Abstract
Background As aging is the most significant risk factor for cancer development, long-term prostate cancer (PCa) survivors have an evident risk of developing subsequent primary cancers (SPCs). Radiotherapy itself is an additional risk factor for cancer development and the SPCs appearing beyond five years after radiotherapy in the original treatment field can be considered as radiation-induced subsequent primary cancers (RISPCs).Material and Methods During the years 1999-2008, 241 patients with localized PCa who underwent LDR-BT with I125 and were followed-up in Kuopio University Hospital, were included in this study. In this study the incidences and types of SPCs and RISPCs with a very long follow-up time after low dose-rate brachytherapy (LDR-BT) were evaluated.Results During the median follow-up time of 11.4 years, a total of 34 (14.1%) patients developed a metachronous SPC. The crude incidence rate of RISPC was 1.7% (n=4). Half of the SPC cases (50%) were diagnosed during the latter half of the follow-up time as the risk to develop an SPC continued throughout the whole follow-up time with the actuarial 10-year SPC rate of 7.0%. The crude death rates due to metachronous out-of-field SPCs and RISPCs were high, 50% and 50%, respectively.Conclusion The crude rate of SPC was significant, but in line with previous data. The incidence of RISPC was very low supporting the role of LDR-BT as a safe treatment option for patients with localized PCa. However, both the SPCs and the RISPCs after LDR-BT were serious diseases with high mortality rates.
Reply to ‘Comment on ‘30 years follow-up and increased risks of breast cancer and leukaemia after long-term low-dose-rate radiation exposure’’
