Analysis of Cancer Incidence in Zhejiang Cancer Registry in China during 2000 to 2009

OBJECTIVE
The Zhejiang Provincial Cancer Prevention and Control Office collected cancer registration data during 2000 to 2009 from 6 cancer registries in Zhejiang province of China in order to analyze the cancer incidence.


METHODS
Descriptive analysis included cancer incidence stratified by sex, age and cancer site group. The proportions and cumulative rates of 10 common cancers in different groups were also calculated. Chinese population census in 1982 and Segi's population were used for calculating age-standardized incidence rates. The log-linear model was used for fitting to calculate the incidence trends.


RESULTS
The 6 cancer registries in Zhejiang province in China covered a total of 60,087,888 person-years during 2000 to 2009 (males 30,445,904, females 29,641,984). The total number of new cancer cases were 163,104 (males 92,982, females 70,122). The morphology verified cases accounted for 69.7%, and the new cases verified only by information from death certification accounted for 1.23%. The crude incidence rate in Zhejiang cancer registration areas was 271.5/105 during 2000 to 2009 (male 305.41/105, female 236.58/105), age-standardized incidence rates by Chinese standard population (ASIRC) and by world standard population (ASIRW) were 147.1/105 and 188.2/105, the cumulative incidence rate (aged from 0 to 74) being 21.7%. The crude incidence rate was 209.6/105 in 2000, and it increased to 320.20/105 in 2009 (52.8%), with an annual percent change (APC) of 4.51% (95% confidence interval, 3.25%-5.79%). Age-specific incidence rate of 80-84 age group was achieved at the highest point of the incidence curve. Overall with different age groups, the cancer incidences differed, the incidence of liver cancer being highest in 15-44 age group in males; the incidence of breast cancer was the highest in 15-64 age group in females; the incidences of lung cancer were the highest in both males and females over the age of 65 years.


CONCLUSIONS
Lung cancer, digestive system malignancies and breast cancer are the most common cancers in Zhejiang province in China requiring an especial focus. The incidences of thyroid cancer, prostate cancer, cervical cancer and lymphoma have increased rapidly. Prevention and control measures should be implemented for these cancers.


Introduction
Population-based cancer registry collects the data on cancer incidence and mortality deaths from covered population to describe and survey the epidemics in certain areas (Parkin, 2006).According to the data published by WHO International Agency for Research on Cancer (IACR) (GLOBOCAN 2012), there were 14, 100, 000 new incidence cases, and 8, 200, 000 new death cases in 2012 in the world.There were 3, 060, 000 new incidence cases and 2, 200, 000 new death cases in China (Ferlay et al., 2012).National Central Cancer Registry (NCCR) of China reported the incidence rate was 184.81/10 5 in

Analysis of Cancer Incidence in Zhejiang Cancer Registry in China during 2000 to 2009
Ling-Bin Du 1 , Hui-Zhang Li 1 , Xiang-Hui Wang 1 , Chen Zhu 1 , Qing-Min Liu 2 , Qi-Long Li 3 , Xue-Qin Li 4 , Yong-Zhou Shen 5 , Xin-Pei Zhang 6 , Jiang-Wei Ying 7 , Chuan-Ding Yu 1 , Wei-Min Mao 1 * 1989, and it increased to 285.91/10 5 in 2009 in Chinese cancer registries (Chen et al., 2012;Chen et al., 2013).We checked, sorted and analyzed the incidence data in Zhejiang cancer registry from 2000 to 2009, in order to utilize the data in scientific researches, clinical trials and making decision of cancer prevention and control strategies.

Data source
The cancer incidence data were collected from 6 cancer registries in Zhejiang province, including Jiashan, Jiaxing,

Quality control
Proportion of morphological verification (MV%), percentage of cancer case identified with death certification only (DCO%), mortality to incidence ratio (M/I), percentage of cancer with undefined or unknown primary site (secondary) (O&U%) were used to evaluate the completeness, validity and reliability of cancer statistics.According to the IACR and NCCR requirements of cancer registry data (Parkin et al., 2002;Curado et al., 2008), our data evaluation was as follows: MV% was 69.74%, DCO% was 1.23%, M/I was 0.58, O&U% was 6.09%.

Statistical analysis
The qualitfied data was assessed based on "Guideline of Chinese Cancer Registration" and referred to the criteria for "Cancer Incidence in Five Continents Volume Ⅸ" by IACR and IARC.The data were stratified by cancer site, sex and age (group by 0, 1-4, 5-9, …80-84, 85 years old and above), and crude incidence rates were calculated, age-standardized incidence rates according to the 1982 Chinese population and World Segi's population were also calculated.Proportion and cumulative rates were also calculated.Softwares, including MS-Excel, SAS, IACRcrgTools and Joinpoint Regression Program (4.0.0) were used for checking and evaluating data (Kim et al., 2000).

Age-specific incidence rate
From 2000 to 2009 in Zhejiang registration areas, the cancer incidence rate of all cancer was relatively low before 34 years old.Then it increased dramatically after 35 years old and finally reached the peak in the age group of 80-84 years (1321.44/10 5 ).Then it slightly decreased after 85 years old.The cancer incidence in the male in the age group of 15-49 years was lower than that in the female.But the incidence rate in the male was higher than that in the female after 50 years old, and the disparity of incidence rates between the male and the female was striking after age group 55 (Figure 1).The time trends of incidence rate The incidence rate in 2000 was 209.56/10 5 and it increased to 320.20/10 5 in 2009 which increased about 52.78%, with the Annual Percent Change (APC) of 4.51% (95% confidence interval (CI), 3.25%-5.79%)(Figure 2).Among the male the incidence rate was 239.44/10 5 in 2000, it increased to 361.59/10 5 in 2009, with APC of 4.28% (95% CI, 3.04%-5.53%)(Figure 2).In female, the incidence rate in 2000 was 178.31/10 5 .It increased to 278.30/10 5 in 2009, with the Annual Percent Change (APC) of 4.90% (95% CI, 3.42%-6.40%)(Figure 2).After standardizing age, the increment of incidence rate was reduced.ASIRC rate was 118.52/10 5 in 2000, it increased to 161.99/10 5 in 2009, the ASIRW rate was 153.40/10 5 in 2000, it increased to 207.92/10 5 in 2009 (Figure 3).

Incidence rates of 10 most common cancers
Lung cancer was the most common cancer in Zhejiang cancer registration areas in China, followed by stomach cancer, colorectal cancer, liver cancer, and breast cancer.The 10 most common cancers accounted for 73.66% of new cases of all sites.Meanwhile it was 81.60% in the male and 74.73% in the female, respectively.Lung cancer was the most frequently diagnosed cancer in males followed by stomach cancer, liver cancer, colorectal cancer and esophageal cancer.Breast cancer was the most frequently diagnosed cancers followed by lung cancer, colorectal cancer, stomach cancer and liver cancer in females (Table 2).

Incidence rates for 10 most common cancers in each age group
Different types of cancers occurred differently at each age group and gender.Whether in the male, female or both sexes, leukemia, lymphoma and brain tumor were the top 3 most common cancer, and leukemia ranked the first, accounting for 41.99% of all new cases in the age group of 0-14 years.Among male, liver cancer was the most common cancer in the age group of 15-44 years, accounting for 19.25% of all new cases, followed by colorectal cancer, lung cancer, stomach cancer and brain tumor; While breast cancer was the most common cancer in female, accounting for 23.02% of all new cases, followed by cervix cancer, thyroid gland cancer, colorectal cancer and stomach cancer in the age group of 15-44 years.Lung cancer became to the most common cancer in the age group of 45-64 years in men, accounting for 20.99% of all new cases, followed by liver cancer, stomach cancer, colorectal cancer, and esophagus cancer.In the age group of 45-64 years, breast cancer was the still most common cancer in female and it accounted for 22.03% of all new cases, followed by lung cancer, colorectal cancer, stomach cancer and liver cancer.In the 65 years old and over 65 years old age group, lung cancer was the most common cancer in the male, accounting for 27.18% of all new cases, followed by stomach cancer, colorectal cancer, liver cancer and esophagus cancer and meanwhile in the female lung cancer accounted for 17.46% of all new cases, followed by colorectal cancer, stomach cancer, liver cancer and breast cancer, respectively (Table 3).

Discussion
Zhejiang province, located on the east coast of China, belongs to more economically advanced regions, and the per capita GDP exceeded $10000 for the first time in 2012.With the economic and social development, population aging and increasingly serious environmental pollution, the incidence of cancer in Zhejiang province in China showed obviously upward trend (Wu et al., 2013;Li et al., 2013;Shen et al., 2014;Ding et al., 2014;Li et al., 2014;Wang et al., 2014;Li et al., 2014).Now we made a preliminary presentation on the incidence of cancer registries in Zhejiang in China in the first decade of the 21st century in order to provide basic data for cancer control.
The crude incidence rate from 2000 to 2009 in Zhejiang registration areas was 271.50/10 5 .The incidence rate was higher in males than that in females, and the ratio of incidence rate was 1.29.The age-standardized incidence rate was 147.06/10 5 by Chinese population (ASIRC), which is slightly higher than the figure in the National Cancer Institute National Cancer Registry's from 2003 to 2007 (Zhao et al., 2012) and its incidence rate was 144.25/10 5 (Hao et al., 2012).The incidence rate was 209.56/10 5 in 2000, and it increased to 320.20/10 5 in 2009 which increased about 52.78%, with the Annual Percent Change (APC) of 4.51%.The ASIRC rate was 118.52/10 5 in 2000, and it increased to 161.99/10 5 in 2009, the increment is significantly higher than that of the national incidence rates which were 133.04/10 5 in 2000 and 149.93 in 2009 (Hao et al., 2012).
Age-specific incidence rate of 80-84 years old achieved at the highest point, which reached 1321.44/10 5 in Zhejiang registration areas.While in the national registration areas, the incidence peak was in the age group of 80-84 years in urban areas and peak in the age group of 75-79 years in rural areas, respectively (Hao et al., 2012).It might be the reason that most of cancer registrations in Zhejiang province are urban areas.In the age group of 0-14 years, leukemia was the most common cancer followed by lymphoma and brain tumor, accounting for 41.99% of all new cases.In males, the incidence of liver cancer was the highest in 15-44 years old group and lung cancer became the most common cancer in the age group of 45-64 years.In females, the incidence of breast cancer was the highest in 15-64 years old group.However, Wu et al reported that the age-specific incidence curve of female breast cancer had two peaks: age of 50-54 years and over 85 years old (Wu et al., 2014).Another group also found that the incidence was higher in the age group of 50-54 years and 65-69 years (Zhang et al., 2012).Further studies focused on breast cancer could clarify whether this "twopeaks" was a common phenomenon.In the age group of 65 years and over, the incidence of lung cancer was the highest both in males or females.Based on the incidences of various types of tumors in age groups, we can plan to  Lung cancer was the most common cancer in both sexes, followed by stomach cancer and colorectal cancer.Lung cancer was the most frequently diagnosed cancer in the male followed by stomach cancer and liver cancer, which is consistent with the national cancer incidence rate from 2003-2007(Zhao et al., 2012)).According to the latest Chinese Cancer Registry Annual Report, breast cancer ranks the most common cancer among Chinese women, and it was also the most frequently diagnosed cancer in Zhejiang province followed by lung cancer and colorectal cancer (Hao et al., 2012).The age-standardized incidence rate by ASIRC of prostate cancer in the male is 4.47/10 5 and ranked No.7, higher than 4.05/10 5 in Chinese other registration areas (Zhao et al., 2012).The ASIRC of thyroid cancer in the female is 7.24/10 5 and ranked No. 7, while the incidence of thyroid cancer failed to rank in the top 10 in China cancer registries (Zhao et al., 2012).Lung cancer, digestive malignancies and breast cancer were the most common cancers in Zhejiang province in China, these cancers should be focused on.At the same time, the incidence rates of thyroid cancer, prostate cancer, cervical cancer and lymphoma increased, therefore prevention and control should be implemented on these cancers.
The data of Zhejiang cancer registration areas in China shows that the incidence of cancer is rising, and it is consistent with the National cancer intelligence, but some cancer incidence showed slightly higher, such as thyroid cancer and prostate cancer.According to the cancer feature of our province, we should be done: targeting to carry out synthetical prevention, strengthening early diagnosis and treatment of cancer screening work, making basic and clinical research in depth, to further improve the geographical distribution of the province cancer registry, combining prevention with control, so as to effectively control the cancer hazard.
Figure 2. The Changes of Crude Incidence Rate in Zhejiang in China from 2000 to 2009

Age-Specific Cancer Incidence in Zhejiang Province in China from 2000 to 2009 Table 1. Distribution of Total Population and New Incidence Cases in Zhejiang Cancer Registries from 2000 to 2009
Analysis of Cancer Incidence in Zhejiang Cancer Registries in China during 2000 to 2009 DOI:http://dx.doi.org/10.7314/APJCP.2014.15.14.5839