Clinical Study

British Journal of Cancer (2009) 101, 7–11. doi:10.1038/sj.bjc.6605117 www.bjcancer.com
Published online 16 June 2009

Prognosis and predictive value of KIT exon 11 deletion in GISTs

J-B Bachet1,2, I Hostein3, A Le Cesne4, S Brahimi1,5, A Beauchet6, S Tabone-Eglinger7, F Subra8, B Bui9, F Duffaud10, P Terrier11, J-M Coindre12, J-Y Blay7 and J-F Emile1,5

  1. 1EA4340 'Epidémiologie et Oncogénesè des tumeurs digestives', Faculté de médecine PIFO, UVSQ, 9 boulevard d'Alembert, 78280 Guyancourt, France
  2. 2Service de Gastroentérologie et Oncologie Digestive, Hôpital Ambroise Paré, APHP, 9 avenue Charles de Gaulle, 92100 Boulogne, France
  3. 3Service de Génétique Tumorale, Institut Bergonié, 229 Cours de l'Argonne, 33076 Bordeaux, France
  4. 4Service d'Oncologie, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif, France
  5. 5Service d'Anatomo-cyto-pathologie, Hôpital Ambroise Paré, APHP, 9 avenue Charles de Gaulle, 92100 Boulogne, France
  6. 6Unité de recherche clinique, Hôpital Ambroise Paré, APHP, 9 avenue Charles de Gaulle, 92100 Boulogne, France
  7. 7INSERM U590, Centre Léon Bérard, 28 rue Laennec, 69373 Lyon Cedex 08, France
  8. 8LBPA – UMR 8113, école normale supérieure de Cachan 61 avenue du Président Wilson, 94235 Cachan cedex, France
  9. 9Service de Médecine, Institut Bergonié, 229 Cours de l'Argonne, 33076 Bordeaux, France
  10. 10Service d'Oncologie médicale, CHU la Timone, APHM, 13385, Marseille cedex 05, France
  11. 11Service d'Anatomo-cyto-pathologie, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif, France
  12. 12Service d'anatomo-cyto-pathologie, Institut Bergonié, 229 Cours de l'Argonne, 33076 Bordeaux, France

Correspondence: Dr J-F Emile, Pathology Department, Ambroise Pare University Hospital, 9 Avenue Charles De Gaulle, 92104 Boulogne Billancourt, France. E-mail: jean-francois.emile@apr.aphp.fr

Revised 29 April 2009; Accepted 1 May 2009; Published online 16 June 2009.

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Abstract

Background:

  

KIT exon 11 mutations are observed in 60% of gastrointestinal stromal tumours (GIST). Exon 11 codes for residues Tyr568 and Tyr570, which play a major role in signal transduction and degradation of KIT. Our aim was to compare the outcome of patients with deletion of both Tyr568–570 (delTyr) and the most frequent deletion delWK557–558 (delWK).

Methods:

  

Pathology and clinical characteristics of 68 patients with delTyr (n=26) or delWK (n=42) were reviewed and compared.

Results:

  

GISTs with delTyr were more frequently extragastric than those with delWK (69 vs 26%, P<0.0005). After curative surgery, median relapse-free survival were 10.8 and 11.1 months for patients with delTyr (n=14) and delWK (n=29), respectively (P=0.92). All patients treated with imatinib for a non-resectable or metastatic GIST had an objective response (n=15) or a stable disease (n=21) as best response, regardless of mutation. Median progression-free survival with imatinib were 21.9 and 18.9 months for patients with GIST with delTyr (n=14) and delWK (n=22), respectively (P=0.43).

Conclusion:

  

In this large retrospective series, the type of KIT exon 11 mutation was correlated with the origin of GIST, but not with prognosis or response to imatinib.

Keywords:

gastrointestinal stromal tumour, GIST, metastasis, prognostic, survival