Intrauterine device use and risk of endometrial cancer.

The relationship between intrauterine device (IUD) use and risk of endometrial cancer has been analysed in a case-control study conducted in Italy between 1983 and 1992, including 453 patients with histologically confirmed endometrial cancer and 1,451 controls admitted for acute, non-gynaecological, non-hormonal, non-neoplastic conditions to the same network of hospitals where cases had been identified. Two (0.4%) cases versus 36 (2.3%) controls reported ever using an IUD. The corresponding multivariate relative risk was 0.4 (95% CI 0.1-1.0). The results of this study and the few published available epidemiological data suggest a protective role of IUD use on endometrial carcinogenesis, but potential selective mechanisms for IUD utilisation (indication bias) should be carefully considered in the interpretation

Oral contraceptive use and the risk of epithelial ovarian cancer.

The relation between the use of combination oral contraceptives (OCs) and the risk of epithelial ovarian cancer was investigated in a case-control study conducted in Milan on 209 women below the age of 60 with histologically confirmed epithelial ovarian cancer, and 418 age-matched controls with a spectrum of acute conditions apparently unrelated to OC use. Combination oral contraceptives were used by 18 (9%) cases, and 59 (14%) controls, giving a relative risk estimate of 0.6 (95% confidence interval = 0.3-1.0, P less than 0.05). The risk of ovarian cancer decreased with increasing duration of use and the point estimate remained below unity long after cessation of use. These results were not accounted for by parity, infertility, or other identified potential confounding factors. Thus, the findings of the present study add further support to the evidence emerging from American data of a reduction of approximately 40% in the risk of epithelial ovarian cancer among women who had used oral contraceptives

Selected physical activities and the risk of endometrial cancer.

The relationship between various indicators of physical activity and endometrial cancer risk was analysed using data of a case-control study conducted in 1988-1991 in Switzerland and Italy on 274 histologically confirmed cases and 572 controls admitted to hospital for acute, non neoplastic, non hormone-related diseases. Using a self-rated assessment of total physical activity, there was a systematic tendency for the cases to report more frequently 'low' or 'very low' physical activity. The relative risks were similar for 'very high' or 'moderately high' physical activity, but increased in the two lowest levels, with point estimates, in various decades of age, between 1.3 and 2.3 for 'moderately low' and over 2.5 for 'very low' physical activity. Although the association was apparently stronger at older ages, all the trends in risk were significant. Allowance for major identified potential distorting factors, including body mass index and a measure of total energy intake, could explain only in part the association, and the inverse trends in risk remained statistically significant. When selected types of physical activity were analysed, no association was observed with climbing stairs or walking, but the risk estimates for the lowest level of activity was over 4 for housework, and between 1.5 and 1.9 for sport and leisure and occupational activity. Thus, the present findings suggest that a moderate or high physical activity is an indicator of reduced endometrial cancer risk, although this observation still requires epidemiologic confirmation and clearer definition from a pathogenic point of view

Incidence of invasive cancers following carcinoma in situ of the cervix.

Women with carcinoma in situ (CIS) of the cervix uteri, notified to the population-based Cancer Registry of the Swiss Canton of Vaud between 1974 and 1993, were actively followed up to 31 December 1993 for the occurrence of subsequent invasive neoplasms. Among 2190 incident cases of CIS, followed for a total of 22,225 person-years, 95 metachronous cancers were observed vs 77.9 expected, corresponding to a significant standardised incidence ratio (SIR) of 1.2. Ten cases of invasive cervical cancer were observed vs 3.0 expected (SIR = 3.4, P < 0.01), the excess being larger in the first 10 years since CIS diagnosis. A total of 11 cases of four major tobacco-related sites (lung, mouth or pharynx, oesophagus and urinary bladder) were observed vs 5.1 expected, corresponding to a significant SIR of 2.2. The excess was observed > or = 10 years after CIS diagnosis. There was also an excess of non-melanomatous skin cancers (29 observed, 16.9 expected, SIR = 1.7; P < 0.01), but not of skin melanoma and of any of the other neoplasms considered, including breast and corpus uteri. This population-based study, therefore, finds an excess of invasive cervical cancer in the short term after CIS diagnosis, and a medium- to long-term excess risk of tobacco-related and non-melanomatous skin neoplasms. These findings are discussed in terms of increased surveillance and case ascertainment after CIS, and of potential shared risk factors (tobacco and/or viral infections)

Morphologic analysis of digestive cancers from the registry of Vaud, Switzerland.

Detailed data and statistics per each morphological site of various digestive neoplasms were obtained for the period 1976-87 from the Vaud Cancer Registry datafile, a population-based cancer registration scheme covering about 530,000 inhabitants from the French-speaking part of Switzerland. Tabulations presented include absolute number of cases (1,041 oral and pharyngeal, 545 oesophageal, 1,131 gastric, 83 small intestine, 1,980 colon, 1,267 rectal, 357 liver, 328 gallbladder and 725 pancreatic cancers), percent distributions, age-standardised rates, sex ratios and 5-year survival. The report has essentially a descriptive value, and should be viewed as a contribution towards quantification, in a well surveilled population of the West-central part of Europe, of the proportional distribution of digestive neoplasms by morphological type, and corresponding incidence and survival rates. Among the points deserving specific attention, there are the elevated frequency of upper digestive tract cancers, the very high male-to-female ratios for squamous cell carcinomas, adenocarcinomas of the oesophagus and hepatocellular carcinomas of the liver, the female excesses in infiltrating carcinoids of the colon, transitional and squamous cell carcinomas of the rectum and adenocarcinomas of the gallbladder, and the crossover in male-to-female ratio in squamous cell carcinoma along the digestive tract (i.e. from 6.0 at the level of the mouth/pharynx to 0.5 in the rectum). As concerns survival, rates were higher for lymphomas and sarcomas than for carcinomas in oral cavity and stomach, similar for carcinoids and carcinomas in the small bowel (about 35% at 5 years), as well as for colon (34%) and rectal (37%) cancers. Some of the findings, such as the higher survival of carcinomas arising from polyps in the colon and rectum, or the higher proportion of cholangiocellular and combined cholangio- and hepatocellular carcinomas in females than in males find plausible prognostic or aetiologic correlates, but others, such as the large proportions of squamous and transitional cell cancers of the rectum in females are more difficult to explain. These and several other indications emerging from careful examination of the data herein presented underline the interest of morphological analyses of digestive tract cancers

Trends in lip cancer incidence in Vaud, Switzerland.

Recent trends in lip cancer incidence in the Swiss Canton of Vaud (approximately 600,000 inhabitants in 1990) were analysed over the period 1975-1990, when a total of 87 cases were registered. A steady and substantial decline was observed in both sexes, since age-standardised (world) rates declined from 1.8 to 0.6/100,000 males and from 0.14 to 0.02/100,000 females. These downward trends were evident across subsequent age groups. These trends were apparently not due to changes in registration or classification criteria in the study period and are discussed in terms of decreased occupational exposure to ultraviolet light, and reduced pipe and cigar smoking