The document summarizes two studies on the relationship between calcium, vitamin D, and breast cancer risk. The first study found that higher intakes of calcium and vitamin D were associated with lower breast cancer risk in premenopausal women but not postmenopausal women. The second study examined long-term dietary calcium intake in a cohort of Swedish women and found that higher calcium intake was associated with a 34% lower risk of developing estrogen receptor-negative and progesterone receptor-negative breast cancer. Both studies provide evidence that calcium and vitamin D may reduce breast cancer risk, particularly for hormone receptor-negative breast cancers, though more research is still needed.

1. Breast Cancer
SEAN DAVENPORT
BRIANNA CANTRELL
ASHLEY CLARK
DANA OMARI
EMILY SMITH
OLIVIA WOOLIVER

2. Breast Cancer
 Breast cancer refers to a malignant tumor that has
developed from cells in the breast
 Cells of the lobules

Milk producing glands
 Ducts
 Passages that drain milk from the lobules to the nipple
 Less commonly:
 Stromal tissues, which include the fatty and fibrous connective
tissues of the breast.

3. What are the symptoms?
 Swelling of all or part of the breast
 Skin irritation or dimpling
 Breast pain
 Nipple pain or the nipple turning inward
 Redness, scaliness, or thickening of the
nipple or breast skin
 Nipple discharge other than breast milk
 Lump in the underarm area

4. Overview of Vitamin D
 Role in serum calcium homeostasis – acts to
increase or decrease serum calcium levels
 Also aids in calcium homeostasis in other
areas such as bone, kidney, intestine, etc.
 Helps to maintain/control normal cell
growth, differentiation, and proliferation

5. Overview of Calcium
 Calcium plays a regulatory role in cell proliferation,
differentiation, and apoptosis
 Experimental studies show that Calcium intake is
related to:



An inverse relationship with mammographic breast density
Decreased fat-induced epithelial hyperproliferation of the
mammary gland and chemically-induced mammary
carcinogenesis in rodents
Reduced amount of breast cancer precursors in epidemiologic
studies

6. Study 1: Intakes of Calcium and Vitamin
D and Breast Cancer Risk in Women
 Background
 Increasing Calcium and Vitamin D intake in female mice led
to regression in mammary tumors.
 Evaluation of Calcium and Vitamin D intake
 Subjects were divided into groups
 10,578
Premenopausal women
 20,909 Post menopausal women
45 years or older

7. Dietary Assessment
 Food frequency questionnaire
 Average
use of food and beverages past 12
months
 Calcium and Vitamin D intakes included
sources from both Diets and Supplements

8. Ascertainment of Breast Cancer Cases
 Follow up questionnaires on whether breast cancer
was diagnosed
 Every 6 months for first year
 Annually after first year
 Medical records attained to confirm
diagnosis/death
 Average 10 year follow-up of incident invasive
breast cancer
 276 premenopausal women diagnosed
 743 post menopausal women diagnosed

9. Influences
 Examination of dietary factors
 Vitamin
D
 Phosphorus
 Fat
 Lactose

10. Results
 Relation to function:
 Premenopausal
women
Higher intakes of total Calcium & Vitamin D
were associated with lower risk of breast cancer
 Postmenopausal women
No association between calcium/Vitamin D
levels and risk of breast cancer
 Possible explanation: relationship between
Calcium, Vitamin D, and IGFs

11. Discussion
 Calcium, Vitamin D, and IGFs:
 Suggestion
that Calcium & Vitamin D have
anti-cancer effects on breast cancer cells
expressing high levels of IGF-1 & IGF
binding protein 3
 Promote growth inhibition
 IGF levels decline with age

12. Discussion
Strengths
Weaknesses
 Large sample size
 Possible confound
 Prospective design
 Nutrient intake only
 Long duration
assessed once
 Vitamin D intake from
sunlight exposure
 High follow-up rates

13. Study 2: Long-term dietary calcium intake
and breast cancer risk in a prospective cohort of women
 To examine the potential association
between Calcium intake and breast
cancer risk and whether this
association varies by ER/PR status of
the breast tumor

14. Subjects and Methods
 Swedish Mammography Cohort
 Population-based cohort of 61,433 women cancer-
free at baseline
 Enrollment: 1987-1990
 Two questionnaires:


Baseline
1997
 Case ascertainment for ER/PR status
 Pathology labs, Clinical databases

15. Results
 17.4 year follow up on average 4.81% developed
invasive breast cancer
 Of these cases:
 62.4% ER+/PR+
 20.2% ER+/PR 12.9% ER-/PR 4.5% ER-/PR+
 Adjustments made for:
 Dietary Vitamin D
 Conjugated Linoleic Acid intake

16. Results

17. Results
 Highest Calcium Intake

34% less likely to develop ER-/PR- breast cancer
 Overall Calcium Intake


Decreased receptor-negative species of breast cancer
However, association was not statistically significant

18. Discussion
Strengths
Weakness
 Prospective and
 Dietary intake was self-
population based
design
 Large sample size
 Detailed info on diet
 Info on hormone
receptor status
administered FFQ
 Confounding variables

19. Conclusion
 Nutrient Mechanisms:


Calcium absorption is positively correlated with vitamin D
intake
Vitamin D works inversely with estrogen receptors (ERs) and
progesterone receptors (PRs), and actually has its own
receptors (VDRs) in mammary glands/tissue
 Apart from its role in aiding calcium absorption, the
receptors for vitamin D found here could indicate a bigger
part in preventing cancer
 This facet needs further research for conclusive evidence

20. Cohort: designed to show incidence; best for predicting risk
factors in research, based on exposure or no exposure
Pros
Cons
 Easier to administer
 Hard to identify
 Cheaper than
controls
 Blinding is difficult
 Recall &/or volunteer
bias
conducting a
Randomized Control
Study (RCT)

21. Questions