<b>Medical Journal Article Annotated Citations</b>

<b>NOTE: </b>GISTs [GastroIntestinal Stromal Tumors] and GI LMS were often pooled and considered LMS.  GISTs are very chemoresistant, and the survival statistics showed that.  Since the development of Gleevec [Glivec] in 2000/2001, however, many GIST tumors are now managed and the disease is held stable.  With the development of Gleevec, the statistics for survival for people with GIST are much better.  With the removal of GISTs from the LMS tumor pool, it is clear that the statistics for survival for GI LMS are better as well.  GIST and LMS are now considered two different tumors.  Consequently, pre-2001 publications on survival statistics for GI LMS are seriously flawed.

For Latest Pubmed/Medline Search on Leiomyosarcoma &&url  </b>


Am J Surg Pathol 2000 Oct;24(10):1339-52 
<b>Gastrointestinal stromal tumors and leiomyosarcomas in the colon: a clinicopathologic, immunohistochemical, and molecular genetic study of 44 cases.</b> 
Miettinen M, Sarlomo-Rikala M, Sobin LH, Lasota J. Department of Soft Tissue Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA. 

Gastrointestinal stromal tumors (GISTs), mesenchymal tumors largely specific for the gastrointestinal tract, have been well defined in the stomach and small intestine, but have not been extensively documented or contrasted with true smooth muscle tumors in the colon. <b>This study was undertaken to determine the clinicopathologic features of GISTs of the colon, excluding the rectum, and to compare them with leiomyosarcomas (LMSs) of the same location.</b>  A total of 37 colonic GISTs and seven LMSs from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki were analyzed. The GISTs occurred predominantly in adults older than 50 years of age (median, 67 yrs), and most were histologically malignant; four small benign tumors (< or = 1 cm) were incidentally detected, and 10 others had minimal mitotic activity (five or fewer mitoses per 50 high-power fields). The colonic GISTs were typically transmural tumors with frequent intraluminal and outward bulging components. Histologically, they usually showed a spindle cell pattern (92%), whereas 8% were epithelioid. Most tumors (19 of 25) were positive for CD117 (KIT) and for CD34 (16 of 27); six tumors coexpressed alpha-smooth muscle actin and CD117; none showed desmin or S-100 protein. C-kit mutations in exon 11 were seen in 5 (36%) of 14 colonic GISTs. None of the patients with incidental small tumors had a recurrence, whereas 2 of 10 patients with tumors larger than 1 cm but minimal mitotic activity died of the disease with liver metastasis. Nearly all patients whose tumor was larger than 1 cm and showed more than five mitoses per 50 high-power fields died of disease; half had evidence of metastasis. LMSs were typically intraluminally bulging, polypoid masses that showed a histologic likeness to differentiated smooth muscle cells. They occurred in five men and two women with a median age of 61 years. Most LMSs were high-grade histologically and showed smooth muscle actin, desmin, or both. All were negative for CD34 and CD117 and lacked c-kit mutations. Five of the seven patients died of disease, and two had a long-term survival, despite high mitotic activity. <b>These results show that KIT-positive GISTs are more common than LMSs of the colon, and these tumor groups have clinicopathologic differences that warrant their separation.</b>  

&&url PMID: 11023095 


J Clin Oncol 2000 Sep 15;18(18):3211-20 
<b>Soft tissue leiomyosarcomas and malignant gastrointestinal stromal tumors: differences in clinical outcome and expression of multidrug resistance proteins. </b>
Plaat BE, Hollema H, Molenaar WM, Torn Broers GH, Pijpe J, Mastik MF, Hoekstra HJ, van den Berg E, Scheper RJ, van der Graaf WT. Department of Pathology, University Hospital Groningen, The Netherlands. b.e.ch.plaat@kno.azg.nl 

,,, <b>Several studies have reported clinical behavior and chemotherapy resistance in leiomyosarcomas, but these studies did not differentiate between soft tissue leiomyosarcomas (LMS) and malignant gastrointestinal stromal tumors (GIST).</b>  Multidrug resistance (MDR) has been associated with the expression of P-glycoprotein (P-gp), multidrug resistance protein (MRP(1)), and lung resistance protein (LRP). The aim of the present study was to compare LMS and GIST with respect to clinical outcome and MDR parameters. ,,,  Clinical outcome was evaluated in 29 patients with a primary deep-seated LMS and 26 patients with a primary malignant GIST. Paraffin-embedded material, available for 26 patients with LMS and 25 with GIST, was used for immunohistochemical detection of P-gp, MRP(1), LRP, and c-kit. 
,,, Mean overall survival (OS) was 72 months for LMS patients and 31 months for GIST patients (P: <.05). Metastases occurred in 16 (59%) of 27 assessable LMS patients and in 10 (56%) of 18 assessable GIST patients. LMS predominantly metastasized to the lungs (14 of 16 patients), whereas GIST tended to spread to the liver (five of 10 patients) and the abdominal cavity (three of 10 patients; P: <.001). P-gp and MRP(1) expression was more pronounced in GIST than in LMS (P: <.05): the mean percentage of P-gp expressing cells was 13.4% in patients with LMS and 38.4% in patients with GIST, and the mean percentage MRP(1) expressing cells was 13.3% in patients with LMS and 35.4% in patients with GIST. LRP expression did not differ between LMS and GIST. c-kit was expressed in 5% of the LMS patients and in 68% of the GIST patients. ,,, <b>LMS patients have a better survival than GIST patients, and the metastatic pattern is different. Expression of MDR proteins in LMS is less pronounced than in GIST.</b> 

&&url PMID: 10986053 
