A Randomized Phase II Study of Irinotecan Plus Cisplatin with or without Simvastatin in Ever-Smokers with Extended Disease Small Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study evaluated whether an addition of simvastatin to chemotherapy improves survival in ever-smokers with extensive disease (ED)–small cell lung cancer (SCLC). @*Materials and Methods@#This is an open-label randomized phase II study conducted in National Cancer Center (Goyang, Korea). Chemonaive patients with ED-SCLC, smoking history (≥ 100 cigarettes lifetime), and Eastern Cooperative Oncology Group performance status of ≤ 2 were eligible. Patients were randomized to receive irinotecan plus cisplatin alone or with simvastatin (40 mg once daily orally) for a maximum of six cycles. Primary endpoint was the the 1-year survival rate. @*Results@#Between September 16, 2011, and September 9, 2021, 125 patients were randomly assigned to the simvastatin (n=62) or control (n=63) groups. The median smoking pack year was 40 years. There was no significant difference in the 1-year survival rate between the simvastatin and control groups (53.2% vs. 58.7%, p=0.535). The median progression-free survival and overall survival between the simvastatin arm vs. the control groups were 6.3 months vs. 6.4 months (p=0.686), and 14.4 months vs. 15.2 months, respectively (p=0.749). The incidence of grade 3-4 adverse events was 62.9% in the simvastatin group and 61.9% in the control group. In the exploratory analysis of lipid profiles, patients with hypertriglyceridemia had significantly higher 1-year survival rates than those with normal triglyceride levels (80.0% vs. 52.7%, p=0.046). @*Conclusion@#Addition of simvastatin to chemotherapy provided no survival benefit in ever-smokers with ED-SCLC. Hypertriglyceridemia may be associated with better prognosis in these patient population.

The Clinical Impact of Capmatinib in the Treatment of Advanced Non–Small Cell Lung Cancer with MET Exon 14 Skipping Mutation or Gene Amplification / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Capmatinib, an oral MET kinase inhibitor, has demonstrated its efficacy against non–small cell lung cancer (NSCLC) with MET dysregulation. We investigated its clinical impact in advanced NSCLC with MET exon 14 skipping mutation (METex14) or gene amplification. @*Materials and Methods@#Patients who participated in the screening of a phase II study of capmatinib for advanced NSCLC were enrolled in this study. MET gene copy number (GCN), protein expression, and METex14 were analyzed and the patients’ clinical outcome were retrospectively reviewed. @*Results@#A total of 72 patients were included in this analysis (group A: GCN ≥ 10 or METex14, n=14; group B: others, n=58). Among them, 13 patients were treated with capmatinib (group A, n=8; group B, n=5), and the overall response rate was 50% for group A, and 0% for group B. In all patients, the median overall survival (OS) was 20.2 months (95% confidence interval [CI], 6.9 to not applicable [NA]) for group A, and 11.3 months (95% CI, 8.2 to 20.3) for group B (p=0.457). However, within group A, median OS was 21.5 months (95% CI, 20.8 to NA) for capmatinib-treated, and 7.5 months (95% CI, 3.2 to NA) for capmatinib-untreated patients (p=0.025). Among all capmatinib-untreated patients (n=59), group A showed a trend towards worse OS to group B (median OS, 7.5 months vs. 11.3 months; p=0.123). @*Conclusion@#Our data suggest that capmatinib is a new compelling treatment for NSCLC with MET GCN ≥ 10 or METex14 based on the improved survival within these patients.

Molecular biomarker testing for non–small cell lung cancer: consensus statement of the Korean Cardiopulmonary Pathology Study Group

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

Molecular biomarker testing for non–small cell lung cancer: consensus statement of the Korean Cardiopulmonary Pathology Study Group

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

Phase II Study of Pemetrexed as a Salvage Chemotherapy for Thymidylate Synthase–Low Squamous Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Squamous cell carcinomas (SqCC) of the lung often express high levels of thymidylate synthase (TS), which is associated with primary resistance to pemetrexed. We explored the efficacy of pemetrexed in a selected population of patients with lung SqCC with low TS expression. @*Materials and Methods@#In this single-arm phase II trial, we enrolled 32 previously-treated patients with advanced lung SqCC exhibiting low immunohistochemical staining for TS (i.e., in 10% or less of tumor cells). The primary endpoint was 12-week progression-free survival (PFS) rate. @*Results@#Of 32 patients, eight patients (25%) had an Eastern Cooperative Oncology Group performance status of 2, and seven patients (22%) had previously received three or more lines of chemotherapy. The disease control rate from pemetrexed treatment was 30%, and no objective response was observed. The 12-week PFS rate was 24.5% (95% confidence interval [CI], 13.0 to 46.1). Median PFS was 1.3 months (95% CI, 1.3 to 2.7), and median overall survival was 11.8 months (95% CI, 8.1 to not applicable). Most of adverse events were grade 1 or 2. @*Conclusion@#Pemetrexed demonstrated modest activity as a salvage chemotherapy in patients with advanced lung SqCC with low TS expression, although its toxicity was generally manageable.

Provisional Guideline Recommendation for EGFR Gene Mutation Testing in Liquid Samples of Lung Cancer Patients: A Proposal by the Korean Cardiopulmonary Pathology Study Group

Liquid biopsy for detection of mutation from circulating tumor DNA is a new technology which is attractive in that it is non-invasive. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) is an effective first line drug for advanced non-small cell lung cancer patients who harbor activating EGFR mutation. During the course of treatment, resistance against TKI arises which can be contributed to EGFR T790M mutation in about 50–60% of patients. Third generation TKI may overcome the resistance. In patients who cannot undergo tissue biopsy due to variable reasons, liquid biopsy is an excellent alternative for the detection of EGFR T790M mutation. However, this relatively novel method requires standardization and vigorous quality insurance. Thus, a standard set of guideline recommendations for liquid biopsy for EGFR mutation testing suitable for the Korean medical community is necessary. In this article, we propose a set of provisional guideline recommendations that was discussed and approved by the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Re-biopsy in Previously Treated Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is widely used for the diagnosis and staging of lung cancer. However, evidence of its usefulness for re-biopsy in treated lung cancer, especially according to the previous treatment, is limited. We evaluated the role of EBUS-TBNA for re-biopsy and its diagnostic values in patients with different treatment histories. MATERIALS AND METHODS: We reviewed the medical records of patients who underwent EBUS-TBNA for re-biopsy of suspicious recurrent or progressive lesions between January 2006 and December 2016 at the National Cancer Center in South Korea. Patients were categorized into three groups based on the previous treatment modalities: surgery, radiation, and palliation. RESULTS: Among the 367 patients (surgery, n=192; radiation, n=40; palliation, n=135) who underwent EBUS-TBNA for re-biopsy, the overall sensitivity, negative predictive value (NPV), and diagnostic accuracy of EBUS-TBNA in detecting malignancy were 95.6%, 82.7%, and 96.3%, respectively. The sensitivity was lower in the radiation group (83.3%) when compared with the surgery (95.7%, p=0.042) and palliation (97.7%, p=0.012) groups. The NPV was lower in the palliation group (50.0%) than in the surgery group (88.5%, p=0.042). The sample adequacy of EBUS-TBNA specimens was lower in the radiation group (80.3%) than in the surgery (95.4%, p < 0.001) or palliation (97.8%, p < 0.001) groups. EGFR mutation analysis was feasible in 94.6% of the 92 cases, in which mutation analysis was requested. There were no major complications. Minor complications were reported in 12 patients (3.3%). CONCLUSION: EBUS-TBNA showed high diagnostic values and high suitability for EGFR mutation analysis with regard to re-biopsy in patients with previously treated lung cancer. The sensitivity was lower in the radiation group and NPV was lower in the palliation group. The complication rate was low.

ERCC1 Expression-Based Randomized Phase II Study of Gemcitabine/Cisplatin Versus Irinotecan/Cisplatin in Patients with Advanced Non-small Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We evaluated the clinical utility of excision repair cross-complementation group 1 (ERCC1) expression as a predictive biomarker for platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Eligible patients were randomly assigned to the GP (gemcitabine 1,250 mg/m² on days 1 and 8, and cisplatin 75 mg/m² on day 1 every 3 weeks) or IP (irinotecan 65 mg/m² and cisplatin 30 mg/m² on days 1 and 8 every 3 weeks) arm. The primary goal of this study was to compare the response rate (RR) of the GP and IP arms according to the ERCC1 expression level. RESULTS: A total of 279 patients were randomly assigned to the GP (n=139) and IP (n=140) arms, among which 63% were ERCC1-positive and 268 patients were assessable for the RR. The GP and IP arms did not differ significantly with respect to the RR (29.8% vs. 27.0%, respectively; p=0.082), median progression-free survival (PFS; 4.5 months vs. 3.9 months, respectively; p=0.117), and overall survival (OS; 16.5 months vs. 16.7 months, respectively; p=0.313). When comparing the efficacy between the ERCC1-positive and ERCC1-negative groups, there was no significant difference in the RR (GP, 28.2% vs. 32.6%, respectively, p=0.509; IP, 30.2% vs. 21.6%, respectively, p=0.536), median PFS (GP, 4.6 months vs. 5.0 months, respectively, p=0.506; IP, 3.9 months vs. 3.7 months, respectively, p=0.748), or median OS (GP, 18.6 months vs. 11.9 months, respectively, p=0.070; IP, 17.5 months vs. 14.0 months, respectively, p=0.821). CONCLUSION: Immunohistochemical analysis of the ERCC1 expression level did not differentiate the efficacy of platinum-based chemotherapy in advanced NSCLC.

Incorporating Erlotinib or Irinotecan Plus Cisplatin into Chemoradiotherapy for Stage III Non-small Cell Lung Cancer According to EGFR Mutation Status / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Concurrent chemoradiotherapy (CCRT) is the standard care for stage III non-small cell lung cancer (NSCLC) patients; however, a more effective regimen is needed to improve the outcome by better controlling occult metastases. We conducted two parallel randomized phase II studies to incorporate erlotinib or irinotecan-cisplatin (IP) into CCRT for stage III NSCLC depending on epidermal growth factor receptor (EGFR) mutation status. MATERIALS AND METHODS: Patients with EGFR-mutant tumors were randomized to receive three cycles of erlotinib first and then either CCRT with erlotinib followed by erlotinib (arm A) or CCRT with IP only (arm B). Patients with EGFR unknown or wild-type tumors were randomized to receive either three cycles of IP before (arm C) or after CCRT with IP (arm D). RESULTS: Seventy-three patients were screened and the study was closed early because of slow accrual after 59 patients were randomized. Overall, there were seven patients in arm A, five in arm B, 22 in arm C, and 25 in arm D. The response rate was 71.4% and 80.0% for arm A and B, and 70.0% and 73.9% for arm C and D. The median overall survival (OS) was 39.3 months versus 31.2 months for arm A and B (p=0.442), and 16.3 months versus 25.3 months for arm C and D (p=0.050). Patients with sensitive EGFR mutations had significantly longer OS than EGFR-wild patients (74.8 months vs. 25.3 months, p=0.034). There were no unexpected toxicities. CONCLUSION: Combined-modality treatment by molecular diagnostics is feasible in stage III NSCLC. EGFR-mutant patients appear to be a distinct subset with longer survival.

Randomized Phase II Study of Afatinib Plus Simvastatin Versus Afatinib Alone in Previously Treated Patients with Advanced Nonadenocarcinomatous Non-small Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This phase II study examined whether the addition of simvastatin to afatinib provides a clinical benefit compared with afatinib monotherapy in previously treated patients with nonadenocarcinomatous non-small cell lung cancer (NA-NSCLC). MATERIALS AND METHODS: Patients with advanced NA-NSCLC who progressed after one or two chemotherapy regimens were randomly assigned to a simvastatin (40 mg/day) plus afatinib (40 mg/day) (AS) arm or to an afatinib (A) arm. The primary endpoint was response rate (RR). RESULTS: Sixty-eight patients were enrolled (36 in the AS arm and 32 in the A arm). The RR was 5.7% (95% confidence interval [CI], 0.7 to 19.2) for AS and 9.4% (95% CI, 2.0 to 25.0) for A (p=0.440). In arms AS and A, the median progression-free survival (PFS) was 1.0 versus 3.6 months (p=0.240) and the overall survival was 10.0 months versus 7.0 months (p=0.930), respectively. Skin rash, stomatitis, and diarrhea were the most common adverse events in both arms. More grade 3 or 4 diarrhea was observed in arm A (18.8% vs. 5.6% in arm AS). In all patients, the median PFS for treatment including afatinib was not correlated with the status of epidermal growth factor receptor (EGFR) mutation (p=0.122), EGFR fluorescence in situ hybridization (p=0.944), or EGFR immunohistochemistry (p=0.976). However, skin rash severity was significantly related to the risk of progression for afatinib (hazard ratio for skin rash grade ≥ 2 vs. grade < 2, 0.44; 95% CI, 0.25 to 0.78; p=0.005). CONCLUSION: There were no significant differences in the efficacy between AS and A arms in patients with NA-NSCLC.

A Phase II Study of Poziotinib in Patients with Epidermal Growth Factor Receptor (EGFR)-Mutant Lung Adenocarcinoma Who Have Acquired Resistance to EGFR–Tyrosine Kinase Inhibitors / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We examined the efficacy of poziotinib, a second-generation epidermal growth factor receptor (EGFR)–tyrosine kinase inhibitor (TKI) in patients with lung adenocarcinoma with activating EGFR mutations, who developed acquired resistance (AR) to EGFR-TKIs. MATERIALS AND METHODS: This single-arm phase II study included EGFR-mutant lung adenocarcinoma with AR to erlotinib or gefitinib based on the Jackman criteria. Patients received poziotinib 16 mg orally once daily in a 28-day cycle. The primary endpoint was progression-free survival (PFS). Prestudy tumor biopsies and blood samples were obtained to determine resistance mechanisms. RESULTS: Thirty-nine patients were treated. Tumor genotyping was determined in 37 patients; 19 EGFR T790M mutations and two PIK3CA mutations were detected in the prestudy tumors, and seven T790M mutations were detected in the plasma assay. Three (8%; 95% confidence interval [CI], 2 to 21) and 17 (44%; 95% CI, 28 to 60) patients had partial response and stable disease, respectively. The median PFS and overall survival were 2.7 months (95% CI, 1.8 to 3.7) and 15.0 months (95% CI, 9.5 to not estimable), respectively. A longer PFS was observed for patients without T790M or PIK3CA mutations in tumor or plasma compared to those with these mutations (5.5 months vs. 1.8 months, p=0.003). The most frequent grade 3 adverse events were rash (59%), mucosal inflammation (26%), and stomatitis (18%). Most patients required one (n=15) or two (n=15) dose reductions. CONCLUSION: Low activity of poziotinib was detected in patients with EGFR-mutant non-small cell lung cancer who developed AR to gefitinib or erlotinib, potentially because of severe-toxicityimposed dose limitation.

Molecular Testing of Lung Cancers

Targeted therapies guided by molecular diagnostics have become a standard treatment of lung cancer. Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements are currently used as the best predictive biomarkers for EGFR tyrosine kinase inhibitors and ALK inhibitors, respectively. Besides EGFR and ALK, the list of druggable genetic alterations has been growing, including ROS1 rearrangements, RET rearrangements, and MET alterations. In this situation, pathologists should carefully manage clinical samples for molecular testing and should do their best to quickly and accurately identify patients who will benefit from precision therapeutics. Here, we grouped molecular biomarkers of lung cancers into three categories—mutations, gene rearrangements, and amplifications—and propose expanded guidelines on molecular testing of lung cancers.

Review of Medical Advisory Services by the Korean Society of Pathologists from 2003 to 2014

BACKGROUND: Since 2003, the Korean Society of Pathologists (KSP) has been officially providing medical advisory services (MAS). We reviewed the cases submitted to the KSP between 2003 and 2014. METHODS: In total, 1,950 cases were submitted, most by private health insurance companies. The main purposes of the consultations were to clarify the initial diagnoses and to assign a proper disease classification code. We comprehensively reviewed 1,803 consultation cases with detailed information. RESULTS: In spite of some fluctuations, the number of submitted cases has been significantly increasing over the 12 study years. The colon and rectum (40.3%), urinary bladder (14.2%), and stomach (6.9%) were the three most common tissues of origin. The most common diagnoses for each of the three tissues of origin were neuroendocrine tumor (50.7%), non-invasive papillary urothelial carcinoma (70.7%), and adenocarcinoma (36.2%). Regardless of the tissue of origin, neuroendocrine tumor of the digestive system was the most common diagnosis (419 of 1,803). CONCLUSIONS: In the current study, we found that pathologic consultations associated with private health insurance accounted for a large proportion of the MAS. Coding of the biologic behavior of diseases was the main issue of the consultations. In spite of the effort of the KSP to set proper guidelines for coding and classification of tumors, this review revealed that problems still exist and will continue to be an important issue.

Analysis of Mutations in Epidermal Growth Factor Receptor Gene in Korean Patients with Non-small Cell Lung Cancer: Summary of a Nationwide Survey

BACKGROUND: Analysis of mutations in the epidermal growth factor receptor gene (EGFR) is important for predicting response to EGFR tyrosine kinase inhibitors. The overall rate of EGFR mutations in Korean patients is variable. To obtain comprehensive data on the status of EGFR mutations in Korean patients with lung cancer, the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists initiated a nationwide survey. METHODS: We obtained 1,753 reports on EGFR mutations in patients with lung cancer from 15 hospitals between January and December 2009. We compared EGFR mutations with patient age, sex, history of smoking, histologic diagnosis, specimen type, procurement site, tumor cell dissection, and laboratory status. RESULTS: The overall EGFR mutation rate was 34.3% in patients with non-small cell lung cancer (NSCLC) and 43.3% in patients with adenocarcinoma. EGFR mutation rate was significantly higher in women, never smokers, patients with adenocarcinoma, and patients who had undergone excisional biopsy. EGFR mutation rates did not differ with respect to patient age or procurement site among patients with NSCLC. CONCLUSIONS: EGFR mutation rates and statuses were similar to those in published data from other East Asian countries.

Guideline Recommendations for Testing of ALK Gene Rearrangement in Lung Cancer: A Proposal of the Korean Cardiopulmonary Pathology Study Group

Rearrangement of anaplastic lymphoma kinase (ALK) gene is the best predictor of response to crizotinib, an ALK tyrosine kinase inhibitor. However, the prevalence of the ALK fusion is low, so accurate patient identification is crucial for successful treatment using ALK inhibitors. Furthermore, most patients with lung cancer present with advanced-stage disease at the time of diagnosis, so it is important for pathologists to detect ALK-rearranged patients while effectively maximizing small biopsy or cytology specimens. In this review, we propose a guideline recommendation for ALK testing approved by the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists.

Post-Progression Survival in Patients with Non-Small Cell Lung Cancer with Clinically Acquired Resistance to Gefitinib

Most patients with tyrosine kinase inhibitor (TKI)-sensitive non-small cell lung cancer (NSCLC) eventually develop acquired resistance to TKIs. Factors that affect TKI-sensitive patient survival after progression during TKI treatment remain unknown. We attempted to identify factors that affected post-progression survival. We retrospectively reviewed 81 advanced NSCLC patients with disease progression following tumor response and durable (> or = 6 months) disease stabilization with first-line or second-line gefitinib. Post-progression survival (PPS) and characteristics were investigated and compared in patients who did (n = 16) and did not (n = 65) resume TKIs. Most patients were female never-smokers with adenocarcinoma. Median overall PPS was 10.3 months (95% confidence interval [CI], 7.458-13.142). Age, gender, smoking history, histology, Eastern Cooperative Oncology Group performance status at gefitinib initiation, initial stage, and platinum-based chemotherapy after gefitinib were not significant predictors of PPS. Pemetrexed use after gefitinib significantly improved PPS (18.5 vs 8.6 months; hazard ratio [HR], 0.45; P = 0.008). Gefitinib reuse tended to lengthen PPS but was insignificant in multivariate analysis (27.4 vs 8.8 months; HR, 0.53; P = 0.095). NSCLC patients assumed to have clinically acquired resistance to TKIs had relatively long PPS. TKIs reuse or pemetrexed use after progression with gefitinib may improve PPS.

Guideline Recommendations for EGFR Mutation Testing in Lung Cancer: Proposal of the Korean Cardiopulmonary Pathology Study Group

Mutations of the epidermal growth factor receptor (EGFR) are the strongest predictive factor for response to EGFR tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib. EGFR TKIs are approved in Korea as a first-line treatment for lung cancer patients with mutated EGFR. Rapid and accurate EGFR mutation testing is essential for patient selection and establishing targeted therapies with EGFR TKIs. Thus, a standard set of guideline recommendations for EGFR mutation testing suitable for the Korean medical community is necessary. In this article, we propose a set of guideline recommendations for EGFR mutation testing that was discussed and approved by the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists.

A Case of Capecitabine-Induced Sarcoidosis / 결핵및호흡기질환

Sarcoidosis is an inflammatory disease involving multiple-organs with an unknown cause. The new onset of sarcoidosis associated with therapeutic agents has been observed in 3 clinical settings; tumor necrosis factor antagonists in autoimmune rheumatologic diseases, interferon alpha with or without ribavirin in patients with chronic hepatitis C or melanoma, and antineoplastic agent-associated sarcoidosis in patients with hematologic malignancies. Here, we report a female patient who developed sarcoidosis after capecitabine treatment as an adjuvant chemotherapy for sigmoid colon cancer. To our knowledge, this is the first report of a capecitabine-induced sarcoidosis.

A Minimal Immunohistochemical Panel for Subtyping Poorly Differentiated Non-Small Cell Lung Carcinoma: A Tissue Microarray Study Simulating Small Biopsy Conditions

PURPOSE: Given the emerging evidence for differential responses to new targeted therapies and the identification of molecular differences between specific subtypes of non-small cell lung carcinoma (NSCLC), there is an increased need for greater accuracy in subtyping NSCLC. In a substantial proportion of cases, standard morphology cannot specifically subtype the tumor, resulting in a final diagnosis of NSCLC-not otherwise specified. In this study, we added newly proposed markers (napsin A, desmocollin-3) to conventional markers (p63, thyroid transcription factor-1 [TTF-1], cytokeratin 5/6 [CK5/6], high molecular weight cytokeratin [HMWCK], cytokeratin 7 [CK7]) and evaluated for the minimal panel of immunohistochemical markers required for subtyping poorly differentiated (PD) NSCLC. MATERIALS AND METHODS: Resection specimens of 110 adenocarcinomas (ADCs) and 171 squamous cell carcinomas (SCCs) were collected and tissue microarrays were constructed to simulate small biopsy conditions. All specimens were stained with TTF-1, napsin A, CK7, p63, CK5/6, HMWCK, desmocollin-3 and mucicarmine. RESULTS: For 32 PD ADC, a combination of TTF-1 and napsin A increased sensitivity (81%). With regard to the 29 PD SCC, a combination of desmocollin-3 and p63 did not substantially increase diagnostic performance. Logistic regression analysis identified napsin A, p63 and TTF-1 as the optimal panel to separate PD ADC and PD SCC. Mucin stains for PD NSCLC increased accuracy rate (88%) for diagnosis of PD ADC. CONCLUSION: We recommend a minimal panel of immunohistochemical and histochemical markers to include TTF-1, p63, napsin A and one of mucin stains for tumor subtyping of PD NSCLC in a small biopsy sample.

Characterization of Monoclonal Antibodies against Human Leukocyte Common Antigen (CD45)

BACKGROUND: The leukocyte common antigen (CD45) is a transmembrane-type protein tyrosine phosphatase that has five isoforms. METHODS: We generated seven murine mAbs against human CD45 by injecting cells from different origins, such as human thymocytes, PBMCs, and leukemic cell lines. By using various immunological methods including flow cytometry, immunohistochemistry, and immunoprecipitation, we evaluated the reactivity of those mAbs to CD45 of thymus as well as tonsil lysates. Furthermore, we transiently transfected COS-7 cells with each of gene constructs that express five human CD45 isoforms respectively, and examined the specificities of the mAbs against the transfected isoforms. RESULTS: In case of thymocytes, lymphocytes, and monocytes, all the seven mAbs demonstrated positive reactivities whereas none was reactive to erythrocytes and platelets. The majority of immune cells in formalin-fixed paraffin-embedded thymus and tonsil tissues displayed strong membranous immunoreactivity, and the main antigen was detected near 220 kDa in all cases. Among the mAbs, four mAbs (AP4, DN11, SHL-1, and P6) recognized a region commonly present in all the five isoforms. One mAb, YG27, recognized four isoforms (ABC, AB, BC, and O). Two mAbs, P1 and P14, recognized the isoforms that contain exon A encoded regions (ABC and AB). CONCLUSION: In this study, we confirmed that AP4, DN11, SHL-1, YG27 and P6, are mAbs reactive with the CD45 antigen whereas P1 and P14 are reactive with the CD45RA antigen.