and early
detection are
shown to
reduce
cancer
mortality
Moreover, several weaknesses are inherent to the planning process within the domain of cancer prevention and control in Pakistan.
Table 7.1 Strategies for the eight most common cancers in Karachi – females
Tumour ? ASIRs Frequency
%
Primary prevention
Early diagnosis
Curative therapy
Pain relief/
palliative care
Breast? 69.1 34.6 + + + ++ ++
Mouth/pharynx? 23.5 17.4 + + + ++ ++
Cervix? 8.6 4.1 + ++ ++ ++
Oesophagus 8.6 3.7 + - - ++
Ovary 7.8 4.2 + - - ++
Lymphoma 7.2 3.5 + + ++ ++
Gall Bladder 5.8 2.6 ++ ++ ++ ++
Skin? 5.6 2.6 ++ ++ ++ ++
Total 72.7
? Listed in order of the eight most common tumours globally
? Curative for the majority of cases provided they are detected early + + effective; + partially effective; - not effective
There is an explicit understanding that clear benefits exist with implementing a cancer prevention and control strategy, regardless of the fiscal situation of the country since evidence-based guidelines exist to ensure the most efficient use of existing resources. Specific Action Agenda items on cancer prevention and control as part of this Action Plan have, therefore, evolved in the light of this evidence. Within this framework, prevention and control of cancers in Pakistan will be discussed under two broad categories – mitigating exposure to risk and early detection or screening as they relate to individual cancers.
Table 7.2 Strategies for the eight most common cancers in Karachi – males
Tumour ? ASIRs Frequency
%
Primary prevention
Early diagnosis
Curative therapy
Pain relief /palliative
care
Mouth/pharynx? 30.7 17.4 ++ + ++ ++
Lung 25.5 11.7 ++ - - ++
Larynx 11.8 6.1 ++ + ++ ++
Urinary bladder? 9.9 4.8 ++ + ++ ++
Prostate 9.8 4.1 + + ++ ++
Lymphoma 9.6 7.0 + + ++ ++
Colon/rectum? 7.8 4.4 + - + ++
Oesophagus 6.3 3.7 + - - ++
Total 59.2
? Listed in order of the eight most common tumours globally
? Curative for the majority of cases provided they are detected early + + effective; + partially effective; - not effective
The following section deals with cancers that are preventable by way of minimizing exposure to risks such as in the case of tobacco and areca nut-related cancers, whereas the subsequent section deals with cancers where the potential for prevention exists through early detection as in the case of breast and cervical cancers. In the former case, the emphasis will be on risk
reduction whereas in the latter, early detection strategies will be discussed in the context of individual cancers. However, in many cancers a combination of both these approaches is relevant.
7.4.1 Risks for cancer
Prevention means eliminating or minimizing exposure to risks. Risks to cancer may be lifestyle, occupation or environment-related. Table 6.1 lists factors that have epidemiological associations with cancers in western populations. These need to be validated in the Pakistani context. There is, therefore, the need to conduct appropriate studies so that precise targets for preventive interventions can be determined.
Table 7.3 Factors epidemiologically associated with cancers
Risk factors Cancers ENVIRONMENTAL
Areca nut ? Oral cavity, pharynx
Diet Breast, oesophageal and colorectal, oral, gastric Physical activity Breast and colo-rectum
Tobacco Lung, oral cavity, larynx, pharynx, oesophagus, urinary bladder Overweight and
obesity
Oesophagus, colo-rectum, breast, endometrium and kidney
Alcohol Oral cavity, pharynx, larynx, oesophagus, liver and breast Hepatitis B and C Liver
Human papilloma virus
Cervical
Helicobacter pylori Gastric, maltoma
Aspergillus (aflatoxin) Liver and as a co-risk factor for oral cavity OCCUPATIONAL
Aniline dyes Urinary bladder
Asbestos Lung, pleura and peritoneum
Benzene Leukemia
Uranium Lung
Chromium Lung
Vinyl chloride Liver, angiosarcoma, bladder OTHERS
Gall stones Gall bladder
? Epidemiological association established in Pakistan
7.4.2 Lifestyle risks for cancer
7.4.2.a Tobacco: tobacco is the single largest preventable risk factor for cancer, accounting for 30% of the cancer-related deaths in the developing countries.217 Section 5 discusses tobacco control.
7.4.2.b Diet, physical activity and obesity: diet, physical activity, overweight and obesity have been described as preventable risk factors for CVD and cancer in western populations. Their association with cancers in Pakistan needs to be determined so that appropriate preventive strategies can be developed.
7.4.2.c Alcohol: alcohol does not feature as a major public health issue in Pakistan. However, the trend of alcohol consumption is anecdotally known to be high in the higher socio-economic class. The magnitude of alcohol use needs to be determined in Pakistan.
7.4.2.d Areca Nut: areca nut leads to submucus fibrosis (SMF); 7.6 % of the cases of SMF develop squamous cell carcinoma of the oral cavity.218 The use of areca nut is largely specific to south Asia and a few other parts of the world with south Asian settlements. In Pakistan, its use is commoner in the south, particularly within the Urdu-speaking population. Areca nut is not grown in Pakistan; it is imported from Indonesia and India and during its transportation, is likely to be contaminated with aspergillus and other biological contaminations, which are hypothesized as being carcinogenic.
Within Pakistan, areca nut imports, distributions and retailing is not regulated despite clear evidence of its causal associations with cancer.218,219 In order to avoid exposure to this carcinogen, legislative measures must be enacted and effectively enforced to regulate its import and ensure that arriving
consignments are not contaminated; alongside, efforts should be initiated to diversify livelihoods of those dependent on areca nut retailing. Health education efforts should aim to step up oral self-examination. In addition, healthcare providers must be sensitized to the need to examine oral cavities of all, particularly the high-risk groups, for suspicious lesions.
Awareness needs to be created about risks to cancer in general. However there are presently no comprehensive health education initiatives focused on cancer prevention and control. The only effort at the national level has involved a mini electronic media intervention by the National Programme for Family Planning and Primary Health Care/Health Education Department involving 100 television spots aired for a duration of 52 seconds at a time, in the last five years.220 These television spots drew public attention to the early warning signs of cancer. However, this is not a sustainable activity as prevention of cancers is presently not part of the programme’s mandate.
Cancer associations and societies have also been involved in ad hoc efforts to develop patient information materials in selected hospitals; these efforts remain isolated without recognizable impact. It is, therefore, important that a comprehensive health education programme addressing lifestyle and
environmental risks to cancer be developed. Cancer prevention must be integrated with the NCD behavioural change communication strategy.
Healthcare providers at all levels need to be trained to reinforce health education messages and to play a role in creating awareness about early