This trimodality approach was feasible in this Southwest Oncology Group (SWOG) study, with an encouraging 26% 3-year survival rate. An Intergroup study is currently being conducted to determine whether surgery adds more to the risk or to the benefit of chemoRT.

Interest in high-dose cytarabine (HDAC) for both induction and postremission therapy for acute myeloid leukemia (AML) prompted the Southwest Oncology Group (SWOG) to initiate a randomized trial comparing HDAC with standard-dose cytarabine (SDAC) for remission induction of previously untreated AML and to compare high-dose treatment versus conventional doses for consolidation therapy. Patients less than 65 years of age with de novo or secondary AML were randomized for induction between SDAC 200 mg/ m2/d for 7 days by continuous infusion or HDAC at 2 g/ m2 intravenously every 12 hours for 12 doses; both groups received daunorubicin (DNR) at 45 mg/m2/d intravenously for 3 days. Complete responders to SDAC were randomized to receive either two additional courses of SDAC plus DNR or one course of HDAC plus DNR. Complete responders to HDAC were nonrandomly assigned to receive one additional course of HDAC plus DNR. Of patients randomized between SDAC (n = 493) and HDAC (n = 172) induction, 361 achieved complete remission (CR). The CR rate was slightly poorer with HDAC: 55% versus 58% with SDAC for patients aged less than 50, and 45% (HDAC) versus 53% (SDAC) for patients aged 50 to 64 (age-adjusted one-tailed P = .96). With a median follow-up time of 51 months, survival was not significantly better with HDAC (P = .41); the estimated survival rate at 4 years was 32% (HDAC) versus 22% (SDAC) for those aged less than 50, and 13% (HDAC) versus 11% (SDAC) for those aged 50 to 64. However, relapse-free survival was somewhat better following HDAC Induction (P = .049): 33% (HDAC) versus 21% (SDAC) at 4 years for those aged less than 50, and 21% (HDAC) versus 9% (SDAC) for those aged 50 to 64. Induction with HDAC was associated with a significantly increased risk of fatal (P = .0033) and neurologic (P < .0001) toxicity. Among patients who achieved CR with SDAC, survival and disease-free survival (DFS) following consolidation randomization were not significantly better with HDAC compared with SDAC (P = .77 and .46, respectively). Patients who received both HDAC induction and consolidation had the best postremission outcomes; however, the proportion of CR patients who did not go on to protocol consolidation therapy was more than twice as high after HDAC induction compared with SDAC. Induction therapy with HDAC plus DNR was associated with greater toxicity than SDAC plus DNR, but with no improvement in CR rate or survival. Following CR induction with SDAC, consolidation with HDAC increased toxicity but not survival or DFS. In a nonrandomized comparison, patients who received both HDAC induction and consolidation had superior survival and DFS compared with those who received SDAC induction with either SDAC or HDAC consolidation.

Resistance to chemotherapy is a major factor limiting successful treatment of acute myeloid leukemia (AML); one of the best characterized drug resistance mechanisms is extrusion of drugs by the energy-dependent multidrug resistance (MDR1) transport protein. Expression of MDR1 is common in AML and has been linked to lower remission induction rates and decreased remission durations. Because MDR1 efflux function may be modified by drugs such as cyclosporin A, accurate identification of MDR1+/efflux+ AML cases will be critical to identify patients who may benefit from therapies that contain such MDR1 modulators. We have optimized single and multiparameter flow cytometric assays to detect efflux of drugs or fluorescent dyes by previously cryopreserved AML blasts. These assays allowed precise identification of efflux by leukemic blasts, and correlation with CD34 and MDR1 expression. We subsequently studied a series of 60 previously untreated AML cases. Functional efflux was identified in 39 cases and was significantly correlated with MDR1 expression (P = .0002). However, discrepant cases were identified; 10 cases were efflux+ without significant MDR1 expression, whereas 6 MDR1+ cases were efflux-. There was also a highly significant correlation of efflux with CD34; 31 (79%) of the 39 efflux+ cases were CD34+ in comparison with only 5 (24%) of the 21 efflux- cases (P < .0001). Multivariate analysis showed that efflux was significantly associated with independent effects of both CD34 (P = .0011) and MDR1 expression (P = .034); the majority of efflux+ cases were CD34+, whereas 5 of the 6 MDR1+ efflux- cases lacked CD34 expression. Cyclosporin A blocked efflux in all but 2 cases regardless of MDR1 expression. Functional efflux in AML is frequently detected without the classic MDR1+ phenotype indicating that alternate non-MDR1-mediated efflux mechanisms may be important. Efflux assays may better identify patients who would benefit from therapies that include efflux modulators.

We compared cisternal and lumbar CSF examination in 14 patients suspected of having leptomeningeal metastasis from cancer. Malignant cells were present in 12 patients--in both cisternal and lumbar CSF in nine patients and only in cisternal CSF in three. Cisternal CSF cytologic examination should be considered in patients suspected of having leptomeningeal metastasis if lumbar CSF is nondiagnostic.

Drug resistance to chemotherapy agents such as doxorubicin appears to be an important cause of therapeutic failure in cancer treatment. Based on preclinical information demonstrating that the phenothiazine calmodulin-inhibitor trifluoperazine can enhance retention and cytotoxicity of doxorubicin in resistant cells, a phase I/II trial of the combination was performed to determine the maximally tolerated dose (MTD) of trifluoperazine that could be administered with doxorubicin. Patients with intrinsic (no previous response) and acquired (previous response with relapse) doxorubicin resistance were eligible. Doxorubicin was administered as a 96-hour continuous infusion (60 mg/m2) on days 2 through 5. Trifluoperazine was administered in divided doses orally on days 1 through 6, with dose escalation from 20 to 100 mg/d. Thirty-six patients were evaluable. The MTD of trifluoperazine was 60 mg/d, with dose-limiting toxicity being extrapyramidal side effects. No alteration of doxorubicin toxicity was observed. Seven of the 36 patients responded (one complete response [CR], six partial responses [PR]), with seven of 21 patients having acquired resistance, and zero of 15 with intrinsic resistance demonstrating responses. Doxorubicin plasma levels were not affected by trifluoperazine, and the maximal trifluoperazine plasma levels achieved were 129.83 ng/mL. This trial demonstrates the combination of trifluoperazine and doxorubicin is well tolerated, and the schedule recommended for phase II trials is doxorubicin, 60 mg/m2 (continuous infusion) days 2 through 5, and trifluoperazine, 15 mg four times per day orally days 1 through 6. Continued investigation of this combination is indicated for patients with acquired doxorubicin resistance.