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. 2018 Feb;13(2):237-245.
doi: 10.1016/j.jtho.2017.10.010. Epub 2017 Oct 31.

Combined Small Cell Carcinoma of the Lung: Is It a Single Entity?

Xiaoliang Zhao  1 , Justine N McCutcheon  2 , Bhaskar Kallakury  2 , Joeffrey J Chahine  2 , Drew Pratt  3 , Mark Raffeld  3 , Yulong Chen  4 , Changli Wang  4 , Giuseppe Giaccone  5
Affiliations

Combined Small Cell Carcinoma of the Lung: Is It a Single Entity?

Xiaoliang Zhao et al. J Thorac Oncol. 2018 Feb.

Abstract

Background: SCLC accounts for 15% and 20% of all lung cancers, with combined SCLC (CSCLC) comprising 2% to 5%. Little is known about the clinical characteristics and molecular changes associated with the various histologic components.

Methods: A total of 205 SCLC cases were resected between 2005 and 2015. Clinical and pathologic features were analyzed. All CSCLC cases were confirmed by histologic examination and immunohistochemistry. The individual components were microdissected using a novel automated dissection system, and DNA was extracted and subjected to targeted exome sequencing.

Results: A total of 10 cases of CSCLC were identified out of 170 cases with adequate histologic material; squamous cell carcinoma comprised the second component in half of these (n = 5). There were no significant differences between CSCLC and pure SCLC with respect to clinical features. The median follow-up time was 36 months. The median survival times of patients with pure SCLC and CSCLC were 58 months and 26 months, respectively (p = 0.030). The different components of three cases of CSCLC were deemed adequate for microdissection and sequencing. Approximately 75% of the identified somatic mutations were present in both components. There were also 15 gene mutations or six amplifications unique to only one of the components.

Conclusions: We identified no significant clinical or pathologic differences between pure SCLC and CSCLC; CSCLC was associated with decreased overall survival compared with pure SCLC. The histologic components of CSCLC had high genetic concordance but also showed divergent genotypes. These findings may suggest a common precursor with subsequent acquisition of oncogenic changes in CSCLC.

Keywords: Combined small cell lung cancer; SCLC; Small cell lung cancer; Targeted gene sequencing.

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Conflict of interest statement

Disclosure: The authors declare no conflict of interest.

Figures

Figure 1.
Figure 1.
Overall survival curves of pure versus combined SCLC (p = 0.030).
Figure 2.
Figure 2.
Immunohistochemical characteristics and boundary areas of different components in four selected cases of combined SCLC. Syn, synaptophysin; TTF-1, thyroid transcription factor 1.
Figure 3.
Figure 3.
(A) The number of mutations in common, unique mutations in the SCLC component and unique mutations in the NSCLC component in three cases of combined SCLC. (B) The number of gene amplifications in common, SCLC component unique amplifications and unique amplifications in the NSCLC component in three cases of combined SCLC.
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References

    1. Chen W, Zheng R, Baade PD, et al. Cancer statistics in China, 2015. CA Cancer J Clin. 2016;66:115–132. - PubMed
    1. van Meerbeeck JP, Fennell DA, De Ruysscher DK. Small-cell lung cancer. Lancet. 2011;378:1741–1755. - PubMed
    1. Byers LA, Rudin CM. Small cell lung cancer: where do we go from here? Cancer. 2015;121:664–672. - PMC - PubMed
    1. Nicholson SA, Beasley MB, Brambilla E, et al. Small cell lung carcinoma (SCLC): a clinicopathologic study of 100 cases with surgical specimens. Am J Surg Pathol. 2002;26:1184–1197. - PubMed
    1. Travis WD,Brambilla E, Nicholson AG, et al. The 2015 World Health Organization classification of lung tumors: impact of genetic, clinical and radiologic advances since the 2004 classification. J Thorac Oncol. 2015;10:1243–1260. - PubMed

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