Overall survival analysis of adjuvant radiation versus observation in stage I testicular seminoma: a surveillance, epidemiology, and end results (SEER) analysis.
OBJECTIVE
The standard adjuvant treatment for men with stage I testicular seminoma remains controversial within the literature. We analyzed survival rates in men with stage I seminoma who underwent adjuvant radiation therapy (RT) or observation (OB) after orchiectomy.


METHODS
Data were obtained from the Surveillance, Epidemiology, and End Results program of the National Cancer Institute from 1973 to 2003. The primary end points were overall survival (OS) and cause-specific survival (CSS). Multivariate Cox regression models were used to study the significance of clinical variables: age at diagnosis, laterality of primary disease, race, and radiation group.


RESULTS
Of 6764 patients eligible for analysis, 5265 were treated with RT and 1499 with OB. After a median follow-up of 7.6 years, the 5-, 10-, and 20-year OS rates for the RT versus OB were 97.9 versus 95.0, 94.8 versus 92.2, and 83.5 versus 84.1 (P=0.0047), respectively. The CSS rates for the same time periods were 99.6 versus 98.7, 99.4 versus 98.7, and 99.2 versus 98.7 (P=0.0015), respectively. Adjuvant RT was associated with improved CSS on multivariate analysis with hazard ratio of 0.37 (confidence interval, 0.20-0.70; P=0.0023).


CONCLUSIONS
Within this large US population analysis, adjuvant RT was associated with improved OS and CSS compared with OB for men with stage I testicular seminoma. Further studies are needed to determine whether modern RT techniques and field-size reductions may lead to greater improvements in the therapeutic ratio, in light of the trend toward chemotherapy as primary treatment.
*Radiation Oncology Branch, National Cancer Institute, Bethesda, MD Departments of ‡Medical Oncology ¶Radiation Oncology, Cancer Care Northwest, Spokane †University of Washington School of Medicine, Seattle, WA Departments of §Radiation Oncology ∥Health Sciences Research, Mayo Clinic, Rochester, MN #Department of Radiation Oncology, Huntsman Cancer Institute, the University of Utah Medical Center, Salt Lake City, UT **Texas Oncology, Baylor-Irving Cancer Center, Irving, TX.
Guy
G
Jones
Benjamin
B
Arthurs
Hakan
H
Kaya
Kenneth
K
Macdonald
Rui
R
Qin
Robert K
RK
Fairbanks
Wayne T
WT
Lamoreaux
Irfan
I
Jawed
Jonathan D
JD
Tward
Danko
D
Martincic
Anand T
AT
Shivnani
Christopher M
CM
Lee
D000328:Adult; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy; D009367:Neoplasm Staging; D011379:Prognosis; D018714:Radiotherapy, Adjuvant / Q000401:mortality*; D018426:SEER Program; D018239:Seminoma / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy; D015996:Survival Rate; D013736:Testicular Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy