Dr. Christian Kollmannsberger
Dr. Kollmannsberger began studying testicular cancer as a resident training in internal medicine, hematology, and medical oncology at the University of Tübingen, Germany. The head of his research team had a testicular cancer research focus, which spurred Dr. Kollmannsberger’s interest.
“When I had an opportunity to come to Canada in 2004 to continue my research there, I jumped on it,” Dr. Kollmannsberger said. “Over the past 14 years, we have expanded our program and now collaborate with a number of research centers worldwide.”
Managing stage II testicular cancer is an exceedingly difficult challenge because of the presence of lymph nodes in the retroperitoneum that may or may not be cancerous.
“We know that many patients have small lymph nodes in the retroperitoneal area, but up to 50% of these patients have no cancer in these nodes,” Dr. Kollmannsberger said. “At this point, we don’t have a way to reliably identify those patients with cancer. Although we know we can cure these patients, the questions have become, ‘Do we need to treat them?’ and ‘Can we avoid unnecessary treatment?’”
Research is currently underway on targeted micro-RNA-based blood tests, specifically microRNA-371-3 and microRNA-367 clusters, which show promise in identifying patients whose lymph nodes are malignant.1 “This blood test could be a game-changer,” Dr. Kollmannsberger noted.
In the interim, Dr. Kollmannsberger said that if physicians find lymph nodes through CT or PET scans, they have the option of removing the lymph nodes, beginning chemotherapy, or waiting 6 to 8 weeks before performing another CT scan to assess any change in their size. During his talk, Dr. Kollmannsberger will discuss the pros and cons of each approach.
Assessing Treatment Options for Stage I Testicular Cancer
Dr. Kollmannsberger and colleagues have grappled with similar issues when determining treatments for stage I testicular cancer. The recurrence rate for patients with stage I seminoma cancer is 10% to 20%, and as high as 15% to 50% for those with stage I non-seminoma cancer. The presence of lymphovascular invasion in the primary tumor has been used to determine risk levels for the latter group, but it is by no means a perfect indicator. The risk of recurrence for patients with lymphovascular invasion is 50%, and the risk drops to 15% for those without.2
“In my view, the optimal approach for stage I seminoma and low-risk stage I non-seminoma cancer is active surveillance, but there is some discussion about the use of this approach for high-risk stage I non-seminoma,” Dr. Kollmannsberger said. “In those cases, we are potentially overtreating 50% of our patients. This is another reason why a test that could tell us with higher certainty whether recurrence is likely would be helpful.”
Overtreatment Remains a Concern
Although testicular cancer is relatively rare, in some countries it is the most common type of cancer found in men between the ages of 15 and 40.3 Furthermore, the number of cases has steadily risen in the United States from 3.7 cases per 100,000 men in 1975 to 6.3 cases per 100,000 men in 2014.4
“The number of cases has not increased in Asia,” Dr. Kollmannsberger said. “It’s a problem we’re seeing particularly in northern countries in the West. Although there are some theories that it may be related to environmental or geographical factors, we don’t know for sure.”
There are also concerns about the long-term effects of testicular cancer treatment. As a result, researchers have been investigating the long-term treatment toxicity related to chemotherapy and radiation.
“It is extremely important to know the long-term effects because the population is so young and has an excellent prognosis,” Dr. Kollmannsberger said. “For example, we know that secondary tumors can occur down the road after cisplatin combination chemotherapy, and chemotherapy and radiation put men at higher risk for cardiovascular disease. We’re always looking for ways to minimize exposure and avoid risk.”
But there are a few perks to specializing in testicular cancer. “Sometimes men come back to tell their doctors that their wives are pregnant, or they come show off their newborn babies,” Dr. Kollmannsberger said. “That is one of the most rewarding situations. It’s a nice moment in oncology.”
– Marilyn Fenichel