Cancer of the endometrium is characterized by the presence of cancer cells in the lining of the uterus (or womb), or endometrium. Treatment for advanced or recurrent endometrial cancer may consist of surgery, chemotherapy, newer immunotherapy combinations or hormone therapy.
Because the uterus is an organ that is highly sensitive to estrogen hormone levels, the growth of endometrial cancer is also sensitive to the presence of hormones. Hormone therapy for endometrial cancer has long included the use of progesterones—such as hydroxyprogesterone, medroxyprogesterone, and megestrol. Megace (megestrol acetate) can help control the symptoms of disease and prolong survival time. This treatment produces responses in 15% to 30% of patients and causes fewer side effects than chemotherapy or radiation therapy. Researchers continue to develop and study new and hopefully more effective drugs and drug combinations. It is thought that the use of tamoxifen, an anti-estrogen hormone therapy and other newer hormonal therapies might help increase the effectiveness of the progestin, allowing the Megace to kill more cancer cells.
Megace + Tamoxifen
A combination of megestrol acetate and tamoxifen may be more effective against advanced or recurrent cancer of the endometrium than megestrol acetate alone, according to researchers from the Gynecologic Oncology Group, who are presenting their findings at the American Society of Clinical Oncology’s annual meeting in New Orleans.
The researchers treated 61 women with recurrent or advanced endometrial cancer with a combination of megestrol and tamoxifen. Twenty-eight percent of these patients had a response to treatment, with 21% having complete disappearance of all detectable cancer. Of those who responded, 50% sustained this response for an average of 20 months. It was noted that, overall, younger women had better responses to the treatment than older women.
From these findings, the researchers concluded that megestrol and tamoxifen appears to be an active combination against advanced and recurrent endometrial cancers. Persons who have this type of disease may wish to talk with their doctor about the risks and benefits of participating in a clinical trial in which megestrol and tamoxifen or other promising new treatments are being studied.
Femara + Ibrance
The addition of Ibrancre (Palbociclib) to Femara (Letrozole) delayed cancer progression and improved survival compared with placebo plus Femara among patients with estrogen receptor (ER)–positive advanced endometrial cancer, according to results of an early phase clinical trial presented at the European Society of Medical Oncology (ESMO) Virtual Congress.3
About Ibrance
Ibrance belongs to a class of drugs known as kinase inhibitors that work by blocking the action of enzymes called kinases. Kinases are involved in many cell functions, including cell signaling, growth, and division. These enzymes may be too active or found at high levels in some types of cancer cells and blocking them may help prevent cancer cells from growing. Specifically, Ibrance inhibits cyclin-dependent kinase (CDK) 4 and 6. These kinases are involved in the growth of Estrogen Receptor (ER)-positive breast, endometrial and other cancers.
In the ENGOT-EN3/NSGO-PALEO clinical trial, 77 women with stage 4 or relapsed ER-positive endometrial cancer were treated with the combination of Ibrance plus Femara or placebo plus Femara and directly compared. Femara is an established treatment for ER positive cancers.
The study reported that women treated with Ibrance plus Femara survived an average of 8.3 months without cancer progression compared to only 3 months for those treated with Femara alone. The disease control rate was also higher at 63.6% in the combination arm compared with 37.8% with letrolzole alone.
Understanding CDK Inhibitor Side Effects
This early phase clinical trial suggests that Ibrance may be an effective treatment for some women with ER positive endometrial cancer however larger, confirmatory clinical trials are necessary to definitively establish its role.
References
- Proceedings of the American Society of Clinical Oncology Thirty-Sixth Annual Meeting, Vol 19, Abstract 1499, p379a, 2000
- Oncology, Vol 56, No 3, pp 198-201, 1999.
- Mirza MR, Bjørge L, Marmé F, et al. A randomised double-blind placebo-controlled phase II trial of palbociclib combined with Femara (L) in patients (pts) with oestrogen receptorpositive (ER+) advanced/recurrent endometrial cancer (EC): NSGO-PALEO/ENGOT-EN3 trial. Presented at: European Society of Medical Oncology (ESMO) Virtual Congress 2020; September 19-21, 2020. Abstract LBA28.
