Population based cancer registry-trends of cancer in Bengaluru rural district

Introduction

Population based cancer registry (PBCR) provides incidence rates and distribution of various cancers in a well-defined population, the emphasis in a PBCR is on the epidemiology and public health. Data on every individual with cancer in a defined population is collected in a population-based cancer registry. Co-operation between medical profession and health care services is pivotal to its success.¹

The National Cancer Registry Programme (NCRP) established in 1982 has given us an idea of the magnitude and pattern of cancer in selected urban centres and in a couple of rural pockets.² The Population Based Cancer Registry at Kidwai Memorial Institute of Oncology (KMIO) was established during June 1981 and included in the NCRP from 1982, with the main objective of assessing the magnitude, incidence and type of various cancers in Bengaluru, and to provide a framework for controlling the impact of cancer in the community apart from carrying out research investigations on cancer etiology through epidemiological studies.About 40% of the cases registered in PBCR are from KMIO. The HBCR records more than 17,000 new cases annually.³

The registry covers Bengaluru Urban District which consists of 198 wards and 38 death registration units; Bengaluru Urban District has an area of 741km2 with an estimated population of 7.9 million as of 2011. The following study was conducted to assess the magnitude, incidence, and type of various cancers in Bengaluru rural district.

Materials and Methods

Community based cross-sectional study was conducted in rural field practice area. The first part of the core proformae – namely, sociodemographic details of the patients are entered into the computer at the time of registration at KMIO as new cases. The second part – namely, diagnostic and treatment details are extracted later from the cases records. The completed proformae are then scrutinized by the senior staff of the Registry in consultation with the medical faculty, wherever necessary. On completion of this core proformae including coding of sites as per the International Classification of Diseases for Oncologyand International Classification of Diseases, data will be entered into the computer. This data is then checked for validity and consistency the software programme provided by NCRP. This data was then analysed using SPSS version 20.0.

Results

A total number of 1,19,727 cases of cancers were reported to the NCRP by the PBCR of Bengaluru since the beginning of Cancer Registry from1982 through 2011.

All new cases of cancer diagnosed in a defined population during a specified period are considered as incident cases. Hence all new cases of cancer diagnosed in the defined area of Bengaluru Urban District during the year 2007-2011 (1st Jan to 31st Dec) formed the incident cases. A total number of 51,346 cases (including DCOs) have been registered as incident cases during this period with 15983 males and 35363 females.

Compared to the cases registered during the year of commencement of the registry in 1982 the number of cancer cases in Bengaluru showed an increasing overall 260% change was observed in 2011 compare to base year in males 264% and in females 256% change observed . In age adjusted rate increased substantially in males 35.6% in females 21.0% change in age adjusted rates in 2011 compare to 1988.

During the year 2012, a total number of 17664 new cases were registered, out of which 9432 (51.0 %) cases were confirmed as cancer cases, with the male /female ratio of 1:1.2.Table 2 gives percentage increase in cancer cases between 1984 to 2012. Overall 73% increase is observed and almost same proportion change is seen in males and females.

Districtwise distribution of cases showed that majority of patients were from Bengaluru District 21.4% where KMIO is located. About 17.0% cases were from outside Karnataka as shown in Table 3.

We found that the Peak age Group at diagnosis was 60-64 years in males and 45-49 years for females as shown in Table 4 and Table 5.

The first ten leading sites of cancers accounted for 70 % of the total cancers in males and 80 % of the total cancers in females. Table 6& Table 7 provide details of ten leading sites of cancer among males and females.

Cancer of the cervix uteri continues to be the most predominant site of cancer and accounted for 28.6 % of all cancers in females followed by cancer of the breast as the second most common site (15.4 %), cancers of oral cavity (10.9%), ovary (5.4 %) and oesophagus (4.5%). Over the years, a gradual decrease in the proportion of cervical cancers and a marginal but steady increase in the numbers and relative proportion of breast cancers is observed.

A total of 412 cases of childhood cancers (Age group 0-14 years) were registered accounting to 4.5% of all cancers. The relative proportion according to broad types of childhood cancers shows that Leukaemia is the predominant (Male: 48.2% Female: 42.0) followed by CNS 14.8% in males and 16.6% in females (Table 8).

Out of 50 villages surveyed 36 cases of carcinoma were found, out of which 16 were male(44.45%) and 20 were female(55.55%). The patterns of cancer found is shown in Table 9 

Discussion

In our study compared to the cases registered during the year of commencement of the registry in 1982 the number of cancer cases in Bengaluru showed an increasing overall 260% change was observed compared to base year in males 264% and in females 256% change observed, this is more than that observed in regional cancer center (RCC) Thiruvanthapuram where a 253% increase was seen since its inception 1982.⁴

The leading cancer site in males in our study showed oral cavity at 13.6% followed by pharynx at 10.8% while in females cancer cervix at 28.6% was the leading site followed by cancer breast at 15.4%. This contrasts with RCC Thiruvanthapuram where the leading site in males was lung cancer at 14.5 followed by oral cavity at 14.2%. While in females the leading site was breast at 29.8% followed by thyroid. The difference maybe due to numerous geographical and environmental factors. While the leading site for cancer in children, that is leukemia was the same in both centers.⁴

Conclusion and recommendations

As the incidence of cancers keep rising, it is imperative that we keep track of the shifting trends of cancer, and population based cancer registries are a very good method to look back and assess which cancer is on the rise and what policies or lifestyles changes are required to tackle them.