Parity and cancer risk in slovakia

Abstract

Mortality data from women aged 45-74 who died between 1968 and 1977 in Slovakia, Czechoslovakia, were used to examine the effect of parity (number of live-born children) on risk of dying from each of 20 common cancers. After controlling for the effects of age and year of death, the effect of parity on risk was statistically significant at the p less than 0.001 level, for cancers of the stomach, liver, gall-bladder, breast, cervix, and ovary; and at the p less than 0.01 level for uterine corpus and brain. No effect of parity was seen for cancer of the colon or rectum. Among parous women the trend relating risk to level of parity was significant at the p less than 0.001 level for cancers of the breast, uterine corpus, ovary and brain; and at the p less than 0.01 level for stomach cancer. The findings relating parity to cancers of the breast and reproductive organs are consistent with previous reports. The associations of parity with cancers of the digestive tract deserve further study.

Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas

“…In line with our findings is the decreased risk of gastric adenocarcinoma in our cohort of oestrogen-exposed prostate cancer patients (Lindblad et al, 2004) and a protective trend by HRT on gastric cancer (La Vecchia et al, 1994;Fernandez et al, 2003). However, results from studies of menstrual, reproductive factors, and parity and risk of gastric cancer are partly conflicting (Miller et al, 1980;Plesko et al, 1985;La Vecchia et al, 1994;Palli et al, 1994;Heuch and Kvale, 2000;Inoue et al, 2002;Kaneko et al, 2003). A longer period of fertility among females, that is, the time from menarche to menopause, increases the lifetime exposure to endogenous oestrogens and has been suggestive of a reduced gastric cancer risk (La Vecchia et al, 1994;Palli et al, 1994;Inoue et al, 2002;Kaneko et al, 2003), although a lack of such association, and an inverse association with age at menarche has also been reported (Heuch and Kvale, 2000).…”

“…A longer period of fertility among females, that is, the time from menarche to menopause, increases the lifetime exposure to endogenous oestrogens and has been suggestive of a reduced gastric cancer risk (La Vecchia et al, 1994;Palli et al, 1994;Inoue et al, 2002;Kaneko et al, 2003), although a lack of such association, and an inverse association with age at menarche has also been reported (Heuch and Kvale, 2000). Multiparity has been associated with both an increased risk of gastric cancer in several studies (Plesko et al, 1985;La Vecchia et al, 1994;Palli et al, 1994;Heuch and Kvale, 2000;Inoue et al, 2002), and a reduced risk of gastric cancer (Kaneko et al, 2003). Experimental data in rats (Furukawa et al, 1982;Campbell-Thompson et al, 1999) suggest that oestrogen may prevent gastric cancer development.…”

“…An increased male-to-female ratio in gastric adenocarcinoma has been claimed as corresponding to a 10-to 15-year delay among females compared with males, possibly due to a protective effect of female sex hormones (Sipponen and Correa, 2002). Studies on menstrual and reproductive factors have suggested associations with the risk of gastric adenocarcinoma (Miller et al, 1980;Plesko et al, 1985;La Vecchia et al, 1994;Palli et al, 1994;Heuch and Kvale, 2000;Inoue et al, 2002;Kaneko et al, 2003). Based on the hypothesis that sex hormones may be involved in the aetiology of oesophageal or gastric adenocarcinoma, we investigated whether hormone replacement therapy (HRT) protects women against either of these tumours.…”

Tamoxifen exposure and risk of oesophageal and gastric adenocarcinoma: a population-based cohort study of breast cancer patients in Sweden

“…A longer fertility period might reduce the gastric cancer risk (La Vecchia et al, 1994;Palli et al, 1994;Kaneko et al, 2003) and multiparity has been linked with a decreased risk (Kaneko et al, 2003). These results have been contradicted, however (Plesko et al, 1985;La Vecchia et al, 1994;Heuch and Kvale, 2000;Inoue et al, 2002). There are some previous results that suggest an increased risk of gastric adenocarcinoma among tamoxifen-treated patients.…”

The pattern of risk factors for breast cancer in a southern France population. Interest for a stratified analysis by age at diagnosis

“…There is agreement by most authors on a list of 'established' (Kelsey & Gammon, 1990) risk factors, made up of reproductive and menstrual variables, socioeconomic status, family history of BC and previous benign breast disease. These have been found in most countries where studies have been conducted: North America (Helmrich et al, 1983;Lubin et al, 1987); Scandinavia (reviewed in Ewertz et al, 1990); Western Europe (Talamini et al, 1985;Le et al, 1984); Eastern Europe (Plesko et al, 1985); Asia (Thein & Theen et al, 1978) and South America (Mirra et al, 1971). However, in several studies, there is no risk increase associated with some of these established factors (Adami et al, 1980;East European Study of BC epidemiology, 1990).…”