What are the current outcomes of advanced gastrointestinal stromal tumors: who are the long-term survivors treated initially with imatinib?

The introduction of imatinib to clinical practice revolutionized therapy of advanced gastrointestinal stromal tumors (GIST), but its long-term results have been only just collected. We have attempted to identify factors related to the long-term survival. We have analyzed the data of 430 inoperable/metastatic/recurrent GIST patients treated with imatinib in reference centers, assessed the factors influencing the long-term overall survival (OS), and compared the outcomes in three periods of initiation of imatinib therapy during one decade (2001-2003, 2004-2006, 2007-2010). During analyzed time periods, we have found decrease in median largest tumor size at the start of imatinib therapy: 90.5 mm (2001-2003) versus 74 mm (2004-2006) versus 58 mm (2007-2010) (p = 0.002). Median progression-free survival (PFS) on 1st line imatinib was 37.5 months, without differences in PFS between three groups. Median OS was 5.8 years, 8-year OS rate was 43%, and no difference in OS was demonstrated for patients treated in analyzed time periods. Independent good prognostic factors for longer OS were as follows: surgery of residual disease, initial WHO performance status 0/1, normal baseline albumin level, and the presence of exon 11 KIT mutations. Current median OS in advanced GIST reaches 6 years. The long-term survivors were characterized by smaller maximal tumors at imatinib start, better blood tests results, better performance status, and the surgical removal of residual disease. The latter might reduce the impact of tumor size and equalize the long-term results of therapy during last decade from introduction of imatinib. After introduction of subsequent lines of therapy (as sunitinib), the effect of primary mutational status on the long-term OS is also less visible.

The outcome and predictive factors of sunitinib therapy in advanced gastrointestinal stromal tumors (GIST) after imatinib failure - one institution study.

BACKGROUND: Gastrointestinal stromal tumors (GIST) mutational status is recognized factor related to the results of tyrosine kinase inhibitors therapy such as imatinib (IM) or sunitinib (SU). Arterial hypertension (AH) is common adverse event related to SU, reported as predictive factor in renal cell carcinoma. The aim of the study was to analyze the outcomes and factors predicting results of SU therapy in inoperable/metastatic CD117(+) GIST patients after IM failure. METHODS: We identified 137 consecutive patients with advanced inoperable/metastatic GIST treated in one center with SU (2nd line treatment). Median follow-up time was 23 months. Additionally, in 39 patients there were analyzed selected constitutive single nucleotide polymorphisms (SNPs) of VEGFA and VEGFR2 genes. RESULTS: One year progression-free survival (PFS; calculated from the start of SU) rate was 42% and median PFS was 43 weeks. The estimated overall survival (OS, calculated both from start of SU or IM) was 74 weeks and 51 months, respectively. One-year PFS was 65% (median 74 weeks) in 55 patients with AH vs. 22% (median 17 weeks) in patients without AH. Patients with primary tumors carrying mutations in KIT exon 9 or wild-type had substantially better 1-year PFS (68% and 57%; median 65.5 and 50.5 weeks, respectively) than patients having tumors with KIT exon 11 or PDGFRA mutations (34% and 15%; median 36.8 and 9 weeks, respectively). We identified two independent factors with significant impact on PFS and OS in univariate and multivariate analysis: primary tumor genotype and presence of AH. The most common adverse events during therapy were: fatigue, AH, hypothyroidism, hand and foot syndrome, mucositis, skin reactions, dyspepsia, and diarrhea. Two deaths were assessed as related to tumor rupture caused by reaction to SU therapy. The presence of C-allele in rs833061 and the T-allele in rs3025039 polymorphism of VEGFA were associated with significantly higher risk of hypothyroidism (OR: 10.0 p = 0.041 and OR: 10.5; p = 0.015, respectively). CONCLUSIONS: We confirmed that many advanced GIST patients benefit from SU therapy with OS > 1.5 year. Primary tumor KIT/PDGFRA genotype and SU-induced AH, as surrogate of its antiangiogenic activity are two independent factors influencing both PFS and OS.

The megavoltage radiation therapy in treatment of patients with advanced or difficult giant cell tumors of bone.

PURPOSE: To assess the outcomes of radiotherapy, in terms of local control and treatment complications, of advanced or difficult giant cell tumors of bone (GCTB) that could not be treated by surgery. METHODS AND MATERIALS: Among 122 consecutive patients with confirmed GCTB from 1985 to 2007, 77 patients were treated by megavoltage radiotherapy because they were inappropriate candidates for surgery. We have performed analysis of all data in terms of progression-free survival (PFS) and treatment morbidity. Median follow-up time was 58 months. RESULTS: In the irradiated group, maximal tumor size ranged from 5 to 18 cm (median, 8.5). Anatomic distribution was as follows: femur, 27 cases; tibia, 19; radial/ulnar bone, 12; sacrum, 9; pelvic bones, 5; other, 5. Twenty-one patients (27%) were referred for local recurrence after ≥1 other treatment procedures. The radiation doses ranged from 26 to 89 Gy (median, 56; administered 1.8-2.0 Gy/fraction with average total duration of treatment of 5-7 weeks); 8 patients (10%) received <50 Gy. All patients tolerated treatment well without acute or late complications. All patients except two are alive. Local control was achieved in 65 patients (84%; bone recalcification/restitution of joint functions), 12 patients showed signs of local progression, all within irradiated fields (9 were treated successfully with salvage surgery). Five- and 10-year local PFS were 83% and 73%, respectively. Three patients developed lungs metastases. Malignant transformation of GCTB occurred in two patients. CONCLUSIONS: GCTB can be safely and effectively treated with megavoltage radiotherapy with local control rate >80% at 5 years. Our study confirms that radiotherapy of GCTB offers an alternative to difficult or complex surgery and may be an option of choice in the treatment of inoperable patients.

Different factors are responsible for predicting relapses after primary tumors resection and for imatinib treatment outcomes in gastrointestinal stromal tumors.

BACKGROUND: The development of accurate diagnostic methods in gastrointestinal stromal tumors (GISTs) and the introduction of imatinib (IM) therapy has focused attention on the factors influencing the prognosis of patients with primary lesions as well as of patients with advanced disease treated with imatinib. MATERIAL/METHODS: The clinico-pathological and genetic factors influencing disease-free survival (DFS) in 335 patients with primary CD117-immunopositive tumors (group A; calculated from primary tumor resection) and progression-free survival (PFS) in 232 metastatic/unresectable GIST patients treated with IM (group B; calculated from the start of imatinib therapy) were analyzed. RESULTS: In group A, statistically significant factors negatively influencing DFS(five-year DFS: 38%), both in univariate and multivariate analysis, were: primary tumor size >5 cm, mitotic index >5/50 HPF (high-power fields), male gender, primary tumor R1 resection or tumor rupture, non-gastric primary tumor localization. In group B, five factors negatively affecting PFS (three-year PFS: 54%) were identified, which were statistically significant both in univariate and multivariate analyses: WHO performance status >/=2, tumor genotype indicating other than exon 11 KIT mutation, high baseline pre-IM granulocyte count, mitotic index >10/50 HPF, and age <45 years at diagnosis. CONCLUSIONS: Different sets of independent biological and pathological prognostic factors were identified for the assessment of the natural course of primary GIST and for the prediction of PFS during IM therapy for advanced GIST.

Risk criteria and prognostic factors for predicting recurrences after resection of primary gastrointestinal stromal tumor.

BACKGROUND: The introduction of adjuvant imatinib in gastrointestinal stromal tumors (GISTs) raised debate over the accuracy of National Institutes of Health risk criteria and the significance of other prognostic factors in GIST. METHODS: Tumor aggressiveness and other clinicopathological factors influencing disease-free survival (DFS) were assessed in 335 patients with primary resectable CD117-immunopositive GISTs (median follow-up, 31 months after primary tumor resection) from a prospectively collected tumor registry. RESULTS: Overall median DFS was 37 months, and estimated 5-year DFS was 37.8 %. In univariate analysis, high or intermediate risk group (P < .000001), mitotic index >5/50 high-power field (P < .00001), primary tumor size >5 cm (P < .00001), nongastric primary location (P = .0001), male sex (P = .01), R1 resection/tumor rupture (P = .0003), and epithelioid cell or mixed cell pathological subtype (P = .05) negatively affected DFS. In multivariate analysis, statistically significant factors negatively influencing DFS for model 1 were mitotic index >5/50 high-power field (P = .004), primary tumor size >5 cm (P = .001), male sex (P = .003), R1 resection/tumor rupture (P = .04), and nongastric primary tumor location (P = .02), and for model 2 were high/intermediate risk primary tumor (P < .0001 and P = .008, respectively), male sex (P = .007), resection R1/tumor rupture (P = .01), and nongastric primary tumor location (P = .02). Five-year DFS for high, intermediate, and low/very low risk group was 20%, 54%, and 96%, respectively. CONCLUSIONS: The risk criteria for assessing the natural course of primary GISTs were validated, but additional independent prognostic factors-primary tumor location and sex--were also identified.

Predictive factors for long-term effects of imatinib therapy in patients with inoperable/metastatic CD117(+) gastrointestinal stromal tumors (GISTs).

THE PURPOSE: To analyze the outcomes of treatment and factors predicting effects of imatinib (IM) therapy in inoperable/metastatic gastrointestinal stromal tumors (GIST) CD117(+) patients. MATERIALS AND METHODS: We identified 232 patients in a prospectively collected Clinical GIST Registry with advanced inoperable/metastatic GIST treated with IM 400-800 mg daily (129 males and 103 females and median age 56 years). Median follow-up time was 26 months. RESULTS: The estimated 3-year progression-free survival (PFS; calculated from the date of the start of IM) was 54% and median PFS was 40.5 months. The following factors significantly and negatively influenced PFS in univariate analysis: poor baseline World Health Organization (WHO) performance status > or = 2 (P < 0.00001), tumor genotype indicating other than KIT exon 11 isoform (P = 0.005), baseline high neutrophils count (P < 0.00001), age <45 years at the diagnosis (P = 0.04), mitotic index >10/50 high-power fields (HPF) (P = 0.001), GIST histological type other than spindle-cell (P = 0.03), baseline low albumin level (P = 0.0005), low baseline hemoglobin level (P < 0.00001), and primary overtly malignant tumors (unresectable and/or metastatic lesions at presentation) (P = 0.05). We identified four factors negatively affecting PFS, statistically significant (P < 0.05) in multivariate analysis: baseline poor WHO performance status > or = 2, high baseline neutrophils count (>5 x 10(9)/l), tumor genotype indicating the presence of non-exon 11 KIT mutant and mitotic index >10/50 HPF. CONCLUSIONS: We confirmed that many advanced GIST patients benefit from IM therapy for a prolonged time, although resistance to therapy is observed. We identified four independent biological factors influencing the PFS during long-term IM therapy.

Surgical treatment of patients with initially inoperable and/or metastatic gastrointestinal stromal tumors (GIST) during therapy with imatinib mesylate.

BACKGROUND: The aim of the study was to analyze the surgical possibilities of unresectable and/or metastatic GIST CD117(+) patients during imatinib treatment. METHODS: We analyzed the results of surgery in 141 patients treated with imatinib for initially inoperable and/or metastatic GIST CD117(+). Median follow-up time was 12 months (range: 3-26). RESULTS: Surgery was performed as subsequent treatment in 24 patients (Group I, 17%) for resection of residual disease after complete/partial response and lack of further response to imatinib and as salvage therapy in eight patients (Group II, 6%), who progressed on initially successful imatinib therapy. In Group I, the viable GIST cells were not detected histologically in only three resection specimens. The first five patients in Group I did not receive imatinib further and we observed four recurrences. In next 19 patients, continuing imatinib after surgery, we observed only one relapse. In Group II, we continued imatinib therapy after high-risk surgical procedures, but in five patients we observed subsequent progression. CONCLUSIONS: Surgical removal of residual disease during imatinib treatment may allow for complete remission in selected GIST patients after response to therapy, theoretically prolonging durable remission, but it is necessary to continue imatinib for its maintenance.

An assessment of the effectiveness of magnetic resonance imaging in delayed sequences after administration of Gd-DTPA contrast in the detection of metastatic lesions in the brain.

BACKGROUND: Advances in oncology in recent years have made it possible to undertake radical interventions even in advanced cases. Local treatment, surgical or radiosurgical, is applied ever more frequently in cases of metastases to the brain. This requires accurate determination of the number and location of metastases by means of imaging techniques. The goal of our research was to establish whether the use of sequences delayed by 20-30 minutes after gadolinium injection improves the number of metastatic lesions detected in the brain by MRI. MATERIAL/METHODS: Twenty-eight patients were studied, ranging in age from 24 to 72 years, diagnosed with malignant tumors and suspected metastases to the brain. MRI examinations were performed with a 2T unit in SE T1 immediately after i.v. administration of a 0.1 mmol/kg dose of gadolinium, and again 20-30 minutes after contrast injection; both sequences were done in axial projection in layers identical as in the SE T1 sequence made before gadolinium injection. The focal lesions were counted and classified by size. The number of detected lesions was calculated in each group, comparing early and late phases after contrast injection. RESULTS: The number of all nodules found in the delayed sequences was significantly higher in comparison to the early phase after gadolinium injection. CONCLUSIONS: Delayed sequence should be used to supplement basic sequences in the diagnosis of malignant metastases to the brain in selected oncological cases.