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NCCN issues first guidelines for gestational trophoblastic neoplasia
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The National Comprehensive Cancer Network released new recommendations that detail treatments for the different variations of gestational trophoblastic neoplasia.
Gestational trophoblastic neoplasia (GTN) is a group of rare cancers that affect women during pregnancy when tumors develop in cells that would normally form the placenta. Although GTN is more common in Asia and Africa, the condition occurs in about one of every 1,000 U.S. pregnancies, according to an NCCN-issued press release.
Given the rarity of GTN and the small number of specialists available, patients are not always provided the best care.
For this reason, the guidelines are “sorely needed,” according to David Mutch, MD, Ira C. and Judith Gall professor and vice chair of obstetrics and gynecology at Washington University School of Medicine in St. Louis.
“By compiling expert consensus, we can standardize the way this uncommon disease is treated,” Mutch, who also leads the NCCN Clinical Practice Guidelines in Oncology Committee for GTN, said in the release. “When treated properly, GTN can almost always be cured, but deviating from that standard can have severe consequences. Plus, by providing clear instructions for how best to treat GTN, we can streamline the insurance approval process for more efficient care.”
HemOnc Today spoke with Mutch about why the guideline is necessary and what it recommends, as well as how guideline-concordant care could improve outcomes for affected women.
Question: How common is GTN and what causes it?
Answer: GTN is a malignancy of the placenta. Although half of malignant disease arises in the placenta, about 25% of cases arise from an ectopic pregnancy, and about 25% arise after a term pregnancy. When GTN starts with an abnormal placenta without a fetus — known as molar pregnancy — we are able to see it on ultrasound and can treat it much earlier than in the past. The treatment of the premalignant condition is suction evacuation. The hormone human chorionic gonadotropin (hCG) is always elevated in these women. We follow the levels and, if they decrease to negative, the woman requires no further therapy. If hCG levels increase, the diagnosis of malignant disease is made.
Low-risk GTN is primarily treated with single-agent chemotherapy, although additional chemotherapy or surgery may be required for persistent disease. With high-risk GTN, treatment typically involves multiagent chemotherapy, with possible radiation therapy for brain metastasis.
Q: What are typical outcomes for these patients and how has treatment varied in recent years?
A: The prognosis is generally excellent if the woman is treated properly. However, women who have a term pregnancy and were not suspected to have a malignancy are often diagnosed with late-stage disease. In women with an ectopic pregnancy, we are able to follow their hormone levels and can catch any issues before it reaches late-stage disease. These women are typically treated with methotrexate for disease management. The cure rate for early-stage, low-risk disease is nearly 100%. Even women with widely metastatic disease to the brain or the liver who are treated with multiagent chemotherapy have a cure rate within the 80% to 90% range.
Q: Why are these guidelines necessary?
A: The NCCN guidelines are critically important because these women are usually treated by their local oncologist. Unfortunately, the disease is not being treated as it should be, because it is rare and the people treating it are not familiar with it. The NCCN guidelines were necessary to make algorithms for physicians to follow. There is a guideline for almost every patient scenario, and this has a twofold benefit. For one, physicians who are unfamiliar with this disease will have a road map. Second, the insurance companies that often deny these regimens because it is not very common will have a template to approve the treatment in a timely manner.
Q: What do the guidelines recommend?
A: The NCCN guidelines spell out almost every possible scenario, but if they are not clear to the individual reading them, we urge physicians to reach out to experts who are happy to answer their questions at any time. These experts can be found at an original trophoblastic disease center, such as The Brewer Center at Northwestern University in Chicago and New England Trophoblastic Disease Center at Harvard University.
Q: How does guideline-concordant care have the potential to improve outcomes?
A: Many physicians do not understand the pathophysiology of this disease and how aggressive it can be. Therapy may be delayed, or women are treated on a 3-week cycle, as is the procedure for other solid tumors. The new guideline spells out which drug can be used based upon risk factors, the frequency of drug administration, the criteria that should be used to switch therapy, and when patients should be re-staged.
Q: Is there anything else that you would like to mention?
A: This is an uncommon disease with a cure rate that should approach 100%, but only if people pay attention and treat patients properly, which is what these guidelines are designed to do. – by Jennifer Southall
Reference:
NCCN Clinical Practice Guidelines in Oncology for Gestational Trophoblastic Neoplasia. Version 1.2019. Aug. 9, 2018. Available at NCCN.org.
For more information:
David Mutch, MD, can be reached at Washington University Medical Campus,
4921 Parkview Place, St. Louis, MO 63110; email: mutchd@wustl.edu.
Disclosure: Mutch reports no relevant financial disclosures.