Objective: To elucidate the patterns and risk factors for loss to follow-up during active surveillance for Stage I seminoma.
Methods: A total of 425 cases with Stage I seminoma underwent radical orchiectomy from 1985 to 2006 at 25 Japanese institutions, including 22 community hospitals and 3 university hospitals. The post-orchiectomy management selected was active surveillance for 186 patients, adjuvant radiotherapy for 182 patients and chemotherapy for 57 patients. The Kaplan-Meier method was used to estimate the recurrence-free survival and loss to follow-up rate. The risk factors for loss to follow-up were examined using Cox's proportional hazards model with multiple variables.
Results: The 2-, 5- and 10-year loss to follow-up rates in the active surveillance group were 14.2, 37.8 and 71.3%, respectively, which were not significantly different in comparison with those in the active surveillance and adjuvant radiotherapy or chemotherapy groups. With regard to the active surveillance group, the multivariate analysis demonstrated that patients younger than 36 years at diagnosis, patients diagnosed since 2000 and patients treated at hospitals that enrolled more than 10 cases had a significant risk for loss to follow-up. No significant correlation between the loss to follow-up rate and pathological risk factors such as tumor size (≤4 versus >4 cm) and rete testis invasion (presence versus absence) was shown.
Conclusions: The loss to follow-up rates beyond 5 years were unsatisfactorily high during active surveillance. Further approaches to improve the quality of active surveillance are needed, especially for high-risk patients such as those of younger age.
Keywords: active surveillance; loss to follow-up; seminoma; testicular cancer; younger age.