Keywords
cancer incidence - age distribution - gender distribution - high-incidence regions
- public health strategies
Introduction
Cancer, as defined by Holland,[1] is a disease characterized by the uncontrolled division of abnormal cells that invade
surrounding tissues, potentially leading to death if left untreated.[2] There are more than 200 distinct types of cancer, typically named after the organ
or cell type of origin. A hallmark of cancer cells is their reduced adhesion compared
with normal cells,[3]
[4] which facilitates detachment and dissemination to other body parts via the blood
or lymphatic system. This process, known as metastasis, results in the formation of
new neoplasms called metastatic tumors.
Several behavioral factors are associated with cancer incidence, screening, recurrence,
and mortality. For example, cigarette smoking significantly contributes to mortality
rates of various cancers, including those of the lung, oral cavity, esophagus, larynx,
bladder, stomach, pancreas, kidney, and cervix.[1]
Cancer is emerging as a significant public health concern in India, including in Himachal
Pradesh. India ranks third globally in estimated new cancer cases, with 1.2 million
diagnoses in 2018, and second in cancer-related deaths, with 785,000 mortalities that
year. According to the Global Cancer Observatory (GLOBOCAN, 2018), the age-standardized
rates per 100,000 people were 89.4 for cancer incidence and 61.4 for cancer mortality.
Cancer can affect any part of the body and individuals of all ages, although the risk
generally increases with age, particularly from middle age onwards. The incidence
rates quadruple between ages 40 and 80 for all cancer types combined.[5]
[6]
Breast cancer is the most common form of cancer affecting both men and women. In India,
the most prevalent cancers among men are oral cancer (age-standardized rate: 13.9),
lung cancer (7.8), stomach cancer (6.2), colorectal cancer (5.8), and esophageal cancer
(5.5%). Among women, the most prevalent types are breast cancer (24.77), cervical
cancer (14.77), ovarian cancer (5.55), oral cancer (4.33), and colorectal cancer (3.11).
The incidence rates of various cancers vary significantly across Indian regions, with
a minimum fivefold difference for any cancer type.[7]
[8] Approximately 18.1 million individuals worldwide live with cancer (National Cancer
Institute, 2020). Lung, stomach, liver, colon, and breast cancer cases cause the most
cancer deaths annually. Cancer is a major public health burden in both developed and
developing countries, with approximately 70% of all cancer deaths in 2020 occurring
in low- and middle-income countries (World Health Organization International Agency
for Research on Cancer, 2020). In India, approximately 850,000 new cancer cases are
diagnosed annually, with approximately 580,000 cancer-related deaths each year.[9]
There is an alarming increase in cancer cases in Himachal Pradesh, with approximately
8,500 cases detected annually, although many cases are unnoticed in remote areas (Times
of India, 2023). Himachal Pradesh, with its rural charm, represents a unique context
for studying cancer burden. Predominantly rural, 89.97% of its population lives in
rural areas. Health indicators show that Himachal Pradesh performs better than other
states, with a crude birth rate of 15.4, a crude death rate of 6.9, an infant mortality
rate of 19, and a total fertility rate of 1.6.[10]
Despite these favorable indicators, the state's increasing incidence of cancer, attributed
to tobacco use, lifestyle patterns, environmental risks, and genetic predispositions,
presents significant public health challenges. In rural Himachal Pradesh, limited
health care access exacerbates the cancer burden, complicating life for individuals,
families, and communities. The state has 12 districts, each with a chief medical officer
and divided into 75 health blocks, each led by a block medical officer. The health
institutions included 3 zonal hospitals, 9 district/regional hospitals, 6 teaching
hospitals, 79 civil hospitals, 93 community health centers, 585 primary health care
centers, and 2,085 health subcenters.
Shimla district, with a population of 814,010 (2011 census), predominantly rural (75%),
has a sex ratio of 916 females per 1,000 males and a literacy rate of 83.64%. Given
the growing cancer burden, it is crucial to study cancer trends in Himachal Pradesh
to inform advanced control measures. The present study aimed to examine the age and
gender trends of cancer patients in rural Shimla district, Himachal Pradesh, India.
Methods
The present study employed a retrospective observational design to examine age and
gender trends among cancer patients in rural Shimla, Himachal Pradesh, India. Cancer
data were sourced from the Regional Cancer Hospital, Indira Gandhi Medical College,
Shimla, for the period 2014 to 2022 as part of the Hospital-Based Cancer Registry.
The inclusion criteria included confirmed cancer diagnoses in rural residents of Shimla
district, excluding urban residents and nonresidents of Himachal Pradesh. The recorded
demographic factors included age (below 11 years and 68 years and above), place of
residence, gender, cancer type, and stage at diagnosis (classified as “early” for
stages I and II or “advanced” for stages III and IV).
Results and Discussion
The present study addresses the following research questions:
Age-Wise Distribution of Cancer Patients
The data on the frequency of cancer incidence across different age groups provide
a clear illustration of the relationship between age and cancer risk. A detailed analysis
and interpretation of the data are provided below.
[Table 1] clearly indicates that the frequency of cancer incidence increases significantly
with age. This trend is particularly evident when examining the cumulative percentage
of cases in each age group. Older adults (those aged 58 years and above) had the highest
frequency of cancer incidence. The 58 to 67 years and 68 years and above age groups
together accounted for 2,142 patients, 57.2% of the total patients.
Table 1
Age-wise distribution of cancer patients in rural areas of Shimla district
|
Age
|
Frequency of incidence
|
%
|
|
Blow 11 y
|
16
|
0.4
|
|
12–17 y
|
22
|
0.6
|
|
18–27 y
|
99
|
2.6
|
|
28–37 y
|
194
|
5.2
|
|
38–47 y
|
456
|
12.2
|
|
48–57 y
|
814
|
21.7
|
|
58–67 y
|
1,111
|
29.7
|
|
68 and above
|
1,031
|
27.5
|
|
Total
|
3,743
|
100
|
The incidence of cancer in middle-aged adults (38–57 years) has notably increased.
Individuals aged between 38 and 57 years, accounted for 1,270 patients, 33.9% of the
total patients. The incidence rate of young adults (18–37 years) has begun to increase,
with 293 cases or 7.8% of the total cases occurring in individuals aged 18 to 37 years.
Among individuals younger than 18 years, children and adolescents (younger than 18
years) had a low frequency of cancer, accounting for only 38 cases or approximately
1.0% of the total cases.
Age-Wise Trend of Cancer Patients in Each Block
The data are presented in [Fig. 1] and the corresponding graph illustrates the distribution of cancer cases across
various age groups in different regions. The analysis is as follows:
Fig. 1 Age-wise trend of cancer patients in each block of the Shimla district.
[Fig. 1] shows that there is a clear trend toward increasing cancer incidence with advancing
age. The number of cases was minimal in the youngest age groups and increased significantly
from 28 years onwards, peaking in the 58 to 67 years age group. Theog consistently
reported the greatest number of cases across all age groups, particularly those aged
38 years and older. Rampur and Jubbal and Kotkhai also had high incidences, especially
in the middle to older age groups. Regions such as Chopal, Rohru, and Chirgaon exhibited
a lower but still significant number of cases, particularly in older age groups.
Chi-Square Test Showing the Association between Age and Gender
The distribution of cancer cases by age and gender was significantly different according
to the chi-square test. The analysis is as follows:
[Table 2] shows gender differences in younger age groups (< 17 and 18–27 years); females tended
to have higher cancer incidences than males did. In the middle aged group (aged 28–57
years), females had a greater incidence of cancer than males did. In older age groups
(those aged 58 years and older), the trend reversed, with males showing higher cancer
incidences than females. However, for both sexes, the incidence of cancer increased
significantly with age, peaking in the 58 to 67 years age group and slightly decreasing
in the 68 years and older age groups. The substantial increase in cancer cases in
middle-aged and older adults highlights the need for targeted screening and early
detection efforts in these age groups. The chi-square value (= 180.18) indicated a
statistically significant difference in cancer incidence according to age and gender.
This high value suggests that the distribution of cancer cases is not uniform across
age groups or between genders.
Table 2
Chi-square test showing the significance of differences between age and gender
|
Age
|
Gender of cancer patients
|
Total
|
Chi-square
|
|
Male
|
Female
|
|
< 17 y
|
24
|
14
|
38
|
180.18[a]
|
|
18–27
|
35
|
64
|
99
|
|
28–37
|
80
|
114
|
194
|
|
38–47
|
149
|
307
|
456
|
|
48–57
|
334
|
480
|
814
|
|
58–67
|
602
|
509
|
1,111
|
|
68 and above
|
654
|
377
|
1,031
|
|
Total
|
1,878
|
1,865
|
3,743
|
a
p < 0.01.
Conclusion
The comprehensive analysis of cancer incidence in Himachal Pradesh reveals crucial
insights into the distribution of cases across age groups, genders, and regions, informing
public health strategies and resource allocation. The data indicate a significant
increase in cancer incidence with age, peaking in the 58 to 67 years age group, and
highlight a noticeable increase in cases starting from 28 years onwards. This underscores
the necessity for targeted cancer screening and early detection programs, particularly
for older adults.
The nearly equal distribution of cancer cases between males (50.1%) and females (49.9%)
suggests that cancer affects both genders similarly, emphasizing the need for gender-neutral
public health interventions. Significant regional disparities are evident, with Theog,
Rampur, and Jubbal and Kotkhai reporting the highest number of cases, collectively
accounting for nearly half of the total cancer burden. Conversely, blocks such as
Kupvi exhibit the lowest incidence rates. The chi-square analysis confirmed a statistically
significant difference in cancer incidence by age and gender, but not by regional
distribution within genders.
Based on these findings, several strategic initiatives are recommended: prioritizing
health care resources in high-incidence regions to ensure equitable access; implementing
widespread and regular cancer screening for high-risk age groups (38 years and older);
conducting region-specific educational campaigns focusing on lifestyle changes, early
detection, and cancer prevention; involving technical experts to educate rural populations
on safe pesticide and chemical use; and strengthening surveillance systems to monitor
cancer trends and evaluate intervention effectiveness.
The present study underscores the need for age-specific, gender-neutral, and region-specific
public health strategies to manage and mitigate the cancer burden in Himachal Pradesh
effectively. By focusing on high-incidence regions and ensuring equitable health care
access, public health systems can improve cancer outcomes and reduce mortality rates
associated with the disease.
