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M R Spitz

Publications and source records attributed to M R Spitz.

At least 127 records · Page 7Linked to original sources
PubMed1994

A race-specific genetic polymorphism in the CYP1A1 gene is not associated with lung cancer in African Americans.

In a case-control study, we tested the hypothesis that a previously described African American-specific polymorphism in an intron 3' to the coding region of the CYP1A1 gene was associated with the occurrence of lung cancer. The study population included 72 African Americans with newly diagnosed, untreated lung cancer who presented to collaborating clinicians at the University of Texas M.D. Anderson Cancer Center and from county, community and Veterans Administration hospitals in the Houston metropolitan area. Controls were 97 African Americans, frequency-matched on gender and age, recruited from community centers, churches, cancer screening programs and from among hospital employees. The prevalence of the variant CYP1A1 genotype did not differ between the cases and controls. The odds ratio for individuals with one or more copies of the variant allele was 0.64 [95% confidence interval (CI) 0.3-1.4]. Overall, 20.7% of the population had one or more variant alleles; the prevalence in cases was 16.7% and in controls it was 23.7%. Two individuals with the homozygous variant genotype were controls while one individual with lung cancer was found to have the homozygous variant genotype. The lack of an association between genotype and lung cancer persisted after subgroup analysis for lifetime cigarette smoking history and tumor histology was performed. The sample size of this study is sufficient to detect odds ratios of three or greater; associations of this magnitude are similar to those reported in studies of a different polymorphism in the same region of the CYP1A1 gene in Japanese. Thus, it is unlikely that this polymorphism is associated with sizable risks for tobacco-induced lung cancer in this population subgroup.

Adult↗
PubMed1994

Mutagen sensitivity as a marker of cancer risk.

There are measurable differences, genetically determined, in susceptibility to carcinogenic activity. Variation in metabolism of xenobiotic chemicals is one determinant of susceptibility and is attributed to polymorphisms in a number of enzymes. There may also be a wide spectrum of DNA-repair capability within the population. A peripheral lymphocyte assay has been developed in which in vitro bleomycin-induced chromosome breaks provides an indirect measurement of such repair. Mutagen sensitivity as defined by this assay has been shown to be an independent risk factor for tobacco-related malignancies, especially those of the upper aerodigestive tract. Preliminary data also suggest familial aggregation of cancer in mutagen-sensitive patients. Risk assessment is now recognized as a multidisciplinary process, extending beyond the scope of traditional epidemiologic methodology to include biological evaluation of interindividual differences in carcinogenic susceptibility. These susceptibility markers will enable us to identify high-risk population subgroups that can be targeted for intensive primary and secondary preventive strategies.

Anticarcinogenic Agents↗
PubMed1994

Excess leukemia and multiple myeloma in a mining county in northeast Texas.

From 1950 to 1979, cancer mortality rates in Titus County, Texas, increased with a significant excess of deaths from leukemia, lymphoma, brain and liver cancers, and melanoma. County residents requested this study to verify the apparent excess of cancer. Newly diagnosed cases of cancer among white residents from 1977 to 1984 were ascertained from the Texas Cancer Registry, hospital records, and death certificates. Direct and indirect methods were used to calculate incidence rates and standardized incidence ratios (SIR). We identified 663 cancers for 148,470 person-years of observation. No overall excess of cancer was found. However, we found a significant excess of leukemia (SIR = 2.53, 95% confidence interval [CI] = 1.86, 3.30) and multiple myeloma (SIR = 1.87, 95% CI = 1.02, 3.14). The reasons for the increased SIRs are unknown. However, the excess of cancers in this mining community may be relevant to the ongoing debate on the health effects of the disposal of combustion wastes from mining and fossil fuel and on the need for stricter regulations. Other potential risk factors include the presence of petrochemical and poultry industries. regulations. Other potential risk factors include the presence of petrochemical and poultry industries.

Cause of Death↗
PubMed1993

Genetic susceptibility to cancer.

For any given level of exposure to a carcinogen, only a proportion of exposed individuals will develop cancer. Interindividual differences in susceptibility at some stage of the carcinogenic process must be postulated. One contributing factor is variation in the activity of metabolizing enzymes responsible for conversion of procarcinogens to proximate carcinogens. There is also a wide spectrum of DNA repair capability within the general population. At one end are the genetic instability syndromes characterized by extreme sensitivity to carcinogenic exposures and high rates of cancer in homozygotes of these traits. Less extreme differences in mutagen sensitivity can be demonstrated by a quantitative assay of chromosome breaks induced by in vitro mutagen exposure. Two case-control studies of patients with previously untreated upper aerodigestive tract cancers have demonstrated mutagen sensitivity to be an independent risk factor for the disease after controlling for the effects of tobacco and alcohol. Mutagen sensitivity also may have prognostic relevance. There was a fourfold elevated risk of developing multiple primary cancers in mutagen-sensitive patients. There are also data suggestive of familial aggregation of cancer in first-degree relatives of mutagen-sensitive patients (twofold risk for having one first-degree relative with cancer and sixfold risk for having two or more relatives with cancer). The preventive implications of identifying markers of carcinogen sensitivity are manifold.

Biomarkers, Tumor↗
PubMed1993

Cancer risk and early detection assessment.

Nurses and physicians form an ideal corps for implementing cancer prevention and early detection efforts: providing health education, promoting health enrichment, defining high-risk groups and identifying patients who belong to them, and providing screening to ensure early diagnosis and prompt treatment. A personal medical history, a history of exposures in life-style, and a family history form the foundation for cancer risk assessment. The physical examination that follows takes into account the incidence and indications of cancer at various sites and the patient's risk profile. Health professionals can incorporate screening techniques into everyday practice by gathering information in the medical history, incorporating cancer detection in the physical examination, following up with more frequent screenings or referrals for those needing them, and becoming cancer detection advocates among patients and professional peers.

Breast Neoplasms↗
PubMed1993

Analysis of human papillomavirus DNA in oral squamous cell carcinomas.

Evidence from several laboratories suggests that HPV plays a role in the etiology of squamous cell carcinomas of the oral cavity. A multifactorial risk factor profile for the development of oral cancer may include HPV in addition to well-established risk factors such as tobacco and alcohol use. The prevalence of oral carcinomas reported to be associated with HPV has varied widely due to differences in the sensitivity of the assay used for HPV detection. The aims of this study were: (1) to ascertain the prevalence of HPV DNA in oral squamous cell carcinomas using the most sensitive technique available, the polymerase chain reaction; (2) to determine the type of HPV in the tumors; and 3) to correlate the virologic data with other risk factor data obtained from patients' records. Fourteen (78%) of 18 primary tumors, 6 (67%) of 9 normal epithelial tissues from the patients and 5 (100%) of 5 neck metastases were HPV DNA-positive. Of the 14 HPV DNA-positive primary tumors, specific typing revealed HPV 16 in 2, HPV 18 in 2, HPV 16 and 18 in 5, HPV 6/11, 16 and 18 in 4, and HPV 6/11 in 1. HPV types in the normal or metastatic tissue were usually the same as those in the respective primary tumor. There was no significant association between HPV presence and any of 12 factors or patient characteristics studied.

Adult↗
PubMed1993

In vitro protective effects of chemopreventive agents against bleomycin-induced genotoxicity in lymphoblastoid cell lines and peripheral blood lymphocytes of head and neck cancer patients.

The protective effects of ascorbic acid (AA), n-acetyl-l-cysteine (NAC), alpha-tocopherol acid (ATA), alpha-tocopherol-acid succinate (TAS), and 13-cis-retinoic acid (CRA) on mutagen-induced chromosomal breakage were studied. Mutagen-sensitivity was determined by the bleomycin assay in human lymphoblastoid cell lines (LCLs) and cultures of peripheral blood lymphocytes (PBLs) from head and neck cancer patients. Preincubation with chemopreventive agents statistically significantly decreased mutagen-induced chromatid breakage in LCLs and PBLs in a dose-related manner. As the concentration of the agents was increased in tenfold increments in the study range, mean breakage rates were reduced by 3.0 to 7.7% in LCLs and by 6.0 to 11.1% in PBLs. The effective concentrations are comparable to those achieved in clinical applications and found in human dietary studies. A similar phenomenon in vivo, if identified, may explain the differences in occurrence of head and neck and other cancers between populations with different dietary habits. The bleomycin assay may be used for studying compounds with presumed chemopreventive properties.

Acetylcysteine↗
PubMed1992

Low incidence of familial breast cancer among Hispanic women.

There is a paucity of data on familial patterns of breast cancer among minority populations. This study compared the frequency of cancer in 1,095 first-degree relatives of 50 White, 46 Black, and 49 Hispanic breast-cancer patients referred to The University of Texas M.D. Anderson Cancer Center (United States). Family histories of cancer were derived from a self-administered questionnaire on risk factors. Expected numbers of cancers were calculated from the Connecticut Tumor Registry for White and Black relatives and from the New Mexico Tumor Registry for Hispanic relatives. Family history of a first-degree relative with breast cancer was the most important risk factor for both Black and White patients. Significantly elevated standardized incidence ratios (SIR) for breast cancer were noted among White (SIR = 4.5, 95 percent confidence interval [CI] = 1.2-11.4) and Black (SIR = 4.1, CI = 1.1-10.4) relatives younger than age 45. Despite the small number of Black patients, the combined effect of family history of breast cancer and the relative's age at diagnosis (under 45 years) was associated with an SIR of 7.1 (CI = 1.9-18.1). A deficit of cancer was noted in Hispanic women; only one patient reported having a first-degree relative with breast cancer. These findings, although based on small numbers, suggest that Hispanics have a lower rate of familial breast cancer than Whites and Blacks, and that they may possess protective factors that reduce their risk for breast cancer.

Adult↗
PubMed1992

Cancer prevention practices among Texas primary care physicians.

Primary care physicians are uniquely positioned to practice primary and secondary cancer prevention. However, despite a positive commitment, many physicians are pessimistic about the success of their interventions. This study describes the self-reported cancer prevention practices and perceived obstacles of 1600 Texas primary care physicians. These practices differed by primary care specialty and by length of time in practice. Time constraints were uniformly perceived as the leading obstacle to the provision of smoking cessation counseling. High cost, lack of third-party reimbursement, and poor patient compliance were cited as the leading barriers to patient referral for screening mammography. Professional education should stress to physicians that interventions need not be elaborate, expensive, or time consuming, the main purpose being to motivate and reinforce patient behavior. The special challenges of introducing health promotion activities into the clinical setting must be addressed with practical aids such as prompting systems, flowsheets, and computer-based aids for monitoring compliance rates.

Female↗
PubMed1991

Familial patterns of prostate cancer: a case-control analysis.

Epidemiological data have not yet enabled physicians to look beyond age and race to identify men at increased risk for prostate cancer. We conducted a hospital-based case-control study of familial patterns of prostate cancer with self-reported data from a risk-factor questionnaire. There were 385 patients with histologically confirmed prostate cancer, and 385 race and age-matched (+/- 5 years) controls with other cancers. Family history, available for 378 patients and 383 controls, was positive for prostate cancer in 13.0% versus 5.7%, respectively. The difference was significant at p = 0.01. The over-all age-adjusted risk estimate for men with a first-degree relative with prostate cancer was significantly elevated (odds ratio of 2.41), as were the individual risk estimates for having a father or brother with prostate cancer (odds ratio of 2.24 and 2.66). Having a second-degree relative (grandfather or uncle) with prostate cancer also conferred elevated but not statistically significant risk. These data accord well with the few previously published case-control studies of familiarity of prostate cancer. On the basis of these findings, one should consider recommending participation in early detection programs for prostate cancer in a man whose father or brother has had the disease.

Age Factors↗
PubMed1991

Risk profiles of women with cervical neoplasia.

Risk-factor profiles were compared in M.D. Anderson Cancer Center patients with various uterine cervix histologic diagnoses. Intraepithelial neoplasia (n = 171) and condyloma (n = 82) were associated with significantly lower patient age (mean 23.6 and 25.8 years, respectively). In addition, these two groups were lowest in annual income, age at beginning intercourse and at first pregnancy, and highest in percentages of black and Hispanic patients, number of sexual partners, and history of gonorrhea. Women with squamous carcinoma in situ (n = 47), who were about a decade older, exhibited a similar socioeconomic distribution and sexual history. All three groups also reported high prevalences of current smokers, were most likely to use oral contraceptives, and were least likely to use diaphragms or condoms. Patients with invasive squamous cell carcinoma (n = 77) had a mean age of 46.3 years, a large lowest-income constituency, and the highest mean number of pregnancies; they were least likely to have used oral contraceptives. Adenocarcinoma (n = 21) was epidemiologically distinct: a predominance of white woman characterized by high socioeconomic status, elevated body mass index, and non of the liberal sexual practices of the other groups. Primary and secondary prevention strategies must be tailored to the unique needs and socioeconomic status of the young at-risk populations.

Adult↗
PubMed1990

Mutagen sensitivity in patients with head and neck cancers: a biologic marker for risk of multiple primary malignancies.

Eighty-four patients with head and neck cancers were evaluated for in vitro sensitivity to mutagens and then followed longitudinally for development of multiple primary malignancies. We assessed mutagen sensitivity by exposing lymphocytes to bleomycin in vitro and quantitating the bleomycin-induced chromosomal breaks per cell. The mutagen-hypersensitive patients, ie, those who expressed greater than 1.0 break per cell, were significantly more likely to develop multiple primary cancers than were patients who were less sensitive (less than or equal to 1.0 break per cell) (relative risk = 4.4; 95% confidence limits = 1.2, 15.8). This relationship was independent of age, sex, site, and treatment of first primary cancer and tobacco or alcohol exposures. Sensitivity to bleomycin-induced chromosomal damage serves as an indicator of genetic susceptibility to multiple primary malignancies in patients with head and neck cancers.

Adult↗
PubMed1990

Salivary gland cancer. A case-control investigation of risk factors.

Unlike most upper aerodigestive tract cancers, salivary gland cancers are relatively infrequent, are characterized by a diversity of histologic subtypes, and have never been etiologically associated with tobacco exposure. We present the results of a case-control study of risk factors for these cancers, with risk estimates derived from self-administered comprehensive risk-factor questionnaires distributed to patients at The University of Texas M. D. Anderson Cancer Center, Houston. Cases were 64 patients with histologically confirmed salivary gland cancer. Control subjects, randomly selected from the same patient population excluding patients with cancer of the head and neck or nonmelanoma skin cancer, were frequency-matched to the cases by age, sex, and ethnicity to achieve a 2:1 control subjects/cases ratio. On multivariate analysis, prior radiotherapy was a significant risk factor for both men (odds ratio [OR] = 2.1) and women (OR = 2.3). Among women, higher educational attainment (OR = 2.4), alcohol use (OR = 2.0), and hairdye use (OR = 2.5) were also significantly associated with risk. There were no significant differences between cases and control subjects with respect to tobacco exposure or specific occupational or leisure-time exposures. There is biological plausibility for associations with hairdye use and alcohol exposure.

Alcohol Drinking↗
PubMed1990

Cigarette smoking patterns in patients after treatment of upper aerodigestive tract cancers.

There is a paucity of data on variables predictive of successful smoking cessation in cancer patients. In this questionnaire-based study, we report the smoking status of 75 patients (46 men, 29 women) with head and neck cancer followed for a minimum of 30 months after definitive therapy. Seventy-one percent of the men and 61% of the women who were current smokers at diagnosis stopped smoking subsequent to diagnosis and treatment. Only 29% and 39%, respectively, continued to smoke, most at decreased intensity. Patients with laryngeal cancer were most likely to have stopped (83%). Conversely, patients with oral cavity cancer were most likely to be continuing smokers (66%). In addition, older age, college education, and lighter smoking habits were somewhat predictive of successful cessation. Fear of recurrent disease and physician advice were the questionnaire-listed incentives most often chosen as contributing to success in cessation. The role health professionals can play in counseling cancer patients to stop smoking is stressed.

Age Factors↗