The pathologic diagnosis of lung cancer historically has relied primarily on morphologic features of tumors in histologic sections. With the emergence of new targeted therapies, the pathologist is called upon increasingly to provide not only accurate typing of lung cancers, but also to provide prognostic and predictive information, based on a growing number of ancillary tests, that may have significant impact on patient management. This review provides an overview of ancillary tests currently used in the pathologic diagnosis of lung cancer, with a focus on immunohistochemistry and molecular diagnostics. 1. Introduction Primary lung cancer has been classified historically into two clinically relevant groups: small cell lung cancer (SCLC) and nonsmall cell lung cancer (NSCLC). This distinction was clinically useful as available treatment strategies differed significantly between these two groups. In recent years, the emerging evidence of differential response to new targeted therapies and the identification of molecular differences between specific subtypes of NSCLC increasingly necessitate greater accuracy in the subtyping of NSCLC. The current WHO classification of lung cancer [1] has been based almost entirely by assessment of morphologic features using standard hematoxylin and eosin (H&E) stained sections of tumors. However, a growing number of ancillary studies can help with classification, such as the use of immunohistochemistry (IHC). Beyond simple classification, however, ancillary testing for molecular aberrations is entering routine practice and delivers additional prognostic and predictive information. A new multidisciplinary classification system for primary lung adenocarcinomas has emerged recently [2]. While this system is still based largely on morphology, it moves towards incorporating recent advances in clinical and molecular medicine. In this review, we summarize ancillary tests currently used in the pathologic diagnosis of lung cancer, with a focus on immunohistochemistry and molecular diagnostics. 2. Immunohistochemistry Immunohistochemistry involves the detection and localization of antigens or proteins in tissue sections by the use of antibodies that bind specifically to the antigen of interest. The antibodies are coupled to a detection system which allows them to be visualized in tissue sections. IHC has a range of applications in the practice of pathology and is commonly used by pathologists to help in distinguishing cell types or their origin, using markers that are expressed differentially between different cell types and organs.
References
[1]
W. D. Travis, E. Brambilla, H. K. Muller-Hermelink, and C. C. Harris, Pathology and Genetics of Tumours of the Lung, Pleura, Thymus, and Heart, World Health Organization Classification of Tumours, IARC, Lyon, France, 2004.
[2]
W. D. Travis, E. Brambilla, M. Noguchi et al., “International association for the study of lung cancer/American Thoracic Society/European Respiratory Society international multidisciplinary classification of lung adenocarcinoma,” Journal of Thoracic Oncology, vol. 6, no. 2, pp. 244–285, 2011.
[3]
B. Xu, N. Thong, D. Tan, and T. Khoury, “Expression of thyroid transcription factor-1 in colorectal carcinoma,” Applied Immunohistochemistry and Molecular Morphology, vol. 18, no. 3, pp. 244–249, 2010.
[4]
P. S. Loo, S. C. Thomas, M. C. Nicolson, M. N. Fyfe, and K. M. Kerr, “Subtyping of undifferentiated non-small cell carcinomas in bronchial biopsy specimens,” Journal of Thoracic Oncology, vol. 5, no. 4, pp. 442–447, 2010.
[5]
A. G. Nicholson, D. Gonzalez, P. Shah et al., “Refining the diagnosis and EGFR status of non-small cell lung carcinoma in biopsy and cytologic material, using a panel of Mucin staining, TTF-1, cytokeratin 5/6, and P63, and EGFR mutation analysis,” Journal of Thoracic Oncology, vol. 5, no. 4, pp. 436–441, 2010.
[6]
J. Ye, J. J. Findeis-Hosey, Q. Yang et al., “Combination of napsin A and TTF-1 immunohistochemistry helps in differentiating primary lung adenocarcinoma from metastatic carcinoma in the lung,” Applied Immunohistochemistry and Molecular Morphology, vol. 19, no. 4, pp. 313–317, 2011.
[7]
V. Monica, P. Ceppi, L. Righi et al., “Desmocollin-3: a new marker of squamous differentiation in undifferentiated large-cell carcinoma of the lung,” Modern Pathology, vol. 22, no. 5, pp. 709–717, 2009.
[8]
J. Schweizer, P. E. Bowden, P. A. Coulombe et al., “New consensus nomenclature for mammalian keratins,” Journal of Cell Biology, vol. 174, no. 2, pp. 169–174, 2006.
[9]
V. Boggaram, “Thyroid transcription factor-I (TTF-I/Nkx2.I/TITFI) gene regulation in the lung,” Clinical Science, vol. 116, no. 1, pp. 27–35, 2009.
[10]
D. H. Johnson, L. Fehrenbacher, W. F. Novotny et al., “Randomized phase II trial comparing bevacizumab plus carboplatin and paclitaxel with carboplatin and paclitaxel alone in previously untreated locally advanced or metastatic non-small-cell lung cancer,” Journal of Clinical Oncology, vol. 22, no. 11, pp. 2184–2191, 2004.
[11]
A. B. Sandler, J. H. Schiller, R. Gray et al., “Retrospective evaluation of the clinical and radiographic risk factors associated with severe pulmonary hemorrhage in first-line advanced, unresectable non-small-cell lung cancer treated with carboplatin and paclitaxel plus bevacizumab,” Journal of Clinical Oncology, vol. 27, no. 9, pp. 1405–1412, 2009.
[12]
M. A. Socinski, S. Novello, J. R. Brahmer et al., “Multicenter, phase II trial of sunitinib in previously treated, advanced non-small-cell lung cancer,” Journal of Clinical Oncology, vol. 26, no. 4, pp. 650–656, 2008.
[13]
G. V. Scagliotti, P. Parikh, J. Von Pawel et al., “Phase III study comparing cisplatin plus gemcitabine with cisplatin plus pemetrexed in chemotherapy-naive patients with advanced-stage non-small-cell lung cancer,” Journal of Clinical Oncology, vol. 26, no. 21, pp. 3543–3551, 2008.
[14]
T. Ciuleanu, T. Brodowicz, C. Zielinski et al., “Maintenance pemetrexed plus best supportive care versus placebo plus best supportive care for non-small-cell lung cancer: a randomised, double-blind, phase 3 study,” The Lancet, vol. 374, no. 9699, pp. 1432–1440, 2009.
[15]
Y. Yatabe, T. Mitsudomi, and T. Takahashi, “TTF-1 expression in pulmonary adenocarcinomas,” American Journal of Surgical Pathology, vol. 26, no. 6, pp. 767–773, 2002.
[16]
N. Fatima, C. Cohen, D. Lawson, and M. T. Siddiqui, “TTF-1 and Napsin A double stain: a useful marker for diagnosing lung adenocarcinoma on fine-needle aspiration cell blocks,” Cancer Cytopathology, vol. 119, no. 2, pp. 127–133, 2011.
[17]
E. Lim, P. Goldstraw, A. G. Nicholson et al., “Proceedings of the IASLC international workshop on advances in pulmonary neuroendocrine tumors 2007,” Journal of Thoracic Oncology, vol. 3, no. 10, pp. 1194–1201, 2008.
[18]
N. Rekhtman, “Neuroendocrine tumors of the lung: an update,” Archives of Pathology and Laboratory Medicine, vol. 134, no. 11, pp. 1628–1638, 2010.
[19]
D. L. Asian, H. E. Gulbahce, S. E. Pambuccian, J. C. Manivel, and J. Jessurun, “Ki-67 immunoreactivity in the differential diagnosis of pulmonary neuroendocrine neoplasms in specimens with extensive crush artifact,” American Journal of Clinical Pathology, vol. 123, no. 6, pp. 874–878, 2005.
[20]
E. Z. Du, P. Goldstraw, J. Zacharias et al., “TTF-1 expression is specific for lung primary in typical and atypical carcinoids: TTF-1-positive carcinoids are predominantly in peripheral location,” Human Pathology, vol. 35, no. 7, pp. 825–831, 2004.
[21]
O. Kaufmann and M. Dietel, “Expression of thyroid transcription factor-1 in pulmonary and extrapulmonary small cell carcinomas and other neuroendocrine carcinomas of various primary sites,” Histopathology, vol. 36, no. 5, pp. 415–420, 2000.
[22]
W. S. El-Deiry, “Review: the p53 pathway and cancer therapy,” The Cancer Journal, vol. 11, pp. 229–236, 1998.
[23]
M. S. Tsao, S. Aviel-Ronen, K. Ding et al., “Prognostic and predictive importance of p53 and RAS for adjuvant chemotherapy in non-small-cell lung cancer,” Journal of Clinical Oncology, vol. 25, no. 33, pp. 5240–5247, 2007.
[24]
M. Miki, D. W. Ball, and R. I. Linnoila, “Insights into the achaete-scute homolog-1 gene (hASH1) in normal and neoplastic human lung,” Lung Cancer, vol. 75, no. 1, pp. 58–65, 2012.
[25]
L. E. Coate, T. John, M. S. Tsao, and F. A. Shepherd, “Molecular predictive and prognostic markers in non-small-cell lung cancer,” The Lancet Oncology, vol. 10, no. 10, pp. 1001–1010, 2009.
[26]
F. R. Hirsch, M. Varella-Garcia, P. A. Bunn Jr. et al., “Epidermal growth factor receptor in non-small-cell lung carcinomas: correlation between gene copy number and protein expression and impact on prognosis,” Journal of Clinical Oncology, vol. 21, no. 20, pp. 3798–3807, 2003.
[27]
R. Rosell, T. Moran, C. Queralt et al., “Screening for epidermal growth factor receptor mutations in lung cancer,” New England Journal of Medicine, vol. 361, no. 10, pp. 958–967, 2009.
[28]
T. S. Mok, Y. L. Wu, S. Thongprasert et al., “Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma,” New England Journal of Medicine, vol. 361, no. 10, pp. 947–957, 2009.
[29]
P. A. Bunn, R. Dziadziuszko, M. Varella-Garcia et al., “Biological markers for non-small cell lung cancer patient selection for epidermal growth factor receptor tyrosine kinase inhibitor therapy,” Clinical Cancer Research, vol. 12, no. 12, pp. 3652–3656, 2006.
[30]
D. M. Jackman, V. A. Miller, L. A. Cioffredi et al., “Impact of epidermal growth factor receptor and KRAS mutations on clinical outcomes in previously untreated non-small cell lung cancer patients: results of an online tumor registry of clinical trials,” Clinical Cancer Research, vol. 15, no. 16, pp. 5267–5273, 2009.
[31]
G. J. Riely, K. A. Politi, V. A. Miller, and W. Pao, “Update on epidermal growth factor receptor mutations in non-small cell lung cancer,” Clinical Cancer Research, vol. 12, no. 24, pp. 7232–7241, 2006.
[32]
T. John, G. Liu, and M. S. Tsao, “Overview of molecular testing in non-small-cell lung cancer: mutational analysis, gene copy number, protein expression and other biomarkers of EGFR for the prediction of response to tyrosine kinase inhibitors,” Oncogene, vol. 28, supplement 1, pp. S14–S23, 2009.
[33]
H. Shigematsu, L. Lin, T. Takahashi et al., “Clinical and biological features associated with epidermal growth factor receptor gene mutations in lung cancers,” Journal of the National Cancer Institute, vol. 97, no. 5, pp. 339–346, 2005.
[34]
J. Yu, S. Kane, J. Wu et al., “Mutation-specific antibodies for the detection of EGFR mutations in non-small-cell lung cancer,” Clinical Cancer Research, vol. 15, no. 9, pp. 3023–3028, 2009.
[35]
S. A. Ahrendt, P. Anthony Decker, E. A. Alawi et al., “Cigarette smoking is strongly associated with mutation of the K-ras gene in patients with primary adenocarcinoma of the lung,” Cancer, vol. 92, no. 6, pp. 1525–1530, 2001.
[36]
C. Mascaux, N. Iannino, B. Martin et al., “The role of RAS oncogene in survival of patients with lung cancer: a systematic review of the literature with meta-analysis,” British Journal of Cancer, vol. 92, no. 1, pp. 131–139, 2005.
[37]
K. Suda, K. Tomizawa, and T. Mitsudomi, “Biological and clinical significance of KRAS mutations in lung cancer: an oncogenic driver that contrasts with EGFR mutation,” Cancer and Metastasis Reviews, vol. 29, no. 1, pp. 49–60, 2010.
[38]
D. M. Jackman, V. A. Miller, L. A. Cioffredi et al., “Impact of epidermal growth factor receptor and KRAS mutations on clinical outcomes in previously untreated non-small cell lung cancer patients: results of an online tumor registry of clinical trials,” Clinical Cancer Research, vol. 15, no. 16, pp. 5267–5273, 2009.
[39]
A. Sakurada and M. S. Tsao, “Predictive biomarkers for EGFR therapy,” IDrugs, vol. 12, no. 1, pp. 34–38, 2009.
[40]
Y. P. Mossé, A. Wood, and J. M. Maris, “Inhibition of ALK signaling for cancer therapy,” Clinical Cancer Research, vol. 15, no. 18, pp. 5609–5614, 2009.
[41]
M. Soda, Y. L. Choi, M. Enomoto et al., “Identification of the transforming EML4-ALK fusion gene in non-small-cell lung cancer,” Nature, vol. 448, no. 7153, pp. 561–566, 2007.
[42]
M. Soda, S. Takada, K. Takeuchi et al., “A mouse model for EML4-ALK-positive lung cancer,” Proceedings of the National Academy of Sciences of the United States of America, vol. 105, no. 50, pp. 19893–19897, 2008.
[43]
E. L. Kwak, Y. J. Bang, D. R. Camidge et al., “Anaplastic lymphoma kinase inhibition in non-small-cell lung cancer,” New England Journal of Medicine, vol. 363, no. 18, pp. 1693–1703, 2010.
[44]
B. Solomon, M. Varella-Garcia, and D. R. Camidge, “ALK gene rearrangements: a new therapeutic target in a molecularly defined subset of non-small cell lung cancer,” Journal of Thoracic Oncology, vol. 4, no. 12, pp. 1450–1454, 2009.
[45]
S. J. Rodig, M. Mino-Kenudson, S. Dacic et al., “Unique clinicopathologic features characterize ALK-rearranged lung adenocarcinoma in the western population,” Clinical Cancer Research, vol. 15, no. 16, pp. 5216–5223, 2009.
[46]
A. T. Shaw, B. Y. Yeap, M. Mino-Kenudson et al., “Clinical features and outcome of patients with non-small-cell lung cancer who harbor EML4-ALK,” Journal of Clinical Oncology, vol. 27, no. 26, pp. 4247–4253, 2009.
[47]
T. Sasaki, S. J. Rodig, L. R. Chirieac, and P. A. J？nne, “The biology and treatment of EML4-ALK non-small cell lung cancer,” European Journal of Cancer, vol. 46, no. 10, pp. 1773–1780, 2010.
[48]
M. Mino-Kenudson, L. R. Chirieac, K. Law et al., “A novel, highly sensitive antibody allows for the routine detection of ALK-rearranged lung adenocarcinomas by standard immunohistochemistry,” Clinical Cancer Research, vol. 16, no. 5, pp. 1561–1571, 2010.
[49]
W. A. Cooper, S. O'toole, M. Boyer, L. Horvath, and A. Mahar, “What's new in non-small cell lung cancer forpathologists: the importance of accurate subtyping, EGFR mutations and ALK rearrangements,” Pathology, vol. 43, no. 2, pp. 103–115, 2011.
[50]
J. G. Christensen, J. Burrows, and R. Salgia, “c-Met as a target for human cancer and characterization of inhibitors for therapeutic intervention,” Cancer Letters, vol. 225, no. 1, pp. 1–26, 2005.
[51]
E. S. Kim and R. Salgia, “MET pathway as a therapeutic target,” Journal of Thoracic Oncology, vol. 4, no. 4, pp. 444–447, 2009.
[52]
F. Cappuzzo, A. Marchetti, M. Skokan et al., “Increased MET gene copy number negatively affects survival of surgically resected non-small-cell lung cancer patients,” Journal of Clinical Oncology, vol. 27, no. 10, pp. 1667–1674, 2009.
[53]
J. A. Engelman, K. Zejnullahu, T. Mitsudomi et al., “MET amplification leads to gefitinib resistance in lung cancer by activating ERBB3 signaling,” Science, vol. 316, no. 5827, pp. 1039–1043, 2007.
[54]
L. V. Sequist, B. A. Waltman, D. Dias-Santagata et al., “Genotypic and histological evolution of lung cancers acquiring resistance to EGFR inhibitors,” Science Translational Medicine, vol. 3, no. 75, 2011.
[55]
H. Kadara, C. Behrens, P. Yuan et al., “A five-gene and corresponding protein signature for stage-I lung adenocarcinoma prognosis,” Clinical Cancer Research, vol. 17, no. 6, pp. 1490–1501, 2011.
[56]
H. Y. Chen, S. L. Yu, C. H. Chen et al., “A five-gene signature and clinical outcome in non-small-cell lung cancer,” New England Journal of Medicine, vol. 356, no. 1, pp. 11–20, 2007.
