Pneumonectomy was the mainstay therapy for resectable lung cancer for nearly two decades (20–21). Since the introduction of lobectomy by the late 1950s, it has become the preferred surgical treatment for early stage NSCLC patients with a reduction in operative morbidity and mortality, as well as a result of observed benefits in long- term survival at 5 years (22).
Surgery should not only perform with complete resection, but also achieve a good quality of life. The surgical therapy for patients may not be universal, as evidence suggests that elderly patients with early- stage NSCLC or patients with intolerance to lobectomy due to poor cardio- pulmonary reserve and multiple comorbidities may favor segmentectomy (19).
Moreover, there have been several promising ongoing RCTs by the JCOG group testing the efficacy of segmentectomy to determine whether segmentectomy could be an appropriate alternative treatment for early lung cancer (23–24).
This meta-analysis failed to report the superiority of segmentectomy over lobectomy. In terms of OS and the LCSS, similar results were shown between two groups.
To the best of our knowledge, some trials have reported that individual surgeon’s decision and/or patient-related factors that may influence the surgical’s choice. Preoperative clinical factors may have effect on the decision to perform accurate mediastinal LN resection, such as clinical stage, patients’ age, differences in limited resections.
The study by Smith et al (25) demonstrated that segmentectomy should be the optional treatment for limited resection of patients with stage IA NSCLC according to the Surveillance, Epidemiology and End Results (SEER)- Medicare registry.
In Veluswamy’s study, which reported that differences arise in elderly patients with the different histology subgroups (26). Conversely, both segmentectomy and lobectomy could be preferred for younger patients. Cao’s meta-analysis demonstrated that “intentionally selected” and “compromised” might have effect on the prognostic difference between two surgical options (27). Lobectomy might be selected for younger patients, whereas segmentectomy should be more adequate for elderly patients.
In addition, patients undergoing complete LN staging were thought to be with a good quality of clinical status and thus scheduled for lobectomy. However, patients with a poor medical condition were more likely to be scheduled for segmentectomy, which may result in that segmentectomy confers a comparable OS and LCSS with lobectomy in both.
Thus, unbalanced baseline characteristics may lead to false-positive results. Since the number of LN examined depends on pathologic reports, further RCTs need to focus on the effect of regional LN scope on the prognostic difference between two surgical treatments (28).
Furthermore, due to all included studies’ retrospective nature, imbalance in baseline demographics and clinical characteristics, bias still exist, and this may impact the comparison of interested outcomes. Thus, it indicated that more well-designed studies with greater statistical power would be imperative to compare the survival outcomes of segmentectomy and lobectomy.