Pulmonary middle lobectomy for non-small-cell lung cancer: effectiveness and prognostic implications

The therapeutic value of pulmonary middle lobectomy (PML) has been questioned. PML is currently regarded as a standard form of lobectomy, even so it shares some surgical features with segmentectomies (SEG) more than with lobectomies. The present study's aim was to assess the therapeutic value of PML with respect to other lobectomies (LOBs) and SEGs.

A total of 902 consecutive patients who underwent lobectomy or SEG with mediastinal lymph node dissection for Stage I-IIIa non-small-cell lung cancer were analysed. Patients with pT4 tumours and/or pathologically incomplete resection were excluded.

PML was performed in 50 patients, SEG in 44 and LOBs were performed in 808. The three study groups were homogeneous, except for gender, pT and grade: females, pT1 and G1 tumours were more frequent in the PML and SEG groups. The lymph node dissection yield was poorer in PML (P < 0.007) and SEG (P < 0.001) groups when compared with LOB group. Five-year overall survival (OS) was 45.3% for PML, 54.0% for SEG and 60.2% for LOB (P = 0.793). When limiting the analysis to G2-3 right-sided tumours, 5-year survival was lower in the PML group than in the LOB group: 41.3 vs 59.0% (P = 0.057). Similar results were found when analysing pT2-3 right-sided tumours: 27.3 vs 57.3% (P = 0.049). Multivariable analysis showed four independent prognostic factors: age (P = 0.001), pathological stage (P < 0.001), gender (P = 0.005) and the type of surgical resection (P = 0.029). PML (hazard ratio, HR = 1.63) and SEG (HR = 1.64) were detrimental in comparison with LOB. After adjusting for baseline differences between groups (propensity score), a trend towards a worse OS in PML group when compared with LOB group was observed (HR = 1.38, P = 0.150).

Both the lymphadenectomy yield and prognosis make PML more similar to SEG than lobectomy, especially for pT2-3 or G2-3 tumours.