A Propensity-matched Study of Lobectomy Versus Segmentectomy for Radiologically Pure Solid Small-sized Non-small Cell Lung Cancer

Terumoto Koike1, Seijiro Sato1, Takehisa Hashimoto1,Tadashi Aoki2, Teruaki Koike2, Katsuo Yoshiya2, Shin-ichi Toyabe3,

Masanori Tsuchida1

1 Division of Thoracic and Cardiovascular Surgery, Niigata University, Niigata, Japan2 Division of Chest Surgery, Niigata Cancer Center Hospital, Niigata, Japan3 Niigata University Crisis Management Office, Niigata University Hospital, Niigata, Japan

Relevant Financial Relationship Disclosure Statement

The authors have no conflicts of interest to declare.

BACKGROUND

1. Lobectomy has been performed as a standard surgical procedure for non-small cell lung cancer (NSCLC) patients.

2. In NSCLC patients with a large proportion of ground-glass opacity (GGO) component on CT, excellent surgical outcomes after limited resection were demonstrated.

3. Indications for limited resection for NSCLC patients with radiologically pure solid tumors remain controversial.

OBJECTIVE

To compare postoperative outcomes after lobectomy and segmentectomy in patients with small radiologically pure solid NSCLC.

METHODS (1)

Patients

Inclusion Criteria:1. cT1a N0 M0 NSCLC (≤2 cm)2. Radiologically “pure solid” appearance3. Peripheral location4. Underwent lobectomy or segmentectomy in 1998—

20095. Complete resection

1. Preoperative characteristics werematched using propensity score methods.2. Overall survival (OS) and disease-free survival (DFS) were evaluatedby the log-rank test and McNemar test.3. The preoperative factors and surgical procedure were

analyzed with a multivariate analysis for OS and DFS.

METHODS (2)

AnalysisRadiologically Pure Solid cT1a

N0 M0 NSCLC Patients (n = 251)

Lobectomy(n = 151)

Segmentectomy(n = 100)

Lobectomy(n = 87)

Segmentectomy(n = 87)

Propensity Score—Matching

RESULTS

Post-adjustment Preoperative Characteristics of the Patients with Radiologically Pure Solid cT1a N0 M0 NSCLC

Characteristic Lobectomy Segmentectomy P value

All cases, n 87 87

Age [y], median (range) 68 (37–81) 68 (42–83) .399

Sex, n (%) Male 48 (55) 51 (59) .760

Female 39 (45) 36 (41)

Smoking index, median (range) 500 (0–2200) 500 (0–2400) .809

Percent predicted VC [%], median (range) 114 (67–156) 114 (57–152) .897

FEV1/FVC ratio [%], median (range) 73 (43–96) 75 (40–89) .620

Preoperative CEA [ng/ml], median (range) 2.8 (0.1–25) 2.8 (0.5–18) .441

Radiological tumor size [cm], median (range) 1.6 (0.8–2.0) 1.6 (0.6–2.0) .919

Tumor histology, n (%) Ad

Sq

Others

68 (78) 70 (80) .915

14 (16) 13 (15)

5 (6) 4 (5)

Overall Survival Curves for Patients in Propensity Score–Matched Lobectomy and Segmentectomy Groups

0 5 10 150

20

40

60

80

100

Lobectomy (n = 87)

Segmentectomy (n = 87)

Years from resection

Ove

rall

s ur v

iva l

[%

]

Patients at riskLobectomySegmentectomy

8787

8381

5848

4134

297

130

10

85.2%

75.4% 65.5%84.2%

80.4%

63.1%

p = 0.767

Disease-free Survival Curves for Patients in Propensity Score–Matched Lobectomy and Segmentectomy Groups

0 5 10 150

20

40

60

80

100

Lobectomy (n = 87)Segmentectomy (n = 87)

Years from resection

Dis

ease

-fre

e s u

rviv

a l [%

]

Patients at riskLobectomySegmentectomy

8787

7674

5544

4031

297

130

10

80.0%

71.7% 63.8%76.9%73.1%

58.0%

p = 0.635

Outcomes of Segmentectomy Compared to Lobectomy for Propensity Score–Matched Pairs of the Patients

Overall Survival, n (%)

Survival Interval Lobectomy Segmentectomy OR (95% CI) P Value

3-year 74 (91.4) 73 (90.1) 1.143 (0.362–3.702) 1.000

5-year 44 (88.0) 40 (80.0) 1.800 (0.542–6.837) .424

7-year 28 (77.8) 28 (77.8) 1.000 (0.299–3.341) 1.000

Disease-free Survival, n (%)

Survival Interval Lobectomy Segmentectomy OR (95% CI) P Value

3-year 68 (84.0) 69 (85.2) 0.923 (0.385–2.194) 1.000

5-year 43 (82.7) 39 (75.0) 1.500 (0.564–4.230) .503

7-year 28 (71.8) 27 (69.2) 1.111 (0.406–3.090) 1.000

Multivariate Cox Proportional Hazard Analysis of OS and DFS for the 174 Propensity Score–Matched Patients

Overall Survival Disease-free Survival

Variable HR 95% CI P Value HR 95% CI P Value

Age [years] 1.063 1.025–1.103 .001 1.040 1.008–1.074 .015

Smoking status (Brinkman Index) 1.001 1.000–1.001 .001 1.001 1.000–1.001 <.001

FEV1/FVC ratio [%] 1.065 1.027–1.104 .001 1.058 1.024–1.093 .001

Preoperative serum CEA [ng/ml] 1.100 1.015–1.193 .021 1.084 1.010–1.164 .024

Segmentectomy was not a significant independent predictor of poor OS or DFS

CONCLUSIONS

Postoperative outcomes of radiologically pure solid small NSCLC patients were compared in propensity score–matched lobectomy and segmentectomy groups.

Oncological outcomes were similar after lobectomy and segmentectomy.

Even for patients with radiologically pure solid NSCLC, outcomes of segmentectomy may be non-inferior.