Department of Pathology, University of Texas Health Science Center, San Antonio, USA.
Arch Pathol Lab Med. 2012 Feb;136(2):163-71. doi: 10.5858/arpa.2011-0320-OA.
Differentiation of non-small cell carcinoma into histologic types is important because of new, successful therapies that target lung adenocarcinoma (ACA). TTF-1 is a favored marker for lung ACA but has limited sensitivity and specificity. Napsin A (Nap-A) is a functional aspartic proteinase that may be an alternative marker for primary lung ACA.
To compare Nap-A versus TTF-1 in the typing of primary lung carcinoma and the differentiation of primary lung ACA from carcinomas of other sites.
Immunohistochemistry for Nap-A and TTF-1 was performed on tissue microarrays of 1674 cases of carcinoma: 303 primary lung ACAs (18.1%), 200 primary squamous cell lung carcinomas (11.9%), 52 primary small cell carcinomas of the lung (3.1%), and carcinomas of the kidney (n = 320; 19.1%), thyroid (n = 96; 5.7%), biliary (n = 89; 5.3%), bladder (n = 47; 2.8%), breast (n = 93; 5.6%), colon (n = 95; 5.7%), liver (n = 96; 5.7%), ovaries (n = 45; 2.7%), pancreas (n = 48; 2.9%), prostate (n = 49; 2.9%), stomach (n = 93; 5.6%), and uterus (n = 48; 2.9%). Cases were evaluated against a negative control as negative, weak positive, and strong positive.
Nap-A was more sensitive than TTF-1 for primary lung ACA (87% versus 64%; P < .001). Nap-A was more specific than TTF-1 for primary lung ACA versus all tumors, excluding kidney, independent of tumor type (P < .001).
Nap-A is superior to TTF-1 in distinguishing primary lung ACA from other carcinomas (except kidney), particularly primary lung small cell carcinoma, and primary thyroid carcinoma. A combination of Nap-A and TTF-1 is useful in the distinction of primary lung ACA (Nap-A(+), TTF-1(+)) from primary lung squamous cell carcinoma (Nap-A(-), TTF-1(-)) and primary lung small cell carcinoma (Nap-A(-), TTF-1(+)).
由于新的、成功的靶向肺腺癌（ACA）的治疗方法，区分非小细胞癌为组织学类型非常重要。甲状腺转录因子 1（TTF-1）是肺 ACA 的首选标志物，但敏感性和特异性有限。天冬氨酸蛋白酶 Nap-A（Nap-A）是一种功能性天冬氨酸蛋白酶，可能是原发性肺 ACA 的另一种标志物。
比较 Nap-A 与 TTF-1 在原发性肺癌分型和原发性肺 ACA 与其他部位癌的鉴别诊断中的作用。
对 1674 例癌组织的组织微阵列进行 Nap-A 和 TTF-1 的免疫组织化学染色：303 例原发性肺 ACA（18.1%）、200 例原发性肺鳞癌（11.9%）、52 例原发性肺小细胞癌（3.1%）、肾（n=320；19.1%）、甲状腺（n=96；5.7%）、胆道（n=89；5.3%）、膀胱（n=47；2.8%）、乳腺（n=93；5.6%）、结肠（n=95；5.7%）、肝（n=96；5.7%）、卵巢（n=45；2.7%）、胰腺（n=48；2.9%）、前列腺（n=49；2.9%）、胃（n=93；5.6%）和子宫（n=48；2.9%）。阴性对照为阴性、弱阳性和强阳性。
Nap-A 对原发性肺 ACA 的敏感性优于 TTF-1（87%比 64%；P<0.001）。与所有肿瘤（除肾外）相比，Nap-A 对原发性肺 ACA 的特异性优于 TTF-1，与肿瘤类型无关（P<0.001）。
与其他癌（肾除外）相比，Nap-A 在鉴别原发性肺 ACA 方面优于 TTF-1，尤其是原发性肺小细胞癌和原发性甲状腺癌。Nap-A 与 TTF-1 的联合应用有助于鉴别原发性肺 ACA（Nap-A（+），TTF-1（+））与原发性肺鳞癌（Nap-A（-），TTF-1（-））和原发性肺小细胞癌（Nap-A（-），TTF-1（+））。
