Diet and ovarian cancer risk: A case-control study in Italy

Abstract

To assess the dietary correlates of cancer of the ovary, the consumption of a wide range of food groups has been investigated in a case-control study conducted between January 1992 and September 1999 in 4 Italian areas. Cases were 1,031 women with incident, histologically confirmed epithelial ovarian cancer; controls were 2,411 women admitted to the same network of hospitals as the cases for acute, non-malignant and non-gynecological conditions, unrelated to hormonal or digestive tract diseases or to long-term modifications of diet. The subjects' usual diet was investigated through a validated food frequency questionnaire including 78 foods and recipes, then grouped into 18 food groups. Odds ratios (OR), and the corresponding 95% confidence intervals (CI) were estimated using unconditional multiple logistic regression models including terms for age, study center, education, year at interview, parity, oral contraceptive use and energy intake. Our knowledge on risk factors of ovarian cancer is mainly related to hormonal and reproductive factors, and include nulliparity, late age at menopause, family history of ovarian and breast cancer, and infrequent oral contraceptive (OC) use. 1 Diet has been suggested to have a potential influence on ovarian carcinogenesis, although dietary associations have not yet been established and well quantified, and only scattered data from epidemiological studies are available. 2 Descriptive epidemiology and ecological studies have reported positive relations between fats, proteins and total calories intake and ovarian cancer risk. 3,4 Data from analytical, mainly casecontrol studies, also supported the hypothesis of a possible increased risk in relation to various types of fat, 5-10 but not with monounsaturated ones. 11 With reference with specific foods, several case-control studies reported a beneficial effect of diet rich in vegetables on ovarian cancer risk. 7,10,12,13 A few case-control studies showed that women with cancer of the ovary reported more frequent meat consumption, 8,10,14 and others suggested that high egg intake may also increase the risk of ovarian cancer. 6,7,9 Fish, on the other hand, seemed to exert a protective effect. 6,8,15,16 The evidence of an association between these foods and cancer of the ovary is, however, inadequate.Ovarian cancer also has been reported to be correlated with per capita milk consumption and lactase persistence, 17,18 and it has been hypothesized that lactose, or its component sugars, may be responsible for this association. 17 Other investigations, however, did not support the hypothesis that galactose plays a role in the development of ovarian cancer, 12,19 -21 and suggested that any potential association between milk consumption and ovarian cancer may be due to the fat content of milk. 16,22,23 To better assess the dietary correlates of cancer of the ovary, the consumption of a wide range of food groups has been investigated in a uniquely large hospital-based case-control study conducted in Italy. MATERIAL AND METHODSA multicentric...

Fruit and vegetable consumption in relation to ovarian cancer incidence: the Swedish mammography cohort

“…Case -control studies on fruit consumption have yielded conflicting results. Although one study in China (Zhang et al, 2002) indicated a statistically significant inverse association between total fruit consumption and risk of ovarian cancer, four other studies found no association (Shu et al, 1989;Bosetti et al, 2001;McCann et al, 2001McCann et al, , 2003 and one study in Mexico (SalazarMartinez et al, 2002) reported a statistically significant positive association.…”

“…All four case -control studies on total vegetable consumption and ovarian cancer risk have reported an inverse association (Bosetti et al, 2001;McCann et al, 2001McCann et al, , 2003Zhang et al, 2002). Case -control studies on fruit consumption have yielded conflicting results.…”

“…In addition to being a major source of dietary vitamin C, folate, and fibre, fruits and vegetables also contain numerous other potentially anticarcinogenic phytochemicals (Park and Pezzuto, 2002). The majority of case -control studies (La Vecchia et al, 1987;Engle et al, 1991;Bertone et al, 2001;Bosetti et al, 2001;Cramer et al, 2001;McCann et al, 2001;Zhang et al, 2002;McCann et al, 2003), although not all (Shu et al, 1989;Salazar-Martinez et al, 2002), have suggested an inverse association of consumption of total vegetables or of certain subgroups of vegetables with ovarian cancer risk. In two prospective cohort studies that have reported results for consumption of total vegetables and ovarian cancer risk (Kushi et al, 1999;Fairfield et al, 2001), a nonsignificant approximately 25% reduction in ovarian cancer risk was observed for the highest in comparison with the lowest category of consumption.…”

“…A recent comprehensive review of the literature on fruit and vegetable consumption and cancer by the IARC Working Group on the Evaluation of Cancer-Preventive Strategies (2003) concluded that 'an increase in consumption of vegetables possibly reduces the risk of ovarian cancer'. In contrast to vegetable consumption, fruit consumption in case -control (Shu et al, 1989;Bosetti et al, 2001;McCann et al, 2001McCann et al, , 2003Salazar-Martinez et al, 2002;Zhang et al, 2002) and cohort studies (Kushi et al, 1999;Fairfield et al, 2001) of ovarian cancer have yielded conflicting results, with both inverse and positive associations.…”

Risk factors and risk reduction of breast and ovarian cancer

“…The evidence remains inconsistent; recent studies suggest that food items high in carotene and lycopene might decrease the risk [48], whereas red meat was associated with an elevated risk [49]. However, all positive studies were case-control studies, and a recent prospective study within the Nurses' Health Study found no association between the usage of vitamins/ carotenoids and ovarian cancer [50].…”