Chronological changes in lung cancer surgery in a single Japanese institution

Figures & data

Table 1 Chronological changes in various clinicopathological factors in the resected patients with lung cancer

Period	1974–1984	1985–1989	1990–1994	1995–1999	2000–2004	2005–2009	2010–2014	P-value
Patient number	68	133	180	263	224	261	487
Age (years)*	61±11	64±10	63±12	66±10	67±10	68±10	69±9	<0.0001a
Female (%)	18 (26.5)	23 (17.3)	60 (33.3)	80 (30.4)	78 (34.8)	106 (40.6)	197 (40.5)	<0.0001a
Histological type
AD (%)	37 (54.4)	50 (37.6)	101 (56.1)	158 (60.1)	140 (62.5)	177 (67.8)	360 (73.9)
SQ (%)	21 (30.1)	62 (46.6)	59 (32.8)	85 (32.3)	61 (27.2)	37 (14.2)	85 (17.5)
LA	5	7	5	6	7	12	19
ADSQ	1	4	7	7	8	19	9
SM	3	7	5	1	3	8	4
CA	1	1	2	1	4	2	5
Others	0	2	1	5	1	6	5	<0.0001b
Tumor size (mm)*	49±36	42±25	41±28	40±24	33±22	29±19	24±14	<0.0001a
Tumor size ≤20 mm (%)	8 (11.8)	27 (20.3)	50 (27.8)	60 (22.8)	74 (33.0)	107 (41.0)	245 (50.3)	<0.0001a
P-stage**
pIA (%)	11 (16.2)	25 (19.1)	44 (25.1)	58 (22.3)	101 (45.3)	116 (46.4)	202 (55.3)
pIB	15	33	36	60	40	54	76
pIIA	16	25	23	33	14	21	18
pIIB	8	25	13	30	13	22	20
pIIIA	15	32	40	72	37	36	43
pIIIB	0	4	3	1	9	0	0
pIV	3	7	16	6	9	1	5	<0.0001b

Notes:

* Mean ± SD;

** 86 cases were excluded since information about pathological lymph node metastasis was not available due to limited resection.

a Kruskal–Wallis test;

b chi-square test.

Abbreviations: AD, adenocarcinoma; SQ, squamous cell carcinoma; LA, large cell carcinoma; ADSQ, adenosquamous carcinoma; SM, small cell carcinoma; CA, carcinoid; P-stage, pathological stage.

Table 2 Chronological changes in surgery for lung cancer

Period	1974–1984	1985–1989	1990–1994	1995–1999	2000–2004	2005–2009	2010–2014	P-value
Surgical method
Sublobar resection (%)	2 (2.9)	3 (2.3)	10 (5.6)	8 (3.0)	14 (6.3)	28 (10.7)	185 (38.0)
Lobectomy	55	93	129	214	195	226	281
Pneumonectomy (%)	11 (16.2)	25 (18.8)	33 (18.3)	24 (9.1)	15 (6.7)	5 (1.9)	18 (3.7)
Combined resection	0 (0.0)	12 (9.0)	8 (4.4)	17 (6.5)	0 (0.0)	2 (0.8%)	3 (0.6%)	<0.0001a
30-day mortality (%)	1 (1.5)	6 (4.5)	4 (2.2)	5 (1.9)	3 (1.3)	0 (0.0)	1 (0.2)	0.0071a
All surgery, n=1,616
OT (min)*	326±79	318±96	267±94	284±92	268±76	249±84	171±72	<0.0001b
IBL (mL)*	874±558	867±782	717±615	588±514	453±457	307±376	121±204	<0.0001b
5-year OS (%)	46.7	34.8	28.8	45.4	55.4	74.9	86.0	<0.0001c
Lobectomy, n=1,196
OT (min)*	322±76	304±85	262±78	281±91	275±68	258±69	201±59	<0.0001b
IBL (mL)*	837±545	699±470	645±508	563±535	452±455	312±365	149±166	<0.0001b
5-year OS (%)	52.2	41.9	33.8	53.4	59.1	73.5	87.8	<0.0001c

Notes:

* Mean ± SD;

a chi-square test;

b Kruskal–Wallis test;

c log-rank test.

Abbreviations: OT, operative time; IBL, intraoperative blood loss; OS, overall survival.

Figure 1 OS curves of all patients who underwent resection for lung cancer show a significant survival difference between patients from 1974 to 2004 (n=868) and those from 2005 to 2014 (n=748; log-rank test, P<0.0001).

Abbreviation: OS, overall survival.

Figure 2 OS curves of p-stage IA patients who underwent resection for lung cancer show a significant survival difference between patients from 1974 to 2004 (n=239) and those from 2005 to 2014 (n=318; log-rank test, P<0.0001).

Abbreviations: OS, overall survival; p-stage, pathological stage.

Figure 3 OS curves of patients are significantly different among four surgical methods including sublobar resection (wedge resection or segmentectomy), lobectomy (including bilobectomy), pneumonectomy, and combined resection with adjacent organs (log-rank test, P<0.0001).

Abbreviation: OS, overall survival.