An Evaluation of the HRT Cancer Link

Hormone Replacement Therapy and Cancer

Hormone Replacement Therapy (HRT) has been in use for many decades all over the world to help women reduce the symptoms of menopause. However, in recent years a possible HRT cancer link has been indicated in several published medical studies. This has led many doctors to question the benefits of HRT for women in comparison to the potential risk of cancer. The American Cancer Society recommends that women who are considering HRT should discuss with their doctors regarding the potential risks of cancer due to this therapy. Depending on the condition of the patient, it may be determined whether it is worth going ahead with hormone replacement therapy.

HRT and the Risk of Uterine Cancer

Research indicates that patients who use Estrogen Replacement Therapy (ERT) may have a heightened risk of endometrial cancer, which is the cancer on the lining of the uterus. Even when the use of ERT is discontinued, the risk continues to remain higher for such patients. Estrogen in any form, whether pills, patches or creams may increase the level of estrogen hormone in a woman’s body.

When progestin and estrogen are given together, which is the combined hormone replacement therapy (HRT), it might reduce menopause symptoms without leading to a higher risk of uterine cancer. A woman who has undergone uterus removal does not bear a risk of getting endometrial cancer, even if she has used HRT or ERT.

HRT and the Risk of Breast Cancer

An extensive study to establish HRT cancer link conducted by the Women’s Health Initiative (WHI) showed that regular use of HRT increases the risk of a woman developing breast cancer by 5 or 6 percent. The longer is the duration of the hormone replacement therapy, the higher is the risk. The results of this WHI study indicated that patients who used HRT were also at a higher risk of late detection of breast cancer when the condition became advanced.

However, the exact nature of relationship between HRT and breast cancer is not conclusively known till now. Many researchers believe that the higher risk of breast cancer occurs due to the addition of progestin as a part of the combined HRT. Currently, studies are underway to determine whether a lower dosage of progestin can help to reduce breast cancer risk, while providing protection against endometrial cancer at the same time. Patients should also know that the risk of breast cancer is higher only for the current or recent users of HRT. Once the patient stops this therapy, the risk returns to normal in about three years of stopping.

ERT and Risk of Ovarian Cancer

Cancer of the ovaries is a rare form of cancer, which makes it more difficult to evaluate its risk factors. Several studies have indicated that women who underwent estrogen replacement therapy faced an enhanced risk of ovarian cancer in comparison to other women. A major study has indicated that women who used ERT for more than five years increased their risk of ovarian cancer by almost 50 percent. The link between ERT and this cancer also indicates that a longer use of ERT increases the risk further.

HRT and Colorectal Cancer Risk

The extensive study conducted at WHI showed that combined hormone replacement therapy (HRT) cut down the risk of colorectal cancer by almost 40 percent. However, the benefit appeared to neutralize a few years after the therapy was stopped. Various other studies have also arrived at similar conclusions of reduced risk of colorectal cancer with HRT. Studies have also indicated that estrogen replacement therapy does not have an impact on the risk of colorectal cancer.