Data in 2 epidemiological studies published recently (Pike et al., 1983; McPherson et al., 1983) have suggested, but not demonstrated with certainty, that prolonged use of oral contraceptives (OCs) at an early age, particularly before the 1st full term pregnancy, has been associated with an increased risk of breast cancer. The 1st of these studies, a case-controlled study conducted in California of 314 women under the age of 37 with breast cancer and 314 controls, demonstrated an increased risk when OC use occurred before the age of 25, exhibited a direct relation with duration of use, and essentially refers to contraceptives with elevated "progestagen potency" as primary factors. The preliminary data of another case-controlled study conducted in Great Britain (McPherson et al., 1983), confirmed the hypothesis of increased risk with OC use before the 1st full term pregnancy. However, in this study no significant difference was seen on the basis of type of OC used. These are the 1st studies to show plausible evidence of an association between OC use and breast cancer, they have resulted in various interpretations, and have been received with critical caution. In particular, 1 of the major areas of controversy following publication of Pike's article was the criteria on which he based his "progestagen potency" values. Actually, OCs with elevated progestagen potencies tend also to have elevated estrogen potencies, and it is difficult, if not arbitrary, to discriminate between the effects of the 2hormones. Whether these reports significantly alter OC use remains to be seen, particularly when taking into account the protective effect of OC use against endometrial and ovarian cancer, with an estimated reduction of risk at 40-50% and persisting for many years after cessation of use. It appears prudent, in the face of uncertainty over safety, to discourage use of the preparations associated in Pike's study with elevated risk of breast cancer. On the basis of common sense it is unjustifiable to use preparations with elevated doses when more limited doses are sufficient to obtain the desired effect. Therefore, the OCs currently marketed in Italy are presented and those with elevated estrogen and progestagen potency are identified. The most commonly used OC in Italy, containing 150 mg of levonorgestrel, is situated in an intermediate place in terms of progestagen potency. It should be remembered, finally, that the risk of breast cancer in OC users is considerably less of a worry than concern over vascular pathology.
Cancer mortality among children in Switzerland was analysed using (1) age-specific and age-standardized (0-14) rates from 1951 to 1984 and (2) comparison of observed numbers of deaths over the period 1960-1984 with expected one obtained by application of age-specific rates for the period 1951-1959 to the population structure of subsequent 5-year calendar periods. Certified mortality fell about 60% for leukaemias, 21% for lymphomas, 66% for Wilms' tumours, 40% for bone sarcomas and 30% for other and unspecified sites. Thus, the overall decline in childhood cancer mortality in Switzerland was around 45%, slightly more marked in females (-48%) than in males (-42%), and more pronounced in younger children (over 50% before age 5). This corresponds to an absolute number of about 50 deaths from childhood cancer per year avoided in the early 1980s as compared with expected numbers computed on the basis of rates registered in the 1950s (30 deaths per year for leukaemias alone). The estimated total number of deaths avoided during the whole period 1960-1980 was 820 (430 leukaemias alone). Trends in childhood cancer mortality persisted steadily downwards in the early 1980s, suggesting that further progress is being achieved in the treatment of these neoplasms.
To evaluate the risk factors for serous, mucinous and endometrioid ovarian cysts, data were collected in a case-control study conducted in the greater Milan area based on 202 women with benign cysts (114 endometrioid and 88 serous or mucinous) of the ovary and 1127 controls. Questions were asked about menstrual and reproductive characteristics, marital status, education, history of various diseases, and lifetime use of oral contraceptives and other hormonal treatments. Higher social class, earlier menarche and longer interval between age at first marriage and first birth, a likely indicator of subfertility, were associated with an increased risk of serous, mucinous and endometrioid cysts. Women with endometrioid cyst were characterized by low parity, less frequent irregular or long menses, more frequent oral contraceptive use and low body mass index, while the most relevant risk factor associated with serous and mucinous cysts was greater age at first birth. The present data point out the epidemiological differences between endometrioid and serous or mucinous cysts. Further, they suggest that analyses of risk factors for epithelial ovarian cancer subdivided by various histotypes may be of interest in order to confirm possible heterogeneities in the aetiology of ovarian epithelial neoplasms.
The decline in childhood cancer mortality in Italy from 1955 to 1980 has been evaluated through (1) comparison of age-specific and age-standardized (0-14 years) rates for the periods 1955-1960 and 1979-1980 and (2) computation of expected numbers of deaths by application of the age-specific rates for the period 1955-1960 to the population structure of subsequent periods. Certified mortality fell by 35% for leukaemias, 90% for Hodgkin's disease, 30% for non-Hodgkin's lymphomas, 40% for bone sarcomas, 30% for kidney (Wilms') tumours, 65% for retinoblastoma. No clear trend was reported for other neoplasms, including neuroblastoma. About 300 cancer deaths per year were avoided in the period 1979-1980 compared with the expected number based on the 1955-1960 rates (170 for leukaemias alone). Although clearly encouraging, these trends are substantially less favourable than those from several other developed countries. It is therefore likely that several dozen other deaths from childhood cancer could be avoided each year through earlier (or more accurate) application of effective therapies, particularly for neoplasms requiring radiotherapy or surgical treatment.
Boyle, P. PhD*; Zheng, T. MD*†; Macfarlane, G. J. MD‡§; McGinn, R. MD*; Maisonneuve, P. Ing*; LaVecchia, C. MD¶; Scully, C. MD§ Author Information
Read moreThe relationship between bladder cancer, occupation and exposure to a number of occupational agents was assessed in a case-control study conducted in the greater Milan area, Northern Italy. The case series consisted of 263 cases (219 males, 44 females) with histologically confirmed invasive bladder cancer, admitted to a network including major teaching and general hospitals in the area under surveillance. The controls were 287 patients (210 males, 77 females), admitted for acute, non-neoplastic or urinary tract diseases to the same network of hospitals. Cases more frequently reported occupation in dyestuff production (relative risk (RR) = 4.6), painting/spraying work (RR = 1.8), chemical industry (RR = 1.7), pharmaceuticals (RR = 1.7) and coal/gas production (RR = 3.1). Only for dyestuff production however, was the excess statistically significant. There was no association with agriculture or related activities, rubber manufacturing, printing, the petroleum industry, food processing and mechanics. In relation to exposure to occupational agents, significant positive trends in risk were observed for dyes/paints (RR = 4.8 for greater than ten years of exposure), herbicides (RR = 4.1), chemicals (RR = 2.4) and gases/fumes (RR = 4.8). No association was found with metals or metal dusts, plastic resins or glues, oil, wood dust, solvents or benzene, asbestos, electricity or radar and coal tar. Besides confirming the well known association between bladder cancer risk and dyestuff production and, to a lesser extent, a wide spectrum of chemical-related activities, this study provides statistically significant evidence of an independent role of herbicides on the risk of bladder cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
Read moreItalianIn questo rapporto vengono presentati e discussi i tassi di mortalità per tumori in Italia nel 1979 sulla base dei dati di certificazione di morte pubblicati dall'Istituto Centrale di Statistica (ISTAT). Un modesto incremento si è registrato nei tassi globali standardizzati per età di mortalità per tutti i tumori non soltanto per i maschi (275,82 vs 271,71/100.000 del 1978 nel tasso troncato 35-64), ma anche per le femmine (161,82 vs 160,02/100.000 donne dai 35 ai 64 anni), dopo sei anni di continue diminuzioni della mortalità globale per tumori nelle donne giovani e di mezza età. Questi andamenti piuttosto sfavorevoli sono in larga misura attribuibili ad un diminuito tasso di decremento per quelle neoplasie che sono state in costante diminuzione nel corso degli ultimi tre decenni. In particolare, i tassi di certificazione di morte per i tumori del (collo) dell'utero sono rimasti totalmente stabili nelle donne giovani e di mezza età e la mortalità per carcinoma gastrico nelle femmine dai 35 ai 64 anni ha addirittura mostrato un leggero incremento. Analogamente, moderati aumenti si sono osservati nella mortalità per leucemie in giovane età in entrambi i sessi. Tra i tumori « altamente curabili », l'unico a mostrare consistenti diminuzioni è stato il morbo di Hodgkin. D'altra parte, sono continuate le tendenze all'aumento nella mortalità per tumori del polmone e degli altri organi associati al tabacco (cavo orale e faringe, laringe, esofago, rene e vescica), quantomeno negli uomini di mezza età o di età più avanzata, e, seppur in misura più limitata, anche nelle donne. Inoltre, nessun accenno a diminuzioni nella mortalità per carcinoma del polmone è per ora evidente neppure nei maschi più giovani (dai 35 ai 44 anni), il che appare in netto contrasto rispetto ai recenti andamenti in molti altri Paesi sviluppati. Aumenti si sono anche registrati per le neoplasie del fegato, dell'intestino e della pleura (i quali tuttavia non sono facilmente interpretabili a causa dei cambiamenti introdotti nella Nona Revisione della Classificazione Internazionale delle Malattie, entrata in uso nel 1979), e per i tumori della cute (melanomi) in giovane età per le femmine, mentre i tassi di mortalità sono rimasti praticamente stabili nel 1979 per le neoplasie della mammella, dell'ovaio e della prostata, quantomeno al di sotto dei 65 anni quando la certificazione di morte è più accurata.
Read moreBetween January 1980 and March 1983, data were collected to evaluate risk factors for breast cancer in a case-control study based on 368 women with breast cancer admitted to the General Hospital of Pordenone (a district in North Eastern Italy with a particularly high breast cancer mortality rate), and 373 age-matched controls. Nulliparity or low parity, late age at first birth and later menopause were associated with an increased risk of breast cancer. The elevated risk associated with nulliparity could be almost completely explained by marital status, thus pointing to a specific protection given by parity, rather than some putative influence of infertility or subfertility in breast cancer cases. Likewise, risk did not vary materially according to history of abortions when marital status was controlled for. Increased risk associated with later age at first birth, on the other hand, was not accounted for by marital status or parity. The population studied, though frequently multiparous, showed late average at first birth: this might, at least partly, explain its high mortality rate from breast cancer. The risk estimate was higher if menarche occurred below age 15; however, there was no evidence of a trend for the relative risk to rise with lower age at menarche. The use of oral contraceptives or other female hormones (such as oestrogen replacement therapy) did not appear to be related to the risk of breast cancer. The role of the major menstrual and reproductive variables considered (age at menarche, parity, age at first birth) was apparently stronger in pre-menopausal women, thus suggesting an influence of these factors (and possibly, their hormonal correlates) on one of the latter stages of the process of carcinogenesis.
Read moreThe relation between ABO blood group, mating patterns of patient/husband blood group, and the risk of gestational trophoblastic disease was investigated in a case-control study conducted in Milan on 286 women with histologically confirmed trophoblastic disease (245 benign hydatidiform moles and 41 persistent trophoblastic disease) and 433 control subjects admitted for normal delivery to the same hospitals where cases had been identified. ABO blood groups were associated with the risk of gestational trophoblastic disease (chi 2(6) for heterogeneity = 14.46, p = 0.02). Compared to women of group O or B, women of group A and AB had an elevated relative risk (RR) of benign mole (RR = 1.4 and 2.3, respectively). The risk estimates were higher for persistent trophoblastic disease, i.e., 2.2 for women of group A and 4.8 of group AB. The tests for linear trend in risk from benign to persistent disease were statistically significant in both A and AB groups. There was a significant interaction between blood group and age, since the ABO-related risk was elevated only for women over the age of 35. When mating combinations of maternal/paternal blood groups were considered, women of group A married to males of group O had a risk estimate not substantially different than those married to group A males.
Read moreData collected by the Cancer Registry of the Canton of Vaud, Switzerland, were used to estimate proportional mortality ratios (PMR) and mortality odds ratios (MOR) for various neoplasms according to social class and sector of occupation (agriculture versus others). Mortality ratios were elevated in lower social classes for cancers of the lung (MOR = 1.18 for social class IV or V vs I or II) and other sites strictly related to tobacco (mouth or pharynx, oesophagus and larynx; MOR = 1.70), and (though not significantly) for cancers of the stomach (MOR = 1.16) and uterus (MOR = 1.30 for cervix and 1.47 for corpus uteri). Furthermore, there was a strong negative social class gradient for thyroid cancer (a neoplasm with particularly elevated incidence and mortality in Switzerland), probably attributable to higher prevalence of iodine deficiency in lower social classes (MOR = 3.17). Positive social class gradients emerged for cancers of the intestines (MOR = 0.77 for social class IV or V), skin (MOR = 0.74) and prostate (MOR = 0.87). Agricultural workers showed decreased ratios for cancers of the lung (MOR = 0.75), cervix uteri (MOR = 0.72) and prostate (MOR = 0.80), and excess mortality from cancers of the upper digestive and respiratory sites (MOR = 1.22), stomach (MOR = 1.18), testis (MOR = 2.05) and lympho-haematopoietic neoplasms, particularly myeloma (MOR = 2.14).
Read moreThe relationship between breast cancer and alcoholic beverage consumption was investigated in a case-control study of 437 women with breast cancer and 437 age-matched controls admitted to the hospital for acute conditions apparently unrelated to alcohol consumption. Compared to the relative risks (RR) for women who had never drunk alcohol, the RR for those reporting 1-3 and more than 3 alcoholic drinks per day were 1.24 and 1.93, respectively. A similar positive trend in risk with increasing daily consumption was evident for wine alone, and the point estimates were above unity for beer and spirits. Allowance for all identified potential confounding factors (including the major risk factors for breast cancer and a few selected dietary items) did not appreciably change any of the alcohol-related estimates. The RR, however, were higher at younger ages and did not rise with increasing duration of use. Nonetheless, the findings of the present study and their similarity with those of another case-control study conducted in northeastern Italy indicate that the association between alcoholic beverage consumption and breast cancer in this population is probably real, though not necessarily causal.
Read moreThe role of different types of alcoholic beverage on cancer of the upper digestive tract was investigated in a case-control study conducted in the northern part of Italy on 305 male cases of cancer of the oral cavity and pharynx, 288 of oesophageal cancer and 1621 controls admitted to hospital for acute, non-neoplastic conditions, unrelated to alcohol intake. Similar significant trends of risk increase with increasing alcohol intake were seen for cancers of the oral cavity, pharynx and oesophagus independent of type (or types) of beverage consumed. Among the heaviest drinkers (i.e. greater than or equal to 84 drinks/week) odds ratios (ORs) of cancer of the oral cavity and pharynx for wine only, wine and spirits, and combination of wine, spirits, and beer were 11.2, 9.9 and 4.1, respectively. Corresponding oesophageal cancer ORs were 15.0, 10.0 and 6.0. This study from an area with high wine consumption confirms that wine per se can greatly enhance the risk of cancer of the upper digestive tract and suggests that the most frequently used alcoholic beverage in each study appears to be the most important determinant of these tumours.
Read moreWe used an age-period-cohort model with arbitrary constraints on the parameters, fitted to the mortality data for the period 1955-84, to project rates in mortality from all cancers and 11 major cancer sites in Italy for the period 1985-1999. For all neoplasms considered, using estimated age and cohort values, two models were fitted, one based on constant period effects, and one on a linear regression on the logarithm of the six calendar periods. Furthermore, "a priori" defined coefficients based on epidemiologic inferences were given to period values for tobacco-related neoplasms (below unity for males, above unity for females, on the basis of recent trends in tobacco prevalence in the two sexes), for breast and ovarian cancer (in relation to the potentially different effect of oral contraceptives, other female hormones, reproductive factors and treatment on these neoplasms), and for total cancer mortality. This produced a range of potential estimates, which were reasonably similar for neoplasms (such as stomach, intestines, breast, ovary or prostate) for which no major change in slope of the cohort effects was evident, but wider (i.e., between 188 and 264/100,000 males aged 40 to 79 in 1995-99) for lung or other tobacco-related cancers. Although this range of variation is far from negligible, the estimated values indicate that lung cancer among Italian males aged 40 to 79, even under the more optimistic assumption, will probably be higher at the end of the century than in the early 1980's, and that lung cancer alone will account for 35 to 42% of all cancer deaths in males between 40 and 79 years. Though any prediction has, by definition, inherent difficulties and uncertainties, cancer mortality in the near future will be strongly influenced by age and cohort effects already known, and hence its projections may offer some indication of public health relevance.
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