Thursday, April 21, 2011

More on Iodine

Chemotherapy, Iodine and Lymphoma

Chemotherapy followed by an iodine preparation may increase the remission rate of follicular lymphoma.

According to researchers at Fred Hutchinson Cancer Research Center in Seattle, Washington, advanced follicular lymphoma (FL) is incurable with conventional chemotherapy and radiotherapy, and optimal front-line management is controversial. The study investigated the efficacy of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy followed by tositumomab/iodine I-131 tositumomab.

From 1999 to 2000, the Southwest Oncology Group (SWOG) conducted a phase II trial (S9911) to test a novel new regimen consisting of six cycles of CHOP chemotherapy followed four to eight weeks later by tositumomab/iodine I-131 tositumomab in 90 eligible patients with previously untreated, advanced-stage FL.

The overall response rate was 91 percent, including a 69 percent complete remission (CR) rate. After a median follow-up time of 5.1 years, the estimated 5-year overall survival (OS) rate was 87 percent, and the progression-free survival (PFS) rate was 67 percent.

The five-year estimates of OS and PFS were each 23 percent better (absolute difference) than the corresponding figures for patients treated on previous SWOG protocols with CHOP alone.

In the study, an analysis according to the Follicular Lymphoma International Prognostic Index showed that 21 percent of patients had high-risk features, 44 percent had intermediate-risk features, and 34 percent had low-risk features. High-risk patients had worse OS than lower risk patients (P = .05), but differences in PFS were not statistically significant (P = .21). Serial monitoring of the t(14;18) translocation in bone marrow by polymerase chain reaction demonstrated that 32 of 38 informative patients obtained molecular CRs, including seven patients (18 percent) after CHOP and 24 additional patients (63 percent) after tositumomab/iodine I-131 tositumomab. (The timing of conversion of one patient was unclear.)

The study concluded stating that a prospective, phase III, randomized Intergroup Trial is currently underway comparing the efficacy of the promising CHOP + tositumomab/iodine I-131 tositumomab regimen with the efficacy of CHOP + rituximab.


1.Press OW, Unger JM, Braziel RM, et al. Phase II trial of CHOP chemotherapy followed by tositumomab/iodine I-131 tositumomab for previously untreated follicular non-Hodgkin's lymphoma: five-year follow-up of Southwest Oncology Group Protocol S9911. J Clin Oncol. 2006 Sep 1;24(25):4143-9. Epub 2006 Aug 8. View Abstract.

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