Aromatase inhibitors are a class of drugs that are sometimes prescribed by doctors treating post-menopausal breast cancer. These inhibitors significantly reduce the production of estrogen in the body of the breast cancer patient. With the reduction of estrogen, there is very less of it available to stimulate growth of specific types of breast cancer cells in the body of the patient. However, this reduction in the level of estrogen in the blood also weakens the bones of the patients. As cancer drugs are long terms drugs, aromatase inhibitors such as anastrozole, letrozole, exemestane, vorozole, formestane and fadrozole given over a long period of time to breast cancer patients increases their chances of bone loss and fracture development considerably.
However, there is now hope through a drug – zoledronic acid, used in the treatment of osteoporosis if taken along with the breast cancer medication can maintain reasonable bone health of the breast cancer patients. Zoledronic acid was found in studies conducted by xxxx to protect against the bone damaging side-effects of cancer medication and treatment (drugs only).(1)
The findings of the study were published early online in Cancer, a peer-reviewed journal of the American Cancer Society.. The study lead by Adam Brufsky, MD, PhD, of the University of Pittsburgh Cancer Institute, was conducted over a five year period covering random 602 post-menopausal women who had been diagnosed with breast cancer and were undergoing breast cancer treatment which included the administration of aromatase inhibitor letrozole in their prescription. The study was popularly called Z-FAST 602 among study circles.(2)
According to Dr. Brufsky, “This study shows that bone loss from aromatase inhibitors can be prevented long term with a safe and effective drug that prevents osteoporosis.”(3)
Zoledronic acid is a biphosphonate. It is approved by the U.S. Food and Drug Administration for conditions including osteoporosis and bone complications of cancer. It is also prescribed to treat cancer from spreading to bones or when chemotherapy has been prescribed as a part of the treatment program. It lowers the risk of fractures and rapid bone loss. In addition it helps reducing the high blood calcium levels in those who suffer from bone cancer.(4)
During the five-year study, the researchers found that they had recorded a remarkable as well as progressive increase in the bone density of the women who were administered zoledronic acid along with their breast cancer drugs right from the start of the program.
In contrast they observed that for such of those women who began their breast program treatment and subsequently recorded low bone density as a result of the treatment and then got on to taking zoledronic acid.
However, zoledronic acid is not prescribed to those breast cancer patients who have conditions of the kidneys as it may bring erious outcomes. Zoledronic acid is also not prescribed by doctors if the cancer patient is on drugs such amphotericin B, aminoglycosides (a type of antibiotic that is usually given in the vein or platinum-based chemotherapy drugs. Besides, administering zoledronic acid while the patient is on chemotherapy drugs like dexamethasone, methylprednisolone, and prednisone may raise the risk of serious damage to the jaw bone. There are similar other restrictions to when and how zoldronic acid may be administered to patients of breast cancer.
It was also noted during the five-year study that there occurred a deceleration over a period of time in the reduction of bone density for those breast cancer patients who got on board later with zoledronic acid. These findings indicate that bone density is maintained more effectively with upfront zoledronic acid, but bone loss is likely reversible so that initiating zoledronic acid, even after bone loss has developed, is helpful.
1. Drug Prevents Bone Loss Side Effects Of Breast Cancer Medication; Science Daily; October 2011;
2. Osteoporosis Drug Helps to Prevent Bone Loss; BreastCancer.co; October, 2011;
3. Drug prevents bone loss side effects of breast cancer medication; Wiley Blackwell Eureka Alert; October 2011;
4. Zoledronic Acid; American Cancer Society; October 2011;