Female patients with soft tissue sarcoma are at a higher risk for developing breast cancer
10071 Background: An increased incidence of MPM has been reported in association with STS. In a series of 1350 adults with STS almost 10% were diagnosed with additional primaries. The incidence of breast cancer (BC) in the general population is 97/105,(Israel-Cancer-Registry) and the incidence of STS is 1.5/105 (Enzinger&Weiss). It is expected that approx. 1.5/105 × 97/105 of the general population will have both BC and STS. Methods: A retrospective search of the database of approx. 1,350 adult STS patients, who were referred, diagnosed, or treated at our center between 1995- 2005. Results: A group of 132 patients (F=62) with STS had at least one additional malignancy. Twenty-five (25/62=40%) had BC, before or after STS. A family history of malignancy was reported by 8/25 patients (32%), 3 with a specific breast cancer family history. STS types varied. Sixteen (16/25) patients had breast cancer as their first primary, 9 as their second or third. Of 17 patients with first primary BC, the sarcoma appeared in the RT field in 2, and in 1 it appeared in a lymphedematous ipsilateral arm. Of eight patients with first primary sarcoma, only one got chemotherapy prior to the diagnosis of BC. Median interval between 1st to 2nd malignancy was 6.9 years (0.7–31y) when the BC was diagnosed first, and 3.8y (0–47y) when the BC was the second. Exposure to carcinogens, or therapeutic radiation and cytotoxics, given for the 1st tumor prior to the 2nd tumor, was recorded in 58%. The incidence of BC among all patients (females + males) with STS-first (in our database) followed by a second malignancy is 8/58 (14%), or 7/23 (30%) female patients with STS-first, or 25/890 (3%) of all female patients with STS in the registry of STS. The incidence of STS among the BC patients is rather low, and most of the cases in this series are not therapy related (14/17). The median survival of patients with BC-first was 312 months, versus 383 months for STS-first (p=NS). Among patients with BC-first, the median survival of patients with RT related sarcoma was 265 months, versus 312 months for RT unrelated STS (p= 0.6). Conclusions: Second primary BC in patients with STS-first is higher than the expected incidence of BC for this population. Screening for BC should be incorporated into the regular follow-up of patients with STS. No significant financial relationships to disclose.