Cancer Causes Control

The role of alcohol, tobacco, and dietary factors in upper aerogastric tract cancers: a prospective study of 10,900 Norwegian men.

Kjaerheim K. Gaard M. Andersen A.
The Cancer Registry of Norway, Institute for Epidemiological Cancer Research, Montebello, Oslo.
Previous knowledge on risk factors for oral, pharyngeal, laryngeal, and esophageal cancer has been based mainly on case-control studies. In the present study, the impact of alcohol consumption, tobacco smoking, and dietary factors on upper aerogastric tract cancer risk was studied in a cohort of 10,960 Norwegian men followed from 1968 through 1992, in which period a total of 71 upper aerogastric tract cancers occurred. The relative risk (RR) of cancer was 3.9 (95 percent confidence interval [CI] = 2.1-7.1) for the highest consumption group of alcohol and 4.7 (CI = 1.7-13.2) for the highest smoking level, compared with the respective reference groups. Among the dietary items, high consumption of oranges was associated with reduced cancer risk (RR = 0.5, CI = 0.3-1.0), as was high consumption of bread (RR = 0.2, CI = 0.1-0.5). Frequent consumption of beef and bacon increased relative cancer risk bordering on significance. The present results are largely in accordance with previous studies. The decreased risk associated with a high intake of bread deserves further investigation.

Increasing incidence of colon and rectal cancer among Hispanics and American Indians in New Mexico (United States), 1969-94.

Year 1998
Chao A. Gilliland FD. Hunt WC. Bulterys M. Becker TM. Key CR.
New Mexico Tumor Registry/Epidemiology and Cancer Control Program, University of New Mexico Cancer Research and Treatment Center, Albuquerque 87131-5306, USA.
OBJECTIVES: This study evaluates time trends in colon and rectal cancer incidence and mortality among the three major race/ethnic groups (Hispanics, American Indians, and non-Hispanic Whites) in New Mexico (United States). METHODS: We used data from the New Mexico Tumor Registry (NMTR) and computed average annual age-standardized incidence and mortality rates. Colon cancer incidence rates were further examined by anatomical subsite. Estimated annual percent change (EAPC) in incidence and mortality over time were computed using Poisson regression. RESULTS: Invasive colorectal cancer incidence rates increased from 1969-89 in all three race/ethnic groups, but decreased among non-Hispanic Whites in 1990-94, while rates continued to increase among minority populations, especially among minority men. Over the 26-year period, EAPC in colon cancer incidence among men was 3.6 percent for Hispanics, 4.7 percent for American Indians, and 0.7 percent for non-Hispanic Whites. Right-sided colon cancers were more common among American Indian women, and among all women aged 65 years and older. Mortality rates decreased steadily among non-Hispanic Whites over the study period, especially among women. CONCLUSIONS: Studies are needed to identify important modifiable risk factors and to develop strategies to increase the use of colorectal cancer screening-procedures among the minority populations.

Trends in colorectal cancer incidence in Sweden 1959-93 by gender, localization, time period, and birth cohort.

Year 1998
Thorn M. Bergstrom R. Kressner U. Sparen P. Zack M. Ekbom A.
Department of Surgery, University Hospital, Uppsala, Sweden.
OBJECTIVES: This study examined invasive colorectal cancer incidence-rates in Sweden from 1959 through 1993 (n = 134,643 cases). METHODS: Age-standardized rates were calculated using the Swedish population in 1970 as a reference. RESULTS: In right-sided colon cancer (ascending and transverse colon including right and left flexures), male age-standardized rates rose from 8.0 to 15.0 (1.8 percent annually, 95 percent confidence interval [CI] = 1.3-2.4) and female rates increased from 9.1 to 14.4 (1.5 percent annually, CI = 1.0-2.0). For left-sided colon cancer (descending and sigmoid colon), the rates have been stable recently. For rectal cancer, the rates among men rose from 18.8 to 23.0 and among women from 10.7 to 14.7. For both men and women, the relative risk (RR) of right-sided colon cancer had been increasing in successive generations, until leveling-off in those born after 1930. The RR of left-sided colon cancer had been almost constant for cohorts born before 1930 but steadily decreasing in later-born cohorts. The RR of rectal cancer was slightly increasing in successive cohorts. CONCLUSIONS: Changes in lifestyle or carcinogenic exposures during early life probably explain Swedish colorectal cancer incidence-trends better than improved diagnostic activities.

Nitrate in drinking water and the incidence of gastric, esophageal, and brain cancer in Yorkshire, England.

Year 1998
Barrett JH. Parslow RC. McKinney PA. Law GR. Forman D.
Cancer Epidemiology and Health Services Research Unit, University of Leeds, UK.
OBJECTIVES: This small-area ecologic study in Yorkshire, northern England, examines the hypothesis that exposure to higher levels of nitrate in drinking water increases the risk of stomach, esophageal, or brain cancer in adults. METHODS: Nitrate levels over the period 1990-95 and numbers of incident cancers from 1975-94 were available for 148 water supply zones, geographically defined areas each supplying water of homogeneous chemical composition to an average population of around 20,000. RESULTS: No relationship was found between nitrate concentrations and the incidence of stomach or esophageal cancers. The incidence of cancer of the brain and central nervous system was found to be higher in areas with higher nitrate levels, with a relative risk of 1.18 (95 percent confidence interval = 1.08-1.30) in the quartile of the population with the highest average levels (mean 29.8 mg/l) compared with the lowest quartile (mean 2.4 mg/l). The increase in risk remained statistically significant (P < 0.01) after allowing for other covariates and for extra-Poisson variation in a regression model. CONCLUSIONS: This study does not support the hypothesis of an increased risk of stomach or esophageal cancer associated with higher nitrate levels in drinking water. The observed relationship with brain cancer requires confirmation in other studies, including those involving data on individuals.

Cancer risk following appendectomy for acute appendicitis (Denmark).

Year 1998
Mellemkjaer L. Johansen C. Linet MS. Gridley G. Olsen JH.
Danish Cancer Society, Institute of Cancer Epidemiology, Copenhagen.
OBJECTIVE: Epidemiologic studies have not been able definitely to exclude that appendectomy carries a cancer risk. This study was conducted to clarify whether appendectomy is associated with a subsequent increase in cancer risk, since appendectomy is frequently an elective procedure. METHODS: The present study included more than 82,000 persons who underwent appendectomy for acute appendicitis during 1977-89 according to the nation-wide Danish Hospital Discharge Register. During a follow-up interval of up to 17 years, cancer incidence was assessed by linkage to the Danish Cancer Registry and compared with the incidence in the general population of Denmark. RESULTS: The total number of malignancies among appendectomized persons was 1.05 times higher than expected with 95 percent confidence intervals of 0.99-1.11. There was no clear significant excess of any specific cancer type. CONCLUSION: During a postsurgery period of nearly two decades, results of our study did not support the hypothesis that either appendectomy or acute appendicitis are likely to be associated with malignant neoplasms.

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

Year 1998
Inoue M. Tajima K. Hirose K. Hamajima N. Takezaki T. Kuroishi T. Tominaga S.
Division of Epidemiology, Aichi Cancer Center Research Institute, Nagoya, 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.