Chance Of Cancer Research Articles

Meta-analysis of prostate-specific antigen and digital rectal examination as screening tests for prostate carcinoma.

Physicians commonly screen for prostate cancer by using prostate-specific antigen (PSA) and digital rectal examination (DRE). The usefulness of these screening mechanisms is not well established, however. A meta-analysis of PSA and DRE to detect prostate carcinoma was conducted with a focus on sensitivity, specificity, and positive predictive value. A literature search of OVID database (1966 to November 1999) using the medical subject headings "prostate-specific antigen" and "mass screening," as well as "prostate carcinoma," was performed. Thirteen articles were selected for the meta-analysis in this study. Most studies included asymptomatic men older than 50 years from various countries. Pooled results were calculated from the individual reports for sensitivity, specificity, and positive predictive value for PSA and DRE based on biopsy result as the reference standard. The overall detection rate of prostate carcinoma was 1.8% based on a positive biopsy. Of the prostate carcinoma detected, 83.4% was localized. The pooled sensitivity, specificity, and positive predictive value for PSA were 72.1%, 93.2% and 25.1%, respectively; and for DRE were 53.2%, 83.6% and 17.8%, respectively. There were two major outcomes of this meta-analysis. One was the potential for detecting early-stage prostate cancer with these screening tests, because 83.4% of total cancers detected were localized. The second important outcome was that the overall sensitivity, specificity, and positive predictive value for PSA were higher than those for DRE when used as a screening tool to detect prostate cancer. When a patient has abnormal findings using PSA and DRE, the chance of cancer is 1 in 4 or 5. Conversely, when findings from PSA and DRE are normal, the chance of missing a cancer is about 10%.

PSA Levels and the Probability of Prostate Cancer on Biopsy

Objectives: Approaches to screening for prostate cancer have continued to be refined since the introduction of prostate-specific antigen (PSA). Since the introduction of PSA, increasing numbers of patients are presenting solely with an elevated PSA, and palpably normal prostate gland. As newer understanding emerges regarding the meaning of an isolated PSA elevation, urologists are becoming more enabled to counsel their patients and project a more accurate prediction of the likelihood of cancer on biopsy. The following will be a review of PSA in determining the presence of cancer on biopsy. Methods: PubMed and Medline literature searches as well as bibliographic reviews of published peer reviewed journals were performed to select articles regarding PSA and screening for prostate cancer. Relevant articles were reviewed and the data summarized as they pertain to interpreting PSA levels and predicting the presence of prostate cancer. Results: Widespread use of PSA for early detection has resulted in clinical stage T1c becoming the most prevalent presenting stage. For values of PSA between 4.0 and 10.0 ng/ml, there exist a 22–27% likelihood of cancer, while those above 10 ng/ml yield up to a 67% chance of cancer. It must be stressed that DRE must be combined with interpretation of PSA as up to 25% of men with prostate cancer have PSA levels within the normal range 0–4 ng/ml. Conclusions: Evaluation of PSA in the context of prostate volume (PSAD), velocity (PSAV), and age-specific reference ranges, percent-free PSA, and predictive nomograms combining values have allowed for more accurate prediction of the likelihood of prostate cancer prior to biopsy.

Recent advances in clinical/molecular andrology.

During the last decade there were extensive investigations in clinical and molecular andrology with emphasis on assisted reproduction, micromanipulation techniques of gametes, sperm/egg interaction, male contraception, diabetes mellitus, varicocele, andropause versus menopause, sexual dysfunction, associated hypertension/stress, prostatic carcinoma and molecular parameters of male reproduction. Sperm hyperactivation is a required step in capacitation sequence. Sperm motility is measured by videotape to evaluate the Straight Line Velocity (microm/s) (VSLI). Fertilization/embryonic development results from single sperm transfer (S-MIST) and multiple sperm transfer. Fertilization/embryo development is achieved by injection of immotile sperm into the perivitelline space. To assess sperm viability, a supravital stain suitable for use in combination with immunofluorescent assay, Hoeschst 33258, is used. The dye fluoresces with an intense blue when bound to DNA. To assess sperm plasma membrane integrity, a hypo-osmotic swelling test (HOST) is performed, using fluoresceinated D-mannose enriched albumin (FITC-DMA). The ability of sperm to swell under hypo-osmotic conditions indicates an intact membrane. A human protein, C-peptide, thought to be a useless byproduct of insulin may protect against devastating heart and nerve damage that diabetes causes. Human diabetics may benefit from the substance. Over 15 million Americans have diabetes, in which blood sugar levels rise out of control. There are two types of diabetics: Type I diabetics produce no insulin, the hormone that regulates blood sugar. Type II diabetics are unable to use their insulin properly. Diabetics are at great risk of heart disease and nerve damage, as arteries throughout the body leak and nerve-cell impulses fail. C-peptide is a byproduct of insulin production; it can be produced by the body or synthetically. Production of this protein is not induced by insulin, so diabetics who take insulin do not get C-peptide with it. Varicocele occurs unilaterally on the left side in 78% to 93% of men. Typically the presence of a varicocele is associated with an abnormal semen analysis (sperm density and morphology) and a decreased testicular volume on the affected side. Impaired sperm motility occurs in 89.5% of all varicocele patients. Varicocele ligation improves semen parameters in two thirds of patients. A few studies on andropause included sexual dysfunction, hormonal changes, medical/psychological correlates of impotence, ostenopenia/osteoporosis and bone loss; indices of bone remodeling, testosterone supplementation, androgen, negative feedback and hypothalamo-pituitary-testicular axis. Prostatic cancer is the second leading cause of cancer death for men between the ages of 60 and 80. Early detection involves a simple blood test for prostate specific antigen (PSA). Regular screening and early detection are essential. This is an important test because a high antigen count can be the only symptom. Since no screening is 100% accurate, physicians recommend both a PSA blood test and a physical examination. Although heredity plays a major role in whether a man will develop prostate cancer, men who lead healthy lives can dramatically reduce their chances of cancer: low-fat diet, eating plenty of fruits and vegetables and not smoking. Recent advances in molecular andrology include peptide hormone binding proteins; gonadotropin-releasing hormone (GnRH) agonists/antagonists analog; gonadotropins/their receptors; growth factors/reproduction; peptides as intratesticular regulators; molecular cloning of reproductive proteins/peptides. Gene cloning is applied for characterization/expression of genes coding. The interaction of gp120 with CD4 receptor plays a role in syncytium formation, apoptosis and CD4 cell deletion in human immunodeficiency virus (HIV) infection. The recombinant V3 peptide of fragment 307-330 of HIV-1 can induce sperm head agglutination. The generation process of react

Biopsy of Occult Breast Lesions and Professional Liability

To the Editor.— The idea of using more stringent mammographic criteria and second opinions before obtaining biopsy specimens from all occult breast lesions is a good one. Unfortunately, it may not be entirely practical in today's medicolegal environment. By using more stringent and specific mammographic criteria, Meyer et al 1 were able to identify many innocuousappearing lesions that had a very low incidence of malignancy. They quote a 1 of 100 or less chance of cancer and state that this alone is not adequate justification for a biopsy. Unfortunately, a 1 to 100 chance of cancer must be an indication for biopsy. Consider that making a wrong diagnosis, missing an occult malignancy, and deciding not to obtain a biopsy specimen could easily result in a million-dollar judgment against the physician who made that call. One would be very unlikely to ignore a 100 to 1 shot when a million

Beliefs related to cigarette smoking among Irish college students.

Beliefs related to cigarette smoking were investigated in a college student sample. Regular smokers, compared with nonsmokers and occasional smokers, perceived more approval for their smoking and believed that their peers smoked more frequently. They perceived positive social and physiological consequences of smoking (e.g., feel more relaxed) to be more likely, and negative consequences (e.g., feel sick) to be less likely. While they did not see long-term health consequences (e.g., increasing chances of cancer) as less likely, they evaluated them less negatively. Finally, smokers placed less importance on the value health than did nonsmokers or occasional smokers. These findings suggest that intervention programs aimed at discouraging smoking by young people should be multifaceted.

Technology Lecture

The Central Electricity Generating Board propose to build a pressurized water reactor at Sizewell in Suffolk. The PWR Task Force was set up in June 1981 to provide a communications centre for developing firm design proposals for this reactor. These were to follow the Standardized Nuclear Unit Power Plant System designed by Bechtel for the Westinghouse nuclear steam supply system for reactors built in the United States. Changes were required to the design to accommodate, for example, the use of two turbine generators and to satisfy British safety requirements. Differences exist between the British and American licensing procedures. In the U.K. the statutory responsibility for the safety of a nuclear power station rests unambiguously with the Generating Boards. In the U.S.A. the Nuclear Regulatory Commission issues detailed written instructions, which must be followed precisely. Much of the debate on the safety of nuclear powrer focuses on the risks of big nuclear accidents. It is necessary to explain to the public what, in a balanced perspective, the risks of accidents actually are. The vocabulary used in the nuclear power industry contributes to the misunderstanding and fear felt by the general public. The long-term consequences of big nuclear accidents can be presented in terms of reduction in life expectancy, increased chance of cancer or the equivalent pattern of compulsory cigarette smoking.

THE CHANCE OF CANCER AND LYMPHATIC METASTASIS IN SMALL COLON TUMORS DISCOVERED ON X-RAY EXAMINATION.

From the Department of Surgery, Presbyterian Hospital, and the Laboratory of Surgical Pathology, College of Physicians and Surgeons, Columbia University, New York, New York