Risk of second malignancies after adjuvant radiotherapy for breast cancer: a large-scale, single-institution review.

PURPOSE: The aim of this study was to estimate the risk of second malignancies (SM) after radiation therapy (RT) for breast cancer (BC) in a large, institutional, homogeneous cohort of patients. METHODS AND MATERIALS: We retrospectively studied 16,705 patients with nonmetastatic BC treated at the Institut Curie in Paris between 1981 and 1997. Adjuvant RT was given to 13,472 of these patients, and no RT was given to 3,233. The SM included all first nonBCs occurring during follow-up. Cumulative risks for each group were calculated using Kaplan-Meier estimates, censoring for contralateral cancer or death. RESULTS: Median patient age at diagnosis of BC was 55 years for the whole population, and 53 and 60 years for patients who had and had not undergone irradiation, respectively. At the 10.5-year median follow-up, 709 patients were diagnosed with SM (113 in the non-RT and 596 in the RT group). There was a significant increase in the rate of sarcomas and lung cancers in the RT group compared with non-RT group (p 0.02). Treatment with RT was not found to increase the risk of other types of cancers such as thyroid cancer, malignant melanoma, gastrointestinal or genitourinary, and hematologic SM. CONCLUSIONS: This study suggests that adjuvant RT increased the rate of sarcomas and lung cancers, whereas it did not increase the rate of other malignancies.

Breast radiotherapy in the lateral decubitus position: A technique to prevent lung and heart irradiation.

PURPOSE: To present an original technique for breast radiotherapy, with the aim of limiting lung and heart irradiation, satisfying quality assurance criteria. METHODS AND MATERIAL: An original radiotherapy technique for breast irradiation has been developed at the Institute Curie in January 1996. It consists of isocentric breast irradiation in the lateral decubitus position (isocentric lateral decubitus [ILD]). This technique is indicated for voluminous or pendulous breasts needing breast irradiation only. Thin carbon fiber supports and special patient positioning devices have been developed especially for this technique. In vivo measurements were performed to check the dose distribution before the routine use of the technique. RESULTS: ILD has been successfully implemented in routine practice, and 500 patients have been already treated. Breast radiotherapy is performed using a dose of 50 Gy at ICRU point in 25 fractions. ILD shows good homogeneity of the dose in breast treatment volume, treatment fields are perpendicular to the skin ensuring its protection, and extremely low dose is delivered to the underlying lung and heart. CONCLUSION: In cases of voluminous breasts or patients with a history of lung and heart disease, our technique provides several advantages over the conventional technique with opposing tangential fields. This technique improves the dose homogeneity according to the ICRU recommendations.

Radiation-induced sarcomas after radiotherapy for breast carcinoma: a large-scale single-institution review.

BACKGROUND: Sarcomas are a rare complication of radiotherapy for breast carcinoma and patients have a poor prognosis. The incidence, histology, and management of patients with sarcomas were reviewed in the current study. METHODS: The authors reviewed the records of 16,705 patients with breast carcinoma. Of these, 13,472 (81%) were treated with megavoltage radiotherapy and 3233 were treated without at the Institute Curie (Paris, France) between 1981 and 1997. Median doses of 50-55 grays (Gy) in 25-27 fractions were delivered to the whole breast over a period of 5-5.5 weeks (2 Gy/day, 5 weekly fractions) followed, when indicated, by a 16-26-Gy boost to the tumor or tumor bed. Treatment of radiation-induced sarcomas (RIS) consisted mostly of radical surgery and chemotherapy. RESULTS: Overall, 35 patients developed sarcomas. Of these, 27 fulfilled the Cahan criteria. The median follow-up was 9.3 years (range, 1-22.4 years). The latency period ranged from 3 years to 20.3 years. Thirteen sarcomas were located in the breast, 5- in the chest wall, 3 in the sternum, 2 in the supraclavicle, 1 in the scapula, and 3 in the axilla. Histologic evaluation identified 13 angiosarcomas, 3 osteosarcomas, 5 undifferentiated sarcomas, 1 malignant fibrous histiocytoma, 2 leiomyosarcomas, 1 fibrosarcoma, 1 rhabdomyosarcoma, and 1 myosarcoma. The cumulative RIS incidence was 0.07% (+/- 0.02) at 5 years, 0.27% (+/- 0.05) at 10 years, and 0.48% (+/- 0.11) at 15 years. Standardized incidence ratios were 10.2 (95% confidence interval, 9.03-11.59) for irradiated patients and 1.3 (0.3-3.6) for nonirradiated patients. Of the 27 patients, 15 died of sarcoma within 1 month to 14.5 years (mean, 34.2 +/- 0.7 months). The 5-year actuarial survival rate after diagnosis of RIS was 36% (+/- 0.11). CONCLUSIONS: The current study confirmed the rarity of RIS. However, it showed that the risk increased with time. Therefore, careful, long-term follow-up of patients treated with radiotherapy is needed for early detection and efficacious treatment of these malignancies.