Abstract

OBJECTIVES:

• To review all prospective studies which provided data about total fruits or vegetables, their subgroups, and specific types of vegetables and fruits, in relationship with ovarian cancer risk, disease progression and mortality/survival.
• To define the amount of consumption found to be related with the described effects on cancer.
• To define possible effect modification by confounders.

DATA SOURCE: The Pubmed database was searched (No start date - Sep 11, 2009) for relevant articles using the keywords "cancer, neoplasm, or neoplasms" combined with "vegetables, vegetable, fruit, or fruits" and a fair amount of other keywords. The exact search term is described in the methods.
Prospective studies published in the English language were included. Reference lists were searched for additional articles.
RESULTS: 16 articles were found which provided information about 17 different cohorts.
Of these, o articles were excluded.
Results are described when any evidence for an association - as defined in the Methods - was found. In addition, data about total vegetables or fruits is described.

• Total disease risk.
  -Data about total vegetables was provided by a pooled analysis of 12 cohorts, and 2 additional cohorts, including a total of 3,224 cases. Suggestive evidence was found for a protective effect of total vegetables against ovarian cancer risk among women diagnosed at age ≥ 63. No level of consumption could be defined for this effect.
  -Data about total fruits was provided by a pooled analysis of 12 cohorts, and 2 additional cohorts, including a total of 3,225 cases. No evidence was found for an association.
  -Data about green leafy vegetables was provided by a pooled analysis of 12 cohorts, and 1 additional cohort, including a total of 2,674 cases. Suggestive evidence was found for a protective effect of green leafy vegetables against ovarian cancer risk. No level of consumption could be defined for this effect.
• Advanced stage/metastatic disease risk or disease progression.
  No data was found.
• Mortality risk.
  -Data about total vegetables was provided by 1 cohort, and therefore to limited to be judged as evidence.
  -Data about total fruits was provided by 2 cohorts. No evidence was found for an association.

CONCLUSION: Overall, few significant effects were described by any article. Suggestive evidence was found for a protective effect of total vegetables against ovarian cancer risk among women diagnosed at age ≥ 63, and suggestive evidence was found for a protective effect of green leafy vegetables against ovarian cancer risk. No other evidence for any other association was found. No levels of consumption could be defined for the described associations.

Total vegetables and ovarian cancer.

Ovarian cancer risk: Data about total vegetables in relation to ovarian cancer risk was provided by a pooled analysis of 12 cohorts (9), and 2 additional cohorts (8, 12), including a total of 3,224 cases.
No (non)significant associations were found.

Inclusion of intermediate levels of consumption:
Data from one cohort was not presented as a categorized variable, and therefore, could not be included (8). No (non)significant effect was found in any of the cohorts at any level of consumption.

Effect modification:
A nonsignificant protective effect was found in the pooled analysis among women diagnosed at ≥ 63 years, but not < 63 years. No effect modification was found by parity, oral contraceptive use, postmenopausal hormone use, smoking status, alcohol consumption, or multivitamin supplement use (9).

Disease progression: No data was found.
Ovarian cancer mortality: Data about the relation with ovarian cancer mortality was provided by 1 cohort (5). A significant protective effect was found.

Conclusion: No associations were found between total vegetables and ovarian cancer risk, but a nonsignificant protective effect was found among women diagnosed at age ≥ 63. Suggestive evidence was found for a protective effect of total vegetables against ovarian cancer risk among women diagnosed at age ≥ 63. No level of consumption could be defined for this effect. Data about disease progression/mortality is to limited to be judged.

Total fruit and ovarian cancer.

Ovarian cancer risk: Data about total fruits in relation to ovarian cancer risk was provided by a pooled analysis of 12 cohorts (9), and 2 additional cohorts (8, 12), including a total of 3,225 cases.
A nonsignificantly increased risk was found in one cohort (8). No other associations were found.

Inclusion of intermediate levels of consumption:
Data from one cohort was not presented as a categorized variable, and therefore, could not be included (8). But the related article stated that "there was evidence for an increased risk for both low (< 150 g/d) and high intake (> 250 g/d)".
A significantly increased risk was found in one cohort of very large size at the level of consumption of 192-310 g/day (12; George SM). No other (non)significant effects were found.

Effect modification: The association tended to differ by age of diagnosis, but not significant (9). No effect modification was found by parity, oral contraceptive use, postmenopausal hormone use, smoking status, alcohol consumption, and multivitamin supplement use.

Disease progression No data was found.
Ovarian cancer mortality Data about the relation with ovarian cancer mortality was provided by 2 cohorts (5, 10). No associations were found.

Conclusion: A nonsignificantly increased ovarian cancer risk was found in one cohort, but no other associations were found. No evidence was found for an association between total fruit and ovarian cancer risk. No data was found about disease progression, and no associations were found with ovarian cancer mortality. No evidence was found for an association between total fruit and disease progression or ovarian cancer mortality.