Choi response criteria are reproducible, more sensitive, and more precise than RECIST in assessing the response of GISTs to imatinib mesylate. Response by Choi criteria, unlike response by RECIST, correlates significantly with TTP and DSS. Response by Choi criteria should be incorporated routinely into future studies of GIST therapy. We should desist using RECIST, at least in GIST.

KIT gain of function mutations play an important role in the pathogenesis of gastrointestinal stromal tumors (GISTs). Imatinib is a selective tyrosine kinase inhibitor of ABL, platelet-derived growth factor receptor (PDGFR), and KIT and represents a new paradigm of targeted therapy against GISTs. Here we report for the first time that, after imatinib treatment, an additional specific and novel KIT mutation occurs in GISTs as they develop resistance to the drug. We studied 12 GIST patients with initial near-complete response to imatinib. Seven harbored mutations in KIT exon 11, and 5 harbored mutations in exon 9. Within 31 months, six imatinib-resistant rapidly progressive peritoneal implants (metastatic foci) developed in five patients. Quiescent residual GISTs persisted in seven patients. All six rapidly progressive imatinib-resistant implants from five patients show an identical novel KIT missense mutation, 1982T3 C, that resulted in Val654Ala in KIT tyrosine kinase domain 1. This novel mutation has never been reported before, is not present in pre-imatinib or post-imatinib residual quiescent GISTs, and is strongly correlated with imatinib resistance. Allelic-specific sequencing data show that this new mutation occurs in the allele that harbors original activation mutation of KIT.

BACKGROUND Angiosarcoma of the breast is a rare entity. The objectives of this study were to evaluate prognostic factors and determine outcomes in a large contemporary series of patients. METHODS Clinical and pathologic factors were analyzed in all patients with angiosarcoma of the breast treated between 1990 and 2003. Overall survival (OS) and disease‐free survival (DFS) were estimated using the methods of Kaplan and Meier. Multivariate analyses were performed to evaluate prognostic factors. RESULTS Fifty‐five women with angiosarcoma of the breast were identified. The median age was 49.1 years, and the median follow‐up time was 3.7 years. The median OS and DFS were 2.96 years and 2.26 years, respectively. For the 32 patients with primary angiosarcoma of the breast 5‐year OS was 59%. Twenty‐three (42%) patients had received prior radiation therapy for the treatment of breast cancer. These patients with radiation therapy‐associated angiosarcoma were on average 30 years older and less likely to present with distant metastatic disease than patients presenting with radiation‐naive angiosarcoma of the breast. Although radiation‐naive patients appeared to have had better early DFS and OS, the Kaplan–Meier curves were not statistically different between patients with radiation therapy‐associated disease and radiation therapy‐naive patients. On multivariate analysis, tumor recurrence (P = 0.006) was the only significant adverse prognostic factor noted for OS. CONCLUSIONS In this series of 55 patients with angiosarcoma of the breast, radiation therapy‐naive angiosarcomas occurred in younger patients, but they behaved similarly to radiation therapy‐associated angiosarcomas. Cancer 2005. © 2005 American Cancer Society.

HDI at 14 g/m2 with mesna and G-CSF is an active salvage regimen for patients with bone and soft tissue sarcomas. There is a definite positive dose-response curve, and bolus administration appears to be more active than continuous infusion.

The authors evaluate the efficacy and feasibility of dose-intensive doxorubicin and ifosfamide combination chemotherapy in patients with sarcomas. From January 1995 to April 1996, 33 evaluable patients with either metastatic sarcoma or primary sarcomas with a high-risk for metastases (all except one was previously untreated with chemotherapy) were treated on two consecutive protocols. The median age was 45 years (range, 15-68 years). The first protocol included doxorubicin at 75 mg/m2 given as a 72-hour infusion on days 1 to 3 along with ifosfamide at 2 g/m2/d over 2 hours x 5, days 1 to 5 (protocol AI 75/10). Granulocyte colony-stimulating factor (G-CSF) was used only if indicated according to American Society of Clinical Oncology guidelines. The second protocol included doxorubicin at 90 mg/m2 as a 72-hour continuous infusion and ifosfamide at 2.5 g/m2/d for 4 days (protocol AI 90/10) with prophylactic G-CSF. A median of four cycles were administered (range, 1-6). Three patients achieved a pathologic complete response (CR) and 18 patients achieved a partial response (PR) for a response rate (RR) of 64% (95% confidence interval (CI), 45-80%). Response rate for the subset of patients with soft-tissue sarcomas was 66% (95% CI, 46-82%). Only three patients progressed on therapy. Febrile neutropenia was noted in 31% of cycles at AI 75/10 and in 56% of cycles at AI 90/10. One patient developed reversible grade 3 central nervous system (CNS) toxicity. There was one treatment-related death on AI 90/10 secondary to doxorubicin cardiac toxicity at a cumulative dose of 435 mg/m2. Dose-intensive doxorubicin plus ifosfamide is feasible in appropriately selected patients and appears to be a very active regimen in patients with sarcomas. The authors are currently testing this regimen with G-CSF and thrombopoietin.