The relationship between smoking and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 151 males with incident, histologically confirmed invasive cancer of the bladder, and controls were 157 males admitted to hospital for acute, non-neoplastic, non-urinary tract, non-smoking-related conditions. With reference to never smokers, ex-smokers had a multivariate odds ratio (OR) of 4.4 [95% confidence interval (CI) 1.7-11.7] and current smokers of 6.6 (95% CI 3.1-13.9). The ORs were 5.4 for < 20 and 7.6 for > or = 20 cigarettes per day. After adjustment for cigarette smoking, the ORs were 0.8 for waterpipe and 0.4 for hashish smokers. The risk was significantly related to duration of smoking (OR of 16.5 for > 40 years), and inversely related to age at starting (OR of 8.8 for starting < 20 years), and inversely related to time since quitting smoking. Compared with never smokers who did not report a clinical history of schistosomiasis, the OR was 9.4 for smokers with a history of schistosomiasis, and 10.7 for smokers ever employed in high-risk occupations compared with non-smokers not reporting such a history. Thus, our results, while not giving indications of an increased bladder cancer risk with habits other than cigarette smoking, found a remarkably strong association with various measures of cigarette smoking that could explain 75% of bladder cancer cases among males from Alexandria. The prevalence of smoking was very low among women, and consequently tobacco was not a relevant risk factor for female bladder cancer.

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.

The incidence of all neoplasms was reduced significantly in men diagnosed with prostate carcinoma. Selection of the population, under-registration of second primary tumors, and reduced surveillance in elderly men with prostate carcinoma may, at least in part, explain this reduction in risk. No excess risk was observed for the complex of urologic neoplasms nor for tobacco-related neoplasms. This finding would not support an association between cigarette smoking and prostate carcinoma.

Thyroid cancer is one of the rarest forms of cancer, and yet there are wide variations in the degree of malignancy, ranging from the most rapidly fatal to the relatively benign. This difference depends almost entirely on the histological type. A "pool" of individuals with occult thyroid carcinomas (in the vast majority of the papillary type) is probably present in most populations even at a young age. Large differences in the estimated frequency of cancer at this site can therefore be caused by variation in diagnostic intensity. Data on changing trends of incidence and mortality are thus subject to reservation, depending on the degree to which they have been influenced by changing diagnostic criteria and the precision of histopathological description. Nevertheless, there is evidence that mortality is slowly falling, whereas incidence is increasing, in several countries. This chapter considers the upward temporal trends of incidence and substantially stable mortality rates for thyroid carcinoma in the past three decades and attempts to interpret these trends in the light of concurrent changes in diagnostic standards and histological classification. Attention will also be drawn to the public health implications of the recent intensive detection and treatment of occult thyroid carcinomas.

The proportion of colorectal cancer attributed to dietary habits is high, but several inconsistencies remain, especially with respect to the influence of some food groups. To further elucidate the role of dietary habits, 1,225 subjects with cancer of the colon, 728 with cancer of the rectum and 4,154 controls, hospitalized with acute non-neoplastic diseases, were interviewed between 1992 and 1996 in 6 different Italian areas. The validated food-frequency questionnaire included 79 questions on food items and recipes, categorised into 16 food groups. After allowance for non-dietary confounding factors and total energy intake, significant trends of increasing risk of colorectal cancer with increasing intake emerged for bread and cereal dishes (odds ratio [OR] in highest vs. lowest quintile = 1.7), potatoes (OR = 1.2), cakes and desserts (OR = 1.1), and refined sugar (OR = 1.4). Intakes of fish (OR = 0.7), raw and cooked vegetables (OR = 0.6 for both) and fruit other than citrus fruit (OR = 0.7) showed a negative association with risk. Consumption of eggs and meat (white, red or processed meats) seemed uninfluential. Most findings were similar for colon and rectum, but some negative associations (i.e., coffee and tea, and fish) appeared stronger for colon cancer. Our findings lead us to reconsider the role of starchy foods and refined sugar in light of recent knowledge on the digestive physiology of carbohydrates and the insulin/colon cancer hypothesis. The beneficial role of most vegetables is confirmed, with more than 20% reduction in risk of colorectal cancer from the addition of one daily serving.

The risk of seromucinous benign ovarian tumours is greater in more educated women and in women with a history of infertility and with long or irregular menstrual cycles.

The relation between oral contraceptives (OC) and cancer risk has been investigated extensively, mainly with reference to breast, female genital tract, liver cancer and cutaneous malignant melanoma, and will be summarized below. There is also some suggestion that OC use is related to other neoplasms, including a reduced risk of colorectal cancer among OC users, but the issue is still controversial and too preliminary to provide indications for informed contraception choice.

EDITOR—Jensen et al observed decreased fecundability among women who drank alcohol compared with those who did not.1 The decrease was found even among women reporting a weekly intake of five or fewer drinks. The authors call for further corroboration of their findings. View this table: Number (percentage) of women having difficulty in conception according to alcohol consumption, Milan, Italy We analysed the relation between alcohol intake and difficulties in …

The role of ovarian function is reviewed with reference to breast, female genital tract neoplasms, and ischaemic heart disease. The risk of breast cancer is increased by early menarche, late menopause and regular menstrual cycles. The associations observed are modest, but are still consistent with an unfavourable effect of ovarian function on breast cancer risk. Ovarian cancer is possibly related to early menarche and associated with late menopause. A protective effect has been observed with irregular menstrual cycles and oral contraceptive use. Ovulation has been related to ovarian cancer risk in terms of the multistage model of carcinogenesis, although the biological process appears more complex. Endometrial cancer risk is increased by early menarche, late menopause, nulliparity, and — in premenopausal women — obesity. The risk of endometrial cancer is increased by oestrogens and decreased by progestins. Thus, anovulation increases endometrial cancer risk. Ischaemic heart disease is not related to age at menarche, but is associated with early menopause. Irregular menstrual cycles may also increase the risk. The impact of ovulation on cardiovascular disease should be viewed with reference to the different role of oestrogens (protective) and progestins (possible adverse). Other hormone imbalances (e.g., hyperandrogenaemia) may also be related to ischaemic heart diseases.