Sakakura Noriaki, Mori Shoichi, Okuda Katsuhiro, Fukui Takayuki, Hatooka Shunzo, Shinoda Masayuki, Matsuo Keitaro, Yatabe Yasushi, Yokoi Kohei, Mitsudomi Tetsuya
Department of Thoracic Surgery, Division of Epidemiology and Prevention, Aichi Cancer Center Hospital, Nagoya, Japan.
Ann Thorac Surg. 2008 Oct;86(4):1084-90. doi: 10.1016/j.athoracsur.2008.04.117.
Lung cancer staging system proposed in 2007 adopts detailed tumor size cut-off values. Alternatively, visceral pleural invasion is deemed an important prognosticator, but has not been easily incorporated into the staging system.
We studied 1,245 patients with resected nonsmall-cell lung cancer. Among patients with current pathologic stage IB (pT2N0M0) disease, those with worse prognosis were reclassified as stage IIA based on tumor size and degree of visceral pleural invasion defined by the Japan Lung Cancer Society: P0 = no pleural involvement beyond elastic layer; P1 = infiltration beyond elastic layer without exposure to pleural surface; and P2 = exposure to pleural surface.
The current pT2 category was divided into five groups based on size (<or= 3, > 3 to <or= 5, and > 5 cm) and degree of visceral pleural invasion (P0-1 or P2). Five-year survival rates in patients with P0-1 tumors greater than 3 cm to 5 cm or less were significantly better (59.5%) than those with tumors greater than 5 cm or P2 tumors (37.5% to 47.3%; p = 0.0014); we defined these two groups as T2a and T2b, respectively, and classified T2aN0M0 as stage IB and T2bN0M0 as stage IIA together with the current T1N1M0. Five-year survival rates for the modified IB and IIA diseases were 70.6% and 60.4%, respectively (p = 0.0414).
Modified subcategorization of the pT2 category resulted in T2a (> 3 to <or= 5 cm and P0-1) and T2b (> 5 cm or P2). Detailed assessment of the degree of visceral pleural invasion could provide more information on tumor characteristics and complement the pathologic staging of lung cancer.
2007年提出的肺癌分期系统采用了详细的肿瘤大小临界值。另外，脏层胸膜侵犯被认为是一个重要的预后因素，但尚未轻易纳入分期系统。
我们研究了1245例接受手术切除的非小细胞肺癌患者。在当前病理分期为IB期（pT2N0M0）的患者中，根据日本肺癌协会定义的肿瘤大小和脏层胸膜侵犯程度，将预后较差的患者重新分类为IIA期：P0 = 弹性层以外无胸膜受累；P1 = 弹性层以外浸润但未暴露于胸膜表面；P2 = 暴露于胸膜表面。
根据大小（≤3 cm、>3 cm至≤5 cm和>5 cm）和脏层胸膜侵犯程度（P0-1或P2），将当前的pT2类别分为五组。P0-1类肿瘤大于3 cm至5 cm或更小的患者的5年生存率（59.5%）显著高于肿瘤大于5 cm或P2类肿瘤的患者（37.5%至47.3%；p = 0.0014）；我们分别将这两组定义为T2a和T2b，并将T2aN0M0与当前的T1N1M0一起分类为IB期，T2bN0M0分类为IIA期。改良后的IB期和IIA期疾病的5年生存率分别为70.6%和60.4%（p = 0.0414）。
pT2类别的改良亚分类产生了T2a（>3 cm至≤5 cm且P0-1）和T2b（>5 cm或P2）。对脏层胸膜侵犯程度的详细评估可为肿瘤特征提供更多信息，并补充肺癌的病理分期。
