Our knowledge has allowed us to reduce morbidity in the more challenging postchemotherapy setting, where patients can be carefully considered for the extent and technique of surgery.
—Stephen B. Riggs, MD
Over the past several decades, the role of postchemotherapy surgery for advanced testicular cancer has evolved with regard to patient selection, surgical planning, lymph node dissection, and surgical technique. To add clarity to this complex clinical setting, The ASCO Post recently spoke with urologic oncologist Stephen B. Riggs, MD, of Levine Cancer Institute, McKay Department of Urology, Carolinas Healthcare System, Charlotte, North Carolina.
Please shed light on the selection process used to determine which patients with advanced testicular cancer should be considered for surgery following chemotherapy.
It takes a team and a process that involves careful consideration within a multidisciplinary approach among experienced surgeons, medical oncologists, radiologists, as well as experts in pathology. Testicular cancer essentially comes in two histologic variations: seminomatous and nonseminomatous tumors. The paradigm by which we select patients for postchemotherapy treatment is different based on which histology a patient has in addition to their pre- and postchemotherapy tumor marker status.
In patients with seminoma, we observe tumors that, after chemotherapy, are less than 3 cm because the chance of viable tumor is exceedingly low.
Secondly, for reasons still unknown, seminomatous tumors develop a desmoplastic reaction after chemotherapy, which can make the surgery more difficult and increases the potential for morbidity.
However, if after chemotherapy a retroperitoneal mass is ≥ 3 cm, then positron-emission tomography (PET with 18F-fluorodeoxyglucose (FDG) imaging is now utilized to assess the clinical situation. PET is very good in this setting because not all patients with tumors greater than 3 cm will need surgery (even though the inherent chance of viable germ cell tumor is greater).
In addition to the percentage change of tumor size from pre- to postchemotherapy, a negative PET scan gives us evidence that surgery is probably not necessary.
Finally, our ability to utilize PET after chemotherapy is unique to patients with seminoma because the residual mass will contain either fibrosis/necrosis or viable germ cells. Fibrosis or necrosis tends not to have a large affinity for the radiotracer but viable germ cells do, so we can determine histology based on PET scan results.
How does the treatment approach differ in nonseminoma?
There are two schools of thought in patients with nonseminomatous histology and a residual mass (with normalized beta-hCG and AFP) following chemotherapy, and at the epicenter is the concern for teratoma or viable cancer.
The first approach is to observe all patients with residual masses smaller than 1 cm, a paradigm that we currently endorse at our institution. This concept is based on robust data from the University of Indiana as well as observational data from the British Columbia Combined Registry, suggesting that patients with pristine postchemotherapy scans, or minute residual disease, have very good outcomes on observation. However, in fact, the overwhelming patients in these studies had a good risk profile.
Nevertheless, there are other institutions that advocate that nearly all postchemotherapy patients should undergo a retroperitoneal lymph node dissection, especially those patients considered intermediate or high risk by International Germ Cell Consensus Group Classification
I think there is fair uncertainty, regarding the long-term outcomes of small amounts of residual teratoma, as well as concern over higher-risk patients so there remains some anxiety (and debate) associated with the observational approach. My own approach is to do a postchemotherapy retroperitoneal lymph node dissection unless there is a good medical or surgical reason not to do so.
Much of the data supporting observation are based on a large group of patients with a very favorable prognosis to begin with. So this is still a debate within the community.
Improved Surgical Techniques
Please briefly discuss the evolution of lymph node dissection in these patients and any advances in nerve-sparing techniques.
Testes cancer gives us good insight into how surgical oncology has evolved in terms of cancer outcomes and morbidity. In retroperitoneal lymph node dissection, we know the flow of lymphatic drainage for each testicle.
Because of this knowledge, we’ve been able to tailor our surgical margins in lymph node dissections, which form our basis for a modified approach. Pioneers utilized this knowledge in addition to the location and understanding of the sympathetic nerve channels located in the retroperitoneum to reduce both the extent of disease and retrograde ejaculation. This modified approach is accomplished by staying above the hypogastric plexus located right below the interior mesenteric artery. Of course, we can also prospectively spare sympathetic nerves in a full bilateral dissection but, unfortunately, nerve sparing is not always possible in the postchemotherapy setting.
There remains some debate in the postchemotherapy realm about whether every patient should get bilateral dissection or if it is appropriate to utilize a more directed modified approach. I believe that patients with less bulky disease (stage IIA or IIB) in the predicted site of drainage can be managed with a more targeted modified approach. When employed, this approach offers a patient a very good chance at preserving his ejaculatory status without compromising cancer control.
Ultimately, the decision with regard to extent of the dissection really comes down to how bulky the initial and remaining disease is. For large tumors, it is much more difficult to spare the nerves and preserve antegrade ejaculation and most importantly, bulky disease can result in crossover drainage (eg, right to left) as well as retrograde drainage out of predicted drainage sites.
What has led to better surgical techniques resulting in less morbidity?
Most importantly, it is our understanding of the anatomy, specifically the location of drainage with in the lymph nodes as well as the vascular and nerve structures within the retroperitoneum. Our knowledge has allowed us to reduce morbidity in the more challenging postchemotherapy setting, where patients can be carefully considered for the extent and technique of surgery.
What’s next in the surgical approach to germ cell tumors?
Laparoscopy is certainly gaining traction. But to be fair, we do not have a lot of data on long-term outcomes in laparoscopy in the postchemotherapy setting which makes it hard to fully endorse this approach. A postchemotherapy retroperitoneal lymph node dissection is a technically demanding operation in its current form, and although robotics may improve our ability, this remains to be seen. Moreover, the adoption of a newer technique is challenged by the paucity of cases seen within some practices, which limits the iterative process that is required to master the technique.
Most importantly, as a surgeon, incomplete resection can potentially do harm to the patient. We know that patients who require “redo” retroperitoneal lymph node dissection do not do as well. Ultimately, you cannot salvage a poor surgery with systemic chemotherapy. So those of us who choose to use a laparoscopic approach need to be very skilled—you only have one shot, as this may be the only factor in a patient’s disease state that we can actually control. In fact, I believe that any surgeon who takes on a postchemotherapy dissection really needs to know what he is doing, as there are many traps for young and inexperienced players.
Is robotic surgery the next leap forward in this clinical setting?
Most likely yes, and this trend has begun. That said, it is the skill behind the robot and an understanding of the nuances of this disease that matters, because no matter how you do this procedure, the cost to the patient of not doing it well is very high. ■
Disclosure: Dr. Riggs reported no potential conflicts of interest.