Table 4 Cox proportional hazard regression analysis of disease-specific survival in patients diagnosed with stage IA micropapillary non-predominant lung adenocarcinoma with a micropapillary component > 5%

Age

1.097

0.977–1.231

0.119

1.066

0.946–1.203

0.294

Sex

 Female

Ref

 Male

0.533

0.097–2.910

0.467

Smoking history

 Non-smoker

Ref

 Smoker

0.630

0.074–5.393

0.673

Surgical procedure

 Open

Ref

 VATS

0.413

0.075–2.259

0.308

Resection range

 Sublobar resection

Ref

 Lobectomy

0.876

0.102–7.506

0.904

Surgical side

 Left

Ref

 Right

1.752

0.319–9.634

0.519

Number of LN dissected

1.033

0.935–1.141

0.526

Tumor size

4.276

0.888–20.591

0.070

3.491

0.636–19.151

0.150

Micropapillary component

0.979

0.884–1.085

0.689

Papillary component

0.981

0.942–1.022

0.366

Solid component

0.917

0.687–1.223

0.555

Acinar component

0.976

0.946–1.007

0.131

0.997

0.954–1.042

0.879

Lepidic component

1.032

1.010–1.055

0.004

1.028

0.996–1.061

0.086

Lymphovascular invasion

 No

Ref

 Yes

0.045

0–3.003E + 5

0.699

Spread through air spaces

 No

Ref

 Yes

0.039

0–3098.496

0.574

pTNM stage

 IA1

Ref

 IA2

5858.593

0–2.722E + 155

0.961

 IA3

15,305.930

0–7.102E + 155

0.957

Adjuvant chemotherapy

 No

Ref

 Yes

0.016

0.000–11.028

0.214