We analyzed the association between history of pelvic inflammatory disease (PID) and the risk of subsequent epithelial ovarian cancer, using data from a large case-control study conducted between 1983-1991 in Italy. Data were collected from a network of hospitals, including the main teaching and general hospitals in the greater Milan area, Northern Italy. The cases studied were 971 women below the age of 75 years (median age, 54 years) with histologically confirmed epithelial ovarian cancer, diagnosed within 1 year before the interview. Control subjects were 2758 women admitted to the same hospitals where cases were identified for acute, nonmalignant, nonhormone-related conditions, who had not undergone bilateral oophorectomy. The median age of the control group was 52 years (range, 23-74). A total of 14 (1.4%) cases and 72 (2.6%) controls reported a history of PID/ salpingitis, the corresponding multivariate relative risk being 0.7 (95% confidence interval, 0.4-1.3). A separate analysis of the association between history of PID/salpingitis and risk of ovarian cancer in strata of parity and education confirmed the results based on the whole series. In conclusion, although based on limited numbers of cases and controls with PID, this studies was able to exclude, at the conventional 95% confidence limit, an increased risk of ovarian cancer of over 30% in women with previous PID in this population.
Epidemiological data on occupational exposure and personal use of hair dyes was reviewed with specific focus on bladder cancer and lymphoid neoplasms. At least seven cohort and 11 case-control studies included data on occupational exposure to hair dyes by hairdressers, barbers and beauticians, and their subsequent bladder cancer risk. The relative risk (RR) estimate was 1.4 (183 observed vs 129 expected) for cohort studies, and in several case-control studies the RRs were somewhat above unity. These results are compatible with some moderate association between past professional exposure to hair dyes and subsequent bladder cancer risk, but also with errors and biases in observational epidemiological studies, particularly since allowance for smoking was lacking or inadequate in most studies. An open question is whether current occupational exposure to modern hair dyes is still related to some excess bladder cancer risk. Five case-control studies included information on personal use of hair dyes and bladder cancer risk. There was no evidence of any association. Nine cohort and eight case-control studies considering occupational exposure to hair dyes and lymphoid neoplasms were reviewed. In the cohort studies, a total of 100 lymphoid neoplasms was observed compared with 84.4 expected (RR 1.2). The RR estimates were 1.5 for non-Hodgkin's lymphomas (NHL, 17 observed vs 11.2 expected) and 1.1 for multiple myeloma (MM, 19 observed cases vs 16.8 expected). Interpretation of case-control studies of occupational exposure is seriously hampered by the small number of exposed cases. Five case-control studies considered personal use of hair dyes and the risk of lymphoid neoplasms. Of these, three reported some association, particularly with NHL and MM. However, the RR estimates were only moderately above unity, and inadequate allowance was made for potential confounding factors, including social class and greying hair, which could be correlates of both hair dye use and lymphoid neoplasms. Further, there is little information on the biodistribution and bioavailability of potential carcinogens in hair dyes, particularly their concentrations in lymphoid tissue. These findings, therefore, require further research, particularly since they may be influenced by selective publication of positive findings (publication bias). None of the other neoplasms extensively studied, including breast, skin and lung was related to hair dye use.
Number of certified deaths, age-specific and age-standardised rates and percentages of all cancer deaths from 30 cancers or groups of cancers (plus total cancer mortality) for each five-year calendar period between 1955 and 1984 in Italy are presented in tabular form. From these data, three graphs are derived, including trends in age-standardised rates, age-specific rates centered on birth cohorts and maps plotted in different shades of grey to represent the surfaces defined by the matrix of various age-specific rates. These analyses quantified the rises in overall cancer mortality in males (from 137 to 192/100,000 world standard), chiefly due to increases in lung and other tobacco-related neoplasms. Overall cancer mortality was stable in females (around 100/100,000). Appreciable cohort effects were evident for tobacco related neoplasms, but also for other major cancer sites, such as intestines or breast, whose rates, after earlier rises, are now stable in earlier middle age. Since the early 1970's, cancer mortality rates have been declining in all age groups below 40 in males and below 55 in females. These declines reflect improvements in therapy for leukemias, lymphomas and germ cell tumors, and general improvements in food availability and storage, hygiene and early diagnosis, which have led to the declines in stomach and cervical cancer. Although moderate in absolute terms and smaller than in other western countries where tobacco-related neoplasms have also been falling in more recent cohorts, these declines are encouraging for the indication they provide on the most likely patterns over the next decades in the same and subsequent generations.
Epidemiological studies on risk factors for CRC have focused mainly on diet. In any case, the results of these studies show several inconsistencies, except for the beneficial role of high intake of vegetables and, to some lesser extent, of fruit. Weight and height have also been studied, partly because they reflect the balance between energy intake and expenditure in different age periods. Energy intake, body size and physical activity will be reviewed in this paper focusing mostly on recent data coming from Italian, English and Scandinavian studies. Overweight has long been recognized as a risk factor for hormone related and other cancers and this is confirmed not simply from case-control studies but from large cohort studies as well. The major findings of recent Italian studies are that excessive weight at various ages predicts colorectal cancer risk in men while in women, abdominal obesity, as indicated by a high WHR, represents a more reliable risk indicator. If all men could reduce their BMI below 25, about 9% of male colorectal cancer might be avoided in Italy. A decrease of WHR below 0.82 might reduce colorectal cancer in women by 19%. In addition, the epidemiological evidence consistently shows that physical activity reduces the risk of colon cancer. On the contrary, evidence on rectal cancer is less impressive. Some uncertainty still exists in relation to the intensity and duration of physical activity. In conclusion, body size control along all life and physical activity represent important factors to prevent colon cancer and a wide range of chronic conditions. Therefore, strategies to favour these goals through counselling from health-care providers, regulatory changes and programs aimed at individuals and communities should be implemented.
1Istituto di Ricerche Farmacologiche “Mario Negri”, 20157, Milan, Italy 2Istituto di Statistica Medica e Biometria, Università degli Studi di Milano,20133 Milan, Italy Fax: (+39) 02 3320 0231 E-mail: [email protected]
