Cancer incidence among members of the Norwegian trade union of insulation workers

Insulation work has been described as an occupation with high exposure to asbestos. A cohort of members of the Norwegian Trade Union of Insulation Workers (n = 1116), hired between 1930 and 1975, was established. During 2002, the cohort was linked to the Cancer Registry of Norway. The standardized incidence ratio (SIR) of pleural mesothelioma was 12.9 (95% confidence interval [CI] = 6.0-24.6). Two cases with peritoneal mesotheliomas were found (SIR, 14.8; 95% CI = 1.8-53.4). The SIR of lung cancer was 3.0 (95% CI = 2.3-3.8). Four cases of lung cancer were observed among cork workers without any exposure to asbestos, but to cork dust and tar smoke (SIR, 5.3; 95% CI = 1.5-13.6). Our study showed a high risk of mesothelioma and an elevated risk of lung cancer among members of the Trade Union of Insulation Workers.     

Severity of infection and seasonal variation of non-typhoid Salmonella occurrence in humans

Non-typhoid Salmonella infections may present as severe gastroenteritis necessitating hospitalization and some patients become septic with bacteraemia. We hypothesized that the seasonal variation of non-typhoid Salmonella occurrence in humans diminishes with increased severity of infection. We examined the seasonal variation of non-typhoid Salmonella infections in three patient groups with differing severity of infection: outpatients treated for gastroenteritis (n=1490); in-patients treated for gastroenteritis (n=492); and in-patients treated for bacteraemia (n=113). The study was population-based and included all non-typhoid Salmonella patients in a Danish county from 1994 to 2003. A periodic regression model was used to compute the peak-to-trough ratio for the three patient groups. The peak-to-trough ratios were 4.3 [95% confidence interval (CI) 3.6-5.0] for outpatients with gastroenteritis, 3.2 (95% CI 2.4-4.2) for in-patients with gastroenteritis, and 1.6 (95% CI 1.0-2.8) for in-patients with bacteraemia. We conclude that the role of seasonal variation diminishes with increased severity of non-typhoid Salmonella infection.     

Multidrug-resistant Acinetobacter infection mortality rate and length of hospitalization

Acinetobacter infections have increased and gained attention because of the organism's prolonged environmental survival and propensity to develop antimicrobial drug resistance. The effect of multidrug-resistant (MDR) Acinetobacter infection on clinical outcomes has not been reported. A retrospective, matched cohort investigation was performed at 2 Baltimore hospitals to examine outcomes of patients with MDR Acinetobacter infection compared with patients with susceptible Acinetobacter infections and patients without Acinetobacter infections. Multivariable analysis controlling for severity of illness and underlying disease identified an independent association between patients with MDR Acinetobacter infection (n = 96) and increased hospital and intensive care unit length of stay compared with 91 patients with susceptible Acinetobacter infection (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.2-5.2 and OR 2.1, 95% CI 1.0-4.3] respectively) and 89 uninfected patients (OR 2.5, 95% CI 1.2-5.4 and OR 4.2, 95% CI 1.5-11.6] respectively). Increased hospitalization associated with MDR Acinetobacter infection emphasizes the need for infection control strategies to prevent cross-transmission in healthcare settings.     

Cohort study of cancer risk among male and female shift workers

OBJECTIVES: Melatonin, a hormone that inhibits experimentally induced cancers, is suppressed by nighttime exposure to light so that nighttime shift workers may be at an increased risk of cancer. Previous studies of shift workers found an increased risk of breast cancer among women and suggested a possible increased risk of colon cancer among women and prostate cancer. The present study was conducted to see whether these previous findings could be confirmed and whether shift workers are at elevated risk for cancer at additional sites. METHODS: Altogether 2 102 126 male and 1 148 661 female workers were identified who worked in both 1960 and 1970. Their jobs were classified according to the percentage of shift workers, and they were followed from 1971 through 1989 or until they were diagnosed with cancer or died. Standardized incidence ratios (SIR) were used to compare the adjusted cancer incidence rates for shift workers with those for nonshift workers. RESULTS: Cancer rates were not elevated for the male shift workers [all sites combined: N=6524 cases among shift workers, SIR 1.02, 95% confidence interval (95% CI) 1.00-1.05; prostate: N=1319, SIR 1.04, 95% CI 0.99-1.10] or for the female shift workers (all sites combined: N=268, SIR 1.00, 95% CI 0.89-1.13; breast: N=70 cases, SIR 0.94, 95% CI 0.74-1.18). CONCLUSIONS: No evidence was found for an association between shift work and breast or prostate cancer, or all cancer sites combined among shift workers.     

Adult nutrient intake as a risk factor for Parkinson's disease

BACKGROUND: This population-based case-control study evaluated nutrient intake as a risk factor for Parkinson's disease (PD) among people aged > or =50 years in metropolitan Detroit. METHODS: Cases (n = 126) were diagnosed between 1991 and 1995 and neurologist-confirmed. Controls (n = 432) were frequency-matched for sex, age (+/-5 years) and race. Using a standardized food frequency questionnaire, subjects reported the foods they ate within the past year. RESULTS: Estimating the association between PD and risk of being in the highest versus the lowest intake quartile, there were elevated odds ratios for total fat (OR 1.94, 95% confidence interval [CI] : 1.05-3.58), cholesterol (OR 2.11, 95% CI: 1.14-3.90), lutein (OR 2.52, 95% CI: 1.32-4.84) and iron (OR 1.88, 95% CI: 1.05-3.38). CONCLUSIONS: These results suggest an association of PD with high intake of total fat, saturated fats, cholesterol, lutein and iron.     

Risk factors for intestinal invasive amebiasis in Japan, 2003-2009

We determined yearly change in prevalence and risk factors for amebic colitis caused by intestinal invasive amebiasis among persons who underwent endoscopy and assessed differences between HIV-positive and HIV-negative persons in Japan. A total of 10,930 patients were selected for analysis, of whom 54 had amebic colitis. Prevalence was in 2009 (0.88%, 12/1360) compared with 2003 (0.16%, 3/1904). Male sex (odds ratio [OR] 8.39, 95% CI 1.99-35.40), age <50 years (OR 4.73, 95% CI 2.43-9.20), history of syphilis (OR 2.90, 95% CI 1.40-5.99), and HIV infection (OR 15.85, 95% CI 7.93-31.70) were independent risk factors. No differences in risk factors were identified between HIV-positive and HIV-negative patients. Contact with commercial sex workers was a new risk factor among HIV-negative patients. Homosexual intercourse, rather than immunosuppressed status, appears to be a risk factor among HIV-positive patients.     

Incidence of cancer among the participants of the Finnish Asbestos Screening Campaign

OBJECTIVES: Cancer risk has been estimated for asbestos production workers or other heavily exposed asbestos workers in numerous studies. The bulk of the asbestos epidemic results come, however, from past intermittent exposures during asbestos product use. This study concentrated on estimating the risk of cancer in such a population. METHODS: Altogether 23285 men and 930 women invited to a nationwide screening campaign for benign asbestos-related diseases in 1990-1992 were followed for cancer through the Finnish Cancer Register up to 1998. Standardized incidence ratios (SIR) were calculated in comparison with the total Finnish population. RESULTS: Altogether 1392 cases of cancer were found among the men. The risk was slightly, but significantly elevated for lung cancer [SIR 1.14, 95% confidence interval (95% CI) 1.01-1.26), mesothelioma (SIR 2.77, 95% CI 1.66-4.31), and prostate cancer (SIR 1.21, 95% CI 1.09-1.34). The risk of lung cancer was slightly higher among the invited nonparticipants (SIR 1.48, 95% CI 1.20-1.79) than among the participants (SIR 1.02, 95% CI 0.88-1.17). About 98% of the lung cancers occurred in current or ex-smokers. CONCLUSIONS: In a population of long-term construction workers, the risk of lung cancer and mesothelioma was increased, but considerably lower than among insulators, asbestos sprayers, or patients with asbestosis. As it was not possible to follow most of the invited nonparticipants in the original screening study, selection bias by smoking or other life-style factors possibly correlated to the individual's decision to participate in the health screening cannot be excluded.     

Increased risk of cancer in patients with type 2 diabetes mellitus: A retrospective cohort study in China

ABSTRACT: BACKGROUND: The aim of this study was to investigate the association between type 2 diabetes mellitus (T2DM) and the risk of developing common cancers in the Chinese population. METHODS: A population-based retrospective cohort study was carried out in the Nan-Hu district of Jiaxing city, Zhejiang province, China. The incidence of cancer cases among type 2 diabetic patients from January 2002 to June 2008 was identified through record-linkage of the Diabetic Surveillance and Registry Database with the Cancer Database. The standardized incidence ratio (SIR) and its 95% CI (confidence interval) were used to estimate the risk of cancer among the patients with type 2 diabetes. RESULTS: The overall incidence of cancer was 1083.6 x 105 in male T2DM patients and 870.2 x 105 in females. Increased risk of developing cancer was found in both male and female T2DM patients with an SIR of 1.331 (95% CI=1.143-1.518) and 1.737 (95% CI=1.478-1.997), respectively. With regard to cancer subtypes, both male and female T2DM patients had a significantly increased risk of pancreatic cancer with the SIRs of 2.973 (95% CI=1.731-4.21.) and 2.687 (1.445-3.928), respectively. Elevated risk of liver and kidney cancers was only found in male T2DM patients with SIRs of 1.538 (1.005-2.072) and 4.091 (1.418-6.764), respectively. Increased risk of developing breast cancer (SIR: 2.209 [1.487-2.93]) and leukemia (SIR: 4.167 [1.584- 6.749]) was found in female patients. CONCLUSIONS: These finding indicated that patients with T2DM have an increased risk of developing cancer. Additional cancer screening should be employed in the management of patients with T2DM.     

Hospital-associated infections during and after care in a paediatric infectious disease ward

Viruses are important causes of paediatric hospital-associated infections (HAIs). We evaluated the frequency of viral HAIs during hospitalisation and after discharge in a paediatric infection ward. Data were collected prospectively for two years with follow-up questionnaires in which parents reported symptoms of new infections. Infections occurring >72 h after admission to hospital or <72 h after discharge were regarded as hospital-associated. The mean age of patients was 3.0 years and the mean hospitalisation time 3.0 days. Twenty-one out of the 1927 patients [1.1%, 95% confidence interval (CI): 0.7-1.7] developed an HAI during hospitalisation, in every case diarrhoea. A total of 1175 (61%) questionnaires were returned. In all, 86 children (7.3%, 95% CI: 5.9-9.0) had new symptoms within 72 h of discharge, most often diarrhoea (49%). Older age protected against HAI [odds ratio (OR, per year in age): 0.92; 95% CI: 0.85-0.99; P=0.02]. Among the patients hospitalised for respiratory infections, a shared room increased the risk of HAI (OR: 2.3; 95% CI: 1.1-4.8; P=0.03). Eight percent of the patients in our ward, where alcohol hand gel is actively used and single rooms are common, developed an HAI. Eighty percent of the HAIs appeared at home, which emphasises the importance of post-discharge follow-up.     

#63 Cancer incidence in the u. s. radiologic technologists health study, 1983–1998

PURPOSE: Few studies have evaluated cancer risk associated with low-dose occupational ionizing radiation exposure to women. We present data on incident cancer risks among a predominantly (77%) female cohort of 73,963 U. S. radiologic technologists followed up from 1983 through 1998.METHODS: Cancer incidence information and data on work history, selected cancer risk factors, personal radiation exposure and other health outcomes were obtained from two mailed questionnaires (administered ~1984 and ~1995). Incident cancers were ascertained from the second survey and supplemented by mortality records. Medical records, obtained for 74% of all self-reported cancers, confirmed the cancer in 85%. We computed standardized incidence ratios (SIR) using cancer incidence rates from the National Cancer Institute's Surveillance Epidemiology and End Results Program.RESULTS: The SIR for all cancers combined in both sexes was 1.04 (95% confidence interval (CI): 1.00, 1.07; n = 3292). The incidence of solid cancers was elevated in women (SIR = 1.06, 95% CI: 1.02, 1.10), but lower than expected among men (SIR = 0.92 , 95% CI 0.85, 0.98). Female technologists had an elevated incidence of breast cancer (SIR = 1.16, 95% CI: 1.09, 1.23). Among both sexes combined, elevated risks were seen for melanoma (SIR = 1.59, 95% CI: 1.38, 1.80) and thyroid cancers (SIR = 1.61, 95% CI: 1.34, 1.88), and decreased risks were observed for buccal cavity/pharynx (SIR = 0.73, 95% CI: 0.55, 0.90), rectum (SIR = 0.62, 95% CI: 0.48, 0.76), and lung (SIR = 0.77, 95% CI: 0.70, 0.85) cancers.CONCLUSION: The elevated risk for breast cancer may be related to occupational radiation exposure. The observed melanoma and thryoid cancer excesses may reflect, at least in part, increased screening among medical workers with easy access to health care.     

Occurrence of hospital infection among interned elderly in a university hospital

OBJECTIVE: Hospital infection is an important cause of morbidity and mortality in the elderly population. The objective of this study was to evaluate the occurrence of hospital infection and risk factors associated with it. METHODS: This is a prospective study of a sample of 332 elderly people, 60 years and older, interned in a university hospital, between September 1999 and February 2000. Sample size was calculated according to the Fisher and Belle formula, with a confidence interval of 0.95%, from a total of 760 elderly patients interned, in proportion to the number of patients present in each in-patient unit, in the 1997. Criteria for defining hospital infection were those established by the Center for Diseases and Prevention Control. Odds ratio and logistic regression were utilized for statistical analysis of the data. RESULTS: The rate of hospital infection was 23.6%. The prevalent topographies of infection were respiratory infections (27.6%), urinary tract infections (26.4%) and surgical wound infections (23.6%). The period of hospitalization of patients who did have hospital infections was 6.9 days, while those who had hospital infections were hospitalized for 15.9 days (p<0.05). Mortality rate among hospitalized patients was 9.6% and the rate of lethality among patients with hospital infection was 22.9% (p<0.05). Risk factors found for hospital infection were cholangiography (odds ratio (OR) =46.4, confidence interval 95% (CI95%) =4.4-485); diabetes mellitus (OR=9.9, CI 95% =4.4-22.3); chronic obstructive pulmonary disease (OR=8.3, CI 95% =2.9-23.7); urinary catheters (OR=5, CI 95% =2.7-11.8); hospitalization with community infection (OR=3.9, CI 95% =1.7-8.9) and mechanic ventilation (OR=3.8, CI 95% =1.9-6.3). CONCLUSIONS: Hospital infection presented elevated incidence and lethality and it increased the period of hospitalization among the elderly studied.     

Mortality and cancer incidence in a copper-zinc cohort

Previous studies of copper-zinc workers have primarily observed significant increases in lung and other respiratory cancers. This study concurrently examined cancer incidence and cause-specific mortality for a cohort of workers at a copper-zinc producer in Ontario, Canada, from 1964 to 2005. Significant elevations in lung cancer incidence were observed for males in the overall cohort (standardized incidence ratio [SIR] = 124, 95% confidence interval [CI] = 102-150) and for surface mine (SIR = 272, 95% CI = 124-517), concentrator (SIR = 191, 95% CI = 102-327), and central maintenance (SIR = 214, 95% CI = 125-343) employees. Significant elevations of non-Hodgkin's lymphoma incidence were observed for male underground mine employees (SIR = 232, 95% CI = 111-426). Occupational etiology cannot be ascertained with the current exploratory study design. Future studies could (1) incorporate exposure assessment for subgroups within the existing cohort and (2) determine the efficacy of wellness programs in partnership with the local health unit.     

Invasive group A streptococcal infections, clinical manifestations and their predictors, Montreal, 1995-2001

We identified 306 invasive group A streptococcal infections (IGASI) by passive population-based surveillance in Montreal, Canada, from 1995 to 2001. The average yearly reported incidence was 2.4 per 100,000 persons, with a 14% death rate. Among clinical manifestations, incidence of pneumonia increased from 0.06 per 100,000 in 1995 to 0.50 per 100,000 in 2000. Over a span of 7 years, the odds of developing pneumonia increased (odds ratio [OR] = 1.21, 95% confidence interval [CI] 1.0-1.5), while they decreased for soft-tissue infections (OR = 0.86, 95% CI 0.7-1.0). Serotypes M1 and M3 accounted for 30% of IGASI. However, neither serotype was significantly associated with specific clinical manifestations, which suggests that manifestation development among IGASI might be attributable to host or environmental factors rather than the pathogen. In our study, these factors included age, gender, underlying medical conditions, and living environment, yet none explained temporal changes in risk for pneumonia and soft-tissue infections.     

Cancer incidence among physicians occupationally exposed to ionizing radiation in Finland

OBJECTIVES: Occupational radiation exposure was estimated, and the cancer incidence among physicians working with radiation was compared to that of unexposed physicians. METHODS: A cohort of 1312 physicians was identified from the Finnish occupational radiation exposure registry. Radiation exposure data were obtained from 1970 to 2001 on the basis of individual dosimeters. Never-monitored Finnish physicians (N=15 821) were used as a reference group, identified from census data of Statistics Finland. Incident cancer cases were identified by record linkage with the Finnish Cancer Registry. RESULTS: The cumulative radiation dose exceeded the recording level (0.3-3.0 mSv during a 3-month period for 1029 radiation-exposed physicians (59.8%). Six percent of the radiologists had received a cumulative dose of 50 mSv or more. Altogether there were 41 cancers observed among the radiation-exposed physicians and 998 cases found in the never-monitored group. Standardized incidence ratios (SIR) for all cancers were comparable with those of the general population among physicians monitored for radiation [SIR 1.0, 95% confidence interval (95% CI) 0.7-1.4] and other physicians (SIR 1.0, 95% CI 1.0-1.1). For specific cancer sites, a slightly elevated risk of female breast cancer was found among monitored physicians when compared with other physicians (rate ratio 1.7, 95% CI 1.0-3.1). No obvious dose-response relationship was found for the overall cancer incidence. CONCLUSIONS: According to the results from a nationwide cohort, occupational exposure to medical radiation is not a strong risk factor for cancer among physicians. Possible excess risk could not be reliably demonstrated even after the follow-up of a nationwide cohort for up to 30 years.     

Behavioral and Psychosocial Risk Factors Associated with First and Recurrent Cystitis in Indian Women: A Case-control Study

Background:

The risk factors for urinary tract infections (UTIs) from developed countries are not applicable to women from developing world.

Objective:

To analyze the behavioral practices and psychosocial aspects pertinent to women in our region and assess their association with acute first time or recurrent UTI.

Materials and Methods:

Sexually active premenopausal women with their first (145) and recurrent (77) cystitis with Escherichia coli as cases and women with no prior history of UTI as healthy controls (257) were enrolled at a tertiary care hospital in India, between June 2011 and February 2013. Questionnaire-based data was collected from each participant through a structured face-to-face interview.

Results:

Using univariate and multivariate regression models, independent risk factors for the first episode of cystitis when compared with healthy controls were (presented in odds ratios [ORs] with its 95% confidence interval [CI]): Anal sex (OR = 3.68, 95% CI = 1.59-8.52), time interval between last sexual intercourse and current episode of UTI was <5 days (OR = 2.27, 95% CI = 1.22-4.23), use of cloth during menstrual cycle (OR = 2.36, 95% CI = 1.31-4.26), >250 ml of tea consumption per day (OR = 4.73, 95% CI = 2.67-8.38), presence of vaginal infection (OR = 3.23, 95% CI = 1.85-5.62) and wiping back to front (OR = 2.52, 95% CI = 1.45-4.38). Along with the latter three, history of UTI in a first-degree female relative (OR = 10.88, 95% CI = 2.41-49.07), constipation (OR = 4.85, 95% CI = 1.97-11.92) and stress incontinence (OR = 2.45, 95% CI = 1.18-5.06) were additional independent risk factors for recurrent cystitis in comparison to healthy controls.

Conclusion:

Most of the risk factors for initial infection are potentially modifiable but sufficient to also pose risk for recurrence. Many of the findings reflect the cultural and ethnic practices in our country.     

Primary liver cancer, other malignancies, and mortality risks following porphyria: a cohort study in Denmark and Sweden.

Cancer incidence and mortality risks were evaluated in a combined cohort of patients who were hospitalized for porphyria in Denmark (1977-1989) and Sweden (1965-1983). Patients were identified by using population-based hospitalization registries. The unique individual identification numbers of 530 patients with porphyria cutanea tarda (PCT) and 296 with acute intermittent porphyria (AIP) were linked to the nationwide cancer and death registries. Among patients with both types of porphyria, the authors found small but significantly elevated risks of all cancers combined (PCT: standardized incidence ratio (SIR) = 1.7, 95% confidence interval (CI) 1.3-2.2; AIP: SIR = 1.8, 95% CI 1.1-2.8) due to pronounced excesses of primary liver cancer (PCT: SIR = 21.2, 95% CI 8.5-43.7; AIP: SIR = 70.4, 95% CI 22.7-164.3) and moderate increases in lung cancer (PCT: SIR = 2.9, 95% CI 1.5-5.2; AIP: SIR = 2.8, 95% CI 0.3-10.2). PCT patients had a significantly increased risk of mortality from liver cirrhosis (standardized mortality ratio (SMR) = 8.4, 95% CI 3.1-18.4) or chronic obstructive pulmonary disease (SMR = 3.1, 95% CI 1.1-6.7). The increased risk of primary liver cancer and the increased risk of mortality from cirrhosis of the liver are consistent with findings from previous clinical surveys, but the new observations of excess lung cancer and chronic obstructive pulmonary disease require confirmation.     

Cancer risk at sites other than the breast following augmentation mammoplasty

PURPOSE: There has been limited investigation of cancer risk other than breast cancer among patients with breast implants, despite some clinical and laboratory evidence suggesting links with certain cancer sites, including hematopoietic and connective tissue malignancies. METHODS: A retrospective cohort study of 13,488 patients who received cosmetic breast implants at 18 plastic surgery practices in six geographic areas was conducted to assess long-term health effects. After an average of 12 years of follow-up, questionnaires were administered to subjects located and alive (78% of eligible population). Attempts were made to obtain death certificates for deceased subjects and medical verification for all reported cancers. Expected numbers of cancers were derived using general population cancer incidence rates and an internal comparison series of 3936 patients who received other types of plastic surgery at the same practices as the implant patients. RESULTS: A total of 359 malignancies was observed versus 295.95 expected based on general population rates, resulting in a standardized incidence ratio (SIR) of 1.21 [95% confidence interval (CI) 1.1-1.4]. Individual malignancies for which incidence was significantly elevated included cancers of the stomach (SIR = 2.65), cervix (SIR = 3.18), vulva (SIR = 2.51), brain (SIR = 2.16), and leukemia (SIR = 2.19). No excess risks were observed for other hematopoietic malignancies, including multiple myeloma. The internal analyses, however, based on cancer rates derived among the comparison patients, showed no increased cancer risk among the implant patients [relative risk (RR) = 1.00, 95% CI 0.8-1.2], as well as no statistically significant elevations for most individual sites. Cervical cancer continued to be elevated (RR = 1.78), although to a lesser extent than in the external analyses, while the risk for respiratory cancers was higher (RR = 2.40). Non-significant elevations in risk persisted in this analysis for liver cancer (RR = 2.65), brain cancer (RR = 2.83), and leukemia (RR = 1.83). Many of the cancers showing excesses were defined on the basis of death certificates, requiring caution in interpretation. The histologies of the leukemias were quite varied, which makes a biologic relationship appear unlikely. However, respiratory cancers showed some evidence of increasing risk with follow-up time and both respiratory and brain cancers were elevated in the mortality analyses. CONCLUSIONS: Although excesses of cervical and vulvar cancer among implant patients might be attributable to lifestyle factors, reasons for excesses of respiratory and brain cancers were less apparent.     

Neoplasms in neurofibromatosis 1 are related to gender but not to family history of cancer

The risk of malignancies among persons with neurofibromatosis 1 (NF1) is higher than in the general population, but the excess risk has not been precisely estimated. The effects of gender and inheritance pattern on cancer risk are unclear. Therefore, we conducted a historical cohort study to determine cancer risk factors by contacting 138 Caucasian NF1 patients originally seen at Baylor College of Medicine (BCM) in Houston between 1978 and 1984. A total of 304 patients of all ethnic groups were evaluated at BCM during this period. We successfully located 173 patients, 138 of who were Caucasian. We computed standardized incidence ratios (SIRs) with the age-, gender-, and time period-specific rates from the Connecticut Tumor Registry for 2,094 person-years of observation (median follow-up = 16 years). Eleven incident tumors were reported. Females were at much higher risk of cancer than males (SIR = 5.6, 95% confidence interval (CI) 2.7-10.3 and SIR = 0.6; 95% CI, 0.0-3.0, respectively). We found no elevated cancer risk in unaffected first-degree relatives, regardless of whether the proband had cancer or not (SIR = 1.1 95% CI, 0.6-1.8 and SIR = 1.0, 95% CI, 0.6-1.5, respectively). Our results suggest that malignancy in the proband is not the result of a modifying gene that has a significant impact on general cancer risk.     

Causes of infertility as predictors of subsequent cancer risk

BACKGROUND: Although studies have found elevated risks of certain cancers linked to infertility, the underlying reasons remain unclear. METHODS: In a retrospective cohort study of 12,193 U.S. women evaluated for infertility between 1965 and 1988, 581 cases of cancer were identified through 1999. We used standardized incidence ratios (SIRs) to compare cancer risk with the general population. Analyses within the cohort estimated rate ratios (RRs) associated with infertility after adjusting for other risk predictors. RESULTS: Infertility patients demonstrated a higher cancer risk than the general population (SIR = 1.23; 95% confidence interval [CI] = 1.1-1.3), with nulligravid (primary infertility) patients at even higher risk (1.43; 1.3-1.6). Particularly elevated risks among primary infertility patients were observed for cancers of the uterus (1.93) and ovaries (2.73). Analyses within the cohort revealed increased RRs of colon, ovarian, and thyroid cancers, and of melanomas associated with endometriosis. Melanomas were linked with anovulatory problems, whereas uterine cancers predominated among patients with tubal disorders. When primary infertility patients with specific causes of infertility were compared with unaffected patients who had secondary infertility, endometriosis was linked with distinctive excesses of cancers of the colon (RR = 2.40; 95% CI = 0.7-8.4), ovaries (2.88; 1.2-7.1), and thyroid (4.65; 0.8-25.6) cancers, as well as melanomas (2.32; 0.8-6.7). Primary infertility due to anovulation particularly predisposed to uterine cancer (2.42; 1.0-5.8), and tubal disorders to ovarian cancer (1.61; 0.7-3.8). Primary infertility associated with male-factor problems was associated with unexpected increases in colon (2.85; 0.9-9.5) and uterine (3.15; 1.0-9.5) cancers. CONCLUSIONS: The effects of infertility may extend beyond gynecologic cancers. Thyroid cancers and melanomas deserve specific attention, particularly with respect to endometriosis.     

Low birth weight in relation to multiple induced abortions.

BACKGROUND. Most studies report that a single induced abortion does not increase risk for delivering a low birth weight infant in a subsequent pregnancy. However, the effect of multiple abortions has not been adequately evaluated. METHODS. This relationship was studied in 6541 White women who delivered their first child between 1984 and 1987. We compared the frequencies of low birth weight (less than 2500 g) among infants born to 1999 women without prior induced abortion and 1999 women with one abortion with the frequencies of low birth weight among infants born to women with two (n = 1850), three (n = 520), and four or more (n = 173) prior induced abortions. RESULTS. After adjustment for confounding variables, we found no linear relationship in risk of low birth weight among women with one (relative risk [RR] = 1.2, 95% confidence interval [CI] = 0.9-1.5), two (RR = 1.5, 95% CI = 1.1-2.0), three (RR = 1.3, 95% CI = 0.8-1.9), or four or more (RR = 1.6, 95% CI = 0.9-2.9) prior induced abortions. CONCLUSIONS. These findings confirm earlier reports of little or no evidence of harmful effects on birth weight by one or by two or more induced abortions. We further report that risk is not significantly elevated even in women with three, four, or more prior terminations of pregnancy when compared with women with one or two abortions.