Sensitivity and prognostic value of thyroid transcription factor-1 and napsin A in primary adenocarcinoma of the lung

Introduction: Lung cancer has been the most common cause of cancer deaths in the past few decades worldwide. In the differentiation of the histopathological types, two basic markers are currently used, which are napsin A and thyroid transcription factor-1 (TIT-1). Aim: To assess the sensitivity of TTF-1, napsin A and combined use of both markers in detecting primary lung adenocarcinoma. The second aim was to examine the role of TIT-1 and napsin A both alone and in combination as prognostic markers. Material and methods: In the course of the study, patients' data were collected and histological specimens were evaluated using TTF-1 and napsin A as cancer markers. Results: The sensitivities for TIT-1 and napsin A when used separately were 74.58% and 49.15% respectively. When a panel of both TTF-1 and napsin A was used the sensitivity increased to 79.17% as 38 out of 48 cases were positive for either or both of the immunohistochemical markers. The results for 1-, 3-, 4-year survival data were 87.9%, 70.7 %, 58.6%, with TTF-1 positive patients having better survival. Conclusions: We have shown that both TIT-1 and napsin A are sensitive markers of primary lung adenocarcinoma with TTF-1 being more sensitive. Sensitivity increases when both markers are used in combination.