Changing patterns of cancer burden among elderly across Indian states: Evidence from the global burden of disease study 1990–2019

Abstract Objective To investigate the trends and patterns of the cancer burden among the elderly in different regions of India at a subnational level. Methods Data were extracted from the Global Burden of Disease (GBD) Studies India Compare 2019. Prevalence rate, disability‐adjusted life years (DALY), and annual percentage change techniques were used to analyze data. Results The three age groups with the highest prevalence of cancer were those aged 60–64 years, 65–69 years, and 70–74 years. In 2019, The prevalence of cancer among the elderly ranged from 7048.815 in Karnataka to 5743.040 in Jharkhand. Kerala has the most significant annual percentage change in the cancer prevalence rate of 0.291 between 1990 and 2019. The highest DALY rate was observed among individuals aged 80–84 years in 2019. That year, the DALY rate among the elderly was 8112.283 in India. The top five cancers with higher DALY rates among the elderly in India in 2019 were tracheal, bronchus, and lung cancer (908.473), colon and rectum cancer (752.961), stomach cancer (707.464), breast cancer (597.881), and lip and oral cavity cancer (557.637). Conclusion Elderly individuals demonstrated a higher vulnerable to cancer compared to other age groups. There is a need for state‐specific government intervention to minimize the risk of cancer among the elderly due to the heterogeneity in the burden of cancer across Indian states.

as measured by disability-adjusted life years (DALY). 3 Additionally, other studies found a twofold increase in the proportion of cancer in the burden of diseases between 1990 and 2016. Although the agestandardized incidence rate for cancer cases remained unchanged during this period, there was a 2.6-fold change in the burden of the disease in terms of DALY rates across different states in India. 4 In 2011, the incidence of cancer in India reached a total of 1,193,426 cases, with a higher occurrence among females (603,560) compared to males (589,866). It has been forecasted that there will be an estimated 1,869,983 new cancer cases, with 934,268 cases among males and 935,715 cases among females by 2026. 5 Cancer cases can be categorized into two types: infectious and noninfectious. Infectious cancers are stomach cancer, cervical cancer, and liver cancer, while noninfectious cancers are lung cancer and breast cancer. As the country develops, there is a shift in the burden of cancer from infectious to noninfectious causes. Noninfectious cancers are primarily influenced by changes in age distribution and lifestylerelated factors. 6,7 Consequently, the incidence rate of breast cancer has experienced a significant increase of 40. 7% between 1990 and 2016, while the incidence rates of stomach cancer, lip and oral cavity cancer, cervical cancer, and leukemia have shown a declining trend in India. 4 In addition, late marriage and dietary patterns have been identified as potential contributing factors to the rise in breast cancer. [8][9][10][11] Geographical variation in the burden of cancer was observed across different regions of India. 4,12 The prevalence of specific cancers, such as breast, colorectal, and prostate cancer, tends to be higher in industrialized societies. 13,14 The average age at which breast and ovarian cancer typically developed was around 45-50 years in India, which was 10 years younger compared to developed nations where the onset age is typically over 60 years. 15 The incidence rate for ovarian cancer did not substantially increase for individuals aged 30-64 years between 1976 and 2005. 16 Additionally, cervical cancer is the most common cancer among women aged between 30 and 69, accounting for 17% of all cancer-related deaths. 13,14 However, the incidence rate of cervical cancer declined in India over the period. 16,17 Other risk factors such as smoking and physical inactivity are associated with a higher incidence of cancer. 18 The rise in the global elderly population was due to improvements in life expectancy over the past few decades. 19 The elderly had a higher burden of cancer compared to other age groups. 5,18,[20][21][22] Consequently, the growing number of elderly people in India will be expected to contribute to a twofold rise in cancer incidence by the year 2040. 7 The existing research on cancer in India has primarily focused on incidence rates, mortality rates, and the burden of cancer. Although some studies have explored the cancer burden among different states in India, they have been limited to specific years and specific types of cancer. Only one study conducted by Dhillon et al. in 2018 4 used data from the Global Burden of Disease Study (GBD) 2016 to analyze patterns and trends of cancer among all age groups in the states of India. Additionally, the elderly population accounted for 9.15% of the total population in India in 2019, 23 and they experienced the highest incidence rates of cancer. 5 Therefore, the objective of this study is to examine the trends and patterns of the cancer burden among the elderly in different regions of India at a subnational level. The causes of disease are categorized into four levels. Cancer (neoplasms) is located at level three, encompassing all causes of cancer.
Further, level four provides more detailed information on specific causes of cancer, such as breast cancer, stomach cancer, and other causes of cancer. 25 In this study data extracted at levels three and four of the causes of disease spanning from 1990 to 2019 to collect cancer information.
GBD India Compare 26 provided data on the following age groups; 60-64 years, 65-69 years, and 70 years and above. By summing the cancer burden among these three age groups, we obtained the burden of cancer among the elderly. In addition, data on the prevalence of cancer cases and the accompanying DALY associated with cancer have been extracted to estimate the burden of cancer.

| Methods
DALY is a standardized measure that consists of the loss of healthy life years from fatality (YLL) and the loss of healthy life years from nonfatality (YLD). The unit of measurement for DALY is years. One DALY represents the loss of 1 year of healthy life. 25 Murray (1994) 26 and WHO (2020) 27 have described the calculation of GBD data using the following formulas for YLD and YLL: In Equation (2), P x is the number of prevalence cases among age group x, DW is the disability weightage, and L x is the average duration of illness among age group x in years. Disability weightage varies from zero to one. Zero disability weightage shows perfect health and one disability weightage shows death.
In Equation (3), d x is the number of fatality cases in different age groups, and e x = expected standard life loss among different age groups. Expected standard life expectancy can be found by using the "abridged life table." To avoid an overestimation of the disease burden, adjustments should be made for the presence of comorbidity. 27 It was assumed that the prevalence of one disease was independent of the other.
The estimation of comorbidity was adjusted using Equation (4). The GBD India Compare dataset provides information on the total prevalence of cancer cases and the prevalence of cancer cases per 100,000 people within the age groups of 60-64 years, 65-69 years, and 70 years and above. However, for this study, the analysis focused on the elderly. Therefore, it is necessary to sum up the total prevalence of cancer cases across these three age groups to obtain the total prevalence of cancer cases among the elderly.
Additionally, when estimating the prevalence of cancer cases per 100,000 elderly, it is essential to have information on the total population of the elderly. Equation (5) was utilized in this study to obtain the total number of elderly.

(5)
Total population = Total prevalence of cancer cases Prevalence of cancer cases per 100,000 people × 100,000 Prevalence of cancer per 100,000 people = Total prevalence of cancer cases Total population × 100,000 DALY per 100,000 people for cancer = Total DALY for cancer Total population × 100,000

| RE SULTS
The prevalence of cancer per 100,000 people (prevalence rate) continuously increased with age up to 65-69 years and then declined.  1 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 (Table S1). In addition, the statewise unequal spread of the prevalence rate for cancer in 2019 is reflected in Figure 2. The prevalence rate of cancer ranged from 7048.815 in Karnataka to 5743.040 in Jharkhand, as given in Table S2. The trends of the prevalence rate of cancer in terms of the annual percentage change are reflected in Figure 3. The highest annual percentage change in the cancer prevalence rate in Kerala  it began to decline again, as presented in Figure 4 and Table S3.  (Table S4).  (Table S4).
The present study has certain limitations that prevent it from addressing all questions regarding cancer in the elderly. Further detailed studies are required to answer specific questions regarding cancer among the elderly.

AUTH O R CO NTR I B UTI O N S
CKS and HSR conceived the idea. CKS, SP, PKS, and HSR designed the study. CKS and SP collected the required data. CKS, SP, and US analyzed the data. HSR, US, and PKS interpreted the data. CKS and SP wrote the manuscript. All authors critically reviewed the manuscript and approved the final version submitted to Aging Medicine.

FU N D I N G I N FO R M ATI O N
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.