The typical initial treatment for patients with Stage I seminoma is orchiectomy of the affected testicle and the spermatic cord. But after that, according to a new long-term study reported at the American Society of Clinical Oncology Annual Meeting (Abstract 4502), surveillance rather than additional chemotherapy or radiotherapy will be sufficient for the vast majority of men.
In the study, which was included in a news conference before the meeting highlighting selected key research advances, investigators from Denmark reported a 99.5 percent overall survival rate with surveillance alone for men at a median of 15 years after initial diagnosis.
Surveillance is the follow-up strategy of choice after orchiectomy in Denmark, compared with the United States where about half of these patients undergo either radiotherapy or chemotherapy with a carboplatin-based regimen, said Mette Saksø Mortensen, MD, a PhD student in the Department of Oncology at Copenhagen University Hospital. “Now we have solid proof that surveillance is safe and appropriate for most patients with this particular cancer.”
Key prognostic factors for relapse were tumor size larger than 4 cm, invasion of blood or lymphatic vessels, and serum human chorionic gonadotropin (HCG) levels higher than 200 IU/L—factors that might help identify high-risk patients needing adjuvant therapy instead of surveillance. These factors, she noted, had been associated with high-risk patients in prior, smaller studies.
Database, Registries Linked
Using a nationwide population-based clinical database covering germ cell cancer patients diagnosed between 1984 and 2007, the researchers identified 1,822 Stage I seminoma patients who had been followed by surveillance.
Surveillance in Denmark is five years of scheduled physical exams, chest x-rays, CT scans, and blood tests.
Possible prognostic factors for relapse were collected from patient files and pathology reports. “By linking that data with the national patient registry, we were able to collect data on in- and out-patient hospital visits, late relapses, vital status, and cause of death on all patients up to December 2012,” she said.
Median follow-up was 15.4 years, with a wide range of less than one month to 28 years.
The 15-year cancer-specific survival rate was 99.5 percent, Mortensen reported, and 15-year overall survival was 92.1 percent.
A total of 355 patients (19.5%) had relapses after a median 13.7 months (range of 1.2 months to 14 years). These relapses were treated with radiotherapy (216 patients), chemotherapy (136), or surgery (3).
The majority of relapses, 257 (72.4%), occurred within the first two years after orchiectomy; 72 patients (20.3%) relapsed between two and five years; and 26 patients (7.3%) had a relapse at more than five years.
“As only 19.5 percent of patients relapsed, the surveillance strategy spares the remaining 80 percent of patients from unnecessary adjuvant treatment after orchiectomy,” which can include a risk of secondary gastrointestinal cancer or leukemia, she said.
The research was supported in part by the Danish Cancer Society, the Danish Cancer Research Foundation, and the Preben and Anna Simonsen Foundation.
Commenting on the studies during the news conference, ASCO 2013-2014 President Clifford Hudis, MD, Chief of the Breast Cancer Medicine Service and Attending Physician at Memorial Sloan-Kettering Cancer Center, said the results of the Danish study will encourage doctors and patients to opt for surveillance instead of treatment and spare patients from additional therapy and the related complications.
“This important study is one of several recent reminders that sometimes ‘less is more’ in patient care,” he said.
While long-term survival rates for seminoma are excellent, there has not been a standard post-surgical follow-up strategy. “Opting for surveillance spares patients, most of whom are young men, from the harmful side effects of chemotherapy and radiation without diminishing their chances for a long and healthy life.”