Postoperative treatment in margin positive patients of non-small cell lung cancer

The treatment of non-small cell lung cancer varies in local treatment and general treatment. Surgery and radiation are representative strategies of local treatment, while general therapy is conducted choosing cytotoxic agents, molecular targeted agents and immune checkpoint inhibitors. Among local treatment, surgery can most frequently achieve complete removal of cancer lesion, thus the priority is the first to treat patients with NSCLC with limited status. Even among patients with stage IA NSCLC, cancer recurrence occurs in approximately 20% patients who underwent complete resection (R0) (1). These recurrences rise from residual isolated tumor cells (ITCs) underlying in niches of the region, the local and the distant place (2,3), thus the provability of recurrence depends on the tumorigenesis of ITCs (3), the potential of which could be indicated by the morphology of circulating tumor cells (CTCs) surrogating the existing ITCs; cluster CTCs represent extremely higher potential of metastasis than single CTC does (4). The prevalence of cluster CTC associated with the cancer stage (5), thus the potential of recurrence is high in the advanced stage NSCLC. In contrast, the prevalence of single CTC associates with early stage NSCLC and small tumor size and invasiveness (6), thus it is speculated that efficacy of adjuvant treatment is not high in stage IA NSCLC.

Recently Smeltzer et al. repot on survival impact of postoperative therapy modalities according to margin status in NSCLC using National Cancer Database (NCDB) in United States referring National Comprehensive Cancer Network (NCCN) (7,8), resulting in that mono-modality postoperative radiotherapy was not validated for any stage, although specific studies are needed to determine optimal management after incomplete resection. The Smelzer’s comprehension of adjuvant treatment for patients of incompletely resected NSCLC is shown in Table 1. In the analyses using whole cases of NCDB, radiotherapy alone may not effective but validated in stage IA patients which are recommended in NCCN guidelines. Besides they argued that NCCN adjuvant therapy guidelines after complete resection, based on high-level evidence, are validated, but not guidelines for patients with incompletely resected early-stage NSCLC, which are based on low-level evidence.

Table 1 Adjuvant therapy in stage IA–IIIa NSCLC recommended by NCCN and NCDB
Full table

In surgical patients with NSCLC, incomplete resection is not frequent, but the prognosis is poor, thus proper treatment strategy is necessary to improve the outcome. Not to mention, it is crucial to make high quality observation using a data of great number of patients with incompletely resected NSCLC accompanying additional tumorigenic information of residual tumor cells which is able to take from observation on CTCs and ITCs as well as tumor pathology.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned and reviewed by the Section Editor Dr. Wei Guo (Department of Thoracic Surgery, Ruijin Hospital Shanghai Jiaotong University School of Medicine, Shanghai, China).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/vats.2018.03.03). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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