Endometrial Cancer - Could Bone Loss Drugs Help?

A new study reveals that women who use bisphosphonates, a bone medication used to treat osteoporosis and other bone loss diseases, have a reduced risk of endometrial cancer. The results were published in Cancer, a leading peer-reviewed journal. Cancer scare can change your life! Cancer reportedly causes more deaths than AIDS, malaria and tuberculosis combined. Ask a cancer survivor and he would say that he is extremely grateful for every new, healthy day he has.

The endometrium is the lining of the uterus or the womb. Endometrial cancer is a kind of cancer that begins in the uterus. Endometrial cancer is typically seen in postmenopausal women who are between 60 and 70 years of age and with low bone density. After ovarian and cervical cancer, endometrial cancer is the most common cause of death from women’s cancer.

Even though the exact cause is unknown, it is believed that genetic mutation within the endometrial cells could be the most probable cause.

Diagnosis of endometrial cancer:

• Pelvic examination with the help of speculum to view the vagina and cervix for abnormalities.
• Use of a hysteroscope to examine the inside of the uterus and endometrium.
• Transvaginal ultrasound to examine the thickness and texture of the endometrium and look for abnormalities in uterine lining.
• Endometrial biopsy by getting a sample of cells from uterus for laboratory analysis.
• Dilation and curettage (D&C) is performed if enough tissue is not obtained during biopsy.

Risk factors for endometrial cancer

• Fluctuations in female hormones such as estrogen and progesterone.
• Women who have never had a chance of being pregnant have a higher risk of endometrial cancer compared to those who have had at least one pregnancy.
• Obesity and old age increase your risk of endometrial cancer
• Hereditary non-polyposis colorectal cancer (HNPCC), which is caused due to gene mutation, is a syndrome, which could increase the risk of colon cancer and endometrial cancer.

Treatment

• Radiation: Powerful energy beams, such as X-rays are used in an effort to kill the cancerous cells.
• Chemotherapy: It is generally recommended in advanced or recurrent endometrial cancer. You could receive either one single drug or combination therapy, given orally or intravenously.
• Hormone therapy: Hormones such as synthetic progestin could stop the growth of cancer cells. Hormone therapy drugs could lower the estrogen levels in the body; thus endometrial cells, which rely on them to grow eventually, die.
• Surgery: Hysterectomy  or removal of the uterus is generally recommended for women with endometrial cancer. During this procedure, generally the fallopian tubes and the ovaries are also removed. This leads to menopause and the inability to have children in future.

Do bone loss drugs help in treating endometrial cancer?

Past studies have revealed that endometrial cancer accounts for half of all gynecological cancers, which are diagnosed in the US. It is reported to be the fourth most common malignancy in women and the eighth most common reason of cancer death.

Scientists have conducted studies to prove that certain osteoporosis drugs such as bisphosphonates could have powerful anticancer properties. Bisphosphonates are commonly used to treat a condition known as osteoporosis whereby the bones become thin, brittle and weak. They are known to slow or stop the natural dissolving of the bone tissue as well as preventing tumor cells from multiplying or invading healthy cells. Bisphosphonates are marketed under the brand names Actonel, Boniva and Fosamax.

The study conducted and led by Dr. Sharon Alford, of the Henry Ford Health System in Detroit, is the first of its kind, to demonstrate the potential of bisphosphonates in reducing the risk of endometrial cancer. The study team analyzed data from the National Cancer Institute's Prostate, Lung, Colorectal, and Ovarian (PLCO) Screening Trial, which included questionnaires about bone medication use. The results are published in the journal CANCER, which is a peer-reviewed journal of the American Cancer Society.

Study using Nitrogen Form of Bisphosphonates

Researchers chose to conduct the study using bisphosphonates containing nitrogen only, since they have been shown to have stronger anticancer properties. Bisphosphonates have also shown some anti-tumor effects, including inhibiting proliferation, angiogenesis and adhesion of tumor cells.

The study participants included 29,254 women. The researchers also took into account their age, race, history of hormone therapy use, smoking status and body mass index. The scientists found that there were 77 cases of endometrial cancer in the non-bisphosphonate group as compared to 20 in the bisphosphonate-user group. Sixty-nine in the never-user and nineteen in the user groups, respectively, were found to be Type I endometrial tumors. The study revealed that bisphosphonate users were half as likely to develop endometrial cancer with an incidence rate ratio of 0.489.

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Dr. Alford commented, "This study suggests that women who need bone strengthening medications and who have increased risk for endometrial cancer may want to choose the nitrogen form of bisphosphonates because this form may reduce the risk of endometrial cancer."

The drawback of the study was that 92% of the women participants were white non-Hispanic women, thus suggesting a need to conduct further studies in African-American and Hispanic women. The second question that still remains unanswered is whether bisphosphonates affect Type I and Type II endometrial tumors in the same way, since majority of cancer incidences were Type I tumors.