To provide quantitative information on the role of age at any birth for breast cancer risk, we analyzed data from a cooperative Italian case-control study conducted between 1991 and 1994 on 2,569 incident, histologically confirmed breast cancer cases and 2,588 controls in hospital for acute, non-neoplastic, non-gynecological conditions. A single logistic model was fitted, including terms for number of births, age at each birth and at menarche, plus age and center. Age at first birth was the strongest reproductive determinant of subsequent breast cancer risk, with an estimated increase of 4.6% per year of delay of first birth. This was similar to the influence of age at menarche (4.7% decrease in risk per year of delay of menarche). Ages at subsequent births had an independent effect on breast carcinogenesis, with an estimated 0.7% increase in risk per year of delay. Multiparity showed also an independent protection on breast cancer risk, and a protective effect of parity > or = 3 was evident in all strata of age at first birth: the odds ratio was 0.81 for 3 births and 0.70 for > or = 4 births. However, the effect of parity was determined by the age of occurrence of various births.
A case-control study was conducted on 91 cases with histologically-confirmed borderline ovarian turnours and 237 control subjects in hospital for acute non-gynaecological, hormonal or neoplastic disease. Women reporting three or more births, compared to nulliparae, had a relative risk (RR) estimate of 0.6, but this finding was not statistically significant (95% confidence interval (CI): 0.2-1.4). The risk of borderline turnours increased, although not significantly, with later age at first birth: compared to women reporting first birth at age 24 or before, the RRs were 1.3 and 1.7 in those reporting respectively their first birth at age 25-29 and 30 years or more. No significant relationship emerged between borderline ovarian cancer and age at menarche, menopausal status and lifelong menstrual pattern. Cases tended to report a later age at menopause than controls, but the trend in risk was not statistically significant. Nine cases (9.9%) and 68 controls (24.9%) reported oral contraceptive use: compared with never users the multivariate RR for ever users was 0.3, and the risk dropped with duration of use to 0.2 in users for two years or more (X21, trend = 12.70, p<0.001). This study provides epidemiological evidence of a pathogenetic continuum between borderline and invasive ovarian tumours.
To provide quantitative information on the role of age at any birth for breast cancer risk, we analyzed data from a cooperative Italian case-control study conducted between 1991 and 1994 on 2,569 incident, histologically confirmed breast cancer cases and 2,588 controls in hospital for acute, non-neoplastic, non-gynecological conditions. A single logistic model was fitted, including terms for number of births, age at each birth and at menarche, plus age and center. Age at first birth was the strongest reproductive determinant of subsequent breast cancer risk, with an estimated increase of 4.6% per year of delay of first birth. This was similar to the influence of age at menarche (4.7% decrease in risk per year of delay of menarche). Ages at subsequent births had an independent effect on breast carcinogenesis, with an estimated 0.7% increase in risk per year of delay. Multiparity showed also an independent protection on breast cancer risk, and a protective effect of parity ≥3 was evident in all strata of age at first birth: the odds ratio was 0.81 for 3 births and 0.70 for ≥4 births. However, the effect of parity was determined by the age of occurrence of various births. © 1996 Wiley-Liss, Inc.
Cigarette consumption has increased steadily throughout this century in Italy. There were marked increases in three periods: in the 1920s, in the 1950s possibly due to the spread of smoking among young men, and in the 1970s in part due to smoking among women. The average number of cigarettes per adult per day sold legally in 1980 was 6.9 but, taking smuggling into account, the actual average number of cigarettes smoked per day is likely to range between eight and nine. Data from a national sample-based survey conducted in 1980 showed that smoking prevalence in men was broadly similar within age groups, geographical area, education, and socioeconomic groups. Smoking in women, on the other hand, was concentrated in younger and more educated women living in larger towns and in richer areas of the country. This pattern is typical of a recent rapid spread of smoking among women. The average tar yield of Italian cigarettes in 1983-4 was about 17 mg. Tar yield was strongly and negatively correlated with price (r = -0.55). This abnormality should be urgently reversed by government intervention. No material increase in lung cancer mortality in young women was evident up to the lat 1970s. Lung cancer death rates in men correlated closely with the observed changes in cigarette consumption. The highest mortality rates (about 7, 20, and 50/100 000 respectively in the age groups 35-39, 40-44, and 45-49) were reached by the generation born around 1927-30, and the rates have remained fairly constant around these maximum levels for those born up to 1940. As a consequence, Italian lung cancer death rates in middle-aged men (45 to 54) are currently the highest registered in developed countries, and large upward trends are currently detectable in older men.
