In the past 30 years, China's breast cancer "transcript" has been released!

Breast cancer (BC) is the number one cause of cancer incidence and the fifth leading cause of cancer death in women worldwide
.
Although male BC accounts for only 1% of all BC, its incidence is increasing year by year, and the burden cannot be ignored
.
Genetic and non-genetic risk factors associated with BC have been extensively studied
.
For example, BRCA1 and BRCA2 mutations, multiple non-genetic risk factors include age, poor lifestyle, high body mass index (HBMI), metabolic syndrome, radiation exposure, sleep problems, and negative emotions
.

Risk factors for the incidence of BC vary geographically and temporally
.
According to GLOBOCAN 2020, the incidence of BC in developed countries is 88% higher than in developing countries
.
Although China is a developing country, the incidence of BC is the highest among Chinese female cancers in 2020, reaching 37.
7 cases per 100,000 people
.
On the other hand, there are fewer studies on Chinese male BC
.
As a densely populated developing country in East Asia and the Pacific, China shares a similar genetic background and culture with developed Japan and South Korea
.
Therefore, assessment and comparison of projections of BC burden, trends, risk factors, and future burden in women and men in these countries may provide valuable information for cancer control
.

The Global Burden of Disease (GBD) study includes various epidemiological data on the disease since 1990, which provides an unprecedented opportunity for a comparable assessment of BC burden, trends, and risk factors between China, Japan, and South Korea
.
In addition, the study forecasts the BC burden between the three countries by 2034
.
The research results can provide a scientific reference for BC control policies in China and other developing countries, and contribute to the effective allocation of medical resources in BC management and prevention
.

Data on BC cases, deaths, disability-adjusted life years (DALYs), and age-standardized rates (ASR) were obtained from the 2019 Global Burden of Disease Study
.

In 2019, the number of BC cases (375,484), the number of deaths (96,306), and the number of lost DALYs (2,957,453) were the largest, accounting for 58.
27%, 49.
82%, and 48.
83% of the BC burden in East Asia and the Pacific, respectively.
18.
75%, 13.
75% and 14.
34% of the global BC burden
.
The number of incidents, deaths, and DALYs were 5.
03, 6.
0, and 7.
44 times that of Japan, and 18.
47, 23.
55, and 24.
05 times that of South Korea, respectively (Table 1)
.

From 1990 to 2019, the incidence, deaths, and DALYs of BC in both men and women increased significantly in China, Japan, South Korea, and worldwide
.
The largest increase in female BC was in South Korea (488.
66%, 185.
92% and 138.
48%), while the largest increase in male BC was in China (1192.
73%, 659.
46% and 588.
21%) (Table 1)
.

The ASIR of both sexes was positively correlated with the SDI value, however, an interesting phenomenon was that when the SDI value was greater than 0.
853, Japan (ρ = -0.
80; 95%CI: -0.
96- -0.
23, P = 0.
016) and Korea (ρ = -0.
016) 0.
30; 95%CI: -0.
51-0.
83, P = 0.
47) ASIR decreased or remained stable (Figure 1A)
.
In contrast, when the SDI value was below 0.
853, China (ρ = 0.
36; 95% CI: 0–0.
64, P = 0.
048), Japan (ρ = 0.
98; 95% CI: 0.
96–0.
99, P < 0.
001) and South Korea ( ρ = 0.
98; 95% CI: 0.
95–0.
99, P < 0.
001) ASDR was negatively correlated with SDI values ​​in both sexes) (Fig.
1B)
.
The relationship of age-standardized DALY rates for men and women with SDI was similar to that of ASDR with SDI (Fig.
1C)
.
Meanwhile, ASRs in China and South Korea were lower than expected, while most ASRs in Japan were higher than expected as SDI values ​​rose
.

High body mass index (BMI) was the largest contributor to BC death and disability-adjusted life years in Chinese women, while alcohol consumption was the largest risk factor in Japanese and Korean and Chinese men
.

The morbidity and mortality calculated by the BAPC model were compared with the observed incidence of GBD 2019 between 1990 and 2019 and found that they were almost comparable to each other (Fig.
3)
.
Over the period 2020-2034, the ASIR of BC in Chinese, Japanese and Korean women is expected to remain stable or decrease, but the ASIR of BC in Chinese and Japanese men will show an upward trend, especially in Chinese men, with an annual growth rate of 1.
66 %, reaching 0.
93/100000 by 2034 (Table 2)
.

Among the three countries, China has the greatest burden on BC
.
BC cases and deaths are expected to increase in China over the next 15 years, especially among Chinese men
.
Effective prevention and management strategies are urgently needed for BC control in China
.

Original source:

Liu N, Yang DW, Wu YX, Xue WQ, Li DH, Zhang JB, He YQ, Jia WH.
Burden, trends, and risk factors for breast cancer in China from 1990 to 2019 and its predictions until 2034: an up-to -date overview and comparison with those in Japan and South Korea.
BMC Cancer.
2022 Jul 29;22(1):826.
doi: 10.
1186/s12885-022-09923-4.
PMID: 35906569; PMCID: PMC9334732.