Evidence - Uniportal VATS Segment-6 Resection Right

The question of parenchyma-sparing resection in bronchial carcinoma has been intensely discussed for some time. In the revised S3 guideline for lung carcinoma, anatomical segment resection is now recommended for the first time for tumors < 2cm in stages I and II as an alternative and equivalent therapeutic option to lobectomy. In cases of limited operability, anatomical segment resection is also the best oncological therapeutic option for larger tumors in stages I and II. (1)

Extended Tumor Criteria for Limited Resection

In international literature and with the conclusion of several important studies in 2022, additional important radiological criteria besides tumor size have been evaluated. In particular, the ground-glass opacity (GGO) around the tumor site and the derived consolidation to tumor ratio (C/T-Ratio) appear to be promising indicators.

In Japan, a large multicenter study including over 1100 patients demonstrated that segment resection showed improved overall survival compared to lobectomy for patients in stage IA UICC with a C/T-ratio > 0.5. (2)

In another multicenter study, considering GGO typing, even a wedge resection proved to be an oncologically equivalent first-line therapy. (3) This seems plausible as a bimorphological GGO dominance is strongly correlated with the presence of a low-grade adenocarcinoma. (4)

Another prognostic factor is the presence of Spread Through Air Spaces (STAS). This involves tumor spread through the air spaces. While further research and studies on the biological mechanism, genetics, and significance in oncological therapy are required, detection in the pathological specimen is likely an exclusion criterion for limited resection. (5)

Outlook

Following the completion of several major studies in recent years, the indication for anatomical segment resection is also expanded in the updated German S3 guideline. Besides tumor size, no further criteria for patient selection have been defined so far. It is hoped that after the completion of some ongoing and future studies, criteria can be defined that will further reduce the extent of parenchyma resection (wedge resection, anatomical segment resection, or lobectomy) while achieving the best possible oncological outcome.

• A non-randomized confirmatory trial of segmentectomy for clinical T1N0 lung cancer with dominant ground glass opacity based on thin-section computed tomography (JCOG1211)
• Comparison of Different Types of Surgery in Treating Patients With Stage IA Non Small Cell Lung Cancer (CALGB 140503 study, ClinicalTrials.gov Identifier:NCT00499330)

(1) Expertise in Thoracic Surgery. Müller M, Wanka S, Inderbitzi R, Kiefer T, Stubenberger E, Eds. 1st Edition. Stuttgart: Thieme; 2015.

(2) Saji, Hisashi, et al. “Segmentectomy versus Lobectomy in Small-Sized Peripheral Non-Small-Cell Lung Cancer (JCOG0802/WJOG4607L): A Multicentre, Open-Label, Phase 3, Randomised, Controlled, Non-Inferiority Trial.” The Lancet, vol. 399, no. 10335, Apr. 2022, pp. 1607–17.

(3) A nonrandomized confirmatory phase III study of sublobar surgical resection for peripheral ground glass opacity dominant lung cancer defined with thoracic thin-section computed tomography (JCOG0804/WJOG4507L). Kenji Suzuki, Shunichi Watanabe, Masashi Wakabayashi, Yasumitsu Moriya, Ichiro Yoshino, Masahiro Tsuboi, Tetsuya Mitsudomi, and Hisao Asamura, Journal of Clinical Oncology 2017 35:15_suppl, 8561-8561 

(4) Nakamura, Shota & Fukui, Takayuki & Kawaguchi, Koji & Fukumoto, Koichi & Hirakawa, Akihiro & Yokoi, Kohei. (2015). Does Ground Glass Opacity-Dominant Feature Have a Prognostic Significance Even in Clinical T2aN0M0 Lung Adenocarcinoma?. Lung Cancer. 89. 10.1016/j.lungcan.2015.04.011. 

(5) Jia M, Yu S, Gao H, Sun PL. Spread Through Air Spaces (STAS) in Lung Cancer: A Multiple-Perspective and Update Review. Cancer Manag Res. 2020 Apr 23;12:2743-2752. doi: 10.2147/CMAR.S249790. PMID: 32425593; PMCID: PMC7186879.