Ohno T et al. (2007) Long-term survival and risk of second cancers after radiotherapy for cervical cancer. Int J Radiat Oncol Biol Phys 69: 740–745

A serious consequence of radiotherapy among survivors of cervical cancer is the occurrence of a second cancer. High-dose-rate intracavitary brachytherapy (HDR-ICBT) is extensively used in Japan for the management of patients with cervical cancer; however, little is known about the risk of secondary cancer in patients treated with this type of radiotherapy. Ohno et al. evaluated the risk of secondary malignancies in Japanese women who received radiotherapy for cervical carcinoma.

The study included 2,167 patients who underwent HDR-ICBT (82%) or low-dose-rate intracavitary brachytherapy (12%) during the period 1961–1986. The total person-years of follow-up was 25,665 and only 2.8% of the patients were lost to follow-up. Overall, 49% of patients survived for more than 10 years, while 33% and 11% survived for more than 20 and more than 30 years, respectively. In total, 210 secondary cancers were observed and the cumulative risk of secondary cancer at 30 years after radiotherapy was 23.8%. The relative risk and absolute excess risk of second malignancy were 1.2 and 15.8 per 10,000 person-years, respectively, while the excess risk per person per decade of follow-up was 1.6%. The impact of smoking on the risk of secondary cancer was evaluated in 1,031 patients. The relative risk of second malignancies for patients without a smoking history was 1.4, compared with 1.6 for patients with a history of smoking.

The authors conclude that the survival benefit associated with radiotherapy outweighs the risk of secondary malignancies in patients with cervical cancer.