HER-2/<it>neu </it>and CD117 (c-kit) overexpression in patients with pesticide exposure and extensive stage small cell lung carcinoma (ESSCLC)

• Main Authors: Potti Anil, Ganti Apar, Tuchman Sascha A, Sholes Kaley, Langness Eric, Koka Vijay, Koch Michael
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2005-06-01
• Series: Journal of Carcinogenesis
• Subjects: Pesticide exposure; HER-2/<it>neu </it>overexpression; CD117 overexpression; c-kit overexpression; extensive stage small cell lung cancer; survival; epidemiology.
• Online Access: http://www.carcinogenesis.com/content/4/1/8
• ISSN: 0974-6773; 1477-3163

<p>Abstract</p> <p>Background</p> <p>The rate of detection of HER-2/<it>neu </it>and CD117 (c-kit) overexpression in small cell lung cancer (SCLC) has varied widely; between 5–35% and 21–70% respectively.</p> <p>Methods</p> <p>To evaluate the relationship between pesticide exposure and HER-2/<it>neu </it>and CD117 overexpression in extensive stage SCLC (ESSCLC), we identified patients with ESSCLC and assessed pesticide exposure using a predetermined questionnaire. An exposure index (hours/day × days/year × years) ≥ 2400 hours was considered as 'exposed.' HER-2/<it>neu </it>overexpression was evaluated on archival tissue using the DAKO Hercep test, and CD117 testing was performed using immunohistochemistry (A4052 polyclonal antibody).</p> <p>Results</p> <p>193 ESSCLC patients were identified. Pesticide exposure data could be obtained on 174 patients (84 females and 109 males) with a mean age of 68.5 years. 53/174 (30.4%) revealed HER-2/<it>neu </it>overexpression. 54/174 (31.03%) specimens showed CD117 overexpression by IHC. On multivariate analysis, HER-2/<it>neu </it>overexpression was associated with diminished survival (p < 0.001). In comparison, CD117 expression did not have an adverse prognostic value (p = 0.025). 41/53 (77.4%) patients with HER-2/<it>neu </it>overexpression and 47/121 (38.8%) patients without overexpression had exposure to pesticides (odds ratio: 5.38; p < 0.01). Among the cohort tested for CD117, 29/54 (53.7%) patients with CD117 overexpression and 59/120 (49.2%) patients without CD117 overexpression had pesticide exposure (odds ratio: 1.18; p = 0.12).</p> <p>Conclusion</p> <p>Pesticide exposure affects HER-2/<it>neu </it>but not CD117 overexpression. Future studies are needed to determine specific pesticide(s)/pesticide components that are responsible for HER-2/<it>neu </it>overexpression in ESSCLC, and to validate our findings in other solid tumors that overexpress HER-2/<it>neu</it>.</p>