While tamoxifen treatment can result in an improvement in low-density lipoprotein (LDL, the "bad" cholesterol), a switch to an aromatase inhibitor can be accompanied by an increase in harmful cholesterol. This suggests that women who make such a switch should have their cholesterol levels monitored. Now a new study has reported that treatment with Femara (letrozole) after five years on tamoxifen can worsen cholesterol profile.

Recommended cholesterol lowering foods

Below are foods that are known to reduce cholesterol while at the same time protecting against breast cancer.

Apples
Bell peppers
Blueberries
Broccoli
Brown rice
Brussels sprouts
Buckwheat
Cabbage
Canola oil
Carrots
Celery
Cherries
Cranberries

Cucumbers
Dry beans
Flaxseed
Grapes
Greens
Hot peppers
Kale
Lettuce
Mushrooms
Olive oil
Pomegranates
Seaweed
Walnuts

Foods that increase cholesterol

The following foods have been shown to worsen cholesterol profile. Most of these foods are also associated with increased risk of breast cancer.

Bacon
Beef
Butter
Caviar
Cheese
Coffee

Lamb
Whole milk
Partially hydrogenated oil
Pork
Shellfish

Latest research finds Femara after tamoxifen can worsen cholesterol profile

The study referenced at the beginning of this news article was designed to investigate changes in circulating cholesterol and other lipids in women treated with Femara following five years on tamoxifen. Study participants did not initially have high cholesterol and were not taking cholesterol lowering drugs. The study included 183 postmenopausal women in MA.17L, a sub-study of MA.17, a double-blind, placebo-controlled trial of extended treatment with Femara. Study participants' lipids (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, and lipoprotein(a) (an LDL-like particle associated with cardiovascular disease)), were evaluated at baseline, six months, 12 months, then yearly until completion of five years of Femara. Not all participants finished five years of treatment.

Study participants were found to have significant increases compared to baseline in total cholesterol, LDL cholesterol, and lipoprotein(a) at all measurement time points. A five years, total cholesterol was higher by an average of 5.27%; the corresponding increases were 6.75% for HDL cholesterol (the "good cholesterol"), 10.02% for LDL cholesterol, and 105.95% for lipoprotein(a). A total of 103 (56%) participants experienced significantly elevated levels of lipoprotein(a) (106% above baseline) after five years of Femara. The results were similar after excluding the 21% of women who had ever received anti-lipid treatment. On the other hand, there were no statistically significant changes in triglycerides. The authors conclude that significant increases in total cholesterol, HDL cholesterol, LDL cholesterol, and lipoprotein(a) in postmenopausal women were observed after five years of Femara following five years of tamoxifen. Lipid levels of such patients should be monitored in clinical practice, according to the authors.

Please see our article on breast cancer diet during aromatase inhibitor treatment for more information on how to optimize treatment with aromatase inhibitors and reduce side effects.