Risk factors for gallbladder cancer. An international collaborative case-control study.

BACKGROUND: Gallbladder cancer has an unusual geographic and demographic distribution, suggesting many possible etiologies. METHODS: A case-control study was undertaken at four hospitals in La Paz, Bolivia, and at one hospital in Mexico City, Mexico. Eighty-four patients with newly diagnosed, histologically confirmed gallbladder cancer were compared with 126 control subjects without stones and with 264 control subjects with cholelithiasis or choledocholithiasis without cancer. All study subjects underwent abdominal surgery. Study subjects were interviewed regarding demographic characteristics, medical history, family history, diet, and exposure to agents presumed to be risk factors for biliary cancer. RESULTS: Virtually all subjects in Mexico were judged to be mestizos (i.e., persons of mixed ancestry) In contrast, race was a very strong risk factor for gallbladder cancer in Bolivia. Relative to mestizos who spoke neither language, the odds ratio (95% confidence interval [CI]) for cases versus control subjects without stones for those who spoke Aymara well was 15.9 (CI, 1.9-179), whereas it was 1.4 (CI, 0.2-8.2) for those who spoke Quechua well. An increased risk was also noted for elevated maximum body mass index (P = 0.03), family history of gallstones (odds ratio [OR] = 3.6 [CI, 1.3-11.4]), and physician-diagnosed typhoid (OR = 12.7 [CI, 1.5-598]). An increased risk was also seen with elevated maximum body mass index; compared with those with a body mass index less than 24 kg/m2, those with an index of 24-25 kg/m2, 26-28 kg/m2, and greater than 28 kg/m2 had odds ratios of 1.6 (CI, 0.4-7.6), 1.3 (CI, 0.3-5.6), and 2.6 (CI, 0.5-18.6), respectively (asymptotic test for trend, P = 0.03). Finally, a number of associations were noted with certain dietary and cooking habits. CONCLUSIONS: Patients with gallbladder cancer differed from control subjects in race, body mass, physician-diagnosed typhoid, and certain dietary patterns. These findings may provide useful clues to the pathogenesis of gallbladder cancer, but given the number of analyses performed, additional cases need to be studied.

Rarity of hypertensive stigmata in aging renocortical arteries of Bolivians.

Numerous reports have accumulated from around the world throughout the twentieth century of small, remote, self-sufficient populations that do not show a rise of blood pressure with age. Knowing that renocortical arteriosclerosis, a defining feature of hypertensive nephrosclerosis, is a close commensurate of blood pressure, it can be predicted that the elderly members of such populations should fail to show arteriosclerosis of hypertensive degree in the renal cortex. Emigrants from such populations sometimes come to medical attention in places like La Paz, Bolivia. Reported here are findings in autopsy samples of kidney tissue examined in La Paz. These samples have revealed remarkably little renovasculopathy at all ages up to 80 years, a phenomenon that has not previously been observed. Because of these findings, it can now be seen as biologically possible for a whole population of elderly persons to avoid renovasculopathy of hypertensive degree, and by implication, perhaps never experience hypertensive cardiovascular disease.