M. A. Burgess

Correlation of Computed Tomography and Positron Emission Tomography in Patients With Metastatic Gastrointestinal Stromal Tumor Treated at a Single Institution With Imatinib Mesylate: Proposal of New Computed Tomography Response Criteria

PURPOSE Response Evaluation Criteria in Solid Tumors (RECIST) are insensitive in evaluating gastrointestinal stromal tumors (GISTs) treated with imatinib. This study evaluates whether computed tomography (CT) findings of GIST after imatinib treatment correlate with tumor responses by [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and develops reliable, quantitative, CT response criteria. PATIENTS AND METHODS A total of 172 lesions selected by RECIST were evaluated in 40 patients with metastatic GISTs treated with imatinib. All patients had pretreatment and 2-month follow-up CTs and FDG-PETs. Multivariate analysis was performed using tumor size and density (Hounsfield unit [HU]) on CT and maximum standardized uptake value (SUVmax) on FDG-PET. Patients were observed up to 28 months. RESULTS Mean baseline tumor size and density on CT were 5.3 cm and 72.8 HU, respectively, and mean baseline SUVmax on FDG-PET was 5.8. Thirty-three patients had good response on FDG-PET. A decrease in tumor size of more than 10% or a decrease in tumor density of more than 15% on CT had a sensitivity of 97% and a specificity of 100% in identifying PET responders versus 52% and 100% by RECIST. Good responders on CT at 2 months had significantly longer time to progression than those who did not respond (P = .01). CONCLUSION Small changes in tumor size or density on CT are sensitive and specific methods of assessing the response of GISTs. If the prognostic value of our proposed CT response criteria can be confirmed prospectively, the criteria should be employed in future studies of patients with GIST.

We Should Desist Using RECIST, at Least in GIST

PURPOSE Response Evaluation Criteria in Solid Tumors (RECIST) are insensitive in evaluating imatinib-treated gastrointestinal stromal tumors (GISTs). Response by Choi criteria, a 10% decrease in size or a 15% decrease in density on contrast-enhanced CT, correlated well in a small training set of patients who showed response as measured by positron emission tomography, and was more predictive of time to tumor progression (TTP) than response by RECIST. This study was designed to validate these observations in an independent data set. PATIENTS AND METHODS Fifty-eight patients with imatinib-treated GISTs were evaluated by RECIST and Choi criteria. TTP was compared with TTP in the training set. Patients were analyzed initially with follow-up to 28 months, extended to 60 months for survival analysis. RESULTS Patients who met Choi response criteria on CT at 2 months had significantly better TTP than those who did not (P = .0002), whereas response group by RECIST was not significantly correlated with TTP. Even when the 98 patients from both sets were analyzed together, the response group by RECIST did not correlate significantly with TTP, whereas response group by Choi criteria did correlate significantly with TTP. Disease-specific survival (DSS) was also significantly correlated with response group by Choi criteria (P = .04), but not with response group by RECIST. CONCLUSION 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.

A missense mutation in KIT kinase domain 1 correlates with imatinib resistance in gastrointestinal stromal tumors

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, 1982T→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.

Surgical Resection of Gastrointestinal Stromal Tumors After Treatment with Imatinib

BackgroundSurgical resection of gastrointestinal stromal tumors (GISTs) has been the most effective therapy for these rare tumors. Imatinib has been introduced as systemic therapy for locally advanced and metastatic GIST. In this study, the surgical resection rates and long-term outcomes of patients treated with preoperative imatinib for locally advanced primary, recurrent, or metastatic GISTs were evaluated.MethodsPatients were retrospectively assessed for completeness of surgical resection and for disease-free and overall survival after resection.ResultsForty-six patients underwent surgery after treatment with imatinib. Eleven were treated for locally advanced primary GISTs for a median of 11.9 months, followed by complete surgical resection. All eleven were alive at a median of 19.5 months, and ten were free of disease. Thirty-five patients were treated for recurrent or metastatic GIST. Of these, eleven underwent complete resection. Six of the eleven patients had recurrent disease at a median of 15.1 months. All eleven patients were alive at a median of 30.7 months. Patients with a partial radiographic tumor response to imatinib had significantly higher complete resection rates than patients with progressive disease (91% vs. 4%; P < .001). Of the 24 patients with incomplete resection, 18 initially responded to imatinib but were unable to undergo complete resection after they progressed before surgery.ConclusionsPreoperative imatinib can decrease tumor volume and is associated with complete surgical resection in locally advanced primary GISTs. Early surgical intervention should be considered for imatinib-responsive recurrent or metastatic GIST, since complete resection is rarely achieved once tumor progression occurs.

High-dose ifosfamide in bone and soft tissue sarcomas: results of phase II and pilot studies--dose-response and schedule dependence.

PURPOSE To evaluate the efficacy and feasibility of high-dose ifosfamide (HDI) at a total dose of 14 g/m2 per cycle with mesna in combination with granulocyte colony-stimulating factor (G-CSF) in adult patients with sarcomas. PATIENTS AND METHODS Between July 1991 and February 1994, 74 patients with sarcomas (37 bone and 37 soft tissue) were treated on two simultaneous phase II studies that evaluated HDI given as a continuous infusion over 74 hours. G-CSF was started on day 5 at 5 microg/kg/d until recovery of granulocyte count. Additionally, between March 1993 and March 1994, 15 similar patients with previously treated bone or soft tissue sarcomas were treated on a pilot study in which the same total dose of ifosfamide was administered by a bolus schedule, along with mesna and G-CSF. Patients were treated until maximal response, and where possible, surgical resection of gross disease was performed. RESULTS Seventy-two patients from the phase II study using continuous infusion are assessable for response. Four complete responses (CRs) and 17 partial responses (PRs) were noted, for an overall response rate of 29% (95% confidence interval [CI], 19% to 39%). The response rate was 40% (95% CI, 24% to 56%) for bone sarcomas and 19% (95% CI, 6% to 32%) for soft tissue sarcomas. Fourteen patients from the pilot study that used a bolus schedule are assessable for response. One CR and seven PRs were noted, for an overall response rate of 57% (95% CI, 31% to 83%) and a response rate of 45% for soft tissue sarcomas. Two patients developed grade 3 to 4 renal toxicity, three developed grade 3 CNS toxicity, one had possible grade 3 cardiac toxicity, and two developed severe painful peripheral neuropathy. There were no treatment-related deaths. CONCLUSION 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.

Phase I Trial of Preoperative Concurrent Doxorubicin and Radiation Therapy, Surgical Resection, and Intraoperative Electron-Beam Radiation Therapy for Patients With Localized Retroperitoneal Sarcoma

PURPOSE The primary objective of this phase I trial was to define the maximum-tolerated dose of external-beam radiation with concurrent fixed-dose continuous-infusion doxorubicin followed by surgical resection and electron-beam intraoperative radiation therapy (EB-IORT) for patients with localized, potentially resectable retroperitoneal sarcomas (RPS). PATIENTS AND METHODS Thirty-five patients with radiographically resectable primary or recurrent intermediate- or high-grade RPS were treated. Doxorubicin was administered each week for 4 or 5 weeks as an initial bolus (4 mg/m2) followed by a 4-day continuous infusion (4 mg/m2/d). Concurrent radiation therapy was administered in escalating doses of 18.0, 30.6, 36.0, 41.4, 46.8, or 50.4 Gy in 1.8-Gy fractions. Radiographic restaging was performed 4 to 8 weeks after chemoradiation, and patients with localized disease underwent surgical resection with EB-IORT (15 Gy). RESULTS Chemoradiation was completed as outpatient therapy in 31 patients (89%); four patients required hospital admission during chemoradiation or in the postchemoradiation preoperative period. At the highest radiation dose of 50.4 Gy, two (18%) of 11 patients had grade 3 or 4 nausea. Twenty-nine patients (83%) underwent laparotomy; six patients had interval disease progression and did not undergo surgery. Grossly complete resection (R0 or R1) was performed in 26 (90%) of 29 patients who had surgery. EB-IORT was feasible and successfully administered to 22 patients who had R0 or R1 resections. CONCLUSION Preoperative chemoradiation, surgical resection, and EB-IORT are feasible for patients with RPS. Preoperative external-beam radiation can be administered to a total dose of 50.4 Gy with continuous-infusion doxorubicin.

Chemotherapy for metastatic merkel cell carcinoma. Review of the M. D. Anderson hospital's experience

Thirteen patients with regional or distant metastases from Merkel cell carcinoma were treated with combination chemotherapy. Three patients had a complete response to therapy. In two patients with nodal disease the duration of response was 10+ and 4+ years. In addition, three patients had a partial response, and six patients had minor responses. Chemotherapy using a combination of drugs that are active against small cell carcinoma of the lung is recommended in the treatment of unresectable disease in patients with Merkel cell carcinoma; it may produce prolonged responses. While tumor regressions as a result of chemotherapy were often dramatic, once the disease progressed, the course of the disease often moved rapidly downhill and proved to be fatal.

Phase I/II trial of a P-glycoprotein inhibitor, Zosuquidar.3HCl trihydrochloride (LY335979), given orally in combination with the CHOP regimen in patients with non-Hodgkin's lymphoma.

A phase I/II trial was performed to investigate the safety and tolerance of zosuquidar.3HCL, a potent inhibitor of P-glycoprotein (P-gp), when administered orally alone and in combination with the CHOP regimen in patients with untreated non-Hodgkins lymphoma and to determine whether zosuquidar.3HCL affects pharmacokinetics of doxorubicin and vincristine. Doses of CHOP remained constant and the doses of zosuquidar.3HCL were increased from 200 to 500 mg per dose. A total of 15 patients were treated at three dose levels. A target dose providing peak and trough levels compatible with prolonged modulation of P-gp function was obtained in patients receiving three doses of 500 mg of zosuquidar.3HCL p.o. At this dose level, toxicity was minimal and no enhancement of CHOP-related toxicity was observed. Zosuquidar.3HCL did not significantly affect the pharmacokinetics of doxorubicin and had moderate effects on the pharmacokinetics of vincristine. Zosuquidar.3HCL can be safely administered with CHOP therapy using a 24-h schedule.

Combination chemoimmunotherapy of metastatic breast cancer with 5-fluorouracil, adriamycin, cyclophosphamide, and BCG

One hundred and five patients with metastatic breast cancer were treated with 5‐fluorouracil, Adriamycin, cyclophosphamide and BCG (FAC‐BCG). The results were compared to those observed in a group of 44 patients treated with FAC chemotherapy alone. Although the overall response rates were similar (76% for FAC‐BCG and 73% for FAC), the duration of remission was of 9 months for FAC and 14 months for FAC‐BCG (p = 0.04). Similarly, survival of responding patients treated with FAC‐BCG was significantly longer (24 months) than that observed in the chemotherapy alone treated group (15 months). There was no difference in survival or duration on study for nonresponders. Response rates were not influenced by dominant site of disease, menopausal status or disease‐free interval. The duration of remission and survival, however, were significantly longer for patients with bone and soft tissue involvement than for patients with visceral metastasis. Similarly patients with 1 or 2 metastatic sites survived significantly longer than those with more than 3 organ sites involved (p = 0.02). This chemotherapeutic combination is highly effective in inducing remissions. In addition, nonspecific immunotherapy with BCG appears to prolong duration of remission and survival for responding patients.

Impact of Neoadjuvant Chemotherapy on Postoperative Morbidity in Soft Tissue Sarcomas

PURPOSE The purpose of this study was to test the hypothesis that neoadjuvant chemotherapy (NeoCT) does not increase morbidity in patients undergoing radical surgery for soft tissue sarcomas. PATIENTS AND METHODS The records of 309 patients who presented to The University of Texas M.D. Anderson Cancer Center for definitive surgical management of primary soft tissue sarcomas were retrospectively reviewed. One hundred five patients who received NeoCT were compared with 204 patients who had surgery first (Surg). Patients had extremity sarcomas (71 NeoCT patients and 130 Surg patients) or retroperitoneal/visceral sarcomas (34 NeoCT and 74 Surg). RESULTS NeoCT patients had larger tumors (median, 12 v 8 cm), more frequently had high-grade tumors (90% v 64%), and were younger (median age 47 v 55 years). The incidence of surgical complications was not different for NeoCT patients than for Surg patients, both in those with extremity sarcomas (34% v 41%) and in those with retroperitoneal/visceral sarcomas (29% v 34%). The most common complications were wound infections and other wound complications. Preoperative radiation therapy, autologous flap coverage, and extremity tumors were associated with increased wound complications. No significant differences in length of hospital stay, rate of readmission, or rate of reoperation for complications were found between the NeoCT and Surg groups. One of the three postoperative deaths in our series occurred in the NeoCT group. CONCLUSION In this retrospective review, there was no evidence that NeoCT increased postoperative morbidity in patients with soft tissue sarcomas. Prospective, randomized studies are needed to confirm these results.