Biomedical subjects

Siegal Sadetzki

Publications and source records attributed to Siegal Sadetzki.

24 records · Page 2Linked to original sources

PubMed2003

The limitations of using hospital controls in cancer etiology--one more example for Berkson's bias.

The aim of this report was to present an example in which Berkson's bias, most probably, affected the results of a study by overriding the influence of a well-established risk factor (smoking) in the etiology of bladder cancer. The results of a study of 140 male patients with bladder cancer and 280 matched hospital controls confirmed the etiological role of industrial occupation in bladder cancer but failed to confirm the role of smoking. We reanalyzed the proportion of chronic related morbidity as well as the rate of smoking in patients with lung disease in cases and controls. A similar distribution of some chronic diseases known to be highly associated with smoking was found among cases and controls. Highest smoking rates (91%) were found among patients with bladder cancer who also reported a concomitant lung disease, and the lowest rate (67%) was noted among controls without lung disease (p = 0.009). Using the prevalence of smoking in the general Israeli male population (50%), significant odds ratio for bladder cancer among ever smokers compared to never smokers was observed. Our conclusion is that a possibility of Berkson's bias should be considered whenever hospital controls are used. Information on diseases related to the risk factor under consideration and on the prevalence of the risk factor in the general population, may demonstrate the existence of such a bias.

Aged↗

PubMed2002

A possible association between ionizing radiation and pituitary adenoma: a descriptive study.

BACKGROUND: Despite the recognition of ionizing radiation as a causal risk factor for a variety of solid tumors (including brain tumors), to date, such an association with pituitary adenoma (PA) has not been demonstrated. METHODS: To evaluate a possible association between past exposure to radiation and the occurrence of PA, the authors reviewed about 4900 medical records of patients who had been irradiated in childhood for tinea capitis. An additional search for patients was performed using the Israel Cancer Registry. The average radiation dose to the pituitary gland was estimated as 0.56 grays, and, for all patients, a meticulous validation of the irradiation was performed. RESULTS: A group of 16 patients who developed symptomatic PA after childhood exposure to radiotherapy were identified. Overall, the clinical and demographic characteristics of these patients were similar to other series reported in the literature. There was an apparently high rate of second primary tumors (25%), all of them in the irradiated area, diagnosed among this group. The methodologic issues that limit the demonstration of a possible association between radiation and PA and the epidemiologic and experimental findings in the literature are discussed. CONCLUSIONS: In view of the ample amount of evidence identifying low-dose ionizing radiation as a risk factor for a number of intracranial tumors as well as for tumors arising in endocrine organs, a radiation immunity of the pituitary gland is difficult to accept. Hence, the authors suggest that this series should be considered as preliminary observation that supports the role of ionizing radiation in the development of this tumor.

Adenoma↗

PubMed2002

Radiation-induced meningioma: a descriptive study of 253 cases.

OBJECT: Ionizing radiation is the only established risk factor recognized today in the causation of meningioma. The aim of the present report is to describe the demographic and clinical characteristics of a large series of 253 patients with radiation-induced meningiomas (RIMs). These parameters were compared with those of 41 patients with meningiomas in whom there was no previous history of irradiation (non-RIM group) and with other series of patients presented in the literature. METHODS: The cases of RIM were recruited from a cohort of approximately 11,000 individuals who had been treated with ionizing radiation during childhood for tinea capitis and from a group of individuals who, as adults, applied for compensation because of that treatment. The non-RIM group was identified through the Israeli Cancer Registry. Exposure to radiation was carefully validated among all cases of RIM and absence of previous irradiation was verified for all patients in the non-RIM group. Significantly, a lower patient age at diagnosis, higher prevalence of calvarial tumors, higher proportion of multiple meningiomas, and a nonsignificant higher recurrence rate were observed among patients with RIM compared with the non-RIM group. The mean latency period from date of radiation exposure to development of a meningioma among the RIM group was approximately 36 years. CONCLUSIONS: The findings of this study agree with those of other studies indicating the demographic, clinical, and even genetic variability between RIM and non-RIM cases. The existence of two different subtypes of meningiomas may have profound implications for screening, early diagnosis, and therapy of meningiomas.

Adult↗

PubMedDate not supplied

Breast cancer and scleroderma.

INTRODUCTION: Epidemiologic studies have shown that patients with scleroderma have an increased risk of cancer. METHODS: The authors report eight cases and retrospectively review the published data on the possible association between breast cancer and scleroderma of the cutaneous and systemic forms. The records of all patients with scleroderma and breast cancer who were hospitalized during 1980-2002 in the Chaim Sheba Medical Center were surveyed. A literature search for breast cancer and scleroderma was performed. RESULTS: The clinical data of 65 women patients with breast cancer and scleroderma, eight of whom were hospitalized in the Chaim Sheba Medical Center and 57 who were reported in the literature, are summarized. In 29 patients (44%), scleroderma appeared before or simultaneously with the diagnosis of breast cancer. While a higher frequency of systemic scleroderma was described in this group, a higher rate of cutaneous scleroderma appeared in the group where scleroderma followed breast cancer diagnosis (p<0.001). CONCLUSIONS: Large-scale case-control studies are needed to substantiate the possible association between scleroderma-both cutaneous and systemic-and breast cancer.

Adult↗

PubMedDate not supplied

High rates of substance abuse among long-term travelers to the tropics: an interventional study.

BACKGROUND: Drug abuse constitutes a worldwide problem. The purpose of this study was to investigate the characteristics of illicit drug use during long-term travel to the tropics, and to estimate the effects of antidrug brochures provided before travel on the use of drugs during travel. METHODS: An interventional study was done on 1,000 travelers to the tropics aged 18 to 30 years. Pretravel brochures explaining the hazards of drug abuse were provided to 500 of them. A control group of 500 travelers did not receive the brochures. Questionnaires exploring drug abuse habits were sent to all travelers after their return. RESULTS: Among 223 travelers (108 and 115 of the intervention and control groups, respectively) who returned their questionnaires, 82 (36.8%, 95% CI 30.5-43.5%) had experienced illicit drug use during their trip, whereas only 52 of them had tried drugs before (p<0.01). More travelers had used drugs in the Far East (43.3%) than in South America (25.6%, p< 0.01). The strongest predictors of drug abuse were: the compound of female gender and travel to Asia (odds ratio (OR), 4.3), education <or=12 school years (OR 3.5), age <or=25 years (OR 2.7), and no malaria prophylaxis (OR 2.6). The brochures failed to decrease the rate of drug abuse (38.9% vs. 34.8% in the control group, p=NS). CONCLUSIONS: More than one-third of young Israelis who travel to the tropics use illicit drugs. For many, the trip was their first encounter. Brochures as a sole agent are inadequate, and further means are needed to reduce this alarming trend.

Adolescent↗

PubMedDate not supplied

Nonpenetrating deep sclerectomy with the use of adjunctive mitomycin C.

BACKGROUND AND OBJECTIVE: To determine whether adjunctive use of mitomycin C (MMC) would increase the success rate of primary nonpenetrating deep sclerectomy with collagen implant. PATIENTS AND METHODS: Twenty-six patients (26 eyes) with primary open-angle glaucoma uncontrolled with maximally tolerated medical therapy were randomly assigned to undergo nonpenetrating deep sclerectomy and collagen implant, either with (13 eyes) or without (13 eyes) 0.3 mg/mL of adjunctive MMC for 3 minutes. Intraocular pressure (IOP), number of glaucoma medications, and visual acuity were assessed before and 12 and 24 months after surgery. RESULTS: The mean age of the study patients was similar in both groups (MMC = 68.1 +/- 8 years, control = 65.8 +/- 6.8 years). At the 12- and 24-month follow-up visits, the mean IOP with or without medications was lower in the MMC group than in the control group (15.6 +/- 3.5 vs 17.2 +/- 3.9 mm Hg at 12 months and 15.8 +/- 5.6 vs 17.8 +/- 2.8 mm Hg at 24 months, respectively). The IOP with or without medications significantly decreased after surgery in both groups (P < .05). Twelve months after surgery, the IOP decreased by 48% in the MMC group and by 35% in the control group. At the end of follow-up (24 months), the IOP decreased by 48% in the MMC group and by 32% in the control group (P = .01). The mean number of glaucoma medications decreased after surgery, there was no significant difference in complications (hyphema and suprachoroidal hemorrhage), and visual acuity was unchanged throughout the study in both groups. CONCLUSION: The use of MMC in nonpenetrating deep sclerectomy with collagen implant is safe and improves surgical results.

Aged↗