Fruit and breast cancer.

Total breast cancer risk: Data about total fruit in relation to total breast cancer risk was provided by a pooled analysis of 8 cohorts, and 9 additional cohorts, including a total of 18,425 cases.
A weak significant protective effect was found in one cohort of very large size, including 5,815 cases (38). And a weak nonsignificant protective effect was found in the pooled analysis, including 7,377 cases (15). No other (non)significant associations were found. The average RR = 0.96 (excluding incomplete data from Hirvonen T [30], Iwasaki M [20], Jarvinen R [11]).
No levels of consumption were defined in the pooled analysis, but effects were restricted to above median consumption (quartiles 3-4).

Inclusion of intermediate levels of consumption:
(Non)significant effects at any level of consumption were as follows:

  • Shibata A (1) Significant protective at 192-< 296 g/day.
  • George SM (38) Though the trend was significant, the effect was nonsignificantly protective at > 608 g/day.

RRs for the association between total fruit and breast cancer risk (g/day):


Effect modification: Effect modification was found in the pooled analysis of 8 cohorts (Smith-Warner SA). Protective effects against cancer risk were restricted to never users of oral contraceptives.

Disease progression: Data about total fruit in relation to disease progression was provided by 2 cohorts, including a total of 545 cases.
No (non)significant associations were found with breast cancer recurrence. The average RR = 0.82.

Breast cancer mortality: Results were included about a) breast cancer mortality, and b) mortality following diagnosis of breast cancer. If data about both all-cause mortality, and breast cancer-specific mortality were available following diagnosis of breast cancer, total mortality was chosen as end point.
Data about total fruit in relation to breast cancer death was provided by 10 cohorts, including a total of 1,264 cases.
A significant protective effect was found in one cohort (6), and a nonsignificant protective effect was found in one other cohort (31), including a total of 117 cases for both cohorts combined. No other (non)significant associations were found. The average RR = 0.90 (excluding incomplete data from Goodwin PJ [23], Ingram D [6]).

Inclusion of intermediate levels of consumption:
Significant effects at any level of consumption were restricted to one cohort. A significantly increased risk was found at the level of consumption of 235-350 g/d (Pierce JP). Though trends were protective in 2 cohorts, no (non)significant protective effects were found in any cohort.



RRs for the association between total fruit and breast cancer mortality (g/day):


Conclusion: A weak significant protective effect of total fruit against breast cancer risk was found in one cohort of very large size, and a weak nonsignificant protective effect was found in a pooled analysis of 8 cohorts. The combined amount of cases from these cohorts included 72% of all cases. Suggestive evidence was found for a weak protective effect of total fruit against breast cancer risk (- 4%). This effect may be restricted to never users of oral contraceptives. No level of consumption could be defined for this effect, but above median consumption seems required.
Protective effects against mortality were found in 2 cohorts, and these were significant once. These cohorts included 9% of all cases. No associations were found with breast cancer recurrence. No evidence was found for an association between total fruit and breast cancer recurrence or breast cancer mortality.

Prospective studies of total fruit and breast cancer risk:
AuthorCohort nameCasesRelative Risk (RR)
38) George SM (2008)The NIH-AARP Diet and Health Study5,815RR = 0.91 (0.84-1.00; P = 0.01)
30) Hirvonen T (2006)The SU.VI.MAX Study95No significant association (P = 0.73)
24) Sonestedt E (2008)The Malmö Diet and Cancer Cohort544HR = 0.93 (0.70-1.23; P = 0.58)
22) Maynard M (2003)The Boyd Orr Cohort82OR = 1.08 (0.52-2.25; P = 0.61)
21) van Gils CH (2005)The EPIC Study3,659RR = 1.09 (0.94-1.25; P = 0.11)
20) Iwasaki M (2008)The JPHC Study144No significant association (P = 0.79)
15) Smith-Warner SA (2001)Pooled analysis of 8 cohort studies7,377RR = 0.93 (0.86-1.00; P = 0.08)
13) Key TJ (1999)The Hiroshima/Nagasaki Life Span Study402RR = 0.95 (0.71-1.27; P = 0.53)
11) Jarvinen R (1997)The Finnish Mobile Clinic Health Cohort88No significant association (no data shown)
1) Shibata A (1992)The Leisure World Study219RR = 0.82 (0.60-1.12)
Total number of cases: 18,425Average RR = 0.96


Prospective studies of total fruit and breast cancer disease progression:
AuthorCohort nameCasesEnd pointRelative Risk (RR)Dietary assessment following cancer diagnosis
35) Pierce JP (2007)The WHEL Trial517Breast cancer eventsHR = 0.81 (0.57-1.16)Yes
14) Saxe GA (1999)No cohort name defined28Breast cancer recurrenceHR = 0.96 (0.63-1.45)Yes
Total number of cases: 545Average RR = 0.82


Prospective studies of total fruit and total/breast mortality:
AuthorCohort nameCasesRelative Risk (RR)Dietary assessment following cancer diagnosis
35) Pierce JP (2007)The WHEL Trial314HR = 0.76 (0.48-1.19)Yes
32) Fink BN (2006)The Long Cancer Island Breast Cancer Study ProjectPremenopausal: 43.

Posmenopausal: 132.
Premenopausal: HR = 1.10 (0.48-2.52; P = 0.28).

Postmenopausal: HR = 0.87 (0.57-1.35; P = 0.34)
Yes
31) McEligot AJ (2006)No cohort name defined96HR = 0.63 (0.38-1.05; P = 0.08)Yes
23) Goodwin PJ (2003)No cohort name defined52No significant association (no data shown)Yes
22) Maynard M (2003)The Boyd Orr Cohort36OR = 1.25 (0.40-3.92; P = 0.73)No
14) Saxe GA (1999)No cohort name defined26HR = 1.06 (0.69-1.63)Yes
13) Sauvaget C (2003)The Hiroshima/Nagasaki Life Span Study76RR = 0.91 (0.48-1.72; P = 0.70)No
8) Appleby PN (2002)The Health Food Shoppers Study90RR = 0.66 (0.38-1.14)No
6) Ingram D (1994)No cohort name defined21A significant protective effect (P = 0.01)Yes
4) Holmes MD (1999)The Nurses' Health Study378RR = 1.07 (0.77-1.49; P = 0.40)Yes
Total number of cases: 1,264Average RR = 0.90