1425P - Smooth muscle actin expression in gastrointestinal stromal tumors of different localization and morphological types

Date 29 September 2014
Event ESMO 2014
Session Poster Display session
Topics GIST
Translational Research
Presenter Valerie Yakovenko
Citation Annals of Oncology (2014) 25 (suppl_4): iv494-iv510. 10.1093/annonc/mdu354
Authors V. Yakovenko, S. Chekan, A. Korolenko
  • Pathological Anatomy, State Establishment "Dnipropetrovsk medical academy of health ministry of Ukraine", 49000 - Dnipropetrovsk/UA

Abstract

Aim

The most common mesenchymal neoplasms of the gastrointestinal tract are considered gastrointestinal stromal tumor. They can occur in any section of the digestive tube, however, the frequency of their occurrence is reduced as disengaging the stomach, most rarely found GIST in the distal parts of the colon and esophagus. Today, unresolved questions regarding the epidemiological data, morphological similarity with mesenterial tumors, potential malignancy and high cost methods of diagnosis and target therapy substantiates the necessity of precise criteria for the diagnosis and prognosis of GIST.

Methods

The study included 61 sample biopsy and operational material GIST, which had immunohistochemical study using the marker CD117 (c-kit), DOG1, CD34, SMA (Thermo Scientific). On the basis of the following criteria - the intensity of the membrane and/or the cytoplasmic coloring, diffuse/focal character coloring - cases were divided into 3 groups: with positive and negative status, and expression in part of tumor cells.

Results

During our study we found 13 cases (21.3%) with expression of SMA. Among them: most GIST were localized in small intestine – 5 cases (38,5%), whereas SMA neoplasms of stomach reprersented 60.4%. Among SMA+GIST 9 (69,2%) cases was CD117 positive; there were 2 cases with expression in part of tumor cells (15.4%),cases with negative status-2 (15.4%); 12 samples (92.3%) positive with antibody DOG1, most had positive CD34 status (61,5%). Table 1. Expression of SMA in GIST with different clinical and morphological data

SMA CD117+ CD117 In part CD117- CD34+ CD34 In part CD34- DOG1+ DOG1- Epit. type Spin. type mixed type 1* 2* 3* 4* 5*
+ (n=13) 9 (69,2%) 2 (15,4%) 2 (15,4%) 8 (61,5%) 2 (15,4%) 3 (23,3%) 12 (92,3%) 1 (7,7%) 1 (7,7%) 8 (61,5%) 4 (30,8%) 2 (15,4%) 5 (38,5%) 1 (7,7%) 1 (7,7%) 4 (30,8%)
- (n=48) 37 (77,1%) 5 (10,4%) 6 (12,5%) 34 (70,8%) 3 (6,3%) 11 (22,9%) 46 (95,8%) 2 (4,2%) 9 (18,7%) 24 (50%) 15 (31,3%) 29 (60,4%) 8 (16,7%) 5 (10,4%) 3 (6,25%) 3 (6,25%)

* Localization: 1 – stomach; 2 - small intestine; 3 - large intestine; 4 – rectum; 5 - eGIST

Conclusions

Expression of SMA does not depend on location, morphological type of GIST, CD117, DOG1 and/or CD34 status (p>0.05). However, the majority of cases of SMA -ositive tumors were localized in the small intestine, whereas SMA-negative tumors were more common in the stomach. The need to continue the search for correlation criteria between clinical and morphological data is ongoing.

Disclosure

All authors have declared no conflicts of interest.