World J Oncol

World Journal of Oncology, ISSN 1920-4531 print, 1920-454X online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Oncol and Elmer Press Inc

Journal website https://wjon.elmerpub.com

Original Article

Volume 16, Number 3, June 2025, pages 286-294

Time-to-Treatment Initiation and Its Effect on All-Cause Mortality: Insights From the Surveillance, Epidemiology, and End Results Database

**Table 1.** Baseline Characteristics of Participants by Time-to-Treatment Initiation (TTI)
Variable	0 - 1 months	2 - 5 months	6 - 9 months	≥ 10 months	P
Age
< 65	286,531 (45.2%)	147,921 (44.7%)	9,528 (45.1%)	2,771 (45.3%)	< 0.001
65+	347,412 (54.8%)	182,675 (55.3%)	11,592 (54.9%)	3,341 (54.7%)
Sex					< 0.001
Female	400,453 (63.2%)	158,809 (48.0%)	4,716 (22.3%)	1,261 (20.6%)
Male	233,490 (36.8%)	171,787 (52.0%)	16,404 (77.7%)	4,851 (79.4%)
Marital status					< 0.001
Married	353,961 (55.8%)	190,602 (57.7%)	11,718 (55.5%)	3,268 (53.5%)
Separated/divorced	69,932 (11.0%)	36,421 (11.0%)	2,244 (10.6%)	563 (9.2%)
Single/widowed	210,050 (33.1%)	103,573 (31.3%)	7,158 (33.9%)	2,281 (37.3%)
Race/ethnicity					< 0.001
Non-Hispanic White	440,604 (69.5%)	216,209 (65.4%)	12,348 (58.5%)	3,542 (58.0%)
Non-Hispanic unknown race	3,309 (0.5%)	2,060 (0.6%)	227 (1.1%)	76 (1.2%)
Non-Hispanic Black	66,467 (10.5%)	44,072 (13.3%)	3,949 (18.7%)	1,181 (19.3%)
Non-Hispanic Asian or Pacific Islander	53,564 (8.4%)	26,169 (7.9%)	1,594 (7.5%)	456 (7.5%)
Non-Hispanic American Indian/Alaska Native	3,893 (0.6%)	1,846 (0.6%)	146 (0.7%)	31 (0.5%)
Hispanic (all races)	66,106 (10.4%)	40,240 (12.2%)	2,856 (13.5%)	826 (13.5%)
Household income, inflation-adjusted					< 0.001
< $35,000	7,133 (1.1%)	2,770 (0.8%)	149 (0.7%)	47 (0.8%)
$35,000 - $39,999	10,606 (1.7%)	4,293 (1.3%)	253 (1.2%)	68 (1.1%)
$40,000 - $44,999	23,332 (3.7%)	10,177 (3.1%)	600 (2.8%)	190 (3.1%)
$45,000 - $49,999	27,272 (4.3%)	12,407 (3.8%)	781 (3.7%)	245 (4.0%)
$50,000 - $54,999	30,602 (4.8%)	14,190 (4.3%)	824 (3.9%)	209 (3.4%)
$55,000 - $59,999	52,314 (8.3%)	25,424 (7.7%)	1,473 (7.0%)	432 (7.1%)
$60,000 - $64,999	40,911 (6.5%)	20,717 (6.3%)	1,325 (6.3%)	385 (6.3%)
$65,000 - $69,999	66,670 (10.5%)	37,650 (11.4%)	2,565 (12.1%)	757 (12.4%)
$70,000 - $74,999	70,561 (11.1%)	40,390 (12.2%)	2,653 (12.6%)	754 (12.3%)
$75,000+	304,516 (48.0%)	162,565 (49.2%)	10,497 (49.7%)	3,025 (49.5%)
Unknown/missing/no match/not 1990-2021	26 (0.0%)	13 (0.0%)	0 (0.0%)	0 (0.0%)
Region					< 0.001
Non-metropolitan	83,724 (13.2%)	36,173 (10.9%)	2,022 (9.6%)	535 (8.8%)
Metropolitan	550,219 (86.8%)	294,423 (89.1%)	19,098 (90.4%)	5,577 (91.2%)
Stage					< 0.001
In situ	51 (0.0%)	8 (0.0%)	1 (0.0%)	0 (0.0%)
Localized	309,355 (48.8%)	203,458 (61.5%)	14,767 (69.9%)	4,257 (69.6%)
Regional	176,547 (27.8%)	87,852 (26.6%)	4,444 (21.0%)	1,085 (17.8%)
Distant	140,973 (22.2%)	35,844 (10.8%)	1,451 (6.9%)	466 (7.6%)
Unknown/unstaged	7,017 (1.1%)	3,434 (1.0%)	457 (2.2%)	304 (5.0%)
Grade					< 0.001
Well-differentiated/unknown	423,915 (66.9%)	215,536 (65.2%)	14,461 (68.5%)	4,395 (71.9%)
Moderately differentiated	126,946 (20.0%)	75,809 (22.9%)	4,911 (23.3%)	1,284 (21.0%)
Poorly differentiated	78,657 (12.4%)	38,372 (11.6%)	1,726 (8.2%)	428 (7.0%)
Anaplastic	4,425 (0.7%)	879 (0.3%)	22 (0.1%)	5 (0.1%)
Radiation					< 0.001
No	19,656 (3.1%)	11,134 (3.4%)	583 (2.8%)	182 (3.0%)
Yes	614,287 (96.9%)	319,462 (96.6%)	20,537 (97.2%)	5,930 (97.0%)
Chemotherapy					< 0.001
No	378,930 (59.8%)	245,170 (74.2%)	18,795 (89.0%)	5,503 (90.0%)
Yes	255,013 (40.2%)	85,426 (25.8%)	2,325 (11.0%)	609 (10.0%)
Surgery					< 0.001
No	186,609 (29.4%)	113,480 (34.3%)	10,243 (48.5%)	3,131 (51.2%)
Yes	447,334 (70.6%)	217,116 (65.7%)	10,877 (51.5%)	2,981 (48.8%)
Cancer type					< 0.001
Lung	142,456 (22.5%)	66,023 (20.0%)	3,319 (15.7%)	809 (13.2%)
Breast	258,357 (40.8%)	112,258 (34.0%)	2,631 (12.5%)	708 (11.6%)
Prostate	78,211 (12.3%)	120,748 (36.5%)	14,066 (66.6%)	4,224 (69.1%)
Colon	154,919 (24.4%)	31,567 (9.5%)	1,104 (5.2%)	371 (6.1%)

Table 1. Baseline Characteristics of Participants by Time-to-Treatment Initiation (TTI)

Variable

0 - 1 months

2 - 5 months

6 - 9 months

≥ 10 months

Age

< 65

286,531 (45.2%)

147,921 (44.7%)

9,528 (45.1%)

2,771 (45.3%)

< 0.001

65+

347,412 (54.8%)

182,675 (55.3%)

11,592 (54.9%)

3,341 (54.7%)

Sex

< 0.001

Female

400,453 (63.2%)

158,809 (48.0%)

4,716 (22.3%)

1,261 (20.6%)

Male

233,490 (36.8%)

171,787 (52.0%)

16,404 (77.7%)

4,851 (79.4%)

Marital status

< 0.001

Married

353,961 (55.8%)

190,602 (57.7%)

11,718 (55.5%)

3,268 (53.5%)

Separated/divorced

69,932 (11.0%)

36,421 (11.0%)

2,244 (10.6%)

563 (9.2%)

Single/widowed

210,050 (33.1%)

103,573 (31.3%)

7,158 (33.9%)

2,281 (37.3%)

Race/ethnicity

< 0.001

Non-Hispanic White

440,604 (69.5%)

216,209 (65.4%)

12,348 (58.5%)

3,542 (58.0%)

Non-Hispanic unknown race

3,309 (0.5%)

2,060 (0.6%)

227 (1.1%)

76 (1.2%)

Non-Hispanic Black

66,467 (10.5%)

44,072 (13.3%)

3,949 (18.7%)

1,181 (19.3%)

Non-Hispanic Asian or Pacific Islander

53,564 (8.4%)

26,169 (7.9%)

1,594 (7.5%)

456 (7.5%)

Non-Hispanic American Indian/Alaska Native

3,893 (0.6%)

1,846 (0.6%)

146 (0.7%)

31 (0.5%)

Hispanic (all races)

66,106 (10.4%)

40,240 (12.2%)

2,856 (13.5%)

826 (13.5%)

Household income, inflation-adjusted

< 0.001

< $35,000

7,133 (1.1%)

2,770 (0.8%)

149 (0.7%)

47 (0.8%)

$35,000 - $39,999

10,606 (1.7%)

4,293 (1.3%)

253 (1.2%)

68 (1.1%)

$40,000 - $44,999

23,332 (3.7%)

10,177 (3.1%)

600 (2.8%)

190 (3.1%)

$45,000 - $49,999

27,272 (4.3%)

12,407 (3.8%)

781 (3.7%)

245 (4.0%)

$50,000 - $54,999

30,602 (4.8%)

14,190 (4.3%)

824 (3.9%)

209 (3.4%)

$55,000 - $59,999

52,314 (8.3%)

25,424 (7.7%)

1,473 (7.0%)

432 (7.1%)

$60,000 - $64,999

40,911 (6.5%)

20,717 (6.3%)

1,325 (6.3%)

385 (6.3%)

$65,000 - $69,999

66,670 (10.5%)

37,650 (11.4%)

2,565 (12.1%)

757 (12.4%)

$70,000 - $74,999

70,561 (11.1%)

40,390 (12.2%)

2,653 (12.6%)

754 (12.3%)

$75,000+

304,516 (48.0%)

162,565 (49.2%)

10,497 (49.7%)

3,025 (49.5%)

Unknown/missing/no match/not 1990-2021

26 (0.0%)

13 (0.0%)

0 (0.0%)

Region

< 0.001

Non-metropolitan

83,724 (13.2%)

36,173 (10.9%)

2,022 (9.6%)

535 (8.8%)

Metropolitan

550,219 (86.8%)

294,423 (89.1%)

19,098 (90.4%)

5,577 (91.2%)

Stage

< 0.001

In situ

51 (0.0%)

8 (0.0%)

1 (0.0%)

0 (0.0%)

Localized

309,355 (48.8%)

203,458 (61.5%)

14,767 (69.9%)

4,257 (69.6%)

Regional

176,547 (27.8%)

87,852 (26.6%)

4,444 (21.0%)

1,085 (17.8%)

Distant

140,973 (22.2%)

35,844 (10.8%)

1,451 (6.9%)

466 (7.6%)

Unknown/unstaged

7,017 (1.1%)

3,434 (1.0%)

457 (2.2%)

304 (5.0%)

Grade

< 0.001

Well-differentiated/unknown

423,915 (66.9%)

215,536 (65.2%)

14,461 (68.5%)

4,395 (71.9%)

Moderately differentiated

126,946 (20.0%)

75,809 (22.9%)

4,911 (23.3%)

1,284 (21.0%)

Poorly differentiated

78,657 (12.4%)

38,372 (11.6%)

1,726 (8.2%)

428 (7.0%)

Anaplastic

4,425 (0.7%)

879 (0.3%)

22 (0.1%)

5 (0.1%)

Radiation

< 0.001

19,656 (3.1%)

11,134 (3.4%)

583 (2.8%)

182 (3.0%)

Yes

614,287 (96.9%)

319,462 (96.6%)

20,537 (97.2%)

5,930 (97.0%)

Chemotherapy

< 0.001

378,930 (59.8%)

245,170 (74.2%)

18,795 (89.0%)

5,503 (90.0%)

Yes

255,013 (40.2%)

85,426 (25.8%)

2,325 (11.0%)

609 (10.0%)

Surgery

< 0.001

186,609 (29.4%)

113,480 (34.3%)

10,243 (48.5%)

3,131 (51.2%)

Yes

447,334 (70.6%)

217,116 (65.7%)

10,877 (51.5%)

2,981 (48.8%)

Cancer type

< 0.001

Lung

142,456 (22.5%)

66,023 (20.0%)

3,319 (15.7%)

809 (13.2%)

Breast

258,357 (40.8%)

112,258 (34.0%)

2,631 (12.5%)

708 (11.6%)

Prostate

78,211 (12.3%)

120,748 (36.5%)

14,066 (66.6%)

4,224 (69.1%)

Colon

154,919 (24.4%)

31,567 (9.5%)

1,104 (5.2%)

371 (6.1%)

**Table 2.** Overall Mortality and Mortality by Type of Cancer
Cancer type	0 - 1 months	2 - 5 months	6 - 9 months	≥ 10 months
Data presented as event/total.
Overall	165,616/633,943 (26.1%)	52,608/330,596 (15.9%)	2,543/21,120 (12.0%)	694/6,112 (11.4%)
Lung	82,175/142,456 (57.70%)	30,206/66,023 (45.80%)	1,309/3,319 (39.40%)	298/809 (36.80%)
Breast	25,532/254,357 (9.90%)	8,345/112,258 (7.40%)	366/2,631 (13.90%)	98/708 (13.80%)
Prostate	41,825/154,919 (27.00%)	8,347/31,567 (26.40%)	335/1,104 (30.30%)	93/371 (25.10%)
Colon	156,516/633,943 (26.10%)	52,608/330,596 (15.90%)	2,543/21,120 (12.00%)	694/6,112 (11.40%)

Table 2. Overall Mortality and Mortality by Type of Cancer

Cancer type

0 - 1 months

2 - 5 months

6 - 9 months

≥ 10 months

Data presented as event/total.

Overall

165,616/633,943 (26.1%)

52,608/330,596 (15.9%)

2,543/21,120 (12.0%)

694/6,112 (11.4%)

Lung

82,175/142,456 (57.70%)

30,206/66,023 (45.80%)

1,309/3,319 (39.40%)

298/809 (36.80%)

Breast

25,532/254,357 (9.90%)

8,345/112,258 (7.40%)

366/2,631 (13.90%)

98/708 (13.80%)

Prostate

41,825/154,919 (27.00%)

8,347/31,567 (26.40%)

335/1,104 (30.30%)

93/371 (25.10%)

Colon

156,516/633,943 (26.10%)

52,608/330,596 (15.90%)

2,543/21,120 (12.00%)

694/6,112 (11.40%)

**Table 3.** Cox Proportional Hazard Model Accounting for Time-Varying Covariates
Variable	HR (95 % CI)	SE	P
CI: confidence interval; HR: hazard ratio; Ref: reference; SE: standard error; TTI: time-to-treatment initiation.
TTI (months)
0 - 1	Ref	-	-
2 - 5	0.90 (0.88 - 0.92)	0.01	< 0.001
6 - 9	0.78 (0.72 - 0.85)	0.03	< 0.001
≥ 10	0.52 (0.45 - 0.61)	0.04	< 0.001
Age
< 65	Ref	-	-
≥ 65	1.06 (1.05 - 1.08)	0.01	< 0.001
Sex
Female	Ref	-	-
Male	1.08 (1.07 - 1.09)	0.01	< 0.001
Race
Non-Hispanic White	Ref	-	-
Non-Hispanic unknown	0.97 (0.84 - 1.11)	0.07	0.633
Non-Hispanic Black	1.03 (1.02 - 1.05)	0.01	< 0.001
Non-Hispanic Asian/Pacific Islander	0.94 (0.92 - 0.96)	0.01	< 0.001
Non-Hispanic American Indian/Alaska Native	0.98 (0.92 - 1.04)	0.03	0.429
Hispanic (all)	0.99 (0.97 - 1.01)	0.01	0.23
Region
Non-metropolitan	Ref	-	-
Metropolitan	0.93 (0.92 - 0.95)	0.01	< 0.001
Marital status
Married	Ref	-	-
Separated	1.04 (1.03 - 1.06)	0.01	< 0.001
Single/unmarried/unknown/widowed	1.06 (1.05 - 1.08)	0.01	< 0.001
Income (USD)
< 35 k	Ref	-	-
35 - 39 k	0.95 (0.91 - 1.01)	0.03	0.083
40 - 44 k	1.00 (0.95 - 1.05)	0.02	0.999
45 - 49 k	0.99 (0.95 - 1.04)	0.02	0.711
50 - 54 k	0.99 (0.95 - 1.04)	0.02	0.814
55 - 59 k	1.02 (0.98 - 1.07)	0.02	0.323
60 - 64 k	0.97 (0.93 - 1.02)	0.02	0.213
65 - 69 k	0.93 (0.89 - 0.98)	0.02	0.003
70 - 74 k	1.08 (1.03 - 1.13)	0.03	0.001
≥ 75 k	1.04 (0.99 - 1.09)	0.02	0.102
Unknown/missing	0.30 (0.08 - 1.21)	0.21	0.09
Cancer site
Lung	Ref	-	-
Breast	0.81 (0.80 - 0.83)	0.01	< 0.001
Prostate	0.67 (0.66 - 0.69)	0.01	< 0.001
Colon	0.95 (0.94 - 0.97)	0.01	< 0.001
Tumor grade
Well-differentiated	Ref	-	-
Moderately differentiated	0.36 (0.35 - 0.37)	0.01	< 0.001
Poorly differentiated	0.52 (0.50 - 0.53)	0.01	< 0.001
Anaplastic	0.84 (0.77 - 0.91)	0.04	< 0.001
Stage
In situ	Ref	-	-
Localized	0.44 (0.03 - 6.08)	0.59	0.538
Regional	0.67 (0.05 - 9.23)	0.89	0.761
Distant	0.98 (0.07 - 13.62)	1.32	0.989
Unknown/unstaged	0.58 (0.04 - 8.11)	0.78	0.688
Radiation
No	Ref	-	-
Yes	1.00 (0.94 - 1.07)	0.03	0.969
Chemotherapy
No	Ref	-	-
Yes	0.91 (0.89 - 0.93)	0.01	< 0.001
Surgery
No	Ref	-	-
Yes	0.84 (0.83 - 0.85)	0.01	< 0.001
Time-varying covariates
Stage (time-varying)
In situ	Ref	-	-
Localized	0.85 (0.10 - 7.32)	0.94	0.885
Regional	0.77 (0.09 - 6.62)	0.85	0.813
Distant	0.70 (0.08 - 6.04)	0.77	0.75
Unknown/unstaged	0.82 (0.10 - 7.05)	0.9	0.858
Grade (time-varying)
Well-differentiated	Ref	-	-
Moderately differentiated	1.31 (1.30 - 1.33)	0.01	< 0.001
Poorly differentiated	1.22 (1.20 - 1.23)	0.01	< 0.001
Anaplastic	1.03 (0.99 - 1.08)	0.02	0.109
Chemotherapy (time-varying)
No	Ref	-	-
Yes	1.03 (1.02 - 1.04)	0.01	< 0.001
Radiation (time-varying)
No	Ref	-	-
Yes	0.97 (0.95 - 1.00)	0.01	0.039
TTI (months, time-varying)
0 - 1	Ref	-	-
2 - 5	1.02 (1.01 - 1.03)	0.01	< 0.001
6 - 9	1.08 (1.04 - 1.12)	0.02	< 0.001
≥ 10	1.23 (1.16 - 1.31)	0.04	< 0.001

Table 3. Cox Proportional Hazard Model Accounting for Time-Varying Covariates

Variable

HR (95 % CI)

CI: confidence interval; HR: hazard ratio; Ref: reference; SE: standard error; TTI: time-to-treatment initiation.

TTI (months)

0 - 1

Ref

2 - 5

0.90 (0.88 - 0.92)

0.01

< 0.001

6 - 9

0.78 (0.72 - 0.85)

0.03

< 0.001

≥ 10

0.52 (0.45 - 0.61)

0.04

< 0.001

Age

< 65

Ref

≥ 65

1.06 (1.05 - 1.08)

0.01

< 0.001

Sex

Female

Ref

Male

1.08 (1.07 - 1.09)

0.01

< 0.001

Race

Non-Hispanic White

Ref

Non-Hispanic unknown

0.97 (0.84 - 1.11)

0.07

0.633

Non-Hispanic Black

1.03 (1.02 - 1.05)

0.01

< 0.001

Non-Hispanic Asian/Pacific Islander

0.94 (0.92 - 0.96)

0.01

< 0.001

Non-Hispanic American Indian/Alaska Native

0.98 (0.92 - 1.04)

0.03

0.429

Hispanic (all)

0.99 (0.97 - 1.01)

0.01

0.23

Region

Non-metropolitan

Ref

Metropolitan

0.93 (0.92 - 0.95)

0.01

< 0.001

Marital status

Married

Ref

Separated

1.04 (1.03 - 1.06)

0.01

< 0.001

Single/unmarried/unknown/widowed

1.06 (1.05 - 1.08)

0.01

< 0.001

Income (USD)

< 35 k

Ref

35 - 39 k

0.95 (0.91 - 1.01)

0.03

0.083

40 - 44 k

1.00 (0.95 - 1.05)

0.02

0.999

45 - 49 k

0.99 (0.95 - 1.04)

0.02

0.711

50 - 54 k

0.99 (0.95 - 1.04)

0.02

0.814

55 - 59 k

1.02 (0.98 - 1.07)

0.02

0.323

60 - 64 k

0.97 (0.93 - 1.02)

0.02

0.213

65 - 69 k

0.93 (0.89 - 0.98)

0.02

0.003

70 - 74 k

1.08 (1.03 - 1.13)

0.03

0.001

≥ 75 k

1.04 (0.99 - 1.09)

0.02

0.102

Unknown/missing

0.30 (0.08 - 1.21)

0.21

0.09

Cancer site

Lung

Ref

Breast

0.81 (0.80 - 0.83)

0.01

< 0.001

Prostate

0.67 (0.66 - 0.69)

0.01

< 0.001

Colon

0.95 (0.94 - 0.97)

0.01

< 0.001

Tumor grade

Well-differentiated

Ref

Moderately differentiated

0.36 (0.35 - 0.37)

0.01

< 0.001

Poorly differentiated

0.52 (0.50 - 0.53)

0.01

< 0.001

Anaplastic

0.84 (0.77 - 0.91)

0.04

< 0.001

Stage

In situ

Ref

Localized

0.44 (0.03 - 6.08)

0.59

0.538

Regional

0.67 (0.05 - 9.23)

0.89

0.761

Distant

0.98 (0.07 - 13.62)

1.32

0.989

Unknown/unstaged

0.58 (0.04 - 8.11)

0.78

0.688

Radiation

Ref

Yes

1.00 (0.94 - 1.07)

0.03

0.969

Chemotherapy

Ref

Yes

0.91 (0.89 - 0.93)

0.01

< 0.001

Surgery

Ref

Yes

0.84 (0.83 - 0.85)

0.01

< 0.001

Time-varying covariates

Stage (time-varying)

In situ

Ref

Localized

0.85 (0.10 - 7.32)

0.94

0.885

Regional

0.77 (0.09 - 6.62)

0.85

0.813

Distant

0.70 (0.08 - 6.04)

0.77

0.75

Unknown/unstaged

0.82 (0.10 - 7.05)

0.9

0.858

Grade (time-varying)

Well-differentiated

Ref

Moderately differentiated

1.31 (1.30 - 1.33)

0.01

< 0.001

Poorly differentiated

1.22 (1.20 - 1.23)

0.01

< 0.001

Anaplastic

1.03 (0.99 - 1.08)

0.02

0.109

Chemotherapy (time-varying)

Ref

Yes

1.03 (1.02 - 1.04)

0.01

< 0.001

Radiation (time-varying)

Ref

Yes

0.97 (0.95 - 1.00)

0.01

0.039

TTI (months, time-varying)

0 - 1

Ref

2 - 5

1.02 (1.01 - 1.03)

0.01

< 0.001

6 - 9

1.08 (1.04 - 1.12)

0.02

< 0.001

≥ 10

1.23 (1.16 - 1.31)

0.04

< 0.001