Ibritumomab consolidation after 3 cycles of CHOP plus radiotherapy in high-risk limited-stage aggressive B-cell lymphoma: SWOG S0313.

In the S0313 trial, we evaluated the impact of adding ibritumomab tiuxetan consolidation to 3 cycles of standard cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy plus involved field radiotherapy (IFRT) in patients with limited-stage aggressive B-cell non-Hodgkin lymphoma (LD-NHL). Patients with at least 1 stage-modified adverse risk factor (nonbulky stage II, age >60 years, elevated lactate dehydrogenase, or World Health Organization performance status of 2) were treated with CHOP on days 1, 22, and 43, followed 3 weeks later by 40 to 50 Gy of IFRT. An ibritumomab tiuxetan regimen was initiated 3 to 6 weeks following IFRT. Forty-six patients were registered and eligible, with median follow-up of 7.3 years. The progression-free survival estimate is 89% at 2 years, 82% at 5 years, and 75% at 7 years. The overall survival estimate is 91% at 2 years, 87% at 5 years, and 82% at 7 years. Grade 4 adverse events occurring more than once included neutropenia (8), leukopenia (5), and lymphopenia (2). Febrile neutropenia was observed in 4 patients. No cases of treatment-related myeloid neoplasms were noted. In conclusion, patients with high-risk LD-NHL treated with 3 cycles of CHOP plus IFRT followed by ibritumomab tiuxetan consolidation had outcomes that compare favorably to our historical experience. The clinical trial was registered at www.clinicaltrials.gov as #NCT00070018.

alpha6 integrin cleavage: sensitizing human prostate cancer to ionizing radiation.

PURPOSE: The goal was to determine if prostate tumor cells containing a mutant alpha6 integrin would be defective in tumor re-population following clinically relevant fractionated ionizing radiation (IR) treatments. MATERIAL AND METHODS: Human prostate cancer cells derived from PC3N cells were used which conditionally expressed a cleavable, wild type form of alpha6 integrin (PC3N-alpha6-WT) or a mutated non-cleavable form of alpha6 integrin (PC3N-alpha6-RR). The resulting tumor growth before, during and after fractionated doses of IR (3 Gyx10 days) was analyzed using the endpoints of tumor growth inhibition (T/C), tumor growth delay (T-C), tumor doubling time (Td) and tumor cell kill (Log(10) cell kill). RESULTS: The T/C values were 36.1% and 39.5%, the T-C values were 20.5 days and 28.5 days and the Td values were 5.5 and 10.5 days for the irradiated PC3N-alpha6-WT and PC3N-alpha6-RR cells, respectively. The Log(10) was 1.1 for the PC3N-alpha6-WT cells and 0.8 for the PC3N-alpha6-RR cells. The tumor response to IR was altered in tumors expressing the mutant alpha6 integrin as indicated by a significant increase in tumor growth inhibition, an increase in tumor growth delay, an increase in tumor doubling time and an increase in tumor cell kill. CONCLUSIONS: Blocking integrin cleavage in vivo may be efficacious for increasing the IR responsiveness of slow growing, pro-metastatic human prostate cancer.