ErbB1–ErbB4 nuclear and cytoplasmic overexpression, ethnicity and predicted outcome in prostate cancer

Abstract

Few inconclusive studies are reported on ErbB1–ErbB4 overexpression in prostate cancer. The goal of this study is to evaluate ErbB1–ErbB4 nuclear and cytoplasmic expression in prostate cancer patients and to correlate it to the patients’ ethnicity and outcome. T-stage, Gleason score, pre-treatment prostate-specific antigen (PSA) levels and ethnicity were recorded in 50 patients. Ethnicity was defined as either Ashkenazic (immigrated from Europe or North America) or Sephardic origin (Middle East and North Africa). Kattan nomogram was used to predict 5-year progression-free probability (PFP). ErbB1–ErbB4 nuclear and cytoplasmic expression were evaluated by immuno-histochemistry staining. The Ashkenazic (n = 27) and Sephardic (n = 23) patients were comparable in age, T stage, PSA level and Gleason score. ErbB1 cytoplasmic overexpression was found in 66% and none had nuclear overexpression. ErbB2 overexpression was not found in all patients. ErbB3 overexpression was seen in 5%. ErbB4 cytoplasmic and nuclear overexpression was seen in 28% and in 30% to a total of 38%. The ErbB1 and ErbB4 in the Ashkenazic and Sephardic patients were 65, 67, 34 and 44% respectively. PFP of >80%, 60–80% and <60% were seen in 55, 34, and 11% respectively. Ethnicity and overexpression did not significantly contributed to the PFP. In conclusion, ErbB1 and ErbB4 overexpression was seen in 66% and in 38% of prostate cancer patients, while ErbB2 and ErbB3 were almost not overexpressed in prostate cancer patients. Neither overexpression nor ethnicity significantly contributed to the predicted outcome. Further studies on ErbB expression, ethnicity and outcome in prostate cancer patients are warranted.