To explore breast cancer etiology, literature was searched using Medline. We explored the 1) plausibility of smoking in breast carcinogenesis; 2) physiological properties, susceptibility windows, and exposure timing of breast cells; 3) role of exogenous hormones in breast carcinogenesis; 4) biological mechanism of synergistic interactions between smoking and exogenous hormones in breast carcinogenesis; and 5) evidence from epidemiologic studies and the fitted secular trend between smoking rate, exogenous hormone use, and breast cancer incidence in past decades. We deduced that exogenous hormone use per se is not a significant cause and its association with breast cancer is distorted by chronic exposure to environmental carcinogens, especially smoking. We hypothesize that smoking is one of the causes of breast cancer and that this causality is strengthened by synergistic interaction between smoking and exogenous hormone use. Physicians should be cautious of prescribing exogenous hormones for those with chronic exposure to environmental carcinogens to prevent breast cancer.
Breast Neoplasms ; chemically induced ; epidemiology ; etiology ; China ; epidemiology ; Contraceptives, Oral, Hormonal ; adverse effects ; Estrogens ; adverse effects ; Female ; Hormone Replacement Therapy ; adverse effects ; Humans ; Incidence ; MEDLINE ; Progestins ; adverse effects ; PubMed ; Smoking ; adverse effects ; United States ; epidemiology

OBJECTIVE: To investigate the role of previous gynecologic surgery, hormone use, and use of non-steroidal anti-inflammatory drugs on the risk of type 1 and type 2 ovarian cancer. METHODS: We utilized data collected for the Prostate, Lung, Colorectal, and Ovarian cancer screening trial. All diagnosed ovarian cancers were divided into three groups: type 1, endometrioid, clear cell, mucinous, low grade serous, and low grade adenocarcinoma/not otherwise specified (NOS); type 2, high grade serous, undifferentiated, carcinosarcoma, and high grade adenocarcinoma/NOS; and other: adenocarcinoma with grade or histology not specified, borderline tumors, granulosa cell tumors. The odds ratios for type 1, type 2, and other ovarian cancers were assessed with regard to historical information for specific risk factors. RESULTS: Ibuprofen use was associated with a decrease in risk for type 1 ovarian cancer. Tubal ligation and oral contraceptive use were associated with a decrease in risk for type 2 ovarian cancer. A history of ectopic pregnancy was associated with a decreased risk for all ovarian cancers by almost 70%. CONCLUSION: These findings support the hypothesis that carcinogenic pathways for type 1 and type 2 ovarian cancer are different and distinct. The marked reduction in all ovarian cancer risk noted with a history of ectopic pregnancy and salpingectomy implies that the fallopian tube plays a key role in carcinogenesis for both type 1 and type 2 ovarian cancer.
Aged ; Anti-Inflammatory Agents, Non-Steroidal/adverse effects ; Contraceptives, Oral, Hormonal/adverse effects ; *Early Detection of Cancer ; Female ; Gynecologic Surgical Procedures/adverse effects ; Humans ; Ibuprofen/adverse effects ; Middle Aged ; Ovarian Neoplasms/chemically induced/diagnosis/*etiology/pathology ; Pregnancy ; Pregnancy, Ectopic/epidemiology ; Risk Factors ; Surveys and Questionnaires

OBJECTIVETo set a quantitative criteria for determining the risks on cerebral vascular disease (CVD) so to identify that potential risk of an individual dying from CVD and to predict the individual risk of CVD.

METHODSData on case-control and cohort studies published during 1978 to 2003 was collected through retrieval of literatures, and data on surveillance of behavior exposure was provided by Chengdu Municipal Center for Disease Control and Prevention. Pooled odds ratio (OR) and relative risk (RR) of all risk factors for CVD were estimated using software for meta-analysis to enable the varied levels of risk factors be converted into risk fractions by statistical models.

RESULTSA risk score conversion table (quantitative criteria for assessment) of main risk factors for CVD was developed for men and women aged 35 - 69 at an interval of five years, including smoking, passive smoking, hypertension, high blood cholesterol levels, body mass index, lack of physical activity, alcohol drinking, dietary fat consumption, milk intake, oral contraceptive use, past history of diabetes and CVD, family history of CVD etc. Individuals with all these risk factors had a risk score beyond 1.00, but was equal to or below 1.00 when without. The risk score would increase along with the rise of one's risk level.

CONCLUSIONEstimation of risk of dying from CVD was based on risk score conversion table of risk factors for CVD, which could be used to predict individual potential risk of dying from CVD in the following 10 years. Our data provides evidence that education to be strengthened to persuade people to change their unhealthy lifestyles and behaviors.

Alcoholism ; complications ; Body Constitution ; Case-Control Studies ; Cerebrovascular Disorders ; epidemiology ; etiology ; China ; epidemiology ; Cohort Studies ; Contraceptives, Oral, Hormonal ; adverse effects ; Diabetes Complications ; Exercise ; Feeding Behavior ; Female ; Humans ; Hypertension ; complications ; Male ; Odds Ratio ; Risk Assessment ; Risk Factors ; Smoking ; adverse effects ; Urban Population ; statistics & numerical data