# Two Time Point Analysis of the Change in Risk and Aging Factors for Major Cancers: A 10-Year Longitudinal Study in China

Authors: Liu Hui
Journal: BioMed Research International
 (2020)

---

## Abstract

Objective. To quantify the change in risk and aging factors with a two time point analysis for major cancers to assess supportive strategies. Methods. The 2004 and 2015 mortality statistics in China were accessed. The standardized mortality rates of the two periods were used to calculate the ratio of change (RC) value to assess the risk of death associated with time (social development with time) for cancers. The role of age in mortality with time was evaluated by the interaction between time and age using a Poisson regression. Results. In ascending order of RC, the factors were uterus; other malignant neoplasms; esophagus; stomach; skin; liver; leukemia; “lip, oral cavity, and pharynx”; bladder; “colon and rectum”; breast; prostate; lung; ovary; pancreas; “lymphoid, hematopoietic, and related tissue”; and cervix cancers. According to their location on the scatter diagram, the 17 neoplasms could be divided into three groups, comprising undeveloped cancers (including four cancers), developed cancers (including three cancers), and cancers insensitive to social development. Unexpectedly, about 60% (as assessed by type of cancer) and two-thirds (as assessed by constituent ratio of death from all cancers) of cancers did not change with time. Conclusions. Most cancers may be insensitive to social development. Internal factors, including aging, may be a key factor for the occurrence of cancer.


---

## Body

## 1. Introduction

Cancers are complex disorders, and it is virtually impossible to prove what causes a particular cancer, because most cancers have multiple possible causes. However, we can classify cancer-related factors as risk or protective factors to assess preventative strategies. A hitherto unknown number of risk and protective factors contribute to cancer development by interacting with each other. Although cancer can develop at any age, cancer incidence increases with age [1–3]; therefore, it is believed that old age is the most important risk factor for cancer development and was treated as a major variable in the present study.Worldwide, the rates of cancer are increasing, mainly related to the aging population and changes in lifestyle resulting from social development [4–6]. Some cancers seem to be more prevalent in people with a lower quality of life, whereas other cancers may be more prevalent in people with a higher quality of life [7]. Social development or urbanization will result in changes to cancer risk and protective factors, including aging, diet and obesity, lack of physical activity, smoking, radiation, infections, stress, and environmental pollutants [8–10], and their impact on the occurrence of cancer [11–13]. Therefore, in growing economies, whether the time trend of increased social development might influence the development and burden of cancer should be explored, which will allow us to identify and implement appropriate medical strategies. To date, there have been no comprehensive and quantitative two time point analyses on cancers.The cancer incidence (201.7/100000) in China is similar to that of the overall worldwide incidence (197.9/100000) in 2018 [14]. China’s ethnic composition is relatively simple and is presently undergoing rapid urbanization [15–17]. China’s gross domestic product was 1.955 trillion USD in 2004 and 11.016 trillion USD in 2015 (Figure 1). Health and medical care has been markedly affected by economic growth, making China an ideal model to study disease patterns associated with modernization [18–20]. In this study, we analyzed the characteristics of cancers using two properties: (1) age [8] and (2) risk factors [7]. The results showed that although these two properties varied significantly among some cancers, the rates of most cancers were unchanged with time. We also categorized 17 major cancers using two time point analysis and found that about 30% of cancers were sensitive to social development, and more than 60% of cancers were insensitive to social development. An improved understanding of such associations would benefit the development of a theoretical basis for cancer prevention and control strategies.Figure 1
Gross domestic product from 2003 to 2015 in China.


## 2. Materials and Methods

### 2.1. Original Data

Original data was obtained from the 2004 and 2015 data sets of the national disease mortality surveillance system, which was edited by the Chinese Center for Disease Control and Prevention [21, 22], representing data obtained from over 73 million out of the 1.4 billion population of China between 2004 and 2015. In 2004, life expectancy at birth was 73.6 years, whereas in 2015, it was 76.1 years. The International Classification of Diseases- (ICD-) 10 codes [23] were used to classify the underlying causes of death, allowing us to determine the mortality statistics. Tables 1 and 2 show the raw data.Table 1
Age-stratified number of deaths from major cancers in 2004 in China [21].
Age
Cancers
Survival
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
0-
0
0
0
0
1
0
0
2
0
0
0
0
0
0
2
35
13
53
688115
1-
1
0
0
0
7
0
0
2
0
0
0
0
0
1
3
69
6
89
3030920
5-
0
0
0
1
7
0
2
2
0
0
0
0
0
0
5
95
5
117
4604931
10-
1
0
0
3
16
0
2
0
0
2
0
2
1
1
9
146
9
192
6443682
15-
10
0
7
12
34
2
22
2
1
1
2
5
1
0
16
220
13
348
5900624
20-
11
8
15
24
64
0
18
2
5
2
5
1
4
1
15
157
14
346
5467254
25-
24
11
53
47
141
6
60
3
20
6
14
9
1
1
19
125
24
564
6299615
30-
69
27
123
83
422
20
165
11
55
32
35
12
2
5
22
163
35
1281
6992522
35-
114
81
302
123
777
41
365
12
136
65
69
13
0
9
54
205
44
2410
6360862
40-
149
189
436
148
1144
45
575
13
205
104
104
32
4
18
52
149
67
3434
5173403
45-
232
471
867
282
1810
96
1034
22
254
102
135
59
8
24
71
203
78
5748
5115691
50-
337
852
1320
374
2190
141
1709
25
339
108
231
80
14
31
131
211
101
8194
4047509
55-
305
1102
1761
430
2193
166
1950
30
238
117
166
50
19
41
110
154
126
8958
2957812
60-
304
1427
2166
509
2120
241
2523
38
168
94
156
51
26
82
121
169
99
10294
2486122
65-
359
1784
2816
686
2430
276
3363
60
184
102
201
62
74
132
150
192
150
13021
2125649
70-
320
2046
3175
876
2232
328
3961
69
136
83
153
50
145
185
157
178
147
14241
1601637
75-
183
1568
2526
751
1692
269
3045
68
127
64
120
38
140
186
123
126
128
11154
1022733
80-
137
967
1571
525
1011
154
1755
65
72
59
83
25
124
149
80
77
109
6963
545697
>85
72
472
817
332
527
67
930
57
42
35
36
18
104
112
30
39
65
3755
308427
Neoplasms (ICD-10 codes): A: lip, oral cavity, pharynx (C00–C14); B: esophagus (C15); C: stomach (C16); D: colon, rectum (C18–C21); E: liver (C22); F: pancreas (C25); G: trachea, lung (C33–C34); H: skin (C43–C44); I: breast (C50); J: cervix (C53); K: uterus (C54–C55); L: ovary (C56); M: prostate (C61); N: bladder (C67); O: lymphoid, hematopoietic, related tissue (C81–C90, C96); P: leukemia (C91–C95); Q: other malignant neoplasms (C17, C23–C24, C26–C32, C37–C41, C45–C49, C51–C52, C57–C60, C62–C66, C68–C80, and C97); R: all cancers.Table 2
Age-stratified number of deaths from major cancers in 2015 in China [22].
Age
Cancers
Survival
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
0-
0
0
0
1
14
0
1
0
0
0
0
0
0
0
10
88
15
129
2804289
1-
0
0
0
0
32
0
2
1
0
0
0
0
0
0
42
239
31
347
11836631
5-
5
0
1
0
13
2
2
0
0
0
0
0
0
1
39
217
18
298
15322497
10-
4
1
2
2
12
1
5
2
0
0
0
2
0
0
42
207
11
291
12042350
15-
9
1
5
18
33
1
20
5
1
0
2
4
0
1
52
265
14
431
14609389
20-
19
5
33
39
121
10
48
5
9
8
4
8
1
3
57
327
21
718
22895079
25-
31
9
125
84
301
21
160
10
70
38
15
16
2
4
128
380
35
1429
18670345
30-
77
14
209
168
671
43
280
18
165
112
28
34
2
8
99
322
44
2294
15611678
35-
152
43
385
292
1405
72
660
17
335
187
74
53
4
13
143
352
59
4246
19793806
40-
338
245
953
623
3386
241
1957
62
780
465
128
136
10
34
288
508
119
10273
22967145
45-
582
792
1943
1104
5582
479
4174
78
1185
836
254
223
15
62
454
624
153
18540
26394480
50-
737
1573
2899
1470
6787
759
6897
79
1408
938
300
351
44
128
632
670
220
25892
16034245
55-
804
2613
4376
2035
7964
1231
10417
108
1343
800
341
331
86
217
774
730
250
34420
18285929
60-
1025
4531
7151
3098
9985
1703
16323
153
1360
892
329
416
211
397
1109
1065
337
50085
14053811
65-
900
5299
8031
3362
8808
1832
17509
192
861
716
339
349
281
520
1070
896
339
51304
9032555
70-
733
5371
8314
3536
7551
1826
17546
202
652
594
228
273
508
658
1041
860
309
50202
6728141
75-
694
5160
8422
4052
6600
1743
17766
237
587
518
229
211
840
891
932
815
385
50082
5350578
80-
507
4122
6673
3645
4893
1424
13547
298
469
367
182
147
887
887
645
528
382
39603
3320829
>85
329
2607
4366
2727
3064
869
8259
361
405
250
99
88
826
830
335
270
282
25967
1817600
Neoplasms (ICD-10 codes): A: lip, oral cavity, pharynx (C00–C14); B: esophagus (C15); C: stomach (C16); D: colon, rectum (C18–C21); E: liver (C22); F: pancreas (C25); G: trachea, lung (C33–C34); H: skin (C43–C44); I: breast (C50); J: cervix (C53); K: uterus (C54–C55); L: ovary (C56); M: prostate (C61); N: bladder (C67); O: lymphoid, hematopoietic, related tissue (C81–C90, C96); P: leukemia (C91–C95); Q: other malignant neoplasms (C17, C23–C24, C26–C32, C37–C41, C45–C49, C51–C52, C57–C60, C62–C66, C68–C80, and C97); R: all cancers.


### 2.2. Two Time Point Analysis of Deaths Caused by Neoplasms

The mortality rates in 2004 and 2015 were standardized using the 2000 Standard in China [7] and were used to calculate the ratio of change (RC) with time with respect to deaths caused by a particular cancer. The RC values were calculated using the following formula:
(1)RC=P1P0,where P1 represents a cancer’s mortality rate in 2015 and P0 represents the cancer’s mortality rate in 2004.AnRCvalue>1 indicated that the mortality rate had increased with time, whereas a value<1 indicated a decreasing trend with time. To evaluate the degree of deviation from 1 (the values greater than 1 and those less than 1 were comparable), logarithmic transformation was used to transform the RC values into logarithms, with the absolute value, lnRC, serving as the quantitative value for the two time point analysis.A scatter diagram was plotted using the lnRC values. The degree of deviation from 1 and the positions of the various cancers on the scatter diagram were used to sort neoplasms according to the changes in the mortality rate with time.


### 2.3. Assessing the Role of Age on Mortality from Cancer over Time

To evaluate the mortality risk from aging and social development, a loglinear model using the Poisson regression was employed, with covariates of time (2004 and 2015) and a categorical age of 60 years old [7]. Poisson regression is a generalized linear model form of regression analysis used to model count data and contingency tables. Poisson regression assumes the response variable Y has a Poisson distribution and assumes the logarithm of its expected value can be modeled by a linear combination of unknown parameters. From the model, the B coefficients for the interaction between time and age were obtained, in which expB was taken as the risk ratio. The greater the positive value of B, the greater the effect of the aging factor with time was on a particular cancer [7].A probability of atypeIerror≤0.05 was considered statistically significant. SPSS ver. 17.0 software for Windows (IBM, Armonk, NY, USA) was used to analyze the data statistically.


## 2.1. Original Data

Original data was obtained from the 2004 and 2015 data sets of the national disease mortality surveillance system, which was edited by the Chinese Center for Disease Control and Prevention [21, 22], representing data obtained from over 73 million out of the 1.4 billion population of China between 2004 and 2015. In 2004, life expectancy at birth was 73.6 years, whereas in 2015, it was 76.1 years. The International Classification of Diseases- (ICD-) 10 codes [23] were used to classify the underlying causes of death, allowing us to determine the mortality statistics. Tables 1 and 2 show the raw data.Table 1
Age-stratified number of deaths from major cancers in 2004 in China [21].
Age
Cancers
Survival
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
0-
0
0
0
0
1
0
0
2
0
0
0
0
0
0
2
35
13
53
688115
1-
1
0
0
0
7
0
0
2
0
0
0
0
0
1
3
69
6
89
3030920
5-
0
0
0
1
7
0
2
2
0
0
0
0
0
0
5
95
5
117
4604931
10-
1
0
0
3
16
0
2
0
0
2
0
2
1
1
9
146
9
192
6443682
15-
10
0
7
12
34
2
22
2
1
1
2
5
1
0
16
220
13
348
5900624
20-
11
8
15
24
64
0
18
2
5
2
5
1
4
1
15
157
14
346
5467254
25-
24
11
53
47
141
6
60
3
20
6
14
9
1
1
19
125
24
564
6299615
30-
69
27
123
83
422
20
165
11
55
32
35
12
2
5
22
163
35
1281
6992522
35-
114
81
302
123
777
41
365
12
136
65
69
13
0
9
54
205
44
2410
6360862
40-
149
189
436
148
1144
45
575
13
205
104
104
32
4
18
52
149
67
3434
5173403
45-
232
471
867
282
1810
96
1034
22
254
102
135
59
8
24
71
203
78
5748
5115691
50-
337
852
1320
374
2190
141
1709
25
339
108
231
80
14
31
131
211
101
8194
4047509
55-
305
1102
1761
430
2193
166
1950
30
238
117
166
50
19
41
110
154
126
8958
2957812
60-
304
1427
2166
509
2120
241
2523
38
168
94
156
51
26
82
121
169
99
10294
2486122
65-
359
1784
2816
686
2430
276
3363
60
184
102
201
62
74
132
150
192
150
13021
2125649
70-
320
2046
3175
876
2232
328
3961
69
136
83
153
50
145
185
157
178
147
14241
1601637
75-
183
1568
2526
751
1692
269
3045
68
127
64
120
38
140
186
123
126
128
11154
1022733
80-
137
967
1571
525
1011
154
1755
65
72
59
83
25
124
149
80
77
109
6963
545697
>85
72
472
817
332
527
67
930
57
42
35
36
18
104
112
30
39
65
3755
308427
Neoplasms (ICD-10 codes): A: lip, oral cavity, pharynx (C00–C14); B: esophagus (C15); C: stomach (C16); D: colon, rectum (C18–C21); E: liver (C22); F: pancreas (C25); G: trachea, lung (C33–C34); H: skin (C43–C44); I: breast (C50); J: cervix (C53); K: uterus (C54–C55); L: ovary (C56); M: prostate (C61); N: bladder (C67); O: lymphoid, hematopoietic, related tissue (C81–C90, C96); P: leukemia (C91–C95); Q: other malignant neoplasms (C17, C23–C24, C26–C32, C37–C41, C45–C49, C51–C52, C57–C60, C62–C66, C68–C80, and C97); R: all cancers.Table 2
Age-stratified number of deaths from major cancers in 2015 in China [22].
Age
Cancers
Survival
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
0-
0
0
0
1
14
0
1
0
0
0
0
0
0
0
10
88
15
129
2804289
1-
0
0
0
0
32
0
2
1
0
0
0
0
0
0
42
239
31
347
11836631
5-
5
0
1
0
13
2
2
0
0
0
0
0
0
1
39
217
18
298
15322497
10-
4
1
2
2
12
1
5
2
0
0
0
2
0
0
42
207
11
291
12042350
15-
9
1
5
18
33
1
20
5
1
0
2
4
0
1
52
265
14
431
14609389
20-
19
5
33
39
121
10
48
5
9
8
4
8
1
3
57
327
21
718
22895079
25-
31
9
125
84
301
21
160
10
70
38
15
16
2
4
128
380
35
1429
18670345
30-
77
14
209
168
671
43
280
18
165
112
28
34
2
8
99
322
44
2294
15611678
35-
152
43
385
292
1405
72
660
17
335
187
74
53
4
13
143
352
59
4246
19793806
40-
338
245
953
623
3386
241
1957
62
780
465
128
136
10
34
288
508
119
10273
22967145
45-
582
792
1943
1104
5582
479
4174
78
1185
836
254
223
15
62
454
624
153
18540
26394480
50-
737
1573
2899
1470
6787
759
6897
79
1408
938
300
351
44
128
632
670
220
25892
16034245
55-
804
2613
4376
2035
7964
1231
10417
108
1343
800
341
331
86
217
774
730
250
34420
18285929
60-
1025
4531
7151
3098
9985
1703
16323
153
1360
892
329
416
211
397
1109
1065
337
50085
14053811
65-
900
5299
8031
3362
8808
1832
17509
192
861
716
339
349
281
520
1070
896
339
51304
9032555
70-
733
5371
8314
3536
7551
1826
17546
202
652
594
228
273
508
658
1041
860
309
50202
6728141
75-
694
5160
8422
4052
6600
1743
17766
237
587
518
229
211
840
891
932
815
385
50082
5350578
80-
507
4122
6673
3645
4893
1424
13547
298
469
367
182
147
887
887
645
528
382
39603
3320829
>85
329
2607
4366
2727
3064
869
8259
361
405
250
99
88
826
830
335
270
282
25967
1817600
Neoplasms (ICD-10 codes): A: lip, oral cavity, pharynx (C00–C14); B: esophagus (C15); C: stomach (C16); D: colon, rectum (C18–C21); E: liver (C22); F: pancreas (C25); G: trachea, lung (C33–C34); H: skin (C43–C44); I: breast (C50); J: cervix (C53); K: uterus (C54–C55); L: ovary (C56); M: prostate (C61); N: bladder (C67); O: lymphoid, hematopoietic, related tissue (C81–C90, C96); P: leukemia (C91–C95); Q: other malignant neoplasms (C17, C23–C24, C26–C32, C37–C41, C45–C49, C51–C52, C57–C60, C62–C66, C68–C80, and C97); R: all cancers.


## 2.2. Two Time Point Analysis of Deaths Caused by Neoplasms

The mortality rates in 2004 and 2015 were standardized using the 2000 Standard in China [7] and were used to calculate the ratio of change (RC) with time with respect to deaths caused by a particular cancer. The RC values were calculated using the following formula:
(1)RC=P1P0,where P1 represents a cancer’s mortality rate in 2015 and P0 represents the cancer’s mortality rate in 2004.AnRCvalue>1 indicated that the mortality rate had increased with time, whereas a value<1 indicated a decreasing trend with time. To evaluate the degree of deviation from 1 (the values greater than 1 and those less than 1 were comparable), logarithmic transformation was used to transform the RC values into logarithms, with the absolute value, lnRC, serving as the quantitative value for the two time point analysis.A scatter diagram was plotted using the lnRC values. The degree of deviation from 1 and the positions of the various cancers on the scatter diagram were used to sort neoplasms according to the changes in the mortality rate with time.


## 2.3. Assessing the Role of Age on Mortality from Cancer over Time

To evaluate the mortality risk from aging and social development, a loglinear model using the Poisson regression was employed, with covariates of time (2004 and 2015) and a categorical age of 60 years old [7]. Poisson regression is a generalized linear model form of regression analysis used to model count data and contingency tables. Poisson regression assumes the response variable Y has a Poisson distribution and assumes the logarithm of its expected value can be modeled by a linear combination of unknown parameters. From the model, the B coefficients for the interaction between time and age were obtained, in which expB was taken as the risk ratio. The greater the positive value of B, the greater the effect of the aging factor with time was on a particular cancer [7].A probability of atypeIerror≤0.05 was considered statistically significant. SPSS ver. 17.0 software for Windows (IBM, Armonk, NY, USA) was used to analyze the data statistically.


## 3. Results

The two time point analysis of deaths caused by neoplasms is summarized and quantified in Table3. The contributions of time (social development) to different cancers varied: The lnRC value for the 17 neoplasms ranged from −1.04 to 0.38. The greater the lnRC, the greater the disease risk over time. In ascending order of lnRC were uterus; other malignant neoplasms; esophagus; stomach; skin; liver; leukemia; “lip, oral cavity, and pharynx”; bladder; “colon and rectum”; breast; prostate; lung; ovary; pancreas; “lymphoid, hematopoietic, and related tissue”; and cervix cancers.Table 3
Two time point analysis of the mortality rate for different cancers.
Cancers
Standardized mortality rate (annual deaths per 105 population)
RC
lnRC
p
2004
2015
Lip, oral cavity, and pharynx
2.07
1.87
0.90
−0.11
<0.001
Esophagus
14.02
8.21
0.59
−0.53
<0.001
Stomach
22.89
13.80
0.60
−0.51
<0.001
Colon and rectum
6.62
6.68
1.01
0.01
<0.001
Liver
24.28
18.01
0.74
−0.30
<0.001
Pancreas
2.37
3.14
1.32
0.28
<0.001
Trachea and lung
27.41
29.59
1.08
0.08
<0.001
Skin
0.61
0.45
0.74
−0.30
<0.001
Breast
2.57
2.64
1.03
0.03
<0.001
Cervix
1.26
1.85
1.47
0.39
<0.001
Uterus
1.95
0.69
0.35
−1.05
<0.001
Ovary
0.65
0.72
1.11
0.10
<0.001
Prostate
0.82
0.85
1.04
0.04
<0.001
Bladder
1.22
1.12
0.92
−0.08
<0.001
Lymphoid, hematopoietic tissue
1.52
2.20
1.45
0.37
<0.001
Leukemia
3.69
3.03
0.82
−0.20
<0.001
Other malignant neoplasm
1.59
0.81
0.51
−0.67
<0.001
All cancers
123.90
106.14
0.86
−0.15
<0.001
lnRC is the absolute RC (logarithmically transformed RC). A value <1 indicated a decreasing trend of mortality with time.Table4 shows the results of the Poisson regression analysis to evaluate the mortality risk of aging with time (social development) for major cancers. We observed variations in the quantitative values of the effect of age with time on diseases. For the 17 cancers, the B value (the interaction between time and age) ranged from −0.169 to 0.435. A higher value of B indicated a stronger effect on cancer of aging with time (social development). The effect of aging with time was significantly reduced for cancers of the uterus, liver, pancreas, and cervix (p<0.05) and was significantly increased for cancers of the esophagus and leukemia (p<0.05).Table 4
The mortality risk from aging with time for major cancers using Poisson regression analysis.
Group of cancers
B
95% CI
p
Undeveloped
Uterus
−0.144
−0.272~−0.017
0.027
Other malignancy
0.090
−0.046~0.225
0.196
Esophagus
0.164
0.112~0.216
<0.0001
Stomach
0.020
−0.019~0.059
0.322
Insensitive to social development
Skin
−0.085
−0.317~0.147
0.475
Liver
−0.052
−0.085~−0.019
0.002
Leukemia
0.435
0.343~0.528
<0.0001
Lip, oral cavity, and pharynx
−0.040
−0.130~0.051
0.390
Bladder
−0.038
−0.245~0.168
0.717
Colon and rectum
0.009
−0.058~0.075
0.798
Breast
−0.023
−0.123~0.076
0.647
Prostate
0.282
−0.037~0.601
0.084
Lung
−0.028
−0.061~0.005
0.093
Ovary
−0.041
−0.232~0.149
0.670
Developed
Pancreas
−0.124
−0.233~−0.014
0.027
Lymphoid, hematopoietic tissue
−0.005
−0.130~0.119
0.931
Cervix
−0.169
−0.304~0.034
0.014
All cancers
−0.002
−0.017~0.014
0.809
B: measure of the interaction between time and age (a positive value of B indicates an increased aging risk with time); CI: confidence interval.According to their positions on the scatter diagram, the 17 neoplasms could be suggested to divide into three groups (Figure1). Cancers located in the upper right were termed developed cancers (more prevalent in people with a higher quality of life) and comprised three cancers. Cancers in the lower left part were termed undeveloped cancers (more prevalent in people with a lower quality of life) and comprised four cancers. The third group, positioned between the developed and undeveloped groups, was termed as cancers insensitive to social development and comprised ten cancers (58.8%). Figure 2 illustrates the detailed changes with social development for the three groups of cancers.Figure 2
Cancer groups classified on the basis of sensitivity to time. RC: ratio of change with time; rank of lnRC: in order of cancers with lnRC with respect to deaths caused by a particular cancer.The constituent ratios of death from the three groups of cancers are shown in Figure3. The constituent ratio increased from 4.9% in 2004 to 7.33% in 2015 for the developed cancers, decreased from 34.78% in 2004 to 25.06% in 2015 for the undeveloped cancers, and was approximately equal (60.84% in 2004 vs. 67.61% in 2015) for cancers insensitive to social development. The constituent ratios of death from insensitive to social development cancers were approximately two-thirds of all cancers.Figure 3
Changes in the constituent ratio with time for the three groups of cancer.


## 4. Discussion

Life expectancy at birth in 2004 was 73.6 years, and in 2015, it was 76.1 years. Therefore, our data for the two time point analysis could reveal the contribution of social development to the development of cancer. The results revealed that these contributions varied without consideration of age. In the 17 cancers studied, the lnRC value ranged from −1.04 to 0.38 (Table3), indicating that the contributions of social development to different cancers varied.The greater the lnRC, the greater the risk of disease risk with time (social development). The lnRC data showed that among the 17 cancers studied, uterus cancer had the lowest disease risk with time (social development) and cervix cancer had the highest risk. The 17 neoplasms could be divided into developed cancers (for which social development might be a risk factor), undeveloped cancers (for which lack of social development might be a risk factor), and cancers insensitive to social development, according to their position on the scatter diagram (Figure2). The constituent ratio of death from all cancers increased from 4.9% in 2004 to 7.33% in 2015 for developed cancers and decreased from 34.78% in 2004 to 25.06% in 2015 for undeveloped cancers (Figure 3). This suggested that the categories of cancer in this study are accurate and reasonable.Unexpectedly, about 60% (as assessed by type of cancer) and two-thirds (as assessed by constituent ratio of death from all cancers) of cancers were insensitive to social development, which suggested that the improvement in social development and medical care might have played a limited role in altering the rate of death from cancers. Internal factors, including aging, might have a key effect on cancer occurrence.Aging is a significant and uncontrollable risk factor for death [1, 24, 25]; therefore, determining the effects of aging on cancers with social development is important. The different contributions of age to mortality from cancers between 2004 and 2015 could also be considered as the change in the effect of other risk factors on cancers with time (social development). A larger difference indicated an increased effect of aging or a decreased effect of other risk factors on death resulting from cancers with social development. Therefore, changes in the effect of aging with time implied that the structure of the risk factors had changed with increasing social development. Our results showed that the B value (representing the interaction between time and age) for the 17 cancers ranged from −0.169 to 0.435. The effect of aging with social development was significantly reduced for cancers of the uterus, liver, pancreas, and cervix (p<0.05) and was significantly increased for cancers of the esophagus and leukemia (p<0.05), suggesting that the structure of risk factors had changed with increasing social development for these cancers. Moreover, for most of the cancers categorized as insensitive to social development, the level of risk and the structure of the risk factors had not changed with time (Figure 3).The identification of a group of developed cancers, including cervix, pancreas, and “lymphoid, hematopoietic, and related tissue” cancers, showed that risk factors from social development have contributed to increases in the rates of some cancers. The risk factors might have a more important role in the relatively young population for cervix and pancreas cancers. Accordingly, an emphasis on avoiding risk factors from social development or urbanization might contribute to disease prevention for these developed cancers.The presence of a group of undeveloped cancers, including uterus, esophagus, stomach, and other malignant neoplasms, showed that protective factors from social development have contributed to decreases in the rates of some cancers. The protective factors might have a more important role in the relatively young population for esophagus cancer and in the relatively old population for uterus cancer. Accordingly, disease prevention might be aided by an emphasis on public health and increasing basal health status for undeveloped cancers.One limitation of this study is that the social development was not described with more indicators. Time and social development may not be equal. However, China’s gross domestic product was 1.955 trillion USD in 2004 and 11.016 trillion USD in 2015; in 2004, life expectancy at birth was 73.6 years, whereas in 2015, it was 76.1 years. Therefore, time and social development may be parallel during 2004-2015. Increase of gross domestic product and rapid urbanization would change lifestyle; cancer-related risk would also be changed with this processes. Therefore, time could represent social development in this period. The findings also suggested that only about 30% of cancers are sensitive to changes in socioenvironmental factors over time. Analyzing and controlling external risk factors might lead to 30% of cancers being prevented, because the external factors leading to cancers are relatively controllable. Solutions to developed urbanized diseases mainly involve avoiding risk factors, which include tobacco use, overweight, physical inactivity, inadequate diet, sexually transmitted infections, alcohol consumption, and air pollution. General protective interventions for life quality, including nutritional status, lifestyle, and quality of social life, could potentially delay the aging process. Thus, the primary prevention of cancers will be aided by increasing our understanding of the categories of cancer affected by social development. Further studies are warranted to observe correlation between specific risk factors with social development and cancers for developing more available preventative strategies.



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*Source: 9043012-2020-05-07.xml*