SPECIFIC SITES OF CANCER
The following pages provide a summary of some statistical and scientific details on specific sites of cancer. The sites are as per the International Statistical Classification of Diseases (WHO: ICD-10, 1994), and not grouped by system, mainly because of easy comparability of incidence rates with cancer registries throughout the world.
In giving an account of the individual sites (according to ICD-10) of cancer in this chapter, the succeeding guidelines have been followed for selecting the specific sites: Those sites where at least five districts show a higher MAAR than the highest MAAR of that site in the PBCRs under NCRP. A site is also included for description if the MAAR of that site in any district is comparable with the highest incidence rates in the world. Sites of cancer with less than ten cases, even if they have higher MAARs than that of the highest MAARs in the PBCRs are excluded from the bar charts so as to avoid overestimation or misinterpretation. However, in order to place the facts in right perspective the appropriate shades of colour depending on the MAAR are portrayed for districts regardless of the numbers of cancers of that site (except for oropharynx, because of numerous  districts). The latter would also account for districts with small populations and identify potential hot spots of high incidence that could possibly sustain over time. The bar charts and map that impart a pictorial representation are in themselves self-explanatory. Thus, only brief textual description is provided.
Two bar charts and an incidence rate graded and colour shaded district-wise map of India form the basis of the textual description. The first bar chart gives the comparison of the age adjusted incidence rates per 100,000 persons (AAR) of the specific site of cancer in registries in the continents of the world. The reference manual is Cancer Incidence in Five Continents (Parkin et al, 2002). The highest and lowest AAR (average annual of 1993-97) in each of these continents is compared with corresponding AAR (average annual of 1997-99) in the six Population Based Cancer Registries (PBCRs) under the NCRP (blue bars). Since Indians in Singapore have somewhat similar rates the bar chart depicting the AAR for Indians from that registry is also included. The second bar chart gives the comparison of the minimum age adjusted incidence rates per 100,000 persons (MAAR) of the specific site of cancer. The comparison is made between the first 30 districts in India in the order from the highest MAAR for the said site of cancer and the MAAR (average annual of 1997-99) of that site in the PBCRs under the NCRP. A map of India with the 593 districts displayed as units is also portrayed. Depending on the MAAR (higher of MAAR between 2001-2002) of that site for a given district, graded shading, of each of the districts is done. The higher the MAAR the darker the shade. Where data is sparse gray shading is done. Districts with MAAR higher than the highest MAAR amongst the PBCRs are labelled (with values of MAARs in parentheses).
The time periods or the calendar years referred for giving the AAR and the MAAR are indicated above in parentheses. These show variation, but are the latest data that are available. It may be noted that in the preceding chapter (Chapter 5), the average annual rates for the years 2001 and 2002 has been used in most districts for depicting leading sites of cancer, as that is more appropriate for expressing the relative proportions of the common sites.