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M Gail

Publications and source records attributed to M Gail.

At least 19 recordsLinked to original sources
PubMed2000

Association of surface ultraviolet B radiation levels with melanoma and nonmelanoma skin cancer in United States blacks.

Ultraviolet B (UVB) radiation exposure increases the risk of skin cancer in whites. Motivated by indications that United States geographic variation of relative skin cancer risk in blacks approaches that in whites, we used Poisson regression to estimate the risk of skin cancer in blacks as a function of average annual surface-levels of UVB radiation, measured by Robertson-Berger meters. United States data were used on deaths in 506 state economic areas, 1970-1994, and on incident cases in the nine areas of the Surveillance, Epidemiology, and End Results Program, 1973-1994. For black males, the age-adjusted relative risk of mortality for a 50% increase in UVB radiation was significantly above one for malignant melanoma, 1970-1994 (1.16; 95% confidence interval, 1.02-1.32) and nearly so for nonmelanoma skin cancer, 1970-1981 (1.18; 95% confidence interval, 1.00-1.39), for which the time period was chosen to avoid AIDS-related deaths from Kaposi's sarcoma. However, for black females, the relative risk of mortality was not significantly elevated for either skin cancer, and, for both black males and females, the relative risk of incidence was not significantly elevated for melanoma in the period 1973-1994. Incidence data on nonmelanoma skin cancer were not available. Although the public health implication is uncertain because of the much lower absolute risk of skin cancer in blacks compared with whites, the findings suggest that sunlight exposure increases skin cancer risk in blacks.

Adolescent↗
PubMed1999

Estrogen replacement therapy and breast cancer survival in a large screening study.

BACKGROUND: Hormone replacement therapy has been associated in some studies with reductions in breast cancer mortality among women who develop this disease. It is unclear whether this association reflects the biologic activity of the hormones or the earlier detection of tumors among hormone users. We examined breast cancer mortality among women who were diagnosed with axillary lymph node-negative and node-positive breast cancer according to the currency of estrogen use at diagnosis. METHODS: Vital status through June 1995 was determined for 2614 patients with postmenopausal breast cancer diagnosed during the period from 1973 to January 1981. We estimated adjusted hazard-rate ratios (adjusting for tumor size, age, race, Quetelet [body mass] index, and number of positive lymph nodes in women with node-positive disease) and unadjusted cumulative probabilities of breast cancer death over time since diagnosis. RESULTS: Among patients with node-negative disease, rate ratios for breast cancer mortality associated with current use compared with nonuse at diagnosis were 0.5 (95% confidence interval [CI] = 0.3-0.8) until 144 months after diagnosis and 2.2 (95% CI = 0.9-5.2) thereafter. Mortality was not statistically significantly lower in past users. The cumulative probabilities of breast cancer mortality at the end of follow-up were 0.14, 0.14, and 0.09 in nonusers, past users, and current users, respectively. Among women with node-positive disease, the rate ratios associated with current and past use were both 0.5 until 48 months after diagnosis (95% CI = 0.3-0.8 for current users; 95% CI = 0.3-0.9 for past users) and were 1.1 (95% CI = 0.7-1.7) and 1.8 (95% CI = 1.2-2.7), respectively, thereafter. The cumulative probabilities of breast cancer mortality were 0.32, 0.39, and 0.27 in nonusers, past users, and current users, respectively. CONCLUSIONS: Patients with breast cancer who were using replacement estrogens at the time of diagnosis experienced reductions in breast cancer mortality, which waned with the time since diagnosis.

Aged↗
PubMed1998

Risk-based recommendations for mammographic screening for women in their forties.

PURPOSE: To develop risk-based recommendations for mammographic screening for women in their 40s that take into account the woman's age, race, and specific risk factors. METHODS: We assumed that regular mammographic screening is justified for a 50-year-old woman, even one with no risk factors, and that a younger woman with an expected 1-year breast cancer incidence rate as great or greater than that of a 50-year-old woman with no risk factors would benefit sufficiently to justify regular screening. Recommendations under this criterion were based on age- and race-specific breast cancer incidence rates from the National Cancer Institute's (NCI's) Surveillance, Epidemiology, and End Results (SEER) Program; assessments of risk factors from the Breast Cancer Detection and Demonstration Project (BCDDP); and reports in the literature. RESULTS: Two methods, the exact-age procedure (EAP) and the grouped-age procedure (GAP), were developed. The less precise GAP only requires following a flow diagram. The proportion of white women recommended for screening by the EAP ranges from 10% for 40-year-old women to 95% for 49-year-old women, and the corresponding percentages for black women are 16% and 95%. The assumptions that underlie the guidelines are discussed critically. CONCLUSION: For women or physicians who prefer an individualized approach in deciding whether to initiate regular mammographic screening in the age range of 40 to 49 years, the present report offers recommendations based on individualized risk-factor data and clearly stated assumptions that have an empiric basis. These recommendations can be used to facilitate the counseling process.

Adult↗
PubMed1995

Geographic variation in mortality from breast cancer among white women in the United States.

BACKGROUND: For several decades, mortality from breast cancer has been higher in the northeastern part of the United States than in other regions, particularly the South. Rates have also been somewhat higher in the Midwest and West than in the South, especially among older women. The reasons for these geographic variations are not well understood. PURPOSE: The objective of this study was to evaluate geographic differences in U.S. breast cancer mortality rates in 1987, after taking into account regional differences in the distribution of recognized breast cancer risk factors (e.g., late age at first live birth) and certain prognostic factors (e.g., mammography use). METHODS: The 1987 breast cancer mortality rates for four regions of the country were obtained from the National Center for Health Statistics. Regional data on the distribution of breast cancer risk factors were obtained from 1987 National Health Interview Cancer Epidemiology Supplement interviews with 9778 white women aged 20-79 years. Regional data on the distribution of mammography use were obtained from 1987 National Health Interview Cancer Control Supplement interviews with 3795 white women aged 50-79 years. RESULTS: Age-adjusted mortality ratios (MRs) among women 50 years and older were 1.15, 1.18, and 1.30 in the West, Midwest, and Northeast, respectively, compared with the South. Corresponding MRs among women 20-49 years old were 1.01, 1.08, and 1.07 in the West, Midwest, and Northeast, respectively, compared with the South. After adjustment for recognized risk factors and certain prognostic factors, MRs among older women were 1.13 (95% confidence interval [CI] = 1.04-1.23), 1.08 (95% CI = 1.01-1.16), and 1.13 (95% CI = 1.04-1.23) in the West, Midwest, and Northeast, respectively, compared with the South. Corresponding MRs among younger women were 0.94 (95% CI = 0.76-1.16), 1.05 (95% CI = 0.92-1.18), and 0.99 (95% CI = 0.86-1.14), respectively. CONCLUSION: Before adjustment for regional differences in recognized risk factors and prognostic factors, mortality excesses among younger women in the Northeast, Midwest, and West were less than 10% compared with the South. After adjustment, MRs were near unity for all regions. Among older women, the excess mortality was more substantial before adjustment for relevant factors, ranging from 15% in the West to 30% in the Northeast. Approximately 50% of the excesses in the Northeast and Midwest and 10% of the excess in the West could be explained on the basis of regional differences in the prevalence of recognized breast cancer risk factors and prognostic factors. After adjustment for these factors, the magnitude of excess in breast cancer mortality in the Northeast (13%) was comparable to that in the West (13%) but still slightly higher than that in the Midwest (8%).

Adult↗
PubMed1994

High incidence of anal cancer among AIDS patients. The AIDS/Cancer Working Group.

Until now, the only cancers that have been strongly associated with AIDS are Kaposi's sarcoma and non-Hodgkin lymphoma. We used a linkage between AIDS (50,050 reports) and cancer (859,398 reports) registries in seven health departments in the USA to investigate the association between HIV infection and epidermoid anal cancer. We compared the numbers of observed cases and expected cases, calculated from general population rates with adjustment for age, sex, and race. The relative risk of anal cancer at and after AIDS diagnosis was 84.1 (95% CI 46.4-152) among homosexual patients (11 cases) and 37.7 (9.4-151) among non-homosexual patients (2 cases). The relative risk of anal cancer up to 5 years before the AIDS diagnosis (23 cases) was also increased; it was 13.9 (6.6-29.2) in the period 2-5 years before AIDS and 27.4 (15.9-47.2) during the 2 years before AIDS diagnosis (p for trend = 0.004). Among homosexual men, the relative risk of anal cancer was inversely related to age at AIDS onset (p for trend < 0.001). Excess risks were found in all geographical areas. This study establishes a strikingly increased risk of anal cancer among people with AIDS. These data are consistent with a previously hypothesized association between HIV-induced immunodeficiency and anal cancer development, but because homosexual men were at increased risk of anal cancer even before the AIDS epidemic, we cannot say how much of the increased risk is attributable to HIV infection. Nevertheless, clinicians should be aware that AIDS patients have an increased risk of anal cancer.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Nutrition intervention trials in Linxian, China: supplementation with specific vitamin/mineral combinations, cancer incidence, and disease-specific mortality in the general population.

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.

Adult↗
PubMed1993

Ethical dilemmas in continuing a zidovudine trial after early termination of similar trials.

Ethical dilemmas caused by external events and an interim subset analysis raised concerns about continuing a long-term VA clinical trial comparing early with later zidovudine therapy for symptomatic human immunodeficiency virus (HIV) infection. The first external event was the early termination of other, apparently similar, trials conducted by the AIDS Clinical Trials Group (ACTG) and the announced clear benefits for the zidovudine-treated patients. Interim analysis of the VA trial at this time did not show similar benefits. Subset analyses were performed to explore factors that might explain the different results. These suggested a difference in response to zidovudine in white and minority groups. The Data Monitoring Board and a special advisory panel reviewed these data and concluded that, since the VA results were neutral overall and the subset analyses based on small numbers, the trial should continue. By conference call, the study cochairmen and biostatistician discussed this decision with study personnel without revealing interim results, and study personnel passed the information on to patients at the participating centers. The second event was in March 1990, when the Food and Drug Administration (FDA) approved earlier use of zidovudine, which applied to patients still in the VA trial. Patients were asked to reaffirm their participation by signing a new informed consent that explained the findings reported by the ACTG, the FDA-approved revised recommendations, and the rationale for continuation of the VA trial. The consent form emphasized that continued masked therapy was optional and that unmasked treatment and follow-up would be provided to patients requesting it. Seventy-four percent of the participants chose to continue masked therapy. We conclude that when new external data are announced, informed participation in a long-term clinical trial may require a revised consent form and that it is ethical and practical to present this without disclosure of interim study results.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Selecting an efficient design for assessing exposure-disease relationships in an assembled cohort.

We develop approximate methods to compare the efficiencies and to compute the power of alternative potential designs for sampling from a cohort before beginning to collect exposure data. Our methods require only that the cohort be assembled, meaning that the numbers of individuals Nkj at risk at pairs of event times tk and tj greater than or equal to tk are available. To compute Nkj, one needs to know the entry, follow-up, censoring, and event history, but not the exposure, for each individual. Our methods apply to any "unbiased control sampling design," in which cases are compared to a random sample of noncases at risk at the time of an event. We apply our methods to approximate the efficiencies of the nested case-control design, the case-cohort design, and an augmented case-cohort design, compared to the full cohort design, in an assembled cohort of 17,633 members of an insurance cooperative who were followed for mortality from prostatic cancer. The assumptions underlying the approximation are that exposure is unrelated both to the hazard of an event and to the hazard for censoring. The approximations performed well in simulations when both assumptions held and when the exposure was moderately related to censoring.

Biometry↗
PubMed1987

Transmission of HTLV-I and HIV among homosexual men in Trinidad.

Risk for human T-cell lymphotropic virus type (HTLV-I) and human immunodeficiency virus (HIV) infection was evaluated in 100 homosexual or bisexual men from Trinidad. High seropositivity for HTLV-I (15% vs 2.4% in the general population) was linked to duration of homosexuality and numbers of partners, suggesting that HTLV-I, like HIV, can be transmitted by homosexual sex. Forty percent of homosexuals compared with 0.19% of the general population were seropositive for HIV, and sexual contact with US homosexual men and prior history of gonorrhea were major risk factors. The seroprevalence of HIV was three times higher than that for HTLV-I, suggesting that HIV is more efficiently transmitted, especially since HIV appears to have been recently introduced into Trinidad. Altered immune status was prominent in individuals infected with HIV and coinfected with HIV and HTLV-I. Whether HIV/HTLV-I coinfection amplifies clinical effects is a hypothesis that will require further evaluation.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Surgical adjuvant therapy for stage II and stage III adenocarcinoma and large-cell undifferentiated carcinoma.

The Lung Cancer Study Group randomized 141 patients with resected stage II and III adenocarcinoma and large-cell undifferentiated carcinoma to receive postoperative Cytoxan (Bristol-Meyers, Syracuse, NY), Adriamycin (Adria Laboratories, Columbus, Ohio), and cisplatin (CAP) chemotherapy or bacillus Calmette-Guerin (BCG) and levamisole immunotherapy. Careful intraoperative staging was performed on all patients. Before randomization, patients were stratified by stage, weight loss, cardiac arrhythmia, and institution. Prognostic variables such as stage, age, weight loss, and nodal involvement were equally distributed between the two groups. Disease-free survival was significantly prolonged in the group receiving chemotherapy. There was no evidence of a deleterious effect of the immunotherapy. This study indicates that postoperative CAP chemotherapy is effective in prolonging disease-free survival in these patients.

Actuarial Analysis↗
PubMed1985

A randomized comparison of the effects of adjuvant therapy on resected stages II and III non-small cell carcinoma of the lung. The Lung Cancel Study Group.

The Lung Cancer Study Group has evaluated postoperative chemotherapy and immunotherapy in patients with Stages II and III adenocarcinoma and large cell undifferentiated carcinoma. Patients were randomized following surgery and careful intraoperative staging to receive either chemotherapy or immunotherapy. Chemotherapy consisted of CisPlatinum, Adriamycin, and Cytoxan and immunotherapy consisted of Levamisole and Intrapleural BCG. Sixty-eight patients were randomized to the immunotherapy arm and 62 to the chemotherapy arm. There were 49 recurrences in the immunotherapy group and 35 in the chemotherapy group (p = 0.003). These studies indicate that surgical adjuvant chemotherapy is effective in prolonging the disease-free survival in patients with Stages II and III adenocarcinoma and large cell undifferentiated carcinoma. Patients with Stages II and III resected squamous cell carcinoma were randomized to receive postoperative radiation therapy or no further treatment. One hundred and ninety patients were randomized into this study. There was no significant difference in terms of survival between the two treatment groups. However, those who received radiation therapy had a significantly lower incidence of local recurrence (p = 0.001). These studies indicate that postoperative radiation therapy is effective in controlling the local disease but that effective systemic therapy is necessary for improved survival in patients with Stages II and III squamous cell carcinoma of the lung.

Adenocarcinoma↗
PubMed1985

Testing for qualitative interactions between treatment effects and patient subsets.

Evaluation of evidence that treatment efficacy varies substantially among different subsets of patients is an important feature of the analysis of large clinical trials. Qualitative or crossover interactions are said to occur when one treatment is superior for some subsets of patients and the alternative treatment is superior for other subsets. A non-crossover interaction arises when there is variation in the magnitude, but not in the direction, of treatment effects among subsets. Some authors use the term quantitative interaction to mean non-crossover interaction. Non-crossover interactions are usually of less clinical importance than qualitative interactions, which often have major therapeutic significance. A likelihood ratio test is developed to test for qualitative interactions. Exact critical values are determined and tabulated.

Biometry↗
PubMed1983

Quantitative criteria for prediction of the results after displaced fracture of the ankle.

In a series of 146 displaced ankle fractures, the effects of age, sex, side of injury, mechanism of injury, severity as determined by the Lauge-Hansen classification, type of injury (open or closed), open or closed treatment, and internal fixation of one or both malleoli were analyzed using subjective, objective, and radiographic parameters. Statistically significant prognostic features were identified and a prognostic scale was developed using multiple linear-regression analysis. The significant parameters were age, adequacy of the post-reduction positions of the medial and lateral malleoli, and completeness of the restoration of the deltoid ligament and distal tibiofibular syndesmosis. Open reduction proved superior to closed reduction, and in bimalleolar fractures open reduction of both malleoli was better than fixing only the medial side. Using the data on the first 109 fractures, a multiple linear-regression equation was formulated and used to predict the outcomes of the last thirty-seven fractures in the study. The accuracy of the predictions in them was 81 per cent.

Adolescent↗
PubMed1982

A double-blind randomized trial of low-dose oral urea to prevent sickle cell crises.

Seventy-nine homozygous SS patients were randomly assigned to control or oral prophylactic urea treatment in a double-blind trial designed to determine whether prophylactic oral urea, in low doses, prevents sickle cell crises. The average follow-up time for these patients was 13.7 months and 33 patients were diagnosed as having one or more crises during the study. No statistically significant treatment differences were found in weight changes, bilirubin changes, or hemoglobin changes over the course of the study or in the distribution of time to first crises or time to second crisis. This study gives no evidence in favor of the hypothesis that prophylactic oral urea, in low doses, prolongs time to crisis.

Administration, Oral↗
PubMed1980

Cancer-associated serum globulin demonstrated by polyacrylamide gel electrophoresis.

We evaluated the ability of polyacrylamide gel electrophoresis (PAGE) to measure protein band No. 1 (PB1) in serum as a means of discriminating between the sera of cancer patients and controls. Serum samples from 123 cancer patients, 155 subjects without clinically diagnosed cancer, and 6 members of families with a high incidence of cancer (total, 284) were obtained in Israel. An additional 214 serum samples from 80 cancer patients and 134 subjects without cancer were obtained from the Mayo Clinic-National Cancer Institute Serum Bank. Although a significantly higher proportion of serum specimens from cancer patients had positive results for PB1 by the PAGE method, the test at its current stage of development does not seem sufficiently discriminating for use in screening for cancer.

Adolescent↗
PubMed1978

Melanoma skin test antigens of improved sensitivity prepared from vesicular stomatitis virus-infected tumor cells.

Crude membrane (CM) extracts from three different cultured human melanoma lines that were "virus-augmented" (infected with vesicular stomatitis virus (VSV) and subsequently inactivated by ultraviolet light) produced positive skin tests in 17 of 20 (85%), 11 of 20 (55%), and 13 of 18 (72%) tests, respectively, performed in 20 melanoma patients. Identical CM extracts from the same melanoma lines that had not been infected with VSV gave positive skin tests in 2 of 20 (10%), 4 of 20 (20%), and 2 of 18 (11%) tests, respectively, performed in the 20 melanoma patients, and no positive tests in the control patients. The 3 virus-augmented extracts were positive in only 2 of 18 (11%), 0 of 18 (0%), and 1 of 17 (6%) control subjects, respectively. The controls consisted of six normal volunteers and 12 patients with cancers other than melanoma. The "virus-augmented" CM extracts thus exhibited markedly greater sensitivity without significant loss of specificity as compared to nonvirus augmented extracts when used as tumor-specific melaonma skin test antigens.

Adult↗