February/March 2011


Issue Home >>

Data collection methods hamper study: Cancer reporting needs to be mandatory

By Vaneisa Baksh

It has come to pass that everyone knows someone with cancer. Daily, lives are disrupted as family, friends and the afflicted are forced to restructure their ways of living to manage its effects.

Oncologist Dr Anesa Ahamad, and Biostatistician, Dr George Legall have recently concluded a study seeking to estimate the causes of breast cancer and the scope for preventive strategies, based on age at diagnosis in Trinidad and Tobago. That study found a 51% increase in breast cancer, which was consistent with the trend of developing countries. However, statistics also show that in developed countries the reverse is happening: cancer figures are decreasing. Further studies must be done so that developing countries can at least begin to understand what factors keep the trend line climbing.

Breast cancer, for instance constitutes one third of all female cancers (men get it too) and occurs twice as frequently as cervical cancer, the second most common. The study noted that while chemicals or pollutants in air, water, food, soil or other material were often cited as major factors in increasing cancers, lifestyles were also closely linked to the trend. Obesity, low physical activity, alcohol intake, delaying childbearing until over 30 or cancelling it altogether, less breast-feeding, use of oral contraceptive pills and use of hormone replacements at menopause all increased the risk, but were modifiable, said the researchers.

They found too that early detection increased survival rates significantly. (See January issue of UWI Today )

In discussing the limitations of the study, the report noted a major constraint for collecting complete data was underreporting of cancer cases by medical institutions.

Ideally, all cancer cases should be reported to the National Cancer Registry of Trinidad and Tobago, but as it is not a legal requirement, it is not mandatory and this leaves frustrating gaps for research and planning, and ultimately affects health policies.

In this particular study, the researchers used data from the National Cancer Registry, which is the only source of population-based cancer data for T&T citizens and residents. For the period from 1995 to 2006, each case of the entire database was examined.

“This comprised 22,704 cases of invasive malignant neoplasms among which no data was available for primary in 718 (3.16%) of cases. No data for race was available for 4207 (18.5%) of all cases. There were 36 cases of breast carcinoma in situ and these were excluded. There were 53 cases of male breast cancer and 3427 cases of female breast cancer diagnosed over the 12-year period, among whom no data for race was available for 439 (10.4%) of cases,” said the report.

The researchers rightly complained that the information then is of “sub optimal quality.” If cancer reporting were to be made mandatory, then the practice of some medical institutions which “do not facilitate collection of data” would be immediately stopped and there would be some measure of standardisation in the data collected.

A strong advocate for mandatory cancer reporting is Veronica Roach, Registrar at the National Cancer Registry, who fully facilitated the research.

“If it is mandatory, it cannot be refused. Some machinery will have to be put in place for the registration of all cases diagnosed in Trinidad and Tobago. As a population-based registry, it will allow us to see all cases of cancer,” she said.

She outlined the process as it is, where registry officers actually visit hospitals, laboratories, cancer centres and other health service units to abstract data (including from death certificates). When they encounter discrepancies or incomplete information, they check with the treating physicians or the reporting pathologist.

But, as in many developing countries where cancer reporting is not compulsory, resources are scarce to do this kind of investigation, and many institutions are willing to help only when it is convenient to do so.

In September 2007, at a special CARICOM meeting called to address the increase in chronic non-communicable diseases (CNCD), the Port of Spain Declaration: Uniting to Stop the Epidemic of Chronic Diseases, was signed. This approved a programme to tackle CNCD.

Members of CARICOM agreed on several points of action, one being: “That we will establish, as a matter of urgency, the programmes necessary for research and surveillance of the risk factors for NCD with the support of our Universities and the Caribbean Epidemiology Centre/Pan American Health Organisation (CAREC/PAHO).”

Following this meeting, a national population-based registry for stroke, acute myocardial infarction (AMI or heart attack) and cancer was formed in Barbados by the Ministry of Health in partnership with The UWI: the BNR, the Barbados National Registry for Chronic Non-Communicable Diseases.

Rhea Harewood, Registrar for the BNR-Cancer, noted that improving patient care relies on accurate data collection. “Health policy changes do occur, but you have to have data to demonstrate the need for interventions,” she said. The cancer registry has only been collecting data since July 2010 and will need two years of data before interventions can be made, but cancer reporting has been made mandatory.

The figures keep rising in developing countries, but they are falling in the developed ones. Data collection and research are obvious requisites of formulating policies and devising preventive measures to manage cancer. How can expensive projects such as the planned National Oncology Centre and National Cancer Control Programme be relevant and appropriate to the nation if they are not based on reliable, comprehensive information? Mandatory cancer reporting has been recommended in the Draft National Cancer Plan that is under consideration by the Ministry of Health. It would certainly help researchers to find out how to tailor efforts towards reducing the occurrence of cancers.

–This research was conducted by a team based at the Department of Paraclinical Sciences, Faculty of Medical Sciences, UWI, St. Augustine: Anesa Ahamad. Oncologist and Senior Lecturer and George Legall, Biostatistician and Lecturer, School of Basic Health Science. An extract was carried in the January 2011 issue of UWI Today.

(The Port of Spain Declaration: Uniting to Stop the Epidemic of Chronic Diseases)