Secondary Lower‐Body Sarcomas in Cervical Cancer Survivors Following Surgery, Radiotherapy, or Both: A Population‐Based Study

Secondary sarcomas in cervical cancer survivors are understudied. We investigated the incidence and subtypes of secondary sarcomas by treatment modalities, the prognosis of secondary sarcomas, and whether surgery plus radiotherapy increases angiosarcoma incidence. This population-based retrospective cohort study analyzed Osaka Cancer Registry data on women aged 20-84 years diagnosed with cervical cancer (1980-2015), treated with surgery, radiotherapy, or both. Patients with distant metastases, survival time < 1 year, or missing data were excluded. We included 7591 patients with invasive cancer treated with surgery, 3882 with radiotherapy, and 4090 with surgery plus radiotherapy and 13,205 with carcinoma in situ treated with surgery. We assessed the first lower-body sarcoma occurrence ≥ 1 year post-diagnosis. Sarcomas developed in 6 patients treated with surgery (0 angiosarcomas), 10 with radiotherapy (1 angiosarcoma), and 19 with surgery plus radiotherapy (9 angiosarcomas). At 10 years, the cumulative incidence was 0.083% (95% confidence interval [CI], 0.024%-0.24%) for radiotherapy and 0.21% (95% CI, 0.10%-0.41%) for surgery plus radiotherapy, higher than that for surgery (invasive, 0.013%; in situ, 0.028%) (p < 0.001). Angiosarcoma incidence was higher with surgery plus radiotherapy (0.080%; 95% CI, 0.023%-0.23%) than with radiotherapy (0.028%; 95% CI, 0.003%-0.16%) (p = 0.029). Among patients diagnosed with sarcoma after radiotherapy or surgery plus radiotherapy, the 1-year overall survival rate was 33.3% (95% CI, 19.6%-56.8%). Radiotherapy, alone or combined with surgery, increased secondary lower-body sarcoma incidence compared with surgery. To our knowledge, this is the first population-based study to suggest that surgery plus radiotherapy is associated with angiosarcoma in cervical cancer survivors.