Jun Matsubayashi

Novel epidermal growth factor receptor mutation-specific antibodies for non-small cell lung cancer: immunohistochemistry as a possible screening method for epidermal growth factor receptor mutations.

Background: Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) predict better outcome to EGFR tyrosine kinase inhibitors. The most common mutations are exon 19 deletions (most frequently E746–A750) and L858R point mutation in exon 21. Here, we evaluated the accuracy of novel EGFR mutation-specific antibodies in a Japanese cohort with NSCLC and compared with direct DNA sequencing and clinical outcome. Materials and Methods: Immunohistochemistry (IHC) using antibodies specific for the E746–A750 and L858R mutations in EGFR was performed on tissue microarrays of tumors from 70 gefitinib treated NSCLC patients. Extracted DNA was sequenced for mutational analysis of EGFR exons 18 to 21. Results: DNA sequencing showed EGFR mutations in 41 patients (58.6%) and exon 19 deletions in 18 patients (25.7%), 11 of 18 (61%) had a deletion in the range of E746–A750 and 12 (17.1%) had exon 21 mutations (L858R). IHC showed, for the E746–A750 and L858R mutations, sensitivity (81.8 and 75%), specificity (100 and 96.6%), positive predictive value (100 and 81.8%), and negative predictive value (96.7 and 94.9%). Analysis for objective response rates and survival were not correlated to IHC staining, although the combined staining showed nonsignificant trends toward better overall survival for patients with EGFR mutations. Conclusions: The mutation-specific IHC antibodies have high sensitivity and specificity for predefined EFGR mutations and may be suitable for screening for these predefined mutations. However, negative IHC results require further mutation analyses before excluding EGFR-targeted therapy.

Immunohistochemical Analysis of Salivary Gland Tumors: Application for Surgical Pathology Practice

Salivary gland tumors are relatively uncommon and there exists a considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants, in addition to overlapping histological patterns similar to those observed in different tumor entities. The classification is complex, but is closely relevant to the prognostic and therapeutic aspects. Although hematoxylin-eosin staining is still the gold standard method used for the diagnosis, immunohistochemistry (IHC) can enhance the accuracy and be a helpful tool when in cases to investigate the subjects that cannot be assessed by histological examination, such as the cell nature and differentiation status, cell proliferation, and tumor protein expression. This review depicts on the practical diagnostic utility of IHC in salivary gland tumor pathology under the following issues: assessment of cell differentiation, focusing on neoplastic myoepithelial cells; discrimination of histologically mimic tumor groups; diagnosis of specific tumor types, e.g., pleomorphic adenoma, adenoid cystic carcinoma, and salivary duct carcinoma; and evaluation of malignancy and prognostic factors. IHC plays a limited, even though important, role in the diagnosis of salivary gland tumors, but is often useful to support the histological assessment. However, unfortunately few tumor type-specific markers are still currently available. For these reasons, IHC should be considered a method that can be used to assist the final diagnosis, and its results themselves do not directly indicate a definitive diagnosis.

Coexpression of Actin-Related Protein 2 and Wiskott-Aldrich Syndrome Family Verproline-Homologous Protein 2 in Adenocarcinoma of the Lung

Purpose: Highly invasive and metastatic cancer cells, such as adenocarcinoma of the lung cells, form irregular protrusions by assembling a branched network of actin filaments. In mammalian cells, the actin-related protein 2 and 3 (Arp2/3) complex initiates actin assembly to form lamellipodial protrusions by binding to Wiskott-Aldrich syndrome (WASP)/WASP family verproline-homologous protein 2 (WAVE2). In this study, colocalization of Arp2 and WAVE2 in adenocarcinoma of the lung was investigated to elucidate its prognostic value. Experimental Design: Immunohistochemical staining of Arp2 and WAVE2 was done on mirror sections of 115 adenocarcinomas of the lung from pathologic stage IA to IIIA classes. Kaplan-Meier disease-free survival and overall survival curves were analyzed to determine the prognostic significance of the coexpression of Arp2 and WAVE2. Results: Immunoreactivity for both Arp2 and WAVE2 was detected in the same cancer cells in 78 (67.8%) of the 115 lung cancer specimens. The proportion of cancer cells expressing both Arp2 and WAVE2 was significantly higher in cases with lymph-node metastasis (P = 0.0046), and significantly lower in bronchioloalveolar carcinomas (P < 0.0001). The patients whose cancer cells coexpressed them had a shorter disease-free survival time (P < 0.0001) and overall survival time (P < 0.0001). Multivariate Cox regression analysis revealed that coexpression of Arp2 and WAVE2 is an independent risk factor for tumor recurrence. Conclusions: Coexpression of Arp2 and WAVE2 is correlated with poorer patient outcome, and may be involved in the mechanism of cancer metastasis.

Ten cases of sebaceous carcinoma arising in nevus sebaceus.

Although nevus sebaceus is known to develop various types of secondary neoplasms, it rarely causes carcinoma and only 14 cases of secondary sebaceous carcinoma have been reported. In this study, 10 cases of sebaceous carcinoma arising in nevus sebaceus were collected. The clinicopathological features and results of immunohistochemical examinations with adipophilin, perilipin and p53 were summarized. Sebaceous carcinoma arising in nevus sebaceous predominantly occurred on the scalp (8/10) of elderly women (mean age, 67.7 years). No case was associated with Muir–Torre syndrome. We found several pathological features of sebaceous carcinoma; that is, made up mainly of germinative cells, moderate nuclear atypia without pleomorphism and many mitoses (4–28/10 high‐power field). Adipophilin and perilipin antibodies highlighted lipid drops in the cytoplasm of the malignant cells in all cases. Overexpression of p53 was seen in all cases. In two cases there were coexisting benign‐looking sebaceous lesions at the periphery of the main cancer nodule, and in these lesions p53 showed low positivity compared with the clearly malignant area. There was co‐occurrence of another neoplasm in three cases with trichoblastoma, sebaceoma and syringocystadenoma papilliferum, respectively. All cases were treated by excision of the malignant lesion, with or without inclusion of the nevus sebaceus. In a follow‐up period of 1–7 years, there was no case of recurrence, lymph node metastases or distant metastases. With these specific pathological and immunohistochemical findings using adipophilin, perilipin and p53, we have to consider the possibility that there is a tendency to underdiagnose secondary sebaceous carcinomas in nevus sebaceus. These clinicopathological features of sebaceous carcinomas developing in the nevus sebaceus seem to indicate different biological entities from de novo sebaceous carcinoma.

Sebaceous carcinoma of the eyelids: Thirty cases from Japan

Sebaceous carcinoma of the eyelids is rare in Western countries but not uncommon in Asian countries. Diagnosis is difficult both clinically and histologically. Thirty cases of sebaceous carcinoma of the eyelids treated at Tokyo Medical University Hospital were reviewed to elicit characteristic features of pathological findings. The tumor cells were infiltrating in a lobular pattern that consisted mainly of large atypical germinative cells. Sebocytes seen in the lobules had conspicuous nucleolus associated with perinucleolar halo. In 17 cases (57%) there was foamy histiocyte infiltration in and around the tumor nests. Sebaceous duct differentiation, namely holocrine secretion indicating a specific type of coagulation necrosis maintaining a cellular framework or maintaining a bubbly cytoplasm associated with nuclear debris in the periphery, was seen in 24 cases (80%). Although unequivocal squamous differentiation was limited to only 11 carcinomas, scattered individual necrosis with nuclear debris in the background of germinative cells appeared in 29 cases (96.7%). Expression of epithelial membrane antigen, perilipin and adipophilin were detected in all cases. In conclusion, to detect sebaceous differentiation in sebaceous carcinoma, it would be helpful to focus on holocrine secretion, squamous differentiation and foamy macrophage infiltration, and to utilize immunohistochemistry involving anti‐perilipin and anti‐adipophilin stain.

Prognostic impact of number of resected and involved lymph nodes at complete resection on survival in non-small cell lung cancer.

Background: Lymph node (LN) status is a major determinant of stage and survival in patients with lung cancer. In the 7th edition of the TNM Classification of Malignant Tumors, the number of involved LNs is included in the definition of pN factors in breast, stomach, esophageal, and colorectal cancer, and the pN status significantly correlates with prognosis. Methods: We retrospectively investigated the prognostic impact of the number of resected LNs (RLNs) and involved LNs in the context of other established clinical prognostic factors, in a series of 928 consecutive patients with non-small cell lung cancer (NSCLC) who underwent complete resection at our institution between 2000 and 2007. Results: The mean number of RLNs was 15. There was a significant difference in the total number of RLNs categorized between less than 10 and ≥10 (p = 0.0129). Although the incidence of LN involvement was statistically associated with poor prognosis, the largest statistically significant increase in overall survival was observed between 0 to 3 and ≥4 involved LNs (hazard ratio = 7.680; 95% confidence interval = 5.051–11.655, p < 0.0001). On multivariate analysis, we used the ratio between the number of involved LNs and RLNs. The number of RLNs was found to be a strong independent prognostic factor for NSCLC (hazard ratio = 6.803; 95% confidence interval = 4.137–11.186, p < 0.0001). Conclusion: Complete resection including 10 or more LNs influenced survival at complete NSCLC resection. Four involved LNs seemed to be a benchmark for NSCLC prognosis. The number of involved LNs is a strong independent prognostic factor in NSCLC, and the results of this study may provide new information for determining the N category in the next tumor, node, metastasis classification.

Clinical response of large cell neuroendocrine carcinoma of the lung to perioperative adjuvant chemotherapy

Patients with large cell neuroendocrine carcinoma (LCNEC) of the lung are considered to have poor prognosis. However, the benefit of adjuvant chemotherapy for these patients has not been established. In this study, we retrospectively evaluated the efficacy of perioperative chemotherapy for patients with completely resected LCNEC in a single-center setting. From 1999 through 2007, 45 patients with surgically resected LCNEC or mixed LCNEC containing at least one portion of the neuroendocrine differentiation or morphology in non-small cell lung carcinoma were enrolled as participants of this study. Survival rates were calculated by the Kaplan–Meier method. Differences between survival curves were computed with the log-rank test. For multivariate analysis, the Coxs proportional hazards regression model was used to evaluate variables that were significant predictors of survival. Of 1397 patients undergoing surgical resection for primary lung cancer from 1999 to 2007, 45 (3.2%) were classified as LCNEC. Thirty-six (80%) patients were men, and nine (20%) were women. Twenty-four (92%) of 26 patients were present or past smokers. Twenty-three (41%) of 45 patients received perioperative chemotherapy, including seven induction chemotherapies and 16 adjuvant chemotherapies. Survival of patients who underwent perioperative adjuvant chemotherapy was significantly higher than that of those who received surgery alone (P = 0.04). The 5-year survival rate of patients who underwent perioperative adjuvant chemotherapy was 87.5%, whereas that of patients who underwent surgery alone was 58.5%. Even in stage I cases, perioperative adjuvant chemotherapy still favors survival compared with surgery alone. In the Cox proportional hazard multivariate analysis, surgery with or without chemotherapy showed an independent prognostic influence on overall survival (P = 0.0457). Patients who received surgery alone were 9.5 times more likely to die than patients who underwent surgery plus chemotherapy. In conclusion, perioperative chemotherapy will be needed to improve survival in patients with LCNEC. As the population of LCNEC is small, it has been difficult to conduct randomized controlled trials to show the survival benefit of adjuvant chemotherapy. This should be, therefore, evaluated further in prospective multi-institutional phase II trials.

Impact of visceral pleural invasion on the survival of patients with non-small cell lung cancer.

BACKGROUND In this study, we investigated visceral pleural invasion (VPI) as a poor prognostic factor in patients with non-small cell lung cancer (NSCLC) according to the 7th edition of the TNM classification. METHODS Between January 2000 and December 2007, 886 consecutive patients with pathological T1a-T2b NSCLC underwent complete resection with systematic lymph node dissection in Tokyo Medical University. We statistically analyzed the association between VPI and clinicopathologic factors, or clinical outcomes. RESULTS The 5-year overall survival (OS) rates of the pl0, pl1, and pl2 patients were 80.8%, 63.7%, and 49.6%, respectively, with significant differences between pl0 and pl1 (p=0.002), pl1 and pl2 (p=0.03). Thus, the pl1 and pl2 patient groups were defined as patients with VPI. VPI was found to be a significant independent prognostic factor by multivariate survival analysis (p=0.0002). In patients with tumors ≤3 cm, especially with tumors ≤2 cm, VPI was significantly associated with an increased rate of lymph node metastasis, compared with non-VPI (p=0.0003 and p=0.015, respectively). Analysis of the OS of patients stratified by tumor size (≤3 cm, 3.1-5 cm, 5.1-7 cm) and VPI status showed that in any nodal status, patients with 3.1-5 cm/VPI tumors had significantly worse survival than patients with ≤3 cm/VPI tumors (p=0.019) and patients with 3.1-5 cm/non-VPI tumors (p=0.001). On the other hand, there was no significant difference in the OS between patients with 3.1-5 cm/VPI tumors and patients with 5.1-7 cm tumors regardless of lymph node metastasis (T2b tumors). Similar relationships were observed among these groups with N0 disease. CONCLUSION We identified the presence of VPI as an independent poor prognostic factor in patients with NSCLC of ≤7 cm. Tumors 3.1-5cm with VPI should be upstaged to T2b tumors in the future in the TNM classification of the Union of International Cancer Control staging system. In addition, the surgical strategy involving more extensive lymph node dissection for patients with ≤3 cm/VPI tumors, especially ≤2 cm/VPI, is warranted owing to more frequent lymph node metastasis.

EGFR Protein Expression in Non-Small Cell Lung Cancer Predicts Response to an EGFR Tyrosine Kinase Inhibitor - A Novel Antibody for Immunohistochemistry or AQUA Technology

Introduction: Epidermal growth factor receptor (EGFR) protein expression in non–small cell lung cancer (NSCLC) is not recommended for predicting response to EGFR tyrosine kinase inhibitors (TKI) due to conflicting results, all using antibodies detecting EGFR external domain (ED). We tested the predictive value of EGFR protein expression for response to an EGFR TKI with an antibody that detects the intracellular domain (ID) and compared fluorescence-based Automated QUantitative Analysis (AQUA) technology to immunohistochemistry (IHC). Methods: Specimens from 98 gefitinib-treated NSCLC Japanese patients were evaluated by IHC (n = 98 of 98) and AQUA technology (n = 70 of 98). EGFR ID (5B7)- and ED-specific antibodies (3C6 and 31G7) were compared. Results: EGFR expression evaluated with 5B7 was significantly higher in responders versus nonresponders to gefitinib both with IHC and with AQUA. ED-specific antibodies did not significantly predict response. Using AQUA and ID-specific antibody resulted in the best prediction performance with a positive and negative predictive value (PPV/NPV) for responders of 50% and 87%, respectively. EGFR expression with ID-specific antibody and AQUA also predicted responders in EGFR-mutated patients. Increased EGFR expression with the ID antibody is associated with increased median progression free survival (PFS; 11.7 months vs. 5.0, log rank, P = 0.034) and overall survival (OS; 38.6 vs. 14.9, P = 0.040) from gefitinib therapy. Conclusions: EGFR protein expression using an ID-specific antibody specifically predicts response to gefitinib in NSCLC patients, including in EGFR-mutated patients, and increased PFS/OS from gefitinib. These data suggest that the choice of diagnostic antibody and methodology matters to predict response and outcome to specific therapies. The potential clinical application needs further validation. Clin Cancer Res; 17(24); 7796–807. ©2011 AACR.

A proposal for combination of total number and anatomical location of involved lymph nodes for nodal classification in non-small cell lung cancer.

BACKGROUND We previously reported the prognostic impact of the number of involved lymph nodes (LNs) on survival in non-small cell lung cancer (NSCLC). However, it remains unknown whether the total number or anatomic location of involved LNs is a superior prognostic factor. METHODS A total of 689 patients with NSCLC who underwent complete resection involving dissection of the hilar and mediastinal LNs with curative intent of ≥ 10 LNs were enrolled. The association between the total number of LNs (nN) involved and survival was assessed by comparison with the anatomic location of LN involvement (pathologic lymph node [pN]), the present nodal category. RESULTS We classified the patients into five categories according to the combined pN and nN status as follows: pN0-nN0, pN1-nN1-3, pN1-nN4-, pN2-nN1-3, and pN2-nN4. Although there was no statistically significant difference between the pN1-nN4- and pN2-nN1-3 categories, pN2-nN1-3 had better prognoses than pN1-nN4-. On multivariate analysis, the nN category was an independent prognostic factor for overall survival and disease-free survival (vs nN4-; the hazard ratios of nN0 and nN1-3 for overall survival were 0.223 and 0.369, respectively, P < .0001 for all), similar to the pN category. We propose a new classification based on a combination of the pN and nN categories: namely, N0 becomes pN0-nN0, the N1 category becomes pN1-nN1-3, the N2a category becomes pN2-nN1-3 + pN1-nN4-, and the N2b category becomes pN2-nN4. Each survival curve was proportional and was well distributed among the curves. CONCLUSIONS A combined anatomically based pN stage classification and numerically based nN stage classification is a more accurate prognostic determinant in patients with NSCLC, especially in the prognostically heterogeneous pN1 and pN2 cases. Further large-scale international cohort validation analyses are warranted.