604544
research-article2015
IJSXXX10.1177/1066896915604544International Journal of Surgical PathologyRafael et al
Molecular surgical pathology
Molecular Testing in Multiple Synchronous Lung Adenocarcinomas: Case Report and Literature Review
International Journal of Surgical Pathology 2016, Vol. 24(1) 43–46 © The Author(s) 2015 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1066896915604544 ijs.sagepub.com
Oana C. Rafael, MD1, Richard Lazzaro, MD1, and Adnan Hasanovic, MD1
Abstract Discovery of driver mutations in pulmonary adenocarcinoma has revolutionized the field of thoracic oncology with major impact on therapy and diagnosis. Testing for EGFR, ALK, and KRAS mutations has become part of everyday practice. We report a case with multiple synchronous primary pulmonary adenocarcinomas in a 72-year-old female with previous history of smoking. The patient presented with cough and bilateral lung ground glass opacities. A positron emission tomography/computed tomography scan showed no activity in mediastinal lymph nodes. She underwent a left upper lobe biopsy and a right upper lobe wedge resection. Pathology revealed 4 morphologically distinct adenocarcinoma foci, suggestive of synchronous primary lung tumors. Molecular testing demonstrated no mutation in the left tumor. Three different driver mutations were present in the right lung tumors: KRAS codon 12 G12D and G12V and EGFR exon 21 L858R mutation, confirming the initial histologic impression. Subsequently, left upper lobe lobectomy showed 3 additional foci of adenocarcinoma with different morphologies, suggestive of synchronous primaries as well. No additional molecular testing was performed. Synchronous pulmonary adenocarcinomas are not uncommon; however, 4 or more synchronous tumors are rare. Distinguishing multiple primary tumors from intrapulmonary metastases is a common problem in thoracic oncology with major implications for staging, prognosis, and treatment. Lung adenocarcinoma subclassification based on predominant and coexisting histologic patterns can greatly facilitate differentiation between intrapulmonary metastases and multiple synchronous tumors. Use of molecular profiling is recommended since it further increases confidence in the diagnostic workup of multiple pulmonary adenocarcinomas and helps guiding therapy. Keywords lung adenocarcinoma, molecular testing, EGFR, KRAS, ALK, synchronous tumors
Introduction Lung cancer is the leading cause of cancer death in the United States, with only 16% of all patients still alive 5 years after the initial diagnosis.1 Discovery of targetable driver mutations in lung adenocarcinoma has revolutionized the field of thoracic oncology.2,3 Introduction of oral small molecule tyrosine kinase inhibitors (TKIs) targeting products of mutated EGFR and ALK genes and other new drugs used in advanced adenocarcinoma (bevacizumab and pemetrexed) have changed the way these patients are treated. New molecular targets and corresponding drugs are further being identified such as rearrangements in ROS1 and RET genes and MET gene mutations. Increased awareness and recent recommendations for screening populations at risk may lead to earlier detection of smaller lung nodules, and some of the patients will have multiple lesions as well. Diagnosis of multiple foci of lung carcinoma has important prognostic and treatment implications. It is of
crucial significance to differentiate multiple synchronous primary tumors from intrapulmonary metastases. These tumors are staged and treated differently, with a significant difference in prognosis.4,5 Various approaches and algorithms have been described addressing this problem. They take into account the nodal status, histological type, and growth pattern of the tumor, location, and temporal sequence of tumor occurrence.6-10 Multiple lung adenocarcinomas are not that uncommon, and multiple synchronous primary tumors that harbor different mutations have been described previously.10,11 Molecular profiling, along with morphological assessment including pattern analysis, can be used in solving diagnostic 1
North Shore LIJ–Lenox Hill Hospital, New York, NY, USA
Corresponding Author: Oana C. Rafael, Department of Pathology, North Shore LIJ–Lenox Hill Hospital, 100 E 77th Street, New York, NY 10075, USA. Email: [email protected]
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International Journal of Surgical Pathology 24(1)
Figure 1. CT scan of the chest: (A) ground-glass opacity, right upper lobe; (B) 2 ill-defined left upper lobe nodules.
and staging dilemmas that occur when encountering multiple lung adenocarcinomas. Recent detailed genomic studies in other cancers support the concept that key driver mutations are well preserved but secondary mutations are not.12 We report a case of a patient with multiple bilateral lung adenocarcinomas, harboring different morphological patterns and mutational profiles, suggesting distinct independent underlying pathways of tumorigenesis.
Case Report A 72-year-old female presented for evaluation of gastroesophageal reflux disease. She complained of nonproductive cough and occasional night sweats over the course of a year. Her previous medical history included dyslipidemia, hypertension, diabetes mellitus type 2, obesity, and asthma. The patient is a former smoker (50 pack-years, quit > 25 years ago), and her mother died of lung cancer. Computed tomography (CT) scan of the chest demonstrated multiple bilateral pulmonary nodules, including a ground-glass opacity in the right upper lobe (RUL) and 2 nodules in the left upper lobe (LUL). Needle core biopsy of the dominant LUL nodule (1.5 cm) revealed an adenocarcinoma with predominant papillary pattern of growth. Molecular testing was negative for EGFR and KRAS mutations and ALK rearrangement. Two months after the initial assessment, a positron emission tomography (PET)/CT scan showed ground glass opacity with central hypermetabolic nodularity in the RUL, radiologically suspicious for a neoplasm (Figure 1). The remaining pulmonary nodules showed no abnormal F18-fludeoxyglucose uptake. There was no evidence of mediastinal or hilar lymphadenopathy, extrathoracic metastatic disease, or pleural effusion. The patient underwent an uneventful robotic video-assisted thoracoscopic RUL wedge resection. Histological assessment revealed 3 separate foci of invasive adenocarcinoma with significant
amount of lepidic growth, along with various proportions of acinar, papillary, and micropapillary growth patterns. A diagnosis of synchronous primary lung adenocarcinomas was favored based on the different morphology (Figure 2). The lymph nodes were not sampled; however, the PET scan showed no activity and clinically they seemed not to be involved by tumor. The 3 right sided foci were in addition morphologically different from the tumor that was previously sampled in the opposite lung. Lymphovascular invasion was identified, but all surgical margins were negative for invasive carcinoma. Mutational profiling confirmed those to represent distinct independent primary tumors and each of the 3 RUL tumors harbored different driver mutations (Table 1). The short 15-bp (E746-750A) in-frame deletion in exon 19 and point mutation L858R in exon 21 constitute around 90% of all EGFR mutations.13-15 In our patient, presence of KRAS mutations in tumors 1 and 2 pointed toward resistance to TKIs, while EGFR L858R mutation in tumor 3 suggested responsiveness to TKIs therapy.16 Five months after the initial surgery and adjuvant chemotherapy, CT scan identified 2 LUL ill-defined nodules, which were stable from the prior CT. Robotic videoassisted thoracoscopic left upper lobectomy with lymphnode dissection was performed. The specimen showed 3 separate morphologically different foci of well to moderately differentiated adenocarcinoma, consistent with additional separate synchronous primary tumors. The largest focus showed papillary architecture, some foci displayed a mix of lepidic and acinar patterns, while a different nodule was predominantly acinar. The lymph nodes were negative for carcinoma. Additional molecular testing was not performed on that specimen. The patient received several cycles of platinum-based chemotherapy after her surgeries in 2013. She developed severe neuropathy and could not further tolerate the
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
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Rafael et al
Figure 2. Microscopic patterns of the synchronous adenocarcinomas (hematoxylin–eosin, 20×): (A) lepidic; (B) acinar; (C) papillary; (D) micropapillary. Table 1. Molecular Profile of the Synchronous Lung Adenocarcinomas. Lung
Tumor
Mutation
Right
1 2 3
Left
1 2 3 4
KRAS mutation: G12D (c.35G>A), codon 12 KRAS mutation: G12V (c.35G>T), codon 12 EGFR mutation: L858R (2573T>G) point mutation, exon 21 None (EGFR, ALK, KRAS tested) Not tested Not tested Not tested
chemotherapy. Since some of the tumors showed KRAS mutation conferring primary resistance to TKIs, the patient was never treated with any targeted therapy (TKIs). The patient is stable 1½ years after the last surgery. A chest CT showed multiple bilateral pulmonary nodules ranging from 0.3 cm to 0.5 cm and no evidence of recurrent or metastatic disease.
Discussion The finding of multiple foci of lung carcinoma has important diagnostic, prognostic, and treatment implications.
Multiple synchronous primary tumors have better prognosis and are treated differently than intrapulmonary metastatic nodules. A surgical approach to multiple synchronous primary lung cancers may result in survival similar to solitary tumors.4 Chang et al recommend complete surgical resection of synchronous primary lung cancer, nodules, while mentioning that lymph node metastases is an independent adverse prognostic factor in these patients.5 It was also reported that long-term survival after surgical resection is better for patients with synchronous primary lung tumors than in patients with tumors in an advanced stage.17,18 When multiple lung tumors show different histologic types, such as adenocarcinoma and squamous cell carcinoma, they are considered separate synchronous primary tumors. More often, patients present with multiple tumor nodules of the same histologic type, showing variable growth patterns. Involvement of the regional lymph nodes by the tumor is supportive of intrapulmonary metastases.7 Several important characteristics of driver mutations in lung adenocarcinoma were reported. The majority of driver mutations described in lung adenocarcinoma are mutually exclusive clonal events. This finding can be exploited to facilitate accurate staging of multiple lung tumors. Independently arising adenocarcinomas are expected to
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
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International Journal of Surgical Pathology 24(1)
have different mutational profiles and conversely metastatic nodules should share the same driver mutation.18 The Martini and Melamed criteria7 were used for a prolonged period to differentiate between metachronous or synchronous primaries and intrapulmonary metastases. A recent study showed that the percentages of the histological subtypes identified in an adenocarcinoma, as well as the additional histologic features (stromal pattern, necrosis, growth pattern, etc), are helpful in differentiating between synchronous tumors and metastases, correlating with molecular profile in 91% of cases.6 A detailed histologic characterization was suggested as a more effective and faster way of distinguishing intrapulmonary metastasis from independent primary tumors.6 EGFR mutations are more frequent in tumors with predominant papillary and lepidic growth patterns, KRAS mutations in mucinous carcinomas, and ALK rearrangement in tumors with solid and acinar growth patterns with signet ring cell features.6 However, lung adenocarcinoma is a highly heterogeneous disease, and comprehensive histologic subtyping cannot be used to reliably predict the underlying genetic differences and similarities among tumors.6 Other authors recommend that molecular profiling in cases with multiple malignant lesions should be extensive, as it might clarify the association between the lesions found.10 The recently published Molecular Testing Guideline by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology recommends that in multiple, apparently separate primary lung adenocarcinomas, each tumor may be tested; however, the decision depends on each patient’s clinical context and requires communication between the laboratory and clinicians.16 Although synchronous lung cancers have been previously reported, 3 or more synchronous primary tumors are rare. This case highlights the importance of correctly assessing the presence of synchronous lung tumors versus intrapulmonary metastasis, while molecular testing plays an essential role in determining optimal management and prognosis in this subset of patients. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. NCCN Clinical Practice Guidelines in Oncology. Non-small cell lung cancer. Version 3. http://www.nccn.org/professionals/ physician_gls/pdf/nscl.pdf. Accessed March 17, 2014.
2. Lynch TJ, Bell DW, Sordella R, et al. Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med. 2004;350:2129-2139. 3. Soda M, Choi YL, Enomoto M, et al. Identification of the transforming EML4-ALK fusion gene in non-small-cell lung cancer. Nature. 2007;448:561-566. 4. Finley DJ, Yoshizawa A, Travis W, et al. Predictors of outcomes after surgical treatment of synchronous primary lung cancers. J Thorac Oncol. 2010;5:197-205. 5. Chang YL, Wu CT, Lee YC. Surgical treatment of synchronous multiple primary lung cancers: experience of 92 patients. J Thorac Cardiovasc Surg. 2007;134:630-637. 6. Girard N, Deshpande C, Lau C, et al. Comprehensive histologic assessment helps to differentiate multiple lung primary non-small cell carcinomas from metastases. Am J Surg Pathol. 2009;33:1752-1764. 7. Martini N, Melamed MR. Multiple primary lung cancers. J Thorac Cardiovasc Surg. 1975;70:606-612. 8. Chung JH, Choe G, Jheon S, et al. Epidermal growth factor receptor mutation and pathologic-radiologic correlation between multiple lung nodules with ground-glass opacity differentiates multicentric origin from intrapulmonary spread. J Thorac Oncol. 2009;4:1490-1495. 9. Hasegawa H, Kimura H, Shingyoji M, et al. A case of multiple synchronous lung adenocarcinomas with differing EGFR mutations. Int Cancer Conf J. 2013;2:224-228. 10. Stella GM, Cemmi F, Inghilleri S, Zorzetto M, Luisetti M, Pozzi E. Synchronous lung cancers: when same histological types feature different molecular profiles and response phenotypes. J Cancer. 2011;2:474-477. 11. Girard N, Deshpande C, Azzoli CG, et al. Use of epidermal growth factor receptor/Kirsten rat sarcoma 2 viral oncogene homolog mutation testing to define clonal relationships among multiple lung adenocarcinomas: comparison with clinical guidelines. Chest. 2010;137:46-52. 12. Gerlinger M, Rowan AJ, Horswell S, et al. Intratumor heterogeneity and branched evolution revealed by multiregion sequencing. N Engl J Med. 2012;366:883-892. 13. Brandao GD, Brega EF, Spatz A. The role of molecular pathology in non-small-cell lung carcinoma-now and in the future. Curr Oncol. 2012;19(suppl 1):S24-S32. 14. Ma ES, Ng WK, Wong CL. EGFR gene mutation study in cytology specimens. Acta Cytol. 2012;56:661-668. 15. Moreira AL, Hasanovic A. Molecular characterization by immunocytochemistry of lung adenocarcinoma on cytology specimens. Acta Cytol. 2012;56:603-610. 16. Lindeman NI, Cagle PT, Beasley MB, et al. Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. J Thorac Oncol. 2013;8:823-859. 17. Sepehripour AH, Nasir A, Shah R. Multiple synchronous primary tumors in a single lobe. Interact Cardiovasc Thorac Surg. 2012;14:340-341. 18. Girard N, Ostrovnaya I, Lau C, et al. Genomic and mutational profiling to assess clonal relationships between multiple nonsmall cell lung cancers. Clin Cancer Res. 2009;15:5184-5190.
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
research-article2015
IJSXXX10.1177/1066896915604544International Journal of Surgical PathologyRafael et al
Molecular surgical pathology
Molecular Testing in Multiple Synchronous Lung Adenocarcinomas: Case Report and Literature Review
International Journal of Surgical Pathology 2016, Vol. 24(1) 43–46 © The Author(s) 2015 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1066896915604544 ijs.sagepub.com
Oana C. Rafael, MD1, Richard Lazzaro, MD1, and Adnan Hasanovic, MD1
Abstract Discovery of driver mutations in pulmonary adenocarcinoma has revolutionized the field of thoracic oncology with major impact on therapy and diagnosis. Testing for EGFR, ALK, and KRAS mutations has become part of everyday practice. We report a case with multiple synchronous primary pulmonary adenocarcinomas in a 72-year-old female with previous history of smoking. The patient presented with cough and bilateral lung ground glass opacities. A positron emission tomography/computed tomography scan showed no activity in mediastinal lymph nodes. She underwent a left upper lobe biopsy and a right upper lobe wedge resection. Pathology revealed 4 morphologically distinct adenocarcinoma foci, suggestive of synchronous primary lung tumors. Molecular testing demonstrated no mutation in the left tumor. Three different driver mutations were present in the right lung tumors: KRAS codon 12 G12D and G12V and EGFR exon 21 L858R mutation, confirming the initial histologic impression. Subsequently, left upper lobe lobectomy showed 3 additional foci of adenocarcinoma with different morphologies, suggestive of synchronous primaries as well. No additional molecular testing was performed. Synchronous pulmonary adenocarcinomas are not uncommon; however, 4 or more synchronous tumors are rare. Distinguishing multiple primary tumors from intrapulmonary metastases is a common problem in thoracic oncology with major implications for staging, prognosis, and treatment. Lung adenocarcinoma subclassification based on predominant and coexisting histologic patterns can greatly facilitate differentiation between intrapulmonary metastases and multiple synchronous tumors. Use of molecular profiling is recommended since it further increases confidence in the diagnostic workup of multiple pulmonary adenocarcinomas and helps guiding therapy. Keywords lung adenocarcinoma, molecular testing, EGFR, KRAS, ALK, synchronous tumors
Introduction Lung cancer is the leading cause of cancer death in the United States, with only 16% of all patients still alive 5 years after the initial diagnosis.1 Discovery of targetable driver mutations in lung adenocarcinoma has revolutionized the field of thoracic oncology.2,3 Introduction of oral small molecule tyrosine kinase inhibitors (TKIs) targeting products of mutated EGFR and ALK genes and other new drugs used in advanced adenocarcinoma (bevacizumab and pemetrexed) have changed the way these patients are treated. New molecular targets and corresponding drugs are further being identified such as rearrangements in ROS1 and RET genes and MET gene mutations. Increased awareness and recent recommendations for screening populations at risk may lead to earlier detection of smaller lung nodules, and some of the patients will have multiple lesions as well. Diagnosis of multiple foci of lung carcinoma has important prognostic and treatment implications. It is of
crucial significance to differentiate multiple synchronous primary tumors from intrapulmonary metastases. These tumors are staged and treated differently, with a significant difference in prognosis.4,5 Various approaches and algorithms have been described addressing this problem. They take into account the nodal status, histological type, and growth pattern of the tumor, location, and temporal sequence of tumor occurrence.6-10 Multiple lung adenocarcinomas are not that uncommon, and multiple synchronous primary tumors that harbor different mutations have been described previously.10,11 Molecular profiling, along with morphological assessment including pattern analysis, can be used in solving diagnostic 1
North Shore LIJ–Lenox Hill Hospital, New York, NY, USA
Corresponding Author: Oana C. Rafael, Department of Pathology, North Shore LIJ–Lenox Hill Hospital, 100 E 77th Street, New York, NY 10075, USA. Email: [email protected]
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
44
International Journal of Surgical Pathology 24(1)
Figure 1. CT scan of the chest: (A) ground-glass opacity, right upper lobe; (B) 2 ill-defined left upper lobe nodules.
and staging dilemmas that occur when encountering multiple lung adenocarcinomas. Recent detailed genomic studies in other cancers support the concept that key driver mutations are well preserved but secondary mutations are not.12 We report a case of a patient with multiple bilateral lung adenocarcinomas, harboring different morphological patterns and mutational profiles, suggesting distinct independent underlying pathways of tumorigenesis.
Case Report A 72-year-old female presented for evaluation of gastroesophageal reflux disease. She complained of nonproductive cough and occasional night sweats over the course of a year. Her previous medical history included dyslipidemia, hypertension, diabetes mellitus type 2, obesity, and asthma. The patient is a former smoker (50 pack-years, quit > 25 years ago), and her mother died of lung cancer. Computed tomography (CT) scan of the chest demonstrated multiple bilateral pulmonary nodules, including a ground-glass opacity in the right upper lobe (RUL) and 2 nodules in the left upper lobe (LUL). Needle core biopsy of the dominant LUL nodule (1.5 cm) revealed an adenocarcinoma with predominant papillary pattern of growth. Molecular testing was negative for EGFR and KRAS mutations and ALK rearrangement. Two months after the initial assessment, a positron emission tomography (PET)/CT scan showed ground glass opacity with central hypermetabolic nodularity in the RUL, radiologically suspicious for a neoplasm (Figure 1). The remaining pulmonary nodules showed no abnormal F18-fludeoxyglucose uptake. There was no evidence of mediastinal or hilar lymphadenopathy, extrathoracic metastatic disease, or pleural effusion. The patient underwent an uneventful robotic video-assisted thoracoscopic RUL wedge resection. Histological assessment revealed 3 separate foci of invasive adenocarcinoma with significant
amount of lepidic growth, along with various proportions of acinar, papillary, and micropapillary growth patterns. A diagnosis of synchronous primary lung adenocarcinomas was favored based on the different morphology (Figure 2). The lymph nodes were not sampled; however, the PET scan showed no activity and clinically they seemed not to be involved by tumor. The 3 right sided foci were in addition morphologically different from the tumor that was previously sampled in the opposite lung. Lymphovascular invasion was identified, but all surgical margins were negative for invasive carcinoma. Mutational profiling confirmed those to represent distinct independent primary tumors and each of the 3 RUL tumors harbored different driver mutations (Table 1). The short 15-bp (E746-750A) in-frame deletion in exon 19 and point mutation L858R in exon 21 constitute around 90% of all EGFR mutations.13-15 In our patient, presence of KRAS mutations in tumors 1 and 2 pointed toward resistance to TKIs, while EGFR L858R mutation in tumor 3 suggested responsiveness to TKIs therapy.16 Five months after the initial surgery and adjuvant chemotherapy, CT scan identified 2 LUL ill-defined nodules, which were stable from the prior CT. Robotic videoassisted thoracoscopic left upper lobectomy with lymphnode dissection was performed. The specimen showed 3 separate morphologically different foci of well to moderately differentiated adenocarcinoma, consistent with additional separate synchronous primary tumors. The largest focus showed papillary architecture, some foci displayed a mix of lepidic and acinar patterns, while a different nodule was predominantly acinar. The lymph nodes were negative for carcinoma. Additional molecular testing was not performed on that specimen. The patient received several cycles of platinum-based chemotherapy after her surgeries in 2013. She developed severe neuropathy and could not further tolerate the
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
45
Rafael et al
Figure 2. Microscopic patterns of the synchronous adenocarcinomas (hematoxylin–eosin, 20×): (A) lepidic; (B) acinar; (C) papillary; (D) micropapillary. Table 1. Molecular Profile of the Synchronous Lung Adenocarcinomas. Lung
Tumor
Mutation
Right
1 2 3
Left
1 2 3 4
KRAS mutation: G12D (c.35G>A), codon 12 KRAS mutation: G12V (c.35G>T), codon 12 EGFR mutation: L858R (2573T>G) point mutation, exon 21 None (EGFR, ALK, KRAS tested) Not tested Not tested Not tested
chemotherapy. Since some of the tumors showed KRAS mutation conferring primary resistance to TKIs, the patient was never treated with any targeted therapy (TKIs). The patient is stable 1½ years after the last surgery. A chest CT showed multiple bilateral pulmonary nodules ranging from 0.3 cm to 0.5 cm and no evidence of recurrent or metastatic disease.
Discussion The finding of multiple foci of lung carcinoma has important diagnostic, prognostic, and treatment implications.
Multiple synchronous primary tumors have better prognosis and are treated differently than intrapulmonary metastatic nodules. A surgical approach to multiple synchronous primary lung cancers may result in survival similar to solitary tumors.4 Chang et al recommend complete surgical resection of synchronous primary lung cancer, nodules, while mentioning that lymph node metastases is an independent adverse prognostic factor in these patients.5 It was also reported that long-term survival after surgical resection is better for patients with synchronous primary lung tumors than in patients with tumors in an advanced stage.17,18 When multiple lung tumors show different histologic types, such as adenocarcinoma and squamous cell carcinoma, they are considered separate synchronous primary tumors. More often, patients present with multiple tumor nodules of the same histologic type, showing variable growth patterns. Involvement of the regional lymph nodes by the tumor is supportive of intrapulmonary metastases.7 Several important characteristics of driver mutations in lung adenocarcinoma were reported. The majority of driver mutations described in lung adenocarcinoma are mutually exclusive clonal events. This finding can be exploited to facilitate accurate staging of multiple lung tumors. Independently arising adenocarcinomas are expected to
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
46
International Journal of Surgical Pathology 24(1)
have different mutational profiles and conversely metastatic nodules should share the same driver mutation.18 The Martini and Melamed criteria7 were used for a prolonged period to differentiate between metachronous or synchronous primaries and intrapulmonary metastases. A recent study showed that the percentages of the histological subtypes identified in an adenocarcinoma, as well as the additional histologic features (stromal pattern, necrosis, growth pattern, etc), are helpful in differentiating between synchronous tumors and metastases, correlating with molecular profile in 91% of cases.6 A detailed histologic characterization was suggested as a more effective and faster way of distinguishing intrapulmonary metastasis from independent primary tumors.6 EGFR mutations are more frequent in tumors with predominant papillary and lepidic growth patterns, KRAS mutations in mucinous carcinomas, and ALK rearrangement in tumors with solid and acinar growth patterns with signet ring cell features.6 However, lung adenocarcinoma is a highly heterogeneous disease, and comprehensive histologic subtyping cannot be used to reliably predict the underlying genetic differences and similarities among tumors.6 Other authors recommend that molecular profiling in cases with multiple malignant lesions should be extensive, as it might clarify the association between the lesions found.10 The recently published Molecular Testing Guideline by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology recommends that in multiple, apparently separate primary lung adenocarcinomas, each tumor may be tested; however, the decision depends on each patient’s clinical context and requires communication between the laboratory and clinicians.16 Although synchronous lung cancers have been previously reported, 3 or more synchronous primary tumors are rare. This case highlights the importance of correctly assessing the presence of synchronous lung tumors versus intrapulmonary metastasis, while molecular testing plays an essential role in determining optimal management and prognosis in this subset of patients. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. NCCN Clinical Practice Guidelines in Oncology. Non-small cell lung cancer. Version 3. http://www.nccn.org/professionals/ physician_gls/pdf/nscl.pdf. Accessed March 17, 2014.
2. Lynch TJ, Bell DW, Sordella R, et al. Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med. 2004;350:2129-2139. 3. Soda M, Choi YL, Enomoto M, et al. Identification of the transforming EML4-ALK fusion gene in non-small-cell lung cancer. Nature. 2007;448:561-566. 4. Finley DJ, Yoshizawa A, Travis W, et al. Predictors of outcomes after surgical treatment of synchronous primary lung cancers. J Thorac Oncol. 2010;5:197-205. 5. Chang YL, Wu CT, Lee YC. Surgical treatment of synchronous multiple primary lung cancers: experience of 92 patients. J Thorac Cardiovasc Surg. 2007;134:630-637. 6. Girard N, Deshpande C, Lau C, et al. Comprehensive histologic assessment helps to differentiate multiple lung primary non-small cell carcinomas from metastases. Am J Surg Pathol. 2009;33:1752-1764. 7. Martini N, Melamed MR. Multiple primary lung cancers. J Thorac Cardiovasc Surg. 1975;70:606-612. 8. Chung JH, Choe G, Jheon S, et al. Epidermal growth factor receptor mutation and pathologic-radiologic correlation between multiple lung nodules with ground-glass opacity differentiates multicentric origin from intrapulmonary spread. J Thorac Oncol. 2009;4:1490-1495. 9. Hasegawa H, Kimura H, Shingyoji M, et al. A case of multiple synchronous lung adenocarcinomas with differing EGFR mutations. Int Cancer Conf J. 2013;2:224-228. 10. Stella GM, Cemmi F, Inghilleri S, Zorzetto M, Luisetti M, Pozzi E. Synchronous lung cancers: when same histological types feature different molecular profiles and response phenotypes. J Cancer. 2011;2:474-477. 11. Girard N, Deshpande C, Azzoli CG, et al. Use of epidermal growth factor receptor/Kirsten rat sarcoma 2 viral oncogene homolog mutation testing to define clonal relationships among multiple lung adenocarcinomas: comparison with clinical guidelines. Chest. 2010;137:46-52. 12. Gerlinger M, Rowan AJ, Horswell S, et al. Intratumor heterogeneity and branched evolution revealed by multiregion sequencing. N Engl J Med. 2012;366:883-892. 13. Brandao GD, Brega EF, Spatz A. The role of molecular pathology in non-small-cell lung carcinoma-now and in the future. Curr Oncol. 2012;19(suppl 1):S24-S32. 14. Ma ES, Ng WK, Wong CL. EGFR gene mutation study in cytology specimens. Acta Cytol. 2012;56:661-668. 15. Moreira AL, Hasanovic A. Molecular characterization by immunocytochemistry of lung adenocarcinoma on cytology specimens. Acta Cytol. 2012;56:603-610. 16. Lindeman NI, Cagle PT, Beasley MB, et al. Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. J Thorac Oncol. 2013;8:823-859. 17. Sepehripour AH, Nasir A, Shah R. Multiple synchronous primary tumors in a single lobe. Interact Cardiovasc Thorac Surg. 2012;14:340-341. 18. Girard N, Ostrovnaya I, Lau C, et al. Genomic and mutational profiling to assess clonal relationships between multiple nonsmall cell lung cancers. Clin Cancer Res. 2009;15:5184-5190.
Downloaded from ijs.sagepub.com at UNIV CALIFORNIA SAN DIEGO on March 15, 2016
