Long-term effects of oral contraceptives on ovarian cancer risk

Trends in cancer mortality in the Americas, 1970-2000

BACKGROUND

Data and statistics on cancer mortality over the last decades are available for most developed countries, while they are more difficult to obtain, in a standardized and comparable format, for countries of Latin America.

PATIENTS AND METHODS

Age standardized (world population) mortality rates around the year 2000, derived from the WHO database, are presented for 14 selected cancers and total cancer in 10 countries of Latin America, plus, for comparative purposes, Canada and the USA. Trends in mortality are also given over the period 1970-2000.

RESULTS

In 2000, the highest total cancer mortality for males was observed in Argentina and Chile, with rates comparable to those of Canada and the USA, i.e. about 155/100,000. For women, Chile and Cuba had the highest rates in Latin America (114 and 103/100,000, respectively), again comparable to those of North America (around 105/100,000). These reflect the comparatively high mortality from cancer of the stomach (for Chile), lung and intestines (for Argentina) in men, and of stomach and uterus (for Chile), intestines and lung (for Cuba) in women. Colombia, Ecuador and Mexico had the lowest total cancer mortality for men, due to low mortality from stomach, colorectal and lung cancer. For women, the lowest rates were in Brazil and Puerto Rico, reflecting their low stomach and cervical cancer rates. In Argentina, Chile, Colombia, Costa Rica and Venezuela cancer mortality rates tended to decline, particularly in men. Rates were stable in Ecuador and Puerto Rico, and were increasing in Mexico and Cuba.

CONCLUSIONS

Mortality from some common cancers (including colorectal and lung) is still low in Latin America compared with Canada and the USA, and decreasing trends have been observed in the last decades for some cancer sites (including stomach, uterus, lung and other tobacco-related cancers) in several countries. However, mortality from female lung and breast cancers has been increasing in most countries of Latin America, and several countries still show an extremely elevated mortality from cancer of the cervix. Selected neoplasms amenable to treatment, including testis and leukemias, also show unsatisfactory trends in Latin America.

Endogenous Hormones and Ovarian Cancer: Epidemiology and Current Hypotheses

The effect of major epidemiologic risk factors for ovarian cancer has been reviewed in the light of several hormonal hypotheses, including the gonadotropin, androgens, progesterone, estrogens, insulin-like growth factor-I, and insulin hypotheses. The role of inclusion cyst formation and Mullerian epithelium differentiation in the pathology of the disease are also briefly outlined. Although based on limited data, the observed tendency in current evidence suggests possible etiologic roles for elevated androgens and estrogens and decreased progesterone in the pathogenesis of ovarian cancer. A direct effect of gonadotropins cannot be entirely ruled out, but it is plausible that their effect on ovarian cancer risk is mediated by stimulation of ovarian steroidogenesis. Insulin-like growth factor-I also emerges as a hormone that may be directly involved in the pathogenesis of the disease, but thus far only one prospective study has examined this association. Hyperinsulinemia is an unlikely risk factor for ovarian cancer. The observed tendency for an increased risk with androgens from ovarian origin (in premenopausal women), the lack of association with adrenal androgens, and the relatively weak associations observed with obesity, hormonal replacement therapy use, and endogenous hormones after menopause suggest that ovarian synthesis of sex steroids rather than their circulating levels may be etiologically important. More data from prospective studies will be crucial to improve our understanding of the etiologic role of endogenous hormones in the pathogenesis of ovarian cancer. Such data will ultimately provide opportunities for research targeted; at early detection and preventive interventions.

Common risk factors of breast and ovarian cancer: recent view

Clinicians, epidemiologists, and public health specialists tend to examine breast and ovarian cancer separately. Although this seems fairly rational and expected, both malignancies are estrogen related and thus share many risk factors. In this review, we investigate the common familial, reproductive, anthropometric, nutritional, and lifestyle risk factors of breast and ovarian cancer. We believe that the parallel examination of the two cancer types could significantly contribute to an improved prevention of "gynecological cancer" as a whole.

Epithelial ovarian cancer risk by invasiveness and cell type in the Central Valley of California

OBJECTIVE

To evaluate epithelial ovarian cancer (EOC) risk factors by level of invasiveness and histology.

METHODS

A population-based epidemiologic case-control study of EOC was conducted over a 2-year period (January 2000 to December 2001) in 22 counties of Central California that comprise the reporting area for two regional cancer registries. Telephone interviews were conducted with 256 cases and 1122 control frequencies matched on age and ethnicity. The interview obtained information on demographic factors as well as information pertinent to the respondent's menstrual and reproductive experience, use of exogenous hormones, surgical history, and family history of cancer. Adjusted odds ratios were calculated using stratification as well as Logistic regression methods. Analyses were completed by level of invasiveness and cell type.

RESULTS

Strong protective associations were observed for use of oral contraceptives and parity. Risk increased with a family history of ovarian, but not breast cancer and age at first birth was positively associated with increased risk. Hormone replacement therapy was associated with increased risk only in long-term users. Many of the relationships were observed only in specific histologic subtypes of EOC.

CONCLUSION

Risk of EOC is associated with several lifestyle and environmental exposures but the impact of these effects appears to be dependent upon level of invasiveness and histologic subtypes of EOC. However, the sample size available for analysis limits our statistical power and our ability to analyze data by histologic subtype, thus limiting interpretation of our results.

Surgical risk reduction: prophylactic salpingo-oophorectomy and prophylactic mastectomy

Investigators have used retrospective and prospective study designs to provide much needed data on the extent of risk reduction after prophylactic oophorectomy and mastectomy in women at increased risk for breast and ovarian cancer. In this publication we identify those women who may wish to consider prophylactic surgery, review data demonstrating the efficacy of prophylactic surgery, and discuss potential surgical complications. We also present data about the frequency of use and psychosocial impact of prophylactic surgery in this typically young group of women. Finally, we provide general treatment guidelines for the practicing clinician.

A prospective study of pregravid oral contraceptive use in relation to fetal growth

OBJECTIVE

Because oral contraceptives are so widely used, any health consequences may have substantial public health implications. Whether pregravid oral contraceptives could affect subsequent pregnancies has not been adequately studied. The study objectives were to examine whether pregravid oral contraceptive use affects fetal growth and pregnancy hormone levels.

DESIGN

A prospective study of pregnant women followed through pregnancy.

SETTING

A major teaching hospital in Boston, USA.

POPULATION

Two hundred and sixty Caucasian pregnant women, with a mean age of 31, and a parity of no more than two. Seventy-nine percent of the women were pregravid oral contraceptive users.

METHODS

Exposure and covariate data were collected through structured questionnaires. Blood was drawn for hormonal analysis during the 16th and 27th gestational week. Information on pregravid oral contraceptive use included duration and recency of use, and oral contraceptive formulation. Multivariate regression models were used to examine the effect of pregravid oral contraceptive use on birth outcomes and the studied pregnancy hormones.

MAIN OUTCOME MEASURES

Birthweight, placental weight, gestational age, pregnancy hormone levels of oestriol and progesterone at 16th and 27th gestational week.

RESULTS

Adjusting for confounders, pregravid oral contraceptive use increased birthweight (mean difference =+207.3 g, 95% CI =+77.6 to +337.1) and placental weight (mean difference =+64.9 g, 95% CI =+13.0 to +116.9) compared with never use. Women with prior oral contraceptive use had higher levels of serum progesterone (P= 0.002) and oestriol (P= 0.12) at the 27th gestational week measurement. The effect on birthweight, placental weight and hormones was stronger among those using oral contraceptives in the previous year and those using a high progestin/high oestrogen potency preparation.

CONCLUSIONS

Pregravid oral contraceptive use is positively associated with fetal growth, and this effect may be mediated through oestriol and progesterone.

Cancer mortality in Europe, 1995-1999, and an overview of trends since 1960

Mortality data, abstracted from the World Health Organization database, are presented in tabular form for 26 cancer sites or groups of sites, plus total cancer mortality, in 36 European countries during the period 1995-1999. Trends in mortality are also given in graphic form for 23 major countries plus the European Union as a whole over the period 1960-1999. In the European Union, total cancer mortality declined by 7% for both sexes over the last 5 years considered. The fall since the late 1980s was 10% in both sexes, corresponding to the avoidance of over 90000 deaths per year, as compared to the rates of the late 1980s. For the first time, over the last few years, some leveling of mortality was reported also in the Russian Federation, the Czech Republic, Poland, Hungary and other Eastern European countries, although cancer rates in those areas remain exceedingly high. The overall favorable pattern of cancer mortality over recent years is largely driven by the decline of tobacco-related cancer mortality in men. However, important components of the trends are also the persistence of substantial falls in gastric cancer, mainly in Russia and Eastern Europe, the recent decline in intestinal cancer in both sexes and of breast cancer in women, together with the long-term falls in uterine (cervical) cancer, leukemias, Hodgkin's disease and other neoplasms amenable to advancements in diagnosis and treatment. Female lung cancer mortality has been declining in the Russian Federation, but is still rising in other areas of the continent. Thus, urgent intervention is needed to bring under control the tobacco-related lung cancer epidemic in European women before it reaches the high level observed in North America. Supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html

Trends in incidence of and mortality from cancer in The Netherlands in the period 1989-1998

This paper summarises the population-based major trends in cancer incidence and mortality in the period 1989-1998 in The Netherlands. Trends of the European age-adjusted incidence and mortality rates were estimated by the Estimated Annual Percentage Change (EAPC) method. Increases in incidence were found for cancer of the breast and lung for females. For males, an increase was observed for cancer of the prostate, colon, rectum and testis. In both groups, oesophageal and pharyngeal cancer increased, but that of stomach and gallbladder cancer decreased. The main increases in mortality were found for pharyngeal cancer in males, lung in females and oesophageal cancer in both sexes. Decreases were shown for stomach cancer for both sexes and lung cancer for males. Trends in incidence may be a result of changes in behaviour, smoking habits in preceding decades are related to the increase in lung cancer for females, and early detection, screening programmes increased the incidence for breast and prostate cancers. Decreases in mortality may be related to more successful treatment of leukaemia, Hodgkin's lymphoma, colorectal and testicular cancers. Primary prevention of cancer remains important.

Ovarian cancer in Europe: Cross-sectional trends in incidence and mortality in 28 countries, 1953-2000

We have considered trends in incidence and mortality in 28 European countries using incidence data from successive volumes of Cancer Incidence in Five Continents and mortality from the WHO database. Countries with the highest rates in the early 1960s included the Nordic countries, Austria, Germany and the United Kingdom, but trends in these areas have tended to decline over recent calendar periods, particularly with regard to mortality. Southern European countries showed upward trends, at least until the early 1980s for France and Italy. Likewise, in most central and eastern European countries, ovarian cancer incidence and mortality rates were originally relatively low, but tended to rise over time. Falls in mortality, but not in incidence, over recent years were observed in the Czech Republic and Hungary. In several countries, mainly in northern Europe, trends were more favorable at younger age (25-49 years) than in the subsequent age groups. Thus, recent trends in ovarian cancer have led to a leveling of rates across various areas of the continent, although a 2.5-fold variation was still observed in the late 1990s between the highest mortality rate of 9.3/100,000 in Denmark and the lowest one of 3.6 in Portugal. These patterns should be viewed in the light of an observed reduction in parity, mainly in southern and eastern Europe, and the spread of oral contraceptive use, mainly in northern Europe, since these are the best recognized protective factors with regard to ovarian carcinogenesis. The declining mortality trends can also in part be ascribed to improvements in treatment.