Chapter 18: Cancer survival in Manila, Philippines, 1994-1995
Laudico A and Mapua C
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The registry has contributed data on survival from cancers of the breast, cervix, colon and rectum for the first time in this volume of the IARC publication on Cancer Survival in Africa, Asia, the Caribbean and Central America. A random sample of 1300 cases out of the total incident cancers in 1994–1995 comprising about 500 cases each of female breast and cervix cancers (stratified by age) and 300 cases of colorectal cancers (stratified by age and sex) form the material for this study.
The closing date of follow-up was 31st December 2002. The median follow-up ranged from 15 months in cervix cancer to 33 months in breast cancer. Complete follow-up at five years from the incidence date was available in 75–82% of cases. The losses to follow-up have generally occurred in large numbers in the first year of follow-up and decreased through successive intervals of follow-up time.
Abstract
The population-based cancer registry in Manila, Philippines, called the Philippine Cancer Society-Manila Cancer Registry, was established in 1983. Cancer registration is pursued by active methods. The registry contributed survival data on a random sample of total incident cancers of breast (500), cervix (500), colon and rectum (300) registered in 1994–1995. Follow-up has been carried out by passive and active methods, with median follow-up ranging between 15–33 months for different cancers. The proportion of histologically verified diagnosis for various cancers ranged between 78–88%; 74–83% of the total submitted cases were included for survival analysis. Complete follow-up at five years was available in 75–82% of cases. Five-year age-standardized relative survival rates was the highest for cancer of the breast (52%) followed by colon (49%), cervix (36%) and rectum (31%). Five-year relative survival by age group did not display any pattern or trend and was fluctuating. A decreasing survival with increasing extent of disease was noted for all cancers.Philippine cancer society-Manila cancer registry
The population-based cancer registry in Manila called the Philippine Cancer Society-Manila Cancer Registry (PCS-MCR), was established in 1983 as an offshoot of the then ongoing cancer registration activity under the central tumour registry of the Philippines since 1968. PCS-MCR has been contributing data to the quinquennial IARC publication Cancer Incidence in Five Continents since Vol VI[1]. Cancer registration is pursued by active methods[2]. The sources of registration, besides coordination with the Department of Health-Rizal Cancer Registry, include hospitals in the government and private sectors, consultants, pathology laboratories and imaging centres. Data are collected from hospital tumour registries and other records maintained at these places. The registry covers an area of 274.2 km2 and caters to an entirely urban population of about 5.1 million in 1995 with a sex ratio of 1046 females to 1000 males. The average annual age-standardized incidence rate is 222 per 100 000 among males and 206 per 100 000 among females with a lifetime cumulative risk of one in 4 of developing cancer for both sexes in the period 1993–1997. The top ranking cancers among males are lung, liver and prostate. Among females, the order is breast, cervix and ovary.| Map. Map showing location of Manila, Philippines Click here to open map (PDF format) |
Data quality indices
The proportion of cases with histological confirmation of cancer diagnosis in this series ranges from 78% for colon cancer to 88% in rectal and breast cancers. No cases registered-based on a death certificate only were included in the study. Cases without any follow-up information represent 21%, varying between 16–25% for different cancers. Thus, 74–83% of cases considered for the study 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, Manila, Philippines, 1994-1995 cases followed-up until 2002 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 collection of cancer mortality information from the local civil registrar offices. The mortality data are first matched with the incident cancer database. The follow-up information for the unmatched incident cases is then obtained through the attending physicians, repeated scrutiny of records in the respective sources of registration, postal/telephone enquiries and house visits.The closing date of follow-up was 31st December 2002. The median follow-up ranged from 15 months in cervix cancer to 33 months in breast cancer. Complete follow-up at five years from the incidence date was available in 75–82% of cases. The losses to follow-up have generally occurred in large numbers in the first year of follow-up and decreased through successive intervals of follow-up time.
 | Table 2. Number and proportion of cases with complete / incomplete follow-up and median follow-up (in months) by site, Manila, Philippines, 1994-1995 cases followed-up until 2002 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Survival statistics
All ages and both sexes together
The 5-year relative survival estimates are the highest for cancer of the female breast (52%) followed by colon (46%), rectum (37%) and cervix (36%). The age-standardized relative survival (ASRS) for all ages together when compared to the corresponding unadjusted one is higher in colon cancer, lower in rectal cancer and similar for breast and cervix cancers. The ASRS for 0–74 years of age was higher than ASRS for all ages together for breast and cervix cancers, lower for colon cancer and similar for rectal cancer. | Table 3. Comparison of 1-, 3- and 5-year absolute and relative survival and 5-year age-standardized relative survival (ASRS) by site, Manila, Philippines, 1994-1995 cases followed-up until 2002 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Sex
 | Table 4a. Site-wise number of cases, 5-year absolute and relative survival by sex, Manila, Philippines, 1994-1995 cases followed-up until 2002 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Male
The five-year relative survival estimates among cancers of the colon (38%) and rectum (28%) are markedly less than among females.Female
The highest 5-year relative survival was observed in cancer of the colon (54%) followed in order by breast (52%), rectum (44%) and cervix (36%).Age group
The 5-year relative survival by age group does not display any pattern and is observed to be fluctuating with increasing age groups. | Table 4b. Site-wise number of cases, 5-year absolute and relative survival by age group, Manila, Philippines, 1994-1995 cases followed-up until 2002 Click here to open table (PDF format) Click here to open comparative statistics by registry |
Extent of disease
Cases classified as localized by extent of disease form a majority (34%) compared to the regional category (27%) among rectal cancers. Regional spread of disease is the most common among cancers of the breast (46%) and cervix (30%). Distant metastasis accounts for 10–18%, and extent of disease unknown ranges from 9% for breast cancer to 38% for cervix cancer. The 5-year absolute survival by extent of disease follows the expected pattern of having an inverse relationship: a decreasing survival with increasing known extent of disease category. | Table 5. Proportion (%) of cases and 5-year absolute survival by extent of disease and site, Manila, Philippines, 1994-1995 Click here to open table (PDF format) Click here to open comparative statistics by registry |
 | Figure 1a-1d. Absolute survival (%) by extent of disease, Manila, Philippines open the figures in PDF format |
 | Figure 1a. Absolute survival (%) by extent of disease, Manila, Philippines: Cancer of the colon Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 1b. Absolute survival (%) by extent of disease, Manila, Philippines: Cancer of the rectum Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 1c. Absolute survival (%) by extent of disease, Manila, Philippines: Cancer of the breast Click here to open figure (PDF format) Click here to open comparative statistics by cancer site |
 | Figure 1d. Absolute survival (%) by extent of disease, Manila, Philippines: Cancer of the cervix 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) - Laudico AV, Esteban D and Parkin DM. Cancer in the Philippines. IARC Technical Report No. 5. IARCPress, Lyon, 1989.
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