Does Chemotherapy Shorten the Latency Interval of Radiation-induced Sarcomas?

Chemotherapy with radiotherapy influences time-to-development of radiation-induced sarcomas: a multicenter study

Background:

An increasing number and proportion of cancer patients with apparently localised disease are treated with chemotherapy and radiation therapy in contemporary oncology practice. In a pilot study of radiation-induced sarcoma (RIS) patients, we demonstrated that chemotherapy was associated with a reduced time to development of RIS. We now present a multi-centre collaborative study to validate this association.

Methods:

This was a retrospective cohort study of RIS cases across five large international sarcoma centres between 1 January 2000 to 31 December 2014. The primary endpoint was time to development of RIS.

Results:

We identified 419 patients with RIS. Chemotherapy for the first malignancy was associated with a shorter time to RIS development (HR 1.37; 95% CI: 1.08–1.72; P=0.009). In the multi-variable model, older age (HR 2.11; 95% CI 1.83–2.43; P<0.001) and chemotherapy for the first malignancy (HR 1.61; 95% CI 1.26–2.05; P<0·001) were independently associated with a shorter time to RIS. Anthracyclines and alkylating agents significantly contribute to the effect.

Conclusions:

This study confirms an association between chemotherapy given for the first malignancy and a shorter time to development of RIS.

Rapid-onset postchemoradiotherapy rhabdomyosarcoma of the maxillofacial region

Radiation-induced sarcomas of the head and neck are rare and tend to occur decades after treatment. We report a case of rapid-onset postchemoradiotherapy rhabdomyosarcoma of the maxillofacial region and briefly review the literature.

Rhabdomyosarcoma arising in a previously irradiated field: an analysis of 43 patients

Patients with soft tissue sarcomas that arise from previously irradiated fields have traditionally been reported to have a poor prognosis. In this report, we examined the characteristics and outcomes of patients who developed a rhabdomyosarcoma in a previously irradiated field (RMS-RIF); we hypothesize that these patients should have a better outcome compared to other postradiation soft tissue sarcomas as these tumors are chemosensitive and radiosensitive. A PubMed search of the literature from 1961-2010 yielded 33 studies with data for patients with RMS-RIF. The study included 43 patients with a median age of 6.5 years at the time of radiation therapy (RT) for the initial tumor. The median RT dose was 48 Gy. The median latency period, the time from RT to development of RMS-RIF, was 8 years. The 3-year overall survival for RMS-RIF was 42%. The 3-year overall survival was 66% for patients receiving chemotherapy and local treatment (surgery and/or RT) compared to 29% for those who had systemic treatment only or local treatment only (P=.049). Other factors associated with increased 3-year overall survival included retinoblastoma initial diagnosis (P<.001), age ≤ 18 years at diagnosis of RMS-RIF (P=.003), favorable site (P=.008), and stage 1 disease (P=.002). Age at time of RMS-RIF, retinoblastoma initial tumor, favorable site, stage 1 disease, and use of both systemic and local treatment were found to be favorable prognostic factors for 3-year overall survival.