非小細胞肺癌病理學檢查原則NCCN指南2017V3

PRINCIPLES OF PATHOLOGIC REVIEW 病理學檢查原則

NSCLC NCCN Guidelines 2017V3 非小細胞肺癌NCCN指南2017V3

Pathologic Evaluation 病理評估

* The purpose of pathologic evaluation is to classify the histologic type of lung cancer and to determine all staging parameters as recommended by the AJCC, including tumor size, the extent of invasion (pleural and bronchial), adequacy of surgical margins, and presence or absence of lymph node metastasis. Further, determination of the specific molecular abnormalities of the tumor is critical for predicting sensitivity or resistance to an increasing number of drugable targets, primarily tyrosine kinase inhibitors (TKIs) (see Molecular Diagnostic Studies in Lung Cancer in this section). 山東省腫瘤醫院腫瘤內科張品良 *病理評估的目的是分類肺癌的組織學類型並確定AJCC推薦的所有分期數據，包括腫瘤大小、浸潤範圍（胸膜、支氣管）、手術切緣是否適當以及有無淋巴結轉移。此外，測定腫瘤特定的分子異常是預測越來越多的可用靶向藥物敏感性或抵抗性的關鍵，主要是酪氨酸激酶抑製劑（TKIs）（見本節中的肺癌分子診斷研究）。

* The WHO tumor classification system has historically provided the foundation for the classification of lung tumors, including histologic types, clinical features, staging considerations, and the molecular, genetic, and epidemiologic aspects of lung cancer. *歷史上WHO腫瘤分類系統為肺腫瘤的分類提供了基礎，包括組織學類型、臨床特徵、分期需要考慮的事項以及肺癌的分子、遺傳和流行病學方面的研究。

* The pathology diagnostic report should include the histologic classification in resection specimens or small biopsies as described by the WHO for carcinomas of the lung. Use of bronchioloalveolar carcinoma (BAC) terminology is strongly discouraged. *切除或小活檢標本的病理診斷報告應包括WHO對肺惡性腫瘤描述的組織學分類。強烈反對使用細支氣管肺泡癌（BAC）術語。

* The generic term 「non-small cell lung cancer (NSCLC)」 should be avoided as a single diagnostic term. In small biopsies of poorly differentiated carcinomas where immunohistochemistry (IHC) is used, the following terms are acceptable: 「NSCLC favor adenocarcinoma」 or 「NSCLC favor squamous cell carcinoma.」 Mutational testing (eg, epidermal growth factor receptor [EGFR]) is strongly recommended in all NSCLC favor adenocarcinomas. *術語「非小細胞肺癌（NSCLC）」應避免作為一個單獨的診斷術語。應避免作為一個單獨的診斷術語。使用免疫組化（IHC）的低分化癌小活檢中，下列術語是可以接受的：「非小細胞肺癌傾向於腺癌」或「非小細胞肺癌傾向於鱗狀細胞癌。」在所有傾向於腺癌的非小細胞肺癌中強烈建議突變檢測（如，表皮生長因子受體[EGFR] ）。

* Formalin-fixed paraffin-embedded tumor is acceptable for most molecular analyses. *對於大多數的分子分析，福爾馬林固定石蠟包埋的腫瘤是可以接受的。

* Limited use of IHC studies in small tissue samples is strongly recommended in samples that cannot be reliably classified on the basis of routine histology alone, thereby preserving critical tumor tissue for molecular studies, particularly in patients with advanced-stage disease. *在單獨基於常規組織學不能可靠分類的標本中，強烈建議在小組織標本中限制使用免疫組化檢查，從而保留關鍵的腫瘤組織用於分子研究，尤其是在晚期疾病患者中。

A limited panel of one squamous cell carcinoma marker (eg, p63, p40) and one adenocarcinoma marker (eg, TTF-1, napsin A) should suffice for most diagnostic problems. 對於大多數診斷問題，一個鱗狀細胞癌標記 （如p63、p40） 和一個腺癌標記 （如TTF-1、新天冬氨酸蛋白酶A）的有限組合應該足夠。

Adenocarcinoma Classification 腺癌的分類

* Adenocarcinoma in situ (AIS; formerly BAC): ≤3 cm nodule, lepidic growth, mucinous, non-mucinous, or mixed mucinous/non-mucinous types. *原位腺癌（AIS；原名細支氣管肺泡癌）：結節≤3cm、貼壁生長、粘液性、非黏液性或黏液/非黏液混合性。

* Minimally invasive adenocarcinoma (MIA): ≤3 cm nodule with ≤5 mm of invasion, lepidic growth, mucinous, non-mucinous, or mixed mucinous/non-mucinous types. *微浸潤腺癌（MIA）：結節≤3cm、浸潤≤5mm、貼壁生長、粘液性、非黏液性或黏液/非黏液混合性。

* Invasive adenocarcinoma, predominant growth pattern: lepidic >5 mm of invasion, acinar, papillary, micropapillary, or solid with mucin. ＊浸潤腺癌，主要的生長模式：貼壁浸潤>5mm、腺泡狀、乳頭狀、微乳頭狀或伴有黏液的實體瘤。

* Invasive adenocarcinoma variants: mucinous adenocarcinoma, colloid, fetal, and enteric morphologies. *浸潤腺癌：黏液腺癌、膠凍、胚胎及腸道形態。

Immunohistochemical Staining 免疫組化染色

* Judicious use of IHC is strongly recommended to preserve tissue for molecular testing. IHC should be utilized only after consideration of all data including routine H&E histology, clinical findings, imaging studies, and patient』s history. *強烈建議明智、合理使用IHC以保留組織用於分子檢測。只有在評估所有的資料包括常規H&E組織學、臨床表現、影像學檢查及患者的病史之後才應該考慮使用IHC。

* Although the concordance is generally good between the histologic subtype and the immunophenotype seen in small biopsies compared with surgical resection specimens, caution is advised in attempting to subtype small biopsies with limited material or cases with an ambiguous immunophenotype. *與手術切除的標本相比，小活檢標本的組織學亞型和免疫表型之間儘管觀察到的一致性總體而言是好的，但是，試圖對材料有限的小活檢或免疫表型模稜兩可的患者進行亞型診斷時建議應慎重。

* IHC should be used to differentiate primary pulmonary adenocarcinoma from the following: squamous cell carcinoma, large cell carcinoma, metastatic carcinoma, and malignant mesothelioma; to determine whether neuroendocrine differentiation is present. *應使用IHC以鑒別原發性肺腺癌與下列疾病：鱗狀細胞癌、大細胞癌、轉移癌以及惡性間皮瘤；以確定是否存在神經內分泌分化。

* Primary pulmonary adenocarcinoma *原發性肺腺癌

In patients for whom the primary origin of the carcinoma is uncertain, an appropriate panel of immunohistochemical stains is recommended to exclude metastatic carcinoma to the lung. 在腫瘤原發部位尚不明確的患者中，建議適當的免疫組化染色組合以排除肺轉移性癌。

TTF-1 is a homeodomain-containing nuclear transcription protein of the Nkx2 gene family that is expressed in epithelial cells of the embryonal and mature lung and thyroid. TTF-1 immunoreactivity is seen in primary pulmonary adenocarcinoma in the majority (70%–100%) of non-mucinous adenocarcinoma subtypes. Metastatic adenocarcinoma to the lung is virtually always negative for TTF-1 except in metastatic thyroid malignancies, in which case thyroglobulin is also positive. 甲狀腺轉錄因子1（TTF-1）是Nkx2基因家族的一種含同源結構域的核轉錄蛋白，在肺和甲狀腺胚胎以及成熟的上皮細胞中表達。在原發性肺腺癌中見到甲狀腺轉錄因子1（TTF-1）免疫反應活性大多數（70%–100%）為非黏液腺癌亞型。肺的轉移性腺癌中，TTF-1幾乎均陰性，除了轉移性甲狀腺惡性腫瘤外，在轉移性甲狀腺癌病例中，甲狀腺球蛋白也陽性。

Napsin A - an aspartic proteinase expressed in normal type II pneumocytes and in proximal and distal renal tubules - appears to be expressed in >80% of lung adenocarcinomas and may be a useful adjunct to TTF-1. 新天冬氨酸蛋白酶A（Napsin A）——在正常肺泡Ⅱ型上皮細胞和近端與遠端腎小管中表達的一種天門冬氨酸蛋白酶——似乎在80%以上的肺腺癌中表達，因此作為TTF-1的輔助可能是有用的。

The panel of TTF-1 (or alternatively napsin A) and p63 (or alternatively p40) may be useful in reining the diagnosis to either adenocarcinoma or squamous cell carcinoma in small biopsy specimens previously classified as NSCLC NOS. 在既往分類為非小細胞肺癌非特指的小活檢標本中，在「駕馭」腺癌或鱗狀細胞癌診斷時，TTF-1（或Napsin A）和p63（或p40）組合可能是有用的。

* Neuroendocrine differentiation *神經內分泌分化

CD56, chromogranin, and synaptophysin are used to identify neuroendocrine tumors. CD56、嗜鉻素以及突觸素用於鑒別神經內分泌腫瘤。

* Malignant mesothelioma versus pulmonary adenocarcinoma ＊惡性間皮瘤與肺腺癌

The distinction between pulmonary adenocarcinoma and malignant mesothelioma (epithelial type) can be made by correlation of the histology with the clinical impression, imaging studies, and a limited panel of immunomarkers if needed. 肺腺癌與惡性間皮瘤（上皮型）的鑒別可以根據組織學與臨床印象、影像檢查的相互關係以及有限的免疫標記組合（如果需要的話）做出診斷。

Immunostains relatively sensitive and specific for mesothelioma include WT-1, calretinin, D2-40, HMBE-1, and cytokeratin 5/6 (negative in adenocarcinoma). 對於間皮瘤相對敏感且特異的免疫標記包括Wilm"s腫瘤基因（WT-1）、鈣結合蛋白、D2-40、HMBE-1和細胞角蛋白5/6（在腺癌中陰性）。

Antibodies immunoreactive in adenocarcinoma include CEA, B72.3, Ber-EP4, MOC31, CD15, claudin-4, and TTF-1 (negative in mesothelioma). 在腺癌中免疫活性抗體包括CEA、B72.3、Ber-EP4、MOC31、CD15、緊密連接蛋白-4和TTF-1（在間皮瘤中陰性）。

Molecular Diagnostic Studies in Lung Cancer 肺癌的分子診斷研究

* EGFR and KRAS * EGFR和KRAS

EGFR is normally found on the surface of epithelial cells and is often overexpressed in a variety of human malignancies. Presence of EGFR-activating mutations represents a critical biological determinant for proper therapy selection in patients with lung cancer. EGFR通常在上皮細胞中發現，往往在多種人類惡性腫瘤中過表達。表皮生長因子受體活化突變的存在是肺癌患者合理選擇治療的一個關鍵的生物學決定因素。

There is a significant association between EGFR mutations—especially exon 19 deletion and exon 21 (L858R, L861), exon 18 (G719X, G719), and exon 20 (S768I) mutations—and sensitivity to EGFR TKIs. EGFR突變——尤其是外顯子19缺失和外顯子21（L858R，L861）、外顯子18（G719X，G719）和外顯子20（S768I）突變——之間顯著相關並且對EGFR-TKI敏感。

The exon 20 insertion mutation may predict resistance to clinically achievable levels of TKIs. 外顯子20插入突變可預測對酪氨酸激酶抑製劑臨床可達到的耐葯程度。

Overlapping EGFR and KRAS mutations occur in<1% of="" patients="" with="" lung="" cancer.=""> 不到1%的肺癌患者存在EGFR和KRAS基因疊加突變。

KRAS mutations are associated with intrinsic EGFR TKI resistance, and KRAS gene sequencing could be useful for the selection of patients as candidates for EGFR TKI therapy. KRAS testing may identify patients who may not benefit from further molecular diagnostic testing. KRAS突變與EGFR TKI原發耐葯相關，因此，KRAS基因測序對於選擇EGFR TKI治療的候選患者可能是有用的。KRAS檢測可識別出不會獲益於進一步分子診斷檢測的患者。

The prevalence of EGFR mutations in adenocarcinomas is 10% of Western and up to 50% of Asian patients, with higher EGFR mutation frequency in non-smokers, women, and non-mucinous cancers. KRAS mutations are most common in non-Asians, smokers, and in mucinous adenocarcinoma. The most common EGFR mutations result in an arginine for leucine substitution at amino acid 858 in exon 21 (L858R) and in frame deletions at exon 19. Mutations are more common in non-mucinous lung adenocarcinoma with lepidic pattern (former BAC pattern) and in lung adenocarcinoma with papillary (and or micropapillary) pattern. 腺癌EGFR突變的發生率西方患者是10%，而亞洲患者高達50%，在非吸煙者、女性以及非黏液癌中EGFR突變率更高。在非亞洲人、吸煙者和粘液腺癌中KRAS突變最常見。最常見的EGFR突變引起外顯子21（L858R）第858個氨基酸的亮氨酸取代了精氨酸和外顯子19幀缺失。突變在貼壁生長模式（原細支氣管肺泡癌）的非黏液性肺腺癌和乳頭狀（和或微乳頭狀）肺腺癌中更常見。

Primary resistance to EGFR TKI therapy is associated with KRAS mutation. Acquired resistance is associated with second-site mutations within the EGFR kinase domain (such as T790M), amplification of alternative kinases (such as MET), histologic transformation from NSCLC to SCLC, and epithelial to mesenchymal transition (EMT). KRAS突變與對EGFR TKI治療原發性耐葯有關。獲得性耐葯與EGFR激酶域內的第二個位點突變（如T790M）、另一個激酶擴增（如MET）、非小細胞肺癌組織轉化為小細胞肺癌以及上皮間質轉化（EMT）有關。

* ALK

Anaplastic lymphoma kinase (ALK) gene rearrangements represent the fusion between ALK and various partner genes, including echinoderm microtubule-associated protein-like 4 (EML4). ALK fusions have been identified in a subset of patients with NSCLC and represent a unique subset of NSCLC patients for whom ALK inhibitors may represent a very effective therapeutic strategy. Crizotinib, ceritinib, and alectinib are oral ALK inhibitors that are approved by the FDA for patients with metastatic NSCLC who have the ALK gene rearrangement (ie, ALK positive). 間變性淋巴瘤激酶（ALK）基因重排是ALK和各夥伴基因之間的融合，包括棘皮動物微管結合蛋白4（EML4）。ALK融合已在非小細胞肺癌患者的一個亞組中識別出來，代表一個獨特的非小細胞肺癌患者亞組，ALK抑製劑對其可能是一種非常有效的治療策略。克唑替尼、色瑞替尼和阿雷替尼是口服的ALK抑製劑，FDA已批准用於治療有ALK基因重排（即ALK陽性）的轉移性非小細胞肺癌患者。

ALK NSCLC occurs most commonly in a unique subgroup of NSCLC patients who share many of the clinical features of NSCLC patients likely to harbor EGFR mutations. However, for the most part, ALK rearrangements and EGFR mutations are mutually exclusive. ALK非小細胞肺癌最常出現在一個獨特的非小細胞肺癌患者亞組中，同時具有許多臨床特徵的非小細胞肺癌患者可能存在EGFR突變。然而，大多數情況下，ALK重排和EGFR突變是互相排斥的。

The current standard method for detecting ALK NSCLC is fluorescence in situ hybridization (FISH). The appropriate antibody and detection method for ALK protein expression can be used for rapid prescreening of ALK-rearranged lung adenocarcinomas and selection of cases that will subsequently be confirmed by FISH testing. 檢測ALK肺癌目前的標準方法是熒光原位雜交（FISH）。ALK蛋白表達相應的抗體檢測方法可用於快速篩查ALK重排的肺腺癌病例，並隨後將FISH檢測證實的選擇。

* ROS-1

Although ROS1 is a distinct receptor tyrosine kinase, ROS1 has a high degree of homology with ALK (approximately 50% within the kinase domain and 75% within the ATP-binding site). 儘管ROS1是一個獨特的受體酪氨酸激酶，但是ROS1與ALK具有高度的同源性（在激酶結構域中約50%，在ATP結合位點中約75%）。

The majority of patients with ROS1-positive NSCLC respond to the first-generation ALK inhibitor crizotinib; however, certain other ALK inhibitors such as alectinib do not appear to have activity against ROS1-positive NSCLC. ROS1陽性的非小細胞肺癌患者大多數對第一代ALK抑製劑克唑替尼應答；然而，某些其他ALK抑製劑如阿雷替尼對ROS1陽性的非小細胞肺癌似乎無效。

ROS1 rearrangements occur in 1%–2% of patients with NSCLC. Similar to testing for ALK rearrangements, testing for ROS1 is also done using FISH. 1%–2%的非小細胞肺癌患者存在ROS1基因重排。與ALK重排檢測相似，ROS1也用FISH檢測。

* PD-L1

Immune checkpoint inhibitors target programmed death receptor 1 (PD-1) or its ligand, programmed death ligand 1 (PD-L1). 免疫檢查點抑製劑的靶點是程序性死亡受體1（PD-1）或其配體——程序性死亡配體1（PD-L1）。

PD-1 is expressed by T-cells and regulates the activation of T-cells in peripheral tissues. PD-1 has two ligands, PD-L1 (also known as B7-H1 or CD274) and PD-L2 (B7-DC or CD273). These ligands are expressed on a wide range of immune effector cells, antigen-presenting cells, and tumor cells. PD-1 activation by ligand binding with PD-L1 on the tumor cells produces a number of intracellular effects that result in T-cell inactivity and reduced proliferation. PD-1表達於T細胞，並調節外周組織中T細胞的活化。PD-1有兩個配體，PD-L1（也稱為B7-H1或CD274）和PD-L2（B7-DC或CD273）。這些配體表達於各種免疫效應細胞、抗原呈遞細胞和腫瘤細胞。腫瘤細胞上的PD-L1配體與PD-1結合併激活，產生一系列的細胞間作用，引起T細胞失活並降低增殖。

The therapeutic focus in NSCLC has been to interrupt the interaction of PD-1 and its ligand PD-L1 between tumor cells and immune effectors cells using monoclonal antibodies against PD-L1 or PD-1. 在非小細胞肺癌中治療的重點是用抗PD-L1或PD-1的單克隆抗體阻斷PD-1與腫瘤細胞和免疫效應細胞間其配體PD-L1的相互作用。

Anti-PD-L1 IHC may be a biomarker used to select patients with NSCLC more likely to respond to immune checkpoint inhibitors, but the development of a variety of therapeutics, each with a different anti-PD-L1 IHC assay, has raised concerns among both pathologists and oncologists. 抗PD-L1免疫組化可能是一個用於選擇更可能對免疫檢查點抑製劑應答的非小細胞肺癌患者的生物標誌物，但是開發的各種療法，每一種都使用不同的抗PD-L1 IHC檢測，加劇了病理學家和腫瘤學家的擔憂。

The definition of a positive PD-L1 test result varies depending on which biomarker assay is used. PD-L1 expression levels of ≥50% are a positive test result for first-line pembrolizumab therapy. PD-L1檢測結果陽性的定義取決於使用的生物標記法。對於一線派姆單抗治療，PD-L1表達水平≥50%為陽性檢測結果。