Subtyping of nonsmall cell lung cancer on cytology specimens: Reproducibility of cytopathologic diagnoses on sparse material

Cytologic examination of fine‐needle aspiration (material is increasingly used in diagnosing lung cancer. High interobserver agreement in distinguishing small‐cell lung cancer from nonsmall‐cell lung cancer (NSCLC) on cytologic material has been demonstrated. Because of new treatment‐modalities, subclassification of NSCLC into squamous cell carcinoma (SQC) and non‐SQC has clinical impact. Subclassification based on morphology alone may be difficult, but applying immunohistochemistry (IHC) to clot‐material has proved helpful. When insufficient material is available to make a clot from the aspirate, cytoscrape (CS) can convert cytologic material into tissue fragments useful for IHC. The purpose of this study was to test the reproducibility of pulmonary malignant diagnoses, in particular distinction between subgroups of NSCLC, based on smeared material and IHC on CS. A consecutive series of May–Grunwald–Giemsa (MGG) stained smears and CS with IHC on material from 79 patients suspected of having lung cancer was included. The material was circulated twice to four pathologists. The diagnoses were categorized in five groups: SQC, adenocarcinoma of the lung, non‐SQC, benign lesion and other forms of malignancy, including metastases. Reproducibility was analyzed using Kappa statistics. Interobserver reproducibility of the diagnoses in round 1 was good to very good (kappa 0.57–0.71) and very good in round 2 (0.63–0.80). Reproducibility of subclassification of NSCLC based on MGG stained smear and IHC on CS, was very good among experienced pathologists. With only sparse material available, CS should be used to achieve reproducible diagnoses, including subtyping of NSCLC. Diagn. Cytopathol. 2014;42: 105–110. © 2013 Wiley Periodicals, Inc.     

One-step nucleic acid amplification (OSNA) for intraoperative evaluation of sentinel lymph node status in breast cancer: a comparative study between CK19 protein expression and CK19 mRNA level in primary tumors and lymph node metastasis

The one-step nucleic acid amplification (OSNA) method is an increasingly used procedure for intraoperative analysis of sentinel lymph node (SLN) status in breast cancer patients. It measures cytokeratin19 (CK19) mRNA copy numbers in homogenized samples of SLN; CK19 has been chosen for identifying node metastasis because most breast cancers express this molecule. However, to avoid false-negative OSNA results, testing the preoperative needle core biopsy (NCB) of breast carcinomas for CK19 by immunohistochemistry (IHC) has been recommended. This procedure relies on the assumption that protein expression is strictly related to mRNA expression. We developed this study to evaluate if IHC gives similar result to the molecular assay. In a series of breast cancer patients with axillary metastasis, corresponding surgically resected tumor and metastatic lymph node specimens have been tested for CK19 protein by IHC and for CK19 mRNA by real-time PCR; furthermore, CK19 immunostaining has been performed in NCBs when available. Statistical analysis revealed that (1) the immunohistochemical evaluation of CK19 in NCB is a reliable test, reflecting protein expression in the whole tumor and in the metastatic lymph node; (2) there is no correlation between CK19 protein expression and CK19 RNA level neither within the primary breast cancer nor within the metastatic node; moreover, no correlation as well has been found between protein expression in NCB and mRNA level in metastatic lymph nodes. Thus, our results suggest that there is no evidence-based reason to stain every NCB for CK19 before performing OSNA in patients with breast cancer.     

Cytopathologic evaluation of lung carcinomas presenting as brain metastasis.

Brain metastasis is an uncommon initial presentation of lung carcinoma. One arm of this analysis is a retrospective review of 137 cases of surgically diagnosed solitary brain metastasis, which were eventually found to be of lung origin, encountered at Hines VA Hospital during the period 1958 to 1996. The second arm is composed of fine-needle aspiration biopsy specimens of primary lung tumor in 23 patients with an initial clinical diagnosis of brain metastasis and without the benefit of surgery, seen from 1981 through 1996. Our results in both analyses indicate that pulmonary adenocarcinoma is the predominant primary tumor that initially manifests as a brain metastasis, approaching 76% (107 and 17 cases, respectively), followed by small-cell carcinoma at 20% (24 and five cases, respectively) and large-cell undifferentiated carcinoma and squamous-cell carcinoma at 2% each. The predominance of adenocarcinoma as a source of brain metastasis in lung cancer patients probably reflects its rising incidence overall of late. Collateral findings also suggest that surgical resection of a solitary and small brain metastasis as well as of a discrete lung primary, whenever feasible, as the most effective procedure to improve survival and quality of life of patients.     

Value of P63 and CK5/6 in distinguishing squamous cell carcinoma from adenocarcinoma in lung fine‐needle aspiration specimens

The current FDA‐approved standard of care for nonsmall cell lung cancer is Carboplastin/Taxol/Avastin based upon an impressive survival benefit; however, patients with squamous carcinoma (SQCC) cannot receive Avastin because of a 30% mortality rate due to fatal hemoptysis. In this study we evaluated the role of cytomorphology and immunohistochemistry in differentiating SQCC from adenocarcinoma (ADC) in lung FNA specimens. The case cohort included 53 FNA cases of nonsmall cell lung carcinoma with surgical pathology follow‐up. All FNA specimens were reviewed independently by a panel of cytopathologists to differentiate between SQCC and ADC. The cell block material was available in 23 cases (11 ADC and 12 SQCC) to perform immunohistochemical stains for TTF‐1, CK7, CK20, P63, and CK5/6. On surgical resection, 35/53 (66%) cases were diagnosed as ADC and 18/53 (34%) as SQCC. The number of cases classified correctly on the basis of cytomorphology was 66% for ADC and 53% for SQCC (combined accuracy 60%). By immunohistochemical staining, 14/23 (61%) cases expressed TTF‐1. Nine cases were TTF‐1 negative; eight of the TTF‐1 negative cases (89%) were SQCC. Twenty‐three cases expressed CK7 (87%); one ADC case (4%) showed focal CK20 positivity. Both P63 and CK5/6 expression was seen in 9/12 (75%) SQCC cases; none of the ADC cases showed this dual expression. Cytomorphology alone may not be able to stratify all cases of nonsmall cell lung carcinoma into ADC and SQCC in FNA specimens. The immune‐panel of TTF‐1, CK7, CK20, P63, and CK5/6 is useful in differentiating SQCC from ADC. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

非小细胞肺癌中凋亡相关蛋白与伴神经内分泌分化表达的相关性

目的 检测非小细胞肺癌(non-small cell lung carcinoma,NSCLC)中凋亡相关蛋白与神经内分泌(neuroendocrine,NE)分化的表达,探讨其相关性.方法 采用免疫组织化学染色方法,检测NSCLC组织中survivin,bcl-2蛋白与NSE、Syn及CgA等蛋白的表达,并进行相关性作统计学分析.结果 113例NSCLC中,survivin、bcl-2阳性表达率分别为88.5%、58.4%;NSE、Syn和CgA蛋白阳性表达率分别为53.6%、6.2%和26.5%.伴NE分化者占21.2%,其survivin蛋白表达明显高于不伴NE分化组,差异有统计学意义.结论survivin、bcl-2蛋白表达上调可能在NSCLC发生发展中起重要作用.伴NE分化的NSCLC与表达阴性者相比,以survivin为代表的抗凋亡能力明显增强.     

If it's not CK5/6 positive, TTF-1 negative it's not a squamous cell carcinoma of lung

Novel targeted treatment of non-small cell lung cancer (NSCLC) requires accurate classification of NSCLC as squamous cell carcinoma (SCC) and adenocarcinoma (AC). This study details the CK5/6 and TTF-1 immunoprofile of surgical resections of 45 NSCLCs (24 ACs and 21 SCCs) in tissue microarrays. All SCCs were CK5/6 positive, TTF-1 negative. 20 of 24 adenocarcinomas had the reverse pattern. In conclusion, all SCCs in this study were CK5/6 positive and TTF-1 negative, and therefore tumours that do not display this phenotype are unlikely to be SCCs. CK5/6 and TTF-1 is therefore a practical panel for the distinction between pulmonary SCC from AC in routine histopathology practice.     

Immunohistochemistry reliably detects ALK rearrangements in patients with advanced non-small-cell lung cancer

Accurate determination of anaplastic lymphoma kinase (ALK) rearrangements is critical in identifying ALK-positive patients for targeted therapy in non-small-cell lung cancer (NSCLC). Fluorescence in situ hybridization (FISH) is the current standard method to detect ALK rearrangements but is technically challenging and costly. We compared optimised immunohistochemistry (IHC), quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization techniques in this study of 139 samples of advanced NSCLC with non-squamous histology. ALK alteration was found in 32.6 % (43/132) of patients by FISH, 32.9 % (45/137) of patients by IHC and 27.9 % (34/122) of samples by qRT-PCR (concordance rate of 96.9 % between FISH and IHC, 95.7 % between FISH and qRT-PCR, P?<?0.001). IHC sensitivity and specificity were 97.7 % and 96.6 %, respectively, while the sensitivity and specificity of qRT-PCR were 89.2 % and 98.7 %, respectively. ALK rearrangements were more common in young patients (P?=?0.007), non-smokers or light smokers (P?=?0.008) and adenocarcinoma histology, especially with signet ring cell features (P?<?0.001). Optimised IHC could be a useful method in screening ALK rearrangements in clinical practice with qRT-PCR as an alternative diagnostic tool to clarify specific ALK variants.     

Immunoreactivity for LN2 and LN3 distinguishes small cell carcinomas from non-small cell carcinomas in the lung

Immunoreactivity to LN2 and LN3, monoclonal antibodies that recognize components of the class II major histocompatibility complex, was assessed in 72 cases of non-small cell lung carcinoma (NSCLC) (32 biopsy specimens, 40 resection specimens) and 64 cases of small cell carcinoma (56 biopsy specimens, 8 resections) of the lung. All cases were reviewed independently by three pathologists for histological classification. Only 1 of the 64 small cell carcinomas showed immunoreactivity for LN2, and none of the 64 cases showed reactivity for LN3. Among the non-small cell carcinomas, 25 of 48 cases were positive for LN2 and 43 of 71 were positive for LN3; the sensitivity was greater for adenocarcinoma (78.5%) than for squamous cell carcinoma (37%). A combined sensitivity of 64.7% was observed when the results of LN2 and LN3 were combined, and this sensitivity was not significantly diminished in the biopsy subset of cases (59.4%). Differentiation within histological subtypes of NSCLC (ie, well, moderate, or poorly differentiated) did not alter test sensitivity. In conclusion, LN2 and LN3, used alone or in combination, appear highly specific for non-small cell carcinoma and moderately sensitive in both biopsy and resection specimens; therefore, these antibodies may be diagnostically useful in distinguishing small cell from non-small cell carcinoma of the lung.     

Mixed low- and high-grade papillary urothelial carcinoma: histopathogenetic and clinical significance

There are two pathways of urothelial carcinogenesis: low-grade urothelial carcinoma (LGUC) with low rates of gene alterations and high-grade urothelial carcinoma (HGUC) with numerous gene alterations. HGUC often displays strong reactivity for cytokeratin 20 (CK20) and p16. Despite distinct molecular changes, urothelial carcinoma (UC) with both low- and high-grade features is not uncommon. We examined cases with patterns of mixed low- and high-grade UC (MLHGUC). Consecutive cases of UC at our institution were reviewed. There were 45 cases that showed a mixture of both LGUC and HGUC. IHC for CK5, CK20, CD44, p16, and Ki67 was performed. Areas of HGUC displayed strong and diffuse reactivity for p16, CK20, and Ki67 in 20–50 % of the tumor, while LGUC areas had negative or focal reactivity for CK20 and Ki67 in 10–30 %. There were two distinct cohorts of MLHGUC: patients with a history of LGUC (group A) and those without (group B). Group A patients (n?=?8) had a history of LGUC for 1–10 years. The tumor specimens weighed 1.5?±?1.7 g and had HGUC components of 25?±?20 % of the tissue. Superficial invasion was present in one case. All tumors had BCG treatment with one recurrence. In group B (n?=?37), tumor specimens weighed 3?±?3.9 g and had HGUC components in 43?±?21 % of the tissue. Superficial invasion was present in five cases, and muscle invasion with lung metastasis occurred in one case. Four cases were refractory to BCG with an increased proportion of HGUC, and one case requiring cystectomy. Differences in size and proportion of HGUC between groups A and B MLHGUC were significant (P?<?0.05), with group B presenting with a higher tumor burden and proportion of HGUC. MLHGUC is diagnostically challenging and is commonly assigned high grade since this determines prognosis. Group A MLHGUC likely develops as a result of progression from LGUC, whereas group B MLHGUC likely develops de novo, is associated with larger tumors, shows a higher proportion of HGUC, and follows a worse prognosis. Despite the similar histology of groups A and B, assignment to HGUC in a binary system may mask important prognostic information.     

Comparison of HER2 status between surgically resected specimens and matched biopsy specimens of gastric intestinal-type adenocarcinoma

HER2 protein overexpression and gene amplification are important biomarkers for identifying gastric cancer patients who may respond to HER2-targeted therapy using trastuzumab. The aim of this study was to evaluate the concordance between HER2 protein expression and gene amplification in both surgically resected tumors and matched biopsy specimens of gastric cancer. Formalin-fixed, paraffin-embedded sections of 207 surgically resected tumors and 158 biopsy specimens from 207 cases of invasive intestinal-type gastric cancer were analyzed. Protein expression was assessed using immunohistochemistry and graded by the modified scoring criteria for gastric cancer. Gene amplification was evaluated by fluorescence in situ hybridization (FISH). HER2 overexpression was observed in 17 % of both surgically resected tumors (35/207) and biopsy specimens (26/158). HER2 gene amplification was detected in 31 % (61/200) of surgically resected tumors and 32 % (47/147) of biopsy specimens. Except for immunohistochemistry (IHC) equivocal (2+) cases, the concordance rates between IHC and FISH was 90.9 % in surgically resected tumors and 90.2 % in biopsy specimens. In IHC 2+ cases, the rate of HER2 gene amplification was 56 and 38 % in surgically resected tumors and biopsy specimens, respectively. IHC-FISH discordance was mainly due to intratumoral heterogeneity and low-level gene amplification. The concordance rate of IHC results between surgically resected specimens and the corresponding biopsy specimen was 57.0 % (κ?=?0.224), and in discordant cases, HER2 positivity in biopsies and HER2 negativity in surgically resected tumors were most common. The concordance rate of FISH results between surgically resected tumors and biopsy specimens was 72.7 % (κ?=?0.313). Polysomy 17 was detected in 5.5 and 7.5 % of surgically resected tumors and biopsy specimens and significantly correlated with IHC score, but polysomy 17 could explain one IHC score 3+ and FISH-negative tumor only. Although high concordance rates between HER2-protein expression and gene amplification were observed in both surgically resected tumors and biopsy specimens, the agreement levels were evaluated to be fair. Polysomy 17 was infrequent and seemed to have limited impact on gastric HER2 testing. Further investigations are required for an appropriate biopsy method to reduce false results of HER2 testing and to clarify the clinical significance of intratumoral heterogeneity in HER2 status.     

What's new in non-small cell lung cancer for pathologists: the importance of accurate subtyping, EGFR mutations and ALK rearrangements

In the past, the only critical point of distinction in the pathological diagnosis of lung cancer was between small cell and non-small cell lung cancer (NSCLC). The emergence of new targeted therapies and clinical trials demonstrating differing efficacy and toxicity of treatments according to specific histological subtypes of NSCLC, has resulted in an increasing need for improvements in pathological diagnosis. Accurate distinction between adenocarcinoma and squamous cell carcinoma is now critical as histological subtyping has the potential to influence clinical decision making and impact on patient outcome. While morphological criteria remain the most important feature to distinguish NSCLC subtypes, use of mucin and immunohistochemical stains (TTF-1, p63 and CK5/6) can be of assistance in difficult small biopsy cases. With the emergence of selective kinase inhibitors targeting epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), there is a corresponding need to identify the subset of NSCLCs harbouring specific genetic mutations associated with sensitivity to these agents, almost all of which are found in adenocarcinomas. In this review, the importance of accurately subtyping NSCLC is discussed, along with a suggested approach for distinguishing histological subtypes in small biopsy specimens. The significance of EGFR and ALK mutations in NSCLC and the impact of these genotypes on pathology and clinical practice are also reviewed.