Endocrine gland cancer

BACKGROUND

Incidence and prognosis of cancers of the endocrine glands vary greatly by histologic type.

METHODS

Population-based data from SEER registries, 1973-1987, were analyzed.

RESULTS

Thyroid cancer accounts for most (92%) of the cancers of the endocrine glands. The four major histologic types of thyroid cancer display distinct patterns, reflecting different biologic entities. Papillary carcinoma, the most common type, occurs more frequently in women than in men and in whites than in blacks and has an early onset. Follicular carcinoma, the second most common type, shows a steady increase in incidence with age and a female preponderance but no racial disparity. Medullary carcinoma, the rare differentiated thyroid tumor, has a female excess in whites only and a slow increase in incidence with age. Anaplastic carcinoma shows few racial or sex variations and reaches a substantial level only after age 50. The prognosis also varies greatly by histologic type. The overall 5-year relative survival rate is greater than 90% for papillary and follicular carcinomas, 82% for medullary carcinoma, and less than 10% for anaplastic carcinoma. Carcinomas of the suprarenal gland and thymus are rare, accounting for about 3% of endocrine cancers each. These tumors, unlike the differentiated thyroid cancer, show no female preponderance, have a higher incidence rate in blacks, and have a poorer survival rate.

CONCLUSIONS

The marked predominance of papillary carcinoma and the continued increase in its relative frequency characterize the postgoiter era and an increased use of scintigraphy and fine needle aspiration. Underdiagnosis of small tumors may explain the observed lower incidence of papillary carcinoma in blacks.

Anatomic site distribution of colon cancer by race and other colon cancer risk factors

PURPOSE

Black patients with colon cancer are more likely to have poorer survival from colon cancer than are white patients. To determine whether anatomic site differences might contribute to survival differences, we compared anatomic site distributions of black and white patients.

METHODS

As part of the Black/White Cancer Survival Study, we collected medical record data for 1,045 patients from Atlanta, New Orleans, and San Francisco/Oakland, newly diagnosed in 1985 or 1986 and interviewed 745 of them.

RESULTS

In polychotomous logistic regression analysis, site was related to stage, grade, and histologic type and among women with age, parity, and possibly smoking. However, it was not related to race, except perhaps among men age 65 and older, among whom blacks were somewhat likely to have more transverse and distal, not proximal, cancer. These relations were consistent across subgroups and were independent of other factors examined.

CONCLUSION

Results suggest that site differences are unlikely to contribute to poorer survival commonly observed among black colon cancer patients in the United States.

The role of antioxidants in gastric carcinogenesis

The epidemiologic evidence for a role of antioxidants in inhibiting carcinogenesis in humans is briefly summarized. Mechanistic pathways of protection by antioxidants are illustrated with the prevailing model of gastric carcinogenesis in humans. In this model, ascorbic acid may be involved at the early stage of chronic gastritis; its secretion into the stomach is inhibited by infection with Helicobacter pylori, a major cause of gastritis. Ascorbic acid may also play a role in blocking the nitrosation of amines and related compounds in the gastric microenvironment. Carotenoids are also involved in the chain of gastric cancer causation and apparently play an important role in preventing mutations in the advanced stages of the process. The gastric cancer model supports the notion that invasive cancer is the result of insufficient control of oxidative stress applied to replicating cells over a prolonged period of time.

Racial differences in survival from breast cancer. Results of the National Cancer Institute Black/White Cancer Survival Study

OBJECTIVE

To examine the ability of recognized prognostic factors for breast cancer to account for the observed poorer survival in blacks compared with their white counterparts.

DESIGN AND PARTICIPANTS

Subjects included 1130 women (612 blacks and 518 whites) aged 20 to 79 years residing in metropolitan Atlanta, Ga, New Orleans, La, or San Francisco/Oakland, Calif, who were diagnosed with primary invasive breast cancer. Information on stage, tumor characteristics, treatment, comorbid conditions, and sociodemographic factors was obtained from personal interview, physician and hospital records, and a pathology review of biopsy and surgical specimens.

MAIN OUTCOME MEASURE

Multivariable survival models were used to estimate the hazard ratio (relative risk of mortality) for blacks compared with whites, adjusting for various combinations of potential explanatory factors.

RESULTS

After controlling for geographic site and age, the risk of dying was 2.2 times (95% confidence interval [CI], 1.8 to 2.8) greater for blacks than whites. Adjustment for stage reduced the risk from 2.2 to 1.7; further adjustment for sociodemographic variables had no effect. Treatment was not a contributing factor once stage and tumor pathology were in the model. After adjusting for stage, treatment, comorbid illness, and pathologic and sociodemographic variables, blacks continued to demonstrate a slightly increased, but not statistically significant, risk of death (hazard ratio = 1.3; 95% CI, 1.0 to 1.8). Results were similar for all-cause mortality and breast cancer-specific mortality.

CONCLUSIONS

Approximately 75% of the racial difference in survival was explained by the prognostic factors studied. Sociodemographic variables appeared to act largely through racial differences in stage at diagnosis, which may be amenable to change through improved access to and use of screening for black women.

Ascorbic acid, Helicobacter pylori and Lewis phenotype among blacks and whites in New Orleans

Gastric juice ascorbic acid concentrations were examined in black and white patients. Significantly lower concentrations were found in blacks, in the absence of a significant difference in the plasma concentration of vitamin C between races. Blacks had higher prevalence of Helicobacter pylori infection, higher gastric pH, more severe acute and chronic inflammation of the gastric mucosa and higher frequency of Lewis (a-b-) phenotype. Although most of these factors have been related to low ascorbic acid levels in gastric juice, none of them could account entirely for the difference between races either individually or after joint consideration. These observations may help to explain the high incidence of gastric carcinoma among the black population in southern Louisiana.

Environmental tobacco smoke and lung cancer in nonsmoking women. A multicenter study

OBJECTIVE

To determine the relative risk (RR) of lung cancer in lifetime never smokers associated with environmental tobacco smoke (ETS) exposure.

DESIGN

Multicenter population-based case-control study.

SETTING

Five metropolitan areas in the United States: Atlanta, Ga, Houston, Tex, Los Angeles, Calif, New Orleans, La, and the San Francisco Bay Area, Calif.

PATIENTS OR OTHER PARTICIPANTS

Female lifetime never smokers: 653 cases with histologically confirmed lung cancer and 1253 controls selected by random digit dialing and random sampling from the Health Care Financing Administration files for women aged 65 years and older.

MAIN OUTCOME MEASURE

The RR of lung cancer, estimated by adjusted odds ratio (OR) with 95% confidence interval (CI), associated with ETS exposure.

RESULTS

Tobacco use by spouse(s) was associated with a 30% excess risk of lung cancer: all types of primary lung carcinoma (adjusted OR = 1.29; P < .05), pulmonary adenocarcinoma (adjusted OR = 1.28; P < .05), and other primary carcinomas of the lung (adjusted OR = 1.37; P = .18). An increasing RR of lung cancer was observed with increasing pack-years of spousal ETS exposure (trend P = .03), such that an 80% excess risk of lung cancer was observed for subjects with 80 or more pack-years of exposure from a spouse (adjusted OR = 1.79; 95% CI = 0.99 to 3.25). The excess risk of lung cancer among women ever exposed to ETS during adult life in the household was 24%; in the workplace, 39%; and in social settings, 50%. When these sources were considered jointly, an increasing risk of lung cancer with increasing duration of exposure was observed (trend P = .001). At the highest level of exposure, there was a 75% increased risk. No significant association was found between exposure during childhood to household ETS exposure from mother, father, or other household members; however, women who were exposed during childhood had higher RRs associated with adult-life ETS exposures than women with no childhood exposure. At the highest level of adult smoke-years of exposure, the ORs for women with and without childhood exposures were 3.25 (95% CI, 2.42 to 7.46) and 1.77 (95% CI, 0.98 to 3.19), respectively.

CONCLUSION

Exposure to ETS during adult life increases risk of lung cancer in lifetime nonsmokers.

Helicobacter pylori and nucleolar organizer regions in the gastric antral mucosa

The association of Helicobacter pylori with an increased risk of gastric adenocarcinoma has been documented, but its mechanisms have not been elucidated. This study explored these mechanisms by addressing the relationship between H pylori and the silver-staining nucleolar organizer regions (AgNORs) in the gastric antrum. The number of AgNORs per nucleus has been correlated with proliferative rate and ploidy. The results of gastric biopsies performed before and after treatment for H pylori showed that only patients who cleared the H pylori infection had a significant decrease in the number of AgNORs per nucleus. A positive association between AgNOR counts and the severity of polymorphonuclear infiltrate could be demonstrated in patients who did not clear H pylori infection. The authors concluded that H pylori infection alters the replication cycle of the antral mucosa, inducing hyperproliferation and possibly ploidy abnormalities. Whether these alterations are induced directly by the bacterium or by the acute inflammatory infiltrate remains undecided; the data in this study suggest a possible direct effect of the polymorphonuclear leukocytes.

Advanced stage at diagnosis: an explanation for higher than expected cancer death rates in Louisiana?

Data from the Louisiana Tumor Registry, Louisiana Vital Statistics Division, and the SEER program of the National Cancer Institute were explored to evaluate reasons for elevated cancer death rates in the absence of elevated cancer incidence in Louisiana. The results indicate that cancer patients in South Louisiana are more likely to be diagnosed with advanced stage disease than SEER patients. The Louisiana-SEER differences are greater for blacks than whites, and black patients are more likely to have advanced stage cancer than whites in Louisiana as well as in the SEER program. Of particular interest and concern is the finding that the increased risk of advanced stage disease in Louisiana is significant for cancers which can be detected early and, if so, effectively treated: colon, breast, and cervix. The findings reinforce the need for cancer control programs.

Vitamin C concentration in gastric juice before and after anti-Helicobacter pylori treatment

OBJECTIVES

To investigate the change of vitamin C concentration (ascorbic and dehydroascorbic acid) in gastric juice after anti-Helicobacter pylori treatment, and to relate any observed change to gastric pH, inflammatory compromise of the gastric mucosa, plasma vitamin C concentration, and smoking habits.

METHODS

Plasma and gastric juice vitamin C, fasting gastric juice pH, gastric histology, and smoking status were studied in 70 patients with H. pylori-associated gastritis before and after therapy.

RESULTS

Gastric juice ascorbic acid increased significantly after H. pylori clearance. For the most part, this change was confined to patients who experienced reduction of gastric pH. It was also related to improvement of the compromise of the gastric epithelium, reduction of the proportion of vitamin C composed by dehydroascorbic acid, and increase of the gastric juice/plasma vitamin C concentration gradient. Smokers had lower vitamin C concentrations in plasma and gastric juice before and after H. pylori clearance than nonsmokers.

CONCLUSIONS

The findings are consistent with a causal association between H. pylori infection and low ascorbic acid levels in gastric juice, and support two mechanisms for this association: increased oxidation and a decreased secretion of ascorbic acid.

Phenotypic and genotypic events in gastric carcinogenesis

Two main histological variants of gastric carcinoma have been identified: intestinal and diffuse types. The former is preceded by a sequential chain of events characterized as chronic gastritis, atrophy, intestinal metaplasia, dysplasia, intramucosal carcinoma, and invasive neoplasia. The second type (diffuse) lacks well-recognized precursor changes. Genotypic events in the gastric precancerous process are described, but a clear model of their sequence and relevance is lacking. Cadherins may play a role in determining which type of carcinoma develops. Translocated promoter region-MET rearrangements have been identified since early stages of the process. p53 alterations are reported beginning with the dysplasia stage utilizing immunohistochemical techniques. Single-strand conformation polymorphism and sequencing analysis show alterations in early stages, especially G:C to A:T transitions.

Histological characteristics of breast carcinoma in blacks and whites

Tumor characteristics of 963 newly diagnosed invasive breast cancer cases from the population-based Black/White Cancer Survival Study were evaluated. Representative slides of the tumors were requested from all participating hospitals of three metropolitan areas and reviewed by one expert pathologist, blinded in regard to the age and race of patients. Nine tumor characteristics were evaluated for black and white patients. After adjusting for age, stage, and metropolitan area, blacks were significantly more likely to have high grade nuclear atypia [odds ratio (OR) = 1.97, 95% confidence interval (CI) = 1.27-3.04]; high mitotic activity (OR = 2.05, 95% CI = 1.34-3.14), grade 3 tumors (OR = 1.58, 95% CI = 1.02-2.45), and more necrosis (OR = 1.51, 95% CI = 1.16-1.98); and less likely to have well defined tubular formation (OR = 0.57, 95% CI = 0.42-0.77), marked fibrosis (OR = 0.65, 95% CI = 0.45-0.94), and positive estrogen receptor status (OR = 0.78, 95% CI = 0.58-1.05). These black/white differences remained after controlling for socioeconomic status (SES), body mass index, use of alcohol and tobacco, reproductive experience, and health care access and utilization. No significant racial differences were found for blood vessel invasion and lymphatic invasion. Although white women of high SES had more favorable tumors than those of low SES, the same pattern was not observed for blacks. High SES black women had statistically nonsignificant elevated ORs of a high mitotic index and tumor grade. These racial differences in tumor biology may have etiological and clinical implications.

p53 alteration in gastric precancerous lesions

It has been postulated that chronic atrophic gastritis, intestinal metaplasia, and dysplasia are precancerous stages of stomach tumorigenesis. We investigated the timing of p53 alterations in these events of gastric tumorigenesis. Each of 12 cases of archived tissue containing precancerous and cancerous lesions were selected for the detection of p53 alterations. Accumulation of p53 protein was detected by immunohistochemistry. Exons 5 to 8 of p53 gene were examined for mutations by polymerase chain reaction-single strand conformation polymorphism and DNA sequencing. p53 immunoreactivity was detected in 60% of the dysplasia cases and in 60% of the cases with carcinomas. p53 gene alterations were found in 37.5% of the metaplasia cases, 58.3% of the dysplasia cases, and 66.7% of the cases with carcinomas. In 71% of the cases, mutations were shown as G:C-->A:T transition. We conclude that mutation of the p53 gene is an early event in stomach tumorigenesis.

Serum pepsinogens as markers of response to therapy for Helicobacter pylori gastritis

We have investigated the effect of therapy for Helicobacter pylori gastritis on serum concentrations of pepsinogen I and II in 43 patients. In the 22 patients in whom therapy resulted in dramatic decrease in gastritis scores and in clearance of the bacteria, there was a highly significant (P = 0.0001) fall in mean serum pepsinogen II from 13.3 +/- 0.8 to 7.9 +/- 0.7 micrograms/liter, and a less pronounced fall in pepsinogen I from 89.0 +/- 5.9 to 78.5 +/- 0.4 micrograms/liter (P = 0.01). These changes resulted in a significant (P = 0.01) increase in the pepsinogen I/II ratio. In contrast, nonsignificant declines of 3.5% and 11.6% were observed in mean pepsinogen I and II levels in the 21 patients whose gastritis failed to resolve histologically and whose infection did not clear. These findings suggest that serum pepsinogen levels, especially pepsinogen II, are a new tool that may be found to be clinically useful in evaluation of treatment outcome in patients with H. pylori-associated gastritis.

Helicobacter pylori causes hyperproliferation of the gastric epithelium: pre- and post-eradication indices of proliferating cell nuclear antigen

OBJECTIVE

To assess the effect of Helicobacter pylori (HP) eradication on the proliferation of the gastric epithelium by the expression of the proliferating cell nuclear antigen (PCNA).

METHODS

Alcohol-fixed gastric biopsies taken before and after treatment for HP were immunostained with the PC-10 anti-PCNA monoclonal antibody and the labeling index was determined with an image analysis system.

RESULTS

The mean PCNA-labeling index (LI) of 16 patients who remained HP positive did not change significantly (18.95 +/- 1.71 on first visit vs. 17.96 +/- 1.91 on second visit, mean +/- SEM). The mean PCNA LI of 31 patients who cleared HP was reduced significantly (19.95 +/- 1.77 on first visit vs. 14.13 +/- 1.29 on second visit, p < 0.001). Patients who were positive for HP at both first and second visit showed a significantly higher PCNA LI than normal control biopsies (13.05 +/- 1.70) (p < 0.05).

CONCLUSIONS

These results indicate that the gastric mucosa infected with HP is in a state of hyperproliferation. Patients who cleared HP showed a significant histopathological improvement, reflected in the reduction in number of polymorphonuclear and mononuclear cell infiltrates, and a reduction in the amount of superficial mucosa damage. Prolonged hyperproliferation of the gastric epithelium exerted by HP infection could be a major factor for human gastric carcinogenesis.

MNNG-induced gastric carcinoma in ferrets infected with Helicobacter mustelae

N-Methyl-N-nitro-N'-nitrosoguanidine (MNNG) is a gastric carcinogen in several animal species and has been used in a number of systems to dissect the co-carcinogenic potential of various compounds in the induction of gastric adenocarcinoma. Recent epidemiological evidence suggests that Helicobacter pylori may play a role as a co-carcinogen in the etiology of this tumor in humans and we have been interested in developing an animal model to study this possibility. A related organism, H. mustelae, naturally colonizes the ferret stomach and causes persistent chronic gastritis. The pathology elicited by H. mustelae in ferrets has many similarities with the human disease including different stages of multifocal atrophic gastritis which underlie the gastric ulcer and gastric carcinoma syndrome. There is little evidence, however, demonstrating the susceptibility of ferrets toward chemical carcinogenesis. We have consequently undertaken a study to ascertain whether 10 6-month-old female ferrets given a single oral dose of MNNG (50-100 mg/kg) would develop adenocarcinoma of the stomach. Five age-matched unmanipulated control animals were included for comparative purposes. All 15 ferrets were infected with H. mustelae. Nine of 10 ferrets dosed with MNNG developed gastric adenocarcinoma (29-55 months after dosing), while none of the five historical control ferrets examined an average of 63 months after the initiation of the study developed gastric tumors. By comparison, we have not observed gastric adenocarcinoma, nor has it been reported, in > 10 years of observation of untreated ferrets naturally infected with H. mustelae. The H. mustelae-infected ferret, with demonstrated susceptibility to a gastric carcinogen, plus the recent availability of specific pathogen-free ferrets, should now allow longitudinal studies in vivo to probe the role of Helicobacter in the development of gastric cancer.

Breast cancer: factors associated with stage at diagnosis in black and white women. Black/White Cancer Survival Study Group

BACKGROUND

Numerous studies have reported differences in cancer staging at diagnosis and in survival between Black and White patients with breast cancer. Utilizing data obtained from the National Cancer Institute's (NCI's) Black/White Cancer Survival Study for the period 1985-1986, a new study is presented here that systematically examines multiple explanatory factors (e.g., lack of mammograms) associated with these cancer-staging differences.

PURPOSE

We evaluated within a single study the relationship of selected demographic, lifestyle, antecedent medical experiences, and health care access factors to cancer staging at diagnosis in Black and White breast cancer patients.

METHODS

Data utilized in this population-based cohort study of 1222 eligible women (649 Black and 573 White) newly diagnosed for the period 1985-1986 with histologically confirmed primary breast cancer were obtained from the NCI's Black/White Cancer Survival Study. Sources of data included abstracts of hospital medical records, central review of histology slides by a study consultant pathologist, and patient interviews obtained from three metropolitan areas: Atlanta, New Orleans, and San Francisco-Oakland. Within each area, 70% of all Black incident cases were randomly selected, and a sample of White cases, frequency matched by age groups (20-49 years, 50-64 years, and 65-79 years), was selected for comparison. Stage of breast cancer at diagnosis was classified according to the international tumor-lymph node-metastases (TNM) system. Statistical models utilized in this study included the log-linear and polychotomous logistic regression with multiple predictor variables.

RESULTS

Factors associated with cancer staging were differentially expressed in Blacks and Whites. Indicators of access to health care, a lack of mammograms, and an increased body mass index significantly (P < .02) contributed to stage differences in Blacks, whereas income was marginally associated (P = .06) with stage for Whites only. Nuclear grade, having a breast examination by a physician, and a history of patient delay explained approximately 50% of the excess risk for stage III-IV cancer versus stage I-IIN0 cancer among Blacks compared with Whites (odds ratio reduction from 2.19 to 1.68).

CONCLUSION

These findings suggest that no single factor or group of factors can explain more than half of the race-stage differences noted in this study with respect to Black and White breast cancer patients.

Autocrine and paracrine growth control by granulocyte-monocyte colony-stimulating factor of acute lymphoblastic leukemia cells

Blast colony assays were performed on freshly obtained bone marrow samples from 19 newly diagnosed or relapsed children with acute lymphoblastic leukemia (ALL) of B lineage to determine the effect of added granulocyte-monocyte colony-stimulating factor (GM-CSF). Of the 19 marrow samples tested, 7 responded to GM-CSF with a mean increase in ALL blast colonies of 346%. Blast cells from one of the responders chosen for flow cytometric study showed expression of GM-CSF receptors on 38% of cells. These findings prompted us to establish five ALL cell lines of diverse phenotypes to examine the expression of GM-CSF and GM-CSF receptor genes in human leukemia, and to determine the role of GM-CSF in autocrine and paracrine growth control of ALL cells. One line, termed G2, manifested a GM-CSF-mediated autocrine pattern of cell growth with the following features: G2 blast colony growth in a serum-free system without added growth factor was density dependent; exogenous GM-CSF augmented G2 colony formation when the cells were seeded at low density; G2 cells constitutively expressed mRNA for GM-CSF and GM-CSF receptor; G2 cells also produced and secreted measurable amounts of GM-CSF into cell culture supernatant; and, monoclonal anti-GM-CSF antibodies abolished G2 colony growth when added to cultures with cells seeded at low density without growth factors. Of the other four ALL cell lines, three expressed mRNA for GM-CSF receptor and responded in vitro to added GM-CSF with increased blast colony growth; however, none of these four cell lines expressed mRNA for constitutive production of GM-CSF. A fifth ALL cell line lacked receptors for GM-CSF and did not respond in clonogenic assays to added GM-CSF. Thus, a bioregulator of normal hematopoiesis plays a central role in autocrine growth control of G2 ALL cells, and an important paracrine growth-promoting role in three of four other ALL cell lines.

Worksite smoking control, discouragement, and cessation

Smoking control, discouragement, and cessation were investigated at three comparable chemical plants. One plant was randomly assigned to smoking cessation only while the other two plants were assigned to a comprehensive program of smoking control, discouragement, and cessation. Three weeks later, smoking cessation was provided at all three sites. Results are consistent with a previous investigation of the comprehensive program carried out at two oil refineries. Not only was there a greater rate of participation in the smoking cessation program with the comprehensive program, 4 months after completion of smoking cessation treatment revealed significant changes on all outcome variables in the expected direction and suggest the superiority of a comprehensive program of smoking control, discouragement, and cessation over cessation alone.

Passive smoking and lung cancer

The findings of a multicenter national study of lung cancer in lifetime-never smokers are reported. An increased lung cancer risk of approximately 30% was found among women whose husbands smoked. Elevated risks of 40% to 60% were also found associated with workplace exposures and other exposures outside the home. The findings of this study have been included in the recent Environmental Protection Agency assessment of the health effects of passive smoking, and have implications for regulation of environmental tobacco smoke exposure in Louisiana.

The effect of alcohol on the risk of lung cancer in Uruguay

A hospital-based case-control study of the association between alcohol drinking and lung cancer was carried out in Uruguay between January 1988 and December 1990. The sample included 327 men with lung cancer and 350 male controls. Personal interviews were conducted in the Institute of Oncology by trained personnel using a structured questionnaire. The results showed a significant positive association between beer intake and the risk of lung cancer. The odds ratio for beer drinkers in the highest quartile was 3.4 (95% confidence limits, 1.3-6.6) after adjustment for tobacco. The association between beer and lung cancer was consistent for all the cell types, analyzed separately. A moderate effect for total alcohol consumption was also observed, with a relative risk of 2.2 for those subjects in the highest quartile.