Parenchymal preserving anatomic resections result in less pulmonary function loss in patients with Stage I non-small cell lung cancer

Background: A suggested benefit of sublobar resection for stage I non-small cell lung cancer (NSCLC) compared to lobectomy is a relative preservation of pulmonary function. Very little objective data exist, however, supporting this supposition. We sought to evaluate the relative impact of both anatomic segmental and lobar resection on pulmonary function in patients with resected clinical stage I NSCLC. Methods: The records of 159 disease-free patients who underwent anatomic segmentectomy (n = 89) and lobectomy (n = 70) for the treatment of stage I NSCLC with pre- and postoperative pulmonary function tests performed between 6 to 36 months after resection were retrospectively reviewed. Changes in forced expiratory volume in one second (FEV₁) and diffusion capacity of carbon monoxide (DLCO) were analyzed based upon the number of anatomic pulmonary segments removed: 1-2 segments (n = 77) or 3-5 segments (n = 82). Results: Preoperative pulmonary function was worse in the lesser resection cohort (1-2 segments) compared to the greater resection group (3-5 segments) (FEV_{1(%predicted)}: 79% vs. 85%, p = 0.038; DLCO_(%predicted): 63% vs. 73%, p = 0.010). A greater decline in FEV₁ was noted in patients undergoing resection of 3-5 segments (FEV_{1 (observed)}: 0.1 L vs. 0.3 L, p = 0.003; and FEV_{1 (% predicted)}: 4.3% vs. 8.2%, p = 0.055). Changes in DLCO followed this same trend (DLCO_(observed): 1.3 vs. 2.4 mL/min/mmHg, p = 0.015; and DLCO_{(% predicted)}: 3.6% vs. 5.9%, p = 0.280). Conclusions: Parenchymal-sparing resections resulted in better preservation of pulmonary function at a median of one year, suggesting a long-term functional benefit with small anatomic segmental resections (1-2 segments). Prospective studies to evaluate measurable functional changes, as well as quality of life, between segmentectomy and lobectomy with a larger patient cohort appear justified.