14.8 for production staff. There was a socioeconomic gradient in lung cancer at all points in the career and in the incidence of the hematopoietic system cancers at mid-career and at diagnosis. No association between socioeconomic status and colon cancer was found. Social mobility accentuated all these results.

CONCLUSION

Socioeconomic status is involved in the development of cancers. Our study suggests that the transition from social to biological processes could act via specific lifestyle and/or work-related risk factors. When there is a social gradient in the incidence of a cancer, an individual's social change is at least as important as his/her original social status in the relationship between cancer and social class.

Cancer in California school employees, 1988-1992

BACKGROUND

Periodic concerns about excesses of cancer among teachers in California schools prompted our examination of cancer incidence in California school employees.

METHODS

Records of school employees between 1987-1992 were linked to the California Cancer Registry of incident cases diagnosed 1988-1992. Sex-, race-, and age-adjusted standardized incidence ratios were calculated for specific cancer sites. Analyses stratified by sex, race/ethnicity, and job assignment were also performed.

RESULTS

Melanoma of the skin, thyroid cancer, prostate cancer, and female cancers of the breast, uterus, and ovary all occurred more frequently than expected in these school employees. In contrast, cancers of the respiratory system, oral cavity, digestive system, urinary system, and uterine cervix occurred less frequently.

CONCLUSIONS

The incidence of cancers thought to be related to hormones and/or higher socioeconomic status appeared elevated while cancers often linked to smoking and/or alcohol intake occurred less frequently in this large cohort of professional school employees.

Evaluation of a 10-minute comprehensive MR imaging examination of the upper abdomen

PURPOSE

To determine whether a 10-minute magnetic resonance (MR) imaging examination of the upper abdomen provides sufficiently comprehensive information to replace a longer MR protocol.

MATERIALS AND METHODS

Images obtained with selected breathing-independent and breath hold MR sequences, with 2 minutes of total acquisition time and an estimated 10 minutes of total study time, in consecutive MR examinations of the upper abdomen in 72 patients (age range, 23-87 years) were retrospectively reviewed in a blinded fashion by two separate interpreters. Determination was made of major and minor findings, and the two separate retrospective interpretations and the prospective clinical interpretation were correlated by using kappa statistics. Surgical and clinical findings were also correlated with imaging findings.

RESULTS

In 61 patients, all major and minor findings were identical in the original clinical interpretation and the two retrospective readings. In 66 patients, the major findings were identical in these three readings. Close agreement was present between the two separate retrospective readings and the prospective clinical interpretation (kappa = 0.49-1.00).

CONCLUSION

The findings suggest that the diagnostic information provided by a shortened MR imaging protocol that includes breath-hold and breathing-independent sequences is in close agreement with lengthier MR protocols. The advantages of a shortened protocol include increased patient throughput and decreased study cost.

Molecular genetics of gastrointestinal malignancies

OBJECTIVES

To review the genetic model of colon cancer formation and the primary advances and clinical relevance of molecular genetics of pancreatic cancer and other gastrointestinal malignancies.

DATA SOURCES

Research studies, review articles, and textbook chapters.

CONCLUSIONS

Genetic discoveries are influencing the screening and treatment of colorectal cancer and other gastrointestinal malignancies by better targeting chemoprevention and treatment in high-risk and molecular-distinct patient populations.

IMPLICATIONS FOR NURSING PRACTICE

A basic knowledge of cancer genetics and the latest genetic discoveries will assist oncology nurses in patient teaching, counseling, and care.

Radiologic staging of gastrointestinal cancer

Pre-operative staging should define the probable course of a patient's disease, separate the resectable from the unresectable patients, and identify the patients who are candidates for induction therapy. Pre-operative staging must be well tolerated and should provide new or important information that will affect the proposed treatment plan. For some diseases such as colon cancer, pre-operative staging is largely unnecessary, but it can be of great value for other tumors such as pancreatic cancer. Currently, many imaging techniques are available to evaluate gastrointestinal cancers, and each provides information necessary for directing treatment. Although no individual technique can stage patients with complete accuracy, combinations of the various imaging techniques can be used to increase accuracy and promote appropriate decisions about an individual's treatment options. The use of current imaging techniques for staging primary lesions, regional spread, and the intra-abdominal metastatic spread of the most common gastrointestinal malignancies are reviewed.

Automatic record hash coding and linkage for epidemiological follow-up data confidentiality

A protocol is proposed to allow linkage of anonymous medical information within the framework of epidemiological follow-up studies. The protocol is composed of two steps; the first concerns the irreversible transformation of identification data, using a one-way hash function which is used after spelling processing. To avoid dictionary attacks, two large random files of keys, called pads, are introduced. The second step consists in the linkage of files rendered anonymous. The weight given to each linkage field is estimated by a mixture model, the likelihood of which being maximized with the Expectation and Maximization (EM) algorithm. The performance of this method has been assessed by comparing record linkage, based on exclusive use of the automatic procedure, with a manual linkage, obtained by the Burgundy Registry of Digestive Cancers. The result of the linkage of a file of 2,847 cancers with a file of 388,614 hospitalization stays in the Dijon university hospital showed a sensitivity of 97% and a specificity of 93%.

Cancer among a Michigan cohort exposed to polybrominated biphenyls in 1973

The long-term health effects of human exposure to polybrominated biphenyls are not known. In this nested case-control study, we evaluated the association between site-specific cancer risk and serum polybrominated biphenyl levels among a Michigan cohort accidentally exposed to polybrominated biphenyls in 1973. The Michigan Department of Public Health has followed 3,899 people through 1993, among whom 195 primary cancers were identified in 187 persons. Controls were 696 randomly selected cancer-free individuals who were frequency matched to cases by sex and age (in 5-year strata). Baseline serum polybrominated biphenyl levels were measured using standard methods. We found an increasing dose-response relation for digestive system cancer risk with higher serum polybrominated biphenyl category [4-20 parts per billion (ppb), 21-50 ppb, and > 50 ppb] after adjustment for age, family cancer history, cigarette smoking, alcohol drinking, and baseline serum polychlorinated biphenyl level. Adjusted odds ratios (ORs) for each category were 8.23 [95% confidence interval (CI) = 1.27-53.3], 12.3 (95% CI = 0.80-191), and 22.9 (95% CI = 1.34-392), respectively. Univariate analysis for polybrominated biphenyl level and lymphoma risk also showed a dose-response relation, with corresponding ORs of 3.24 (95% CI = 0.24-95.9), 20.5 (95% CI = 1.51-608), and 32.6 (95% CI = 3.33-861).

Mediterranean epidemiological evidence on tomatoes and the prevention of digestive-tract cancers

Tomatoes have been estimated as the second most important source of vitamin C, after oranges, in an Italian population. We have therefore considered the relationship between tomato intake and the risk of digestive tract cancers using data from a series of case-control studies conducted in Italy between 1983 and 1992, and including 317 histologically confirmed, incident cases of cancer of the oral cavity and pharynx, 85 of the esophagus, 723 of the stomach, 955 of the colon, and 629 of the rectum, and a total of 2879 controls admitted for acute, non-neoplastic conditions, unrelated to long-term modifications of diet. Multivariate odds ratios (OR) and 95% confidence intervals (CI) for subsequent quartiles of intake of tomatoes were derived, after allowance for age, sex, study center, education, smoking, alcohol drinking, and total calorie intake. There was a consistent pattern of protection for all sites. The ORs for the highest consumption quartile were 0.65 (95% CI 0.4-1.0) for oral cavity, pharynx, and esophagus, 0.43 (95% CI 0.3-0.6) for stomach, 0.39 (95% CI 0.3-0.5) for colon, and 0.42 (95% CI 0.3-0.6) for rectum. Another study of colorectal cancer, based on 1,953 cases and 4,154 controls, conducted between 1992 and 1996 and using a more detailed food frequency questionnaire, confirmed that tomato intake was significantly protective on colorectal cancer risk, even after allowance for several potential confounding factors, including measures of body mass index, calorie intake, and physical activity. The ORs for the highest consumption quintile were 0.79 (95% CI 0.6-0.9) for colon, and 0.71 (95% CI 0.5-0.9) for rectal cancer. The beneficial effect of tomatoes observed in these epidemiological studies may be due to the fact that they constitute one of the most specific features of the Mediterranean diet. This has both a scientific and a public health relevance.