Joseph F. Fraumeni

Familial cancer syndromes have helped to define the role of tumor suppressor genes in the development of cancer. The dominantly inherited Li-Fraumeni syndrome (LFS) is of particular interest because of the diversity of childhood and adult tumors that occur in affected individuals. The rarity and high mortality of LFS precluded formal linkage analysis. The alternative approach was to select the most plausible candidate gene. The tumor suppressor gene, p53, was studied because of previous indications that this gene is inactivated in the sporadic (nonfamilial) forms of most cancers that are associated with LFS. Germ line p53 mutations have been detected in all five LFS families analyzed. These mutations do not produce amounts of mutant p53 protein expected to exert a trans-dominant loss of function effect on wild-type p53 protein. The frequency of germ line p53 mutations can now be examined in additional families with LFS, and in other cancer patients and families with clinical features that might be attributed to the mutation.

BACKGROUND: Incidence rates for esophageal adenocarcinoma previously were reported to be increasing rapidly, especially among white males. Rates for gastric cardia adenocarcinoma also were observed to be rising, although less rapidly. In this article, the authors update the incidence trends through 1994 and further consider the trends by age group. METHODS: Surveillance, Epidemiology, and End Results (SEER) program data were used to calculate age-adjusted incidence rates for esophageal carcinoma by histologic type and gastric adenocarcinoma by anatomic subsite. RESULTS: Among white males, the incidence of adenocarcinoma of the esophagus rose > 350% since the mid-1970s, surpassing squamous cell carcinoma around 1990. Rates also rose among black males, but remained at much lower levels. To a lesser extent, there were continuing increases in gastric cardia adenocarcinoma among white and black males, which nearly equaled the rates for noncardia tumors of the stomach in white men. The upward trend for both tumors was much greater among older than younger men. Although the incidence also rose among females, rates remained much lower than among males. CONCLUSIONS: Previously reported increases of esophageal adenocarcinoma are continuing, most notably among white males. Cigarette smoking may contribute to the trend through an early stage carcinogenic effect, along with obesity, which may increase intraabdominal pressure and predispose to gastroesophageal reflux disease. Further research into esophageal and gastric cardia adenocarcinoma is needed to clarify the risk factors and mechanisms responsible for the upward trends as well as the racial and gender disparities in incidence.

A case-control study of oral and pharyngeal cancer conducted in four areas of the United States provided information on the tobacco and alcohol use of 1114 patients and 1268 population-based controls. Because of the large study size, it could be shown that the risks of these cancers among nondrinkers increased with amount smoked, and conversely that the risks among nonsmokers increased with the level of alcohol intake. Among consumers of both products, risks of oropharyngeal cancer tended to combine more in a multiplicative than additive fashion and were increased more than 35-fold among those who consumed two or more packs of cigarettes and more than four alcoholic drinks/day. Cigarette, cigar, and pipe smoking were separately implicated, although it was shown for the first time that risk was not as high among male lifelong filter cigarette smokers. Cessation of smoking was associated with a sharply reduced risk of this cancer, with no excess detected among those having quit for 10 or more years, suggesting that smoking affects primarily a late stage in the process of oropharyngeal carcinogenesis. The risks varied by type of alcoholic beverage, being higher among those consuming hard liquor or beer than wine. The relative risk patterns were generally similar among whites and blacks, and among males and females, and showed little difference when oral and pharyngeal cancers were analyzed separately. From calculations of attributable risk, we estimate that tobacco smoking and alcohol drinking combine to account for approximately three-fourths of all oral and pharyngeal cancers in the United States.

BACKGROUND: Epidemiologic evidence indicates that diets high in fruits and vegetables are associated with a reduced risk of several cancers, including cancers of the esophagus and stomach. Vitamins and minerals in these foods may contribute to the reduced cancer risk. The people of Linxian County, China, have one of the world's highest rates of esophageal/gastric cardia cancer and a persistently low intake of several micronutrients. PURPOSE: We sought to determine if dietary supplementation with specific vitamins and minerals can lower mortality from or incidence of cancer as well as mortality from other diseases in Linxian. METHODS: Individuals of ages 40-69 were recruited in 1985 from four Linxian communes. Mortality and cancer incidence during March 1986-May 1991 were ascertained for 29,584 adults who received daily vitamin and mineral supplementation throughout this period. The subjects were randomly assigned to intervention groups according to a one-half replicate of a 2(4) factorial experimental design. This design enabled testing for the effects of four combinations of nutrients: (A) retinol and zinc; (B) riboflavin and niacin; (C) vitamin C and molybdenum; and (D) beta carotene, vitamin E, and selenium. Doses ranged from one to two times U.S. Recommended Daily Allowances. RESULTS: A total of 2127 deaths occurred among trial participants during the intervention period. Cancer was the leading cause of death, with 32% of all deaths due to esophageal or stomach cancer, followed by cerebrovascular disease (25%). Significantly (P = .03) lower total mortality (relative risk [RR] = 0.91; 95% confidence interval [CI] = 0.84-0.99) occurred among those receiving supplementation with beta carotene, vitamin E, and selenium. The reduction was mainly due to lower cancer rates (RR = 0.87; 95% CI = 0.75-1.00), especially stomach cancer (RR = 0.79; 95% CI = 0.64-0.99), with the reduced risk beginning to arise about 1-2 years after the start of supplementation with these vitamins and minerals. No significant effects on mortality rates from all causes were found for supplementation with retinol and zinc, riboflavin and niacin, or vitamin C and molybdenum. Patterns of cancer incidence, on the basis of 1298 cases, generally resembled those for cancer mortality. CONCLUSIONS: The findings indicate that vitamin and mineral supplementation of the diet of Linxian adults, particularly with the combination of beta carotene, vitamin E, and selenium, may effect a reduction in cancer risk in this population. IMPLICATIONS: The results on their own are not definitive, but the promising findings should stimulate further research to clarify the potential benefits of micronutrient supplements.