Carlos Cuello

Geographic pathology of thyroid carcinoma

Pathologic and epidemiologic studies of carcinoma of the thyroid were carried out in an endemic and a nonendemic goiter area. Two hundred twenty‐nine cases from the State of Connecticut, USA, and 217 from Cali, Colombia, were histologically reviewed and classified using a single nomenclature and previously agreed criteria. Tumors were classified in five categories: papillary, follicular, anaplastic, medullary, and others. A detailed pathologic description for papillary and follicular varieties was made, since most of the confusion in nomenclature seems to be due to the absence of well‐defined criteria for these two types of tumor. Incidence of specific histologic types in the two localities were also studied. A statistically significant excess of follicular carcinoma was found in Cali in comparison with Connecticut. An excess of ana‐plastic carcinoma in Cali was also seen, but the number of cases was too small to be significant. No differences were found in the incidence of papillary carcinoma in the two localities. Anaplastic and follicular carcinoma were more often associated with nodular goiter than papillary carcinoma.

Risk factors of gastric precancerous lesions in a high‐risk Colombian population. I. salt

A case-control study for stomach cancer was conducted in a high-risk population in Nariño, Colombia to determine the risk of gastric precancerous lesions associated with salt intake measured by sodium-to-creatinine ratio of a single urine sample. Gastric biopsies and urine samples were collected from 263 individuals. Urinary sodium-to-creatinine ratios were studied in relation to histological data from the biopsies. Significantly high odds ratios for precancerous lesions (chronic atrophic gastritis, intestinal metaplasia, and dysplasia) were associated with higher sodium-to-creatinine ratios. Adjusted odds ratios (OR) of 2.50 for chronic atrophic gastritis and 7.24 for dysplasia were found. The association with intestinal metaplasia was weaker and not significant (OR = 1.57). Furthermore, an excess risk associated with adding salt to food at the table was found among patients with precancerous lesions (OR = 1.80). These findings support the two-step involvement of salt in the process of gastric precancerous lesions.

Risk factors of gastric precancerous lesions in a high‐risk Colombian population. II. nitrate and nitrite

Gastric nitrite content was studied in relation to precancerous lesions of the stomach in a case-control study conducted in a high-risk Colombian population. The proportion of detectable nitrite in gastric juice and the mean pH were significantly higher among those with precancerous lesions (chronic atrophic gastritis, intestinal metaplasia, and dysplasia) than among the controls (normal and superficial gastritis); the proportion and mean pH increased with the progression of histological changes from normal to dysplasia. Nitrite was not detectable in gastric juice with a pH less than 5.0. A positive association was found between the proportion of detectable nitrite and the risk of gastric precancerous lesions. Odds ratios of 4.39 for intestinal metaplasia and 24.72 for dysplasia remained significant after controlling for confounders. This finding suggests that nitrite may be a precursor of a mutagen that targets gastric epithelial cells.

Sodium intake and gastric cancer.

SummaryTo test the hypothesis that excessive intake of sodium chloride is a factor in gastric carcinogenesis, urinary excretion of sodium and creatinine was measured in Colombian subjects. Age, sex, weight, and height regression slopes for creatinine excretion were more similar in Colombia than in other countries. Sodium/creatinine (S/C) ratios correlated with 24-h urinary excretion of sodium revealed higher sodium excretion in populations with higher gastric cancer rates. The S/C ratios were not affected by circadial rhythms, making it possible to use single urine samples to investigate interpopulation differences in sodium excretion.

Hormone-induced regression of medullary (solid) thyroid carcinoma

Abstract A case of metastatic medullary carcinoma of the thyroid with hypothyroidism is presented. Treatment with 100 μg. of triiodothyronine per day induced regression in both the primary tumor and the mediastinal, pulmonary and bony metastases. This suggests that medullary thyroid carcinoma may be hormone-dependent. Changes in the histologic appearance of the tumor before and after treatment are discussed. A review of pertinent facts differentiating this tumor from other types of thyroid tumors is given.

Mutagenic activity of gastric juice

Gastric juice samples from patients of a rural area of the Colombian Andes at high risk to gastric cancer were tested for mutagenesis with Salmonella typhimurium strains TA100 and TA1538. Direct mutagenic effect was found in samples with detectable amounts of nitrite. This effect was not accountable by nitrite alone. Nitrite-negative samples from the same area and samples from the low-risk area of Cali were negative using the same mutagenesis assay.

Nitrite stability and nitrosation potential in human gastric juice

Human gastric juice samples were investigated from high- and low-risk areas (Colombia and Boston) for factors which influence the stability of nitrite and its potential for nitrosamine formation. The samples from individuals with chronic atrophic gastritis and intestinal metaplasia were not reactive to nitrite and supported a rate of nitrosation largely compatible with the nitrite and thiocyanate concentration. The samples from other individuals contained factors which destroyed nitrite and inhibited nitrosation. There were several samples from both groups which had an elevated rate of nitrosation catalyzed by unknown factors. It is suggested that continued hypochlorhydria might deplete gastric juice of its natural protective factors and lead to an elevated risk of gastric cancer in agreement with our earlier etiological model [1].

Dysplastic Changes in Intestinal Metaplasia of the Gastric Mucosa

The role of intestinal metaplasia as a precursor of the intestinal type of gastric cancer has received support from multiple fronts. Bonne and collaborators reported in 1938 that Chinese immigrants to Java had a high frequency of gastric cancer and high prevalence of “goblet-cell metaplasia” while both lesions were rare in the local natives [1]. Jarvi and Lauren in 1951 reported that the majority of gastric cancers originated in islands of intestinal epithelium [10]. Morson in 1955 documented the origin of small gastric carcinomas in areas of metaplasia [12]. Similar findings were reported in Japan by Nagayo [14]. Metaplasia has been induced with carcinogens in experimental animals [5, 11]. Studies of internal migration in Colombia have shown positive correlation between the prevalence of metaplasia in autopsies and the incidence of carcinoma [2]. Metaplasia is more frequent in Japan than in the United States [9]. Patients with metaplasia have about ten times greater risk of carcinoma than people with negative gastric biopsies [13].

The Role of Campylobacter pylori in Gastro-Duodenal Disease

Since 1983 when Warren reported spiral bacteria in 50 percent of gastric biopsies, and the successful culture by Marshall,1 Campylobacter pylori (C.p.), as the “Warren bacteria” was named, has surged to the forefront of gastroenterology and gastrointestinal pathology. Considerable clinical, bacteriologic, and immunologic research is being carried out. Some pathologists and gastroenterologists have reached apparently opposite conclusions concerning its role in human disease: It is considered to be either a common saprophyte or a common pathogenic bacteria, depending on which school of thought interprets the available data. The following review tries to document the association between C.p. and gastritis and to put into perspective the evidence concerning its role in gastrointestinal disease, based on the medical literature and gastrointestinal pathology material from New Orleans, Colombia, and China.

Mutagenic activity of nitrosated foods in an area with a high risk for stomach cancer

In a search for possible sources of mutagens in human foods, a study was made of six common foods in the diet of a population at high risk for gastric cancer (in Nariño, Colombia). No mutagenic activity was demonstrated in nonnitrosated foods. After nitrosation, only one of the foods, fava beans, demonstrated a mutagenic effect. This effect was direct and concentrated in the germ and pulp of the beans.