Sentinel Lymph Node Mapping to Diagnose and Treat Endometrial Cancer

Endometrial cancer is the most common gynecologic cancer in North America. When detected early, it has very good survival outcomes. But when the cancer spreads outside of the uterus and into the lymph nodes, this cancer can become more deadly and cause a higher rate of re-occurrence. Edward Tanner, MD, chief of gynecologic oncology at Northwestern Medicine and a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, discusses the use of sentinel lymph node (SNL) mapping to diagnose and treat endometrial cancer.
Sentinel Lymph Node Mapping to Diagnose and Treat Endometrial Cancer
Featured Speaker:
Edward Tanner, MD
Dr. Edward Tanner is an Associate Professor of Gynecologic Oncology at Northwestern University where he serves as Chief of the Gynecologic Oncology service.Dr. Tanner serves as the Director of Gynecologic Robotic Surgery at Prentice Women’s Hospital and is an internationally recognized leader in the field of gynecologic oncology surgery. 

Learn more about Edward Tanner, MD
Sentinel Lymph Node Mapping to Diagnose and Treat Endometrial Cancer

Melanie: Endometrial cancer is the most common gynecologic cancer in North America. When detected early, it has very good survival outcomes, but in cases where the cancer has spread outside of the uterus and into the lymph nodes, that can make this cancer much more deadly and can also cause a higher rate of recurrence due to the complexity of identifying cancerous cells in the lymph nodes.

 Welcome to Better Edge, a Northwestern Medicine podcast for physicians. I'm Melanie Cole and joining me today is Dr. Edward Tanner. He's the chief of gynecologic oncology at Northwestern Medicine, and he's an internationally recognized leader in the field. He's here with us today to discuss the use of sentinel lymph node mapping as a technique for endometrial cancers.

 Dr. Tanner, it's a pleasure to have you join us today. Sentinel lymph node mapping is a standard of assessment for many early stage gynecologic cancers. In recent years, guidelines have incorporated this mapping as a technique for endometrial cancer. Give us a little brief history of diagnosis and treatment of endometrial cancers and how this really has evolved in recent years.

Dr Edward Tanner: So first, the most important part of treatment for endometrial cancer for most patients is a hysterectomy. So removing the uterus, which is where the cancer starts. A smaller percentage of patients with endometrial cancer will have risk of spread to other organs, most importantly to lymph nodes around the uterus.

So historically, we have performed a lymph node dissection, which is essentially sampling all of the lymph nodes around the uterus to try to determine whether there's any spread and whether any kinds of additional treatment are needed like chemotherapy or radiation. And more recently, we've understood that process of sampling lymph nodes actually causes a lot of harm to patients,   most notably lymphedema. We've been really trying to find ways to get information about whether there's spread to lymph nodes   without causing any harm by doing so.

Melanie: It's a fascinating bit of technology, isn't it? So explain why sentinel lymph node mapping is a key component of diagnosis and treatment now? What are the potential benefits of it?

Dr Edward Tanner: so with sentinal lymph node mapping, we inject a dye into the cervix, which is just the starting point of drainage of the uterus. And then we have a fluorescent camera that uses near-infrared   technology to identify the lymphatic channels   that drain the uterus. And so sentinal lymph node mapping is useful for this because it allows us to identify just the first lymph nodes that drain the uterus. And so if those lymph nodes are negative and don't have cancer in them, then there's no need to sample any additional lymph nodes and cause risk to patients. And this is also important because just removing lymph nodes,   as long as they aren't enlarged with cancer, doesn't seem to have any impact on survival.

So it's really primarily a matter of getting a diagnosis of metastatic disease with spread to lymph nodes. So we're not really helping patients as long as we're doing a lymph node dissection, as long as there aren't any actual enlarged nodes.

Melanie: Thank you for mentioning lymphedema and those side effects. So can you share how SLN mapping has helped to decrease those side effects while still providing the best treatment outcomes?

Dr Edward Tanner: Yeah. So about 20% of women who undergo   a pelvic lymph node dissection for endometrial cancer will develop lymphedema, so chronic swelling in the legs that affects quality of life and movement.   So sentinel lymph node lmapping helps reduce the risk of that by not having to sample quite so many lymph nodes.  The lymphatic drainage of the leg is very intermingled with the lymphatic drainage of the pelvis. So if we only sample one or two lymph nodes on either side of the pelvis, we greatly reduce the risk of a patient developing lymphedema after surgery.

Melanie: Dr. Tanner, in my research on this fascinating topic, studies were discussing some of the challenges with sentinel lymph node mapping, such as dye, color and things along those lines, can you tell us about some of those challenges that you've seen?

Dr Edward Tanner: So traditionally,   we had used a blue dye that was, was visible or radiocolloid dyes to   identify sentinel lymph nodes and much in the same way that's been done for breast cancer for many years. More recently, we found that using the indocyanine green dye with a near-infrared camera provides us with at least equivalent, if not superior, rates of sentienel lymph node identification over some of these other traditional techniques. But it does require an infrared camera, and it really is important to have a surgeon who has expertise with the technique who uses it routinely and can identify the sentinel notes correctly.

Melanie: Well, I'm glad you brought up experience for the physician. How has robotic surgery improved your outcomes and side effects for those types of cancers? Do you have any technical considerations you'd like to share with other providers?

Dr Edward Tanner:  Well, I think for endometrial cancer,   robotics and minimally invasive surgery   more broadly has greatly improved outcomes for patients with endometrial cancer,   lower rates of complications,   shorter hospital stays. Many patients actually are able to go home the same day after robotic hysterectomy with sentinel node mapping.    And that applies even for patients with   medical comorbidities like obesity, high blood pressure,   sleep apnea diabetes, really patients do recover very well  from   minimally invasive and robotic surgery,  and have   lower rates of complications than with more traditional open techniques.

Melanie: Dr. Tanner, how does your role in professional organizations like the Society of Gynecologic Oncology and the American Association of Gynecologic Laparoscopists advance research and contribute to shaping national guidelines for the treatment of gynecologic cancers?

Dr Edward Tanner: I think it's important for these organizations, which I've had the opportunity to participate in     both the research and the   development of position statements,  really help to spread   news  about the latest techniques like sentinel node mapping and why it's important for patients to undergo these techniques. And really share the outcomes are better when patients have minimally invasive surgery like robotics and sentinel lymph node mapping.

So our organizations  are really positioned to help educate our peers  and   general OB-GYNs and primary care doctors that it's important for patients with gynecologic cancers to receive care by gynecologic oncologists at the time of diagnosis, so they can receive best possible care.

Melanie: So where do you see this going in the future and how do you see  sentinel node mapping used as this valuable tool for assessing nodal metastases in these endometrial cancers? Where do you see it going in the future?

Dr Edward Tanner: I think there's probably two areas where we haven't fully clarified the role of sentinel node mapping. The first is what to do with   patients with very low burden of nodal disease. In breast cancer patients with isolated tumor cells, so very tiny amounts of tumor,   seem to be able to avoid   chemotherapy at least in some case. We're still trying to work out those questions for endometrial cancer.    I think there's still also a question of how we'll be able to use sentinel lymph node mapping for cervical cancer, which is a slightly different situation, but there are plans   to study both of those topics in the coming years and really refine   how we use sentinel lymph node mapping   for our patients.

Melanie: What research projects are on the horizon for you and your team? What else would you like providers to know so that they can take forward to optimize patient outcomes? And while you're talking about that, tell us how your outcomes have been with sentinel node mapping.

Dr Edward Tanner: Yeah. So I think one of the things that we are still trying to explore and hopefully we'll have a randomized trial open here at Northwestern  in the next year would be a trial looking at sentinel lymph node mapping for patients with high-grade endometrial cancers and trying to quantify the risk of lymphedema when patients have undergone sentinel lymph node mapping versus full lymph node dissection. So that's a really important question that we still need to answer.

Personally, I think I've found really excellent   outcomes for my patients who've had sentinel lymph node mapping and we've replaced full lymph node dissections,   excellent survival, low rates of recurrence.   It doesn't seem to be compromising the outcomes for patients.  And , I've never really had a patient who underwent sentinel node mapping alone that developed significant lymphedema. Obviously, it can still theoretically happen, but we've really seen   vast improvements in quality of life for patients with the technique.

Melanie: What would you like other providers to know about referral if they have a patient with endometrial cancers and what you're doing there at Northwestern medicine? When do you feel it's important that they refer?

Dr Edward Tanner: Well, for most patients,   the primary and perhaps the only intervention for endometrial cancer is surgery with hysterectomy and lymph node evaluation.   Many patients don't require additional chemotherapy or radiation, although there are certainly some patients that do require more extensive treatment.

    And so it really is important for patients to be treated at high volume centers where there are surgeons who are experienced with the cutting edge techniques surgically. And also for patients with more advanced disease to have access to clinical trials for chemotherapy and other techniques  that are just emerging like immunotherapy. So, I think  having patients be evaluated by an expert GYN surgeon, like we have here at Northwestern is really important   to happen right at the time of diagnosis.

Melanie: Absolutely fascinating. Thank you so much, Dr. Tanner, for joining us today.  To refer your patient or for more information, please visit our website at to get connected with one of our providers.

That concludes this episode of Better Edge, a Northwestern Medicine podcast for physicians. Please remember to subscribe, rate and review this podcast and all the other Northwestern Medicine podcasts. I'm Melanie Cole.