Young Women With History of Breast Cancer at Higher Risk of Osteopenia and Osteoporosis

A recent study in Breast Cancer Research showed that women who have had breast cancer had a 68 percent higher risk of osteopenia and osteoporosis compared to women who have never had cancer.

Background

Osteopenia and osteoporosis are two conditions associated with bone loss. Osteopenia is when your bones are weaker than usual. Osteoporosis is a condition when your bones have become even weaker and brittle, making them more likely to break. Both are common in women over the age of 50. About 15 percent of women over age 50 have osteoporosis and 51 percent have osteopenia.

Bone loss is linked to a number of common conditions and activities, including getting older, a change in hormone levels caused by menopause, lack of exercise, and smoking and drinking. Bone loss is an issue because weakened bones are more prone to breaking, called bone fracture.

Women who have had breast cancer may have increased risk of bone loss due to the effects of cancer treatment on their bones. Taking aromatase inhibitors blocks your body’s production of estrogen, a hormone that helps the cells that make bone. Chemotherapy and tamoxifen treatments can increase bone loss because they cause early menopause in younger women. Chemotherapy can also be toxic to your cells that form bones.

Researchers wanted to study the connection between breast cancer and loss of bone density. They also wanted to understand how the different kinds of cancer treatment impact a woman’s risk of osteopenia and osteoporosis.

Design

This study used participants from a cohort based at the Johns Hopkins Sidney Kimmel Comprehensive Cancer Center in Baltimore. This Baltimore cohort included men and women with a family risk for breast or ovarian cancer. Participants were at least 18 years old and had

• a family history of breast or ovarian cancer
• a BRCA mutation, or
• a diagnosis of breast cancer before the age of 40 with no family history of breast cancer.

In this study, the researchers looked at a group of women from the Baltimore cohort who were diagnosed with breast cancer in the past, and a comparison group of women who had never had breast cancer. Women in the breast cancer group had been diagnosed with breast cancer in the 5 years before they joined the study.

A total of 778 women (211 women with a history of breast cancer and 567 cancer-free) joined the study. All women completed a survey at the beginning of the study. Follow-up surveys, sent every 3 to 4 years, asked whether participants were diagnosed with osteopenia or osteoporosis since joining the study.

Results

Women in this study were mostly white (89 percent), college educated (78 percent) and were an average of 45 years old. Among the women who had been diagnosed with breast cancer:

• 76 percent had hormone receptor-positive breast cancer
• 65 percent of the overall group received hormonal therapy
• 50 percent of the overall group received chemotherapy

The breast cancer group had a 68 percent higher risk of osteopenia or osteoporosis than the group of cancer-free women.

There was no increased risk of osteopenia and osteoporosis for women treated with surgery, chemotherapy, or hormonal therapy alone. However, women with a breast cancer history had a higher risk of osteopenia and osteoporosis if they

• were diagnosed under the age of 50
• had hormone receptor-positive breast cancer
• received aromatase inhibitors alone, or with chemotherapy
• received tamoxifen with chemotherapy
• were diagnosed less than a year before joining the study

Women who had not been through menopause when they were diagnosed also had a higher risk of osteopenia and osteoporosis.

What This Means for You

While all women are at risk of osteopenia and osteoporosis as they age, this study showed that women who have had breast cancer have an increased risk. Researchers have known that breast cancer treatments can interfere with the processes that maintain bone health and strength, but this study shows how they affect risk over the population of women who take them.

If you were recently diagnosed with breast cancer, talk to your healthcare provider about your bone health and having a fracture risk assessment. Protecting your bones early in treatment may help to lower your risk of osteopenia and osteoporosis during and after treatment. Exercise and a diet that includes healthy levels of calcium and vitamin D are recommended to help prevent bone loss. If you are already diagnosed with osteopenia or osteoporosis, speak to your healthcare team about what activities are safe for you.

Ramin, C., May, B. J., Roden, R. B. S., et al. Evaluation of osteopenia and osteoporosis in younger breast cancer survivors compared with cancer-free women: a prospective cohort study. Breast Cancer Research, Nov. 13, 2018. 20(1). doi:10.1186/s13058-018-1061-4

This article was supported by the Grant or Cooperative Agreement Number 1 U58 DP005403, funded by the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention or the Department of Health and Human Services