Chapter 27: Cancer survival in Lampang, Thailand, 1990-2000
Martin N, Pongnikorn S, Patel N and Daoprasert K
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The registry is contributing data on survival from 40 cancer sites or types for the first time in this volume of the IARC publication on Cancer Survival in Africa, Asia, the Caribbean and Central America.
The closing date of follow-up was 31st December 2003. The median follow-up time ranged from less than one month in unspecified leukaemia to 74 months for non melanoma skin cancer. Complete follow-up information at five years from the incidence date ranged from 96–100%.
The 5-year age-standardized relative survival (ASRS) probability for all ages together is generally less than or similar to the corresponding unadjusted one for most cancers. Also, the 5-year ASRS (0–74 years of age) is generally higher than or similar to the corresponding ASRS (all ages) for a majority of cancers.
Abstract
The Lampang cancer registry was established in 1995, with retrospective data collection since 1988. Cancer registration is currently done by passive methods. The registry is contributing data on survival for 40 cancer sites or types registered during 1990–2000. Follow-up has been carried out by passive and active methods with median follow-up ranging from 1–74 months for different cancers. The proportion having a histologically verified diagnosis for various cancers ranged between 30–100%; death certificate only cases (DCOs) comprised 0–33%; 67–100% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 96–100% for different cancers. The 5-year age-standardized relative survival rate was the highest for skin non-melanoma (85%) followed by lip (81%), thyroid (74%), corpus uteri (71%) and penis (71%). The 5-year relative survival by age group showed a fluctuating trend. An overwhelmingly high proportion of cases were diagnosed with a regional spread of disease, ranging from 35–68% for different cancers, and survival was decreasing with increasing extent of disease for most cancers studied.Lampang cancer registry
The Lampang cancer registry was established in 1995 in the Lampang Cancer Centre, Lampang, under the supervision of the National Cancer Institute for cancer prevention and control in the northern part of Thailand. The population-based cancer registration started with retrospective data collection on cancer incidence and mortality from 1988. The registry contributed data to the quinquennial IARC publication Cancer Incidence in Five Continents for the first time in Vol VIII[1]. Data collection for the years 1988–1993 was done by active methods. Cancer registration is currently done by the passive method of notification from 21 sources comprising cancer centres, hospitals in the government and private sectors, provincial public health services and pathological laboratories[2]. The registry covers an area of 12 534 km2 and caters to a mixed urban and rural population of about 0.8 million with a sex ratio of 1004 females to 1000 males in 2000. The average annual age-standardized incidence rate is 180 per 100 000 among males and 155 per 100 000 among females, with a lifetime cumulative risk of one in 6 of developing cancer for both sexes in the period 1993–1997. The top-ranking cancers among males are lung, liver and colon, and among females, the order is lung, cervix and breast.| Map. Map showing location of Lampang, Thailand Click here to open map (PDF format) |
Data quality indices
The proportion of cases having a histologically verified cancer diagnosis in our series is 71%, varying from 30% in liver cancer to 100% in skin melanoma, lymphomas and leukaemias. The proportion of cases registered as death certificates only (DCOs) was 6%, ranging between nil for many cancers and 33%, for bone cancer. Cases excluded without any follow-up are negligible. The exclusion of cases from the survival analysis is the greatest among bone cancer (33%) while none were excluded from many cancers. Thus, 67–100% of the total cases registered are included in the estimation of the survival probability. | Table 1. Data quality indices - Proportion (%) of histologically verified and death certificate only cases, number and proportion of included and excluded cases by site, Lampang, Thailand, 1990–2000 cases followed-up until 2003 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Outcome of follow-up
Follow-up has been carried out by passive and active methods. These included notification of cancer mortality information from the Lampang provincial public health service records. The mortality data are matched with the incident cancer database. Unmatched incident cases are then subjected to one or more of the following to obtain vital status information: repeated scrutiny of records in the respective sources of registration, postal enquiry and house visits.The closing date of follow-up was 31st December 2003. The median follow-up time ranged from less than one month in unspecified leukaemia to 74 months for non melanoma skin cancer. Complete follow-up information at five years from the incidence date ranged from 96–100%.
 | Table 2. Number and proportion of cases with complete / incomplete follow-up and median follow-up (in months) by site, Lampang, Thailand, 1990–2000 cases followed-up until 2003 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Survival statistics
All ages and both sexes together
The top-ranking cancers in terms of 5-year relative survival are non-melanoma skin (85%), corpus uteri (73%), lip (73%), thyroid (67%) and penis (65%). The lowest survival rate is encountered in ill-defined digestive organs (1%) followed by unspecified leukaemia (11%). Major salivary gland (62%) and tonsil (44%), among other head and neck cancers, and colon (39%) and rectum (38%), among gastrointestinal cancers, have higher survival than others. Survival from cancers of the urinary system is 47% for urinary bladder, 37% for kidney and 27% for renal pelvis. Hodgkin and non-Hodgkin lymphoma have similar survival (42%). The survival figures for leukaemias are 40% for lymphoid, 33% for myeloid and 11% for unspecified.The 5-year age-standardized relative survival (ASRS) probability for all ages together is generally less than or similar to the corresponding unadjusted one for most cancers. Also, the 5-year ASRS (0–74 years of age) is generally higher than or similar to the corresponding ASRS (all ages) for a majority of cancers.
 | Table 3. Comparison of 1-, 3- and 5-year absolute and relative survival and 5-year age-standardized relative survival (ASRS) by site, Lampang, Thailand, 1990–2000 cases followed-up until 2003 Click here to open table (PDF format) Click here to open comparative statistics by registry |
 | Figure 1a. Top ten cancers (ranked by survival), Lampang, 1990–2000 Click here to open figure (PDF format) Click here to open graph for all the cancer sites |
Sex
 | Table 4a. Site-wise number of cases, 5-year absolute and relative survival by sex, Lampang, Thailand, 1990–2000 cases followed-up until 2003 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Male
The top five cancers ranked on the 5-year relative survival are non-melanoma skin (86%), lip (73%), penis (65%), testis and prostate (63%). Survival from tongue and kidney is markedly higher among males than females. | Figure 1b. Top five cancers (ranked by survival), Male, Lampang, 1990–2000 Click here to open figure (PDF format) Click here to open graph for all the cancer sites |
Female
The highest 5-year relative survival is observed in non-melanoma skin (84%), followed by corpus uteri (73%), lip (73%), thyroid (72%) and major salivary gland (67%). Survival probabilities for cancers of the breast, cervix and ovary are 65%, 64% and 50%, respectively. The survival is noticeably higher among females than males in cancers of the salivary gland, tonsil, hypopharynx, bone, connective tissue, renal pelvis and thyroid. | Figure 1c. Top five cancers (ranked by survival), Female, Lampang, 1990–2000 Click here to open figure (PDF format) Click here to open graph for all the cancer sites |
Age group
The 5-year relative survival by age group reveals an inverse relationship: a decreasing survival with increasing age at diagnosis for cancer of the vulva only. In the rest, it is observed to be fluctuating. | Table 4b. Site-wise number of cases, 5-year absolute relative survival by age group, Lampang, Thailand, 1990–2000 cases followed-up until 2003 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Extent of disease
An overwhelmingly high proportion of cases among the few selected cancers with reliable information on extent of disease are diagnosed with a regional spread of disease, ranging from 68% for tongue cancer to 35% for ovarian cancer. In colon cancer, 44% are classified under regional and one third under distant metastasis. The extent of disease was unknown in 4–14%. The 5-year absolute survival by extent of disease generally follows a trend: highest survival for localized disease followed by regional and distant metastasis for cancers of larynx, breast, cervix and ovary. | Table 5. Proportion (%) of cases and 5-year absolute survival by extent of disease and site, Lampang, Thailand, 1990–2000 Click here to open table (PDF format) Click here to open comparative statistics by registry |
 | Figure 2a-2h. Absolute survival from selected cancers by extent of disease: Lampang, Thailand Click here to open figures (PDF format) |
 | Figure 2a. Absolute survival by extent of disease: Lampang, Thailand: cancer of the tongue Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2b. Absolute survival by extent of disease: Lampang, Thailand: cancer of the oral cavity Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2c. Absolute survival by extent of disease: Lampang, Thailand: cancer of the colon Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2d. Absolute survival by extent of disease: Lampang, Thailand: cancer of the rectum Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2e. Absolute survival by extent of disease: Lampang, Thailand: cancer of the larynx Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2f. Absolute survival by extent of disease: Lampang, Thailand: cancer of the breast Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2g. Absolute survival by extent of disease: Lampang, Thailand: cancer of the cervix Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 2h. Absolute survival by extent of disease: Lampang, Thailand: cancer of the ovary Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
References
- Parkin DM, Whelan SL, Ferlay J and Storm H. Cancer Incidence in Five Continents, Vol I to VIII: IARC Cancerbase No. 7. IARCPress, Lyon, 2005.
(link to CI5) - Pongnikorn S, Martin N, Pornruangwong W, Daoprasert K. Cancer Incidence and Mortality in Lampang, Thailand, 1990–2000, Vol. III. Lampang Cancer Centre, Lampang, 2004.