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Sunday 1 July 2018

Cancer Survival




Cancer survival in Karunagappally, India, 1991-1997




Abstract

The Rural Cancer Registry of Karunagappally was established in 1990 to study cancer occurrence due to high natural background radiation in the coastal area of Kerala state. Cancer registration was done by active methods. The registry contributed data on survival for 22 cancer sites or types registered during 1991–1997. Follow-up has been carried out predominantly by active methods, with median follow-up time ranging between 3–57 months for various cancers. The proportion of histologically verified diagnosis for different cancers ranged between 39–100%; death certificates only (DCOs) comprised 0–25%; 75–100% of total registered cases were included for survival analysis. The 5-year age-standardized relative survival rates for common cancers were lung (6%), breast (45%), cervix (55%), mouth (42%), oesophagus (14%) and tongue (31%). Five-year relative survival by age group showed no distinct pattern or trend for most cancers. A majority of cases are diagnosed with a regional spread of disease among cancers of the tongue (48%), oral cavity (66%), hypopharynx (54%), larynx (46%), cervix (61%) and breast (53%); survival decreases with increasing extent of disease.

 


Rural Cancer Registry


The Rural Cancer Registry of Karunagappally was established in 1990 as a special purpose registry by the Regional Cancer Centre of Trivandrum, with funding support from the Department of Atomic Energy, Government of India to study cancer occurrence in relation to the high natural background radiation present in the coastal area of Kerala state, which has monazite-rich sands that emit gamma radiation. The registry covers an area of 212 km2 and caters to a mixed rural (96%) and urban (4%) population of 0.4 million with a sex ratio of 1025 females to 1000 males. It has been contributing data to the quinquennial IARC publication Cancer Incidence in Five Continents since Vol VII[1]. The method of cancer registration is entirely done by active methods. There are no dedicated cancer hospitals or laboratories for tissue diagnosis within the registry area. Over 50 sources of registration, comprising hospitals in the government and private sectors, nursing homes, pathology laboratories, imaging centres and hospices, are visited for data collection. In addition, the enumerators undertake field visits to trace new cancer cases. The average annual age-standardized incidence rate is 112 per 100 000 among males and 81 per 100 000 among females with a lifetime cumulative risk of one in 8 for males and one in 11 for females of developing cancer in 1991–2001. The top-ranking cancers among males are lung, followed by oral cavity and oesophagus. Among females, the order is breast, cervix and oral cavity [2].
The registry has contributed data on survival from 22 cancer sites or types for this second volume of the IARC publication on Cancer Survival in Africa, Asia, the Caribbean and Central America.



Data quality indices

The proportion of cases with a histological confirmation of cancer diagnosis in this series is 71%, varying between 39–100%. The proportion of cases registered as death certificates only (DCOs) is 11%, ranging between 0–25%. The exclusion of cases from the survival analysis was the greatest in cancer of the brain and nervous system (25%); it was none for many cancers. Thus, 75–100% of the total cases registered are included in the estimation of the survival probability.


Outcome of follow-up

Follow-up has been carried out predominantly by active methods. These included abstraction of cancer mortality information from the vital statistics division records. The abstracted data are first matched with the incident cancer database. The follow-up information for the unmatched incident cases is then obtained through repeated scrutiny of records in the respective sources of registration, postal/telephone enquiries and house visits. Further, the monthly cancer follow-up clinics held by oncologists from the Regional Cancer Centre in the field office and the pain and palliative care clinics held bi-weekly have helped to obtain maximal follow-up information.

The closing date of follow-up was 31st December 1999. The median follow-up (in months) ranged between 3 for myeloid leukaemia to 59 for non melanoma skin cancer. Complete follow-up at five years from the incidence date ranged from 91% (prostate cancer) to 100%. The losses to follow-up occurred in the first year of follow-up for a majority of cancers.

Survival statistics

All ages and both sexes together

The 5-year relative survival is the highest for thyroid cancer (88%) and the lowest for cancer of the liver (3%) among the cancers studied. The survival figures for other head and neck cancers are oral cavity (41%), larynx (35%), tongue (32%) and hypopharynx (15%). Survival rates from gastrointestinal cancers were rectum (33%) and oesophagus, stomach and pancreas (3%). The survival figures for Non-Hodgkin lymphoma was 30%, lymphoid leukaemia was 37% and myeloid leukaemia 8%.

The 5-year age-standardized relative survival (ASRS) probability for all ages together is less than or very similar to the corresponding unadjusted one for most cancers. The 5-year ASRS (0–74 years of age) is observed to be higher than the corresponding ASRS (all ages) for the majority.

Extent of disease

A majority of cases have been diagnosed with a regional spread of disease among cancers of the tongue (48%), oral cavity (66%), hypopharynx (54%), larynx (46%), cervix (61%) and breast (53%). For ovarian cancer, there are more cases in the distant metastasis category (54%) than others. The extent of disease was unknown in 7–17%. The 5-year absolute survival by extent of disease followed the expected pattern: highest for localized disease followed by regional and distant metastasis among known categories of extent of disease for most cancers.





Cancer survival Harare, Zimbabwe, 1993-1997


Abstract
The Zimbabwe national cancer registry was established in 1985 as a population-based cancer registry covering Harare city. Cancer is not a notifiable disease, and registration of cases is done by active methods. The registry contributed data on randomly drawn sub-samples of Harare resident cases among 17 common cancer sites or types registered during 1993–1997 from black and white populations. Follow-up was carried out predominantly by active methods with median follow-up ranging from 1–54 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged from 20–100%; death certificate only cases (DCOs) comprised 0–34%; 58–97% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 94–100%. Five-year age-standardized relative survival rates of selected cancers among both races combined were cervix (42%), breast (68%), Kaposi sarcoma (4%), liver (3%), oesophagus (12%), stomach (20%) and lung (14%). Survival was markedly higher among white than black populations for most cancers with adequate cases. Five-year relative survival by age group was fluctuating, with no definite pattern or trend.



Zimbabwe national cancer registry


The Zimbabwe national cancer registry was established in 1985 as a population-based cancer registry at the Parirenyatwa Hospital, Medical School of the University of Zimbabwe, Harare, under the support of the Ministry of Health and Child Welfare, IARC and other organizations. It contributed data to the quinquennial IARC publication Cancer Incidence in Five Continents in volumes VII (for African (black) and European (white) populations) and VIII (for black population only)[1]. Cancer is not a notifiable disease, and registration of cases is done by active methods. The principal sources of data are the medical records in the cancer departments, hospitals, pathology laboratories in the public and private sectors and specific clinical research studies. The registry covers the city of Harare and caters to a population of about 1.5 million in 1997 with a sex ratio of 943 females to 1000 males. The average annual age-standardized incidence rate (ASR) of all cancers except non-melanoma skin among the black population was 223 per 100 000 among males and 219 per 100 000 among females in 1993–1997; the corresponding figures for the white population in 1990–1992 were 291 per 100 000 males and 298 per 100 000 females[1,2,3].
The registry has contributed data on survival from the 17 cancer sites or types in this volume of the IARC publication on Cancer Survival in Africa, Asia, the Caribbean and Central America. For this study, only sub-samples of Harare resident cases among 17 common cancers are included. For most cancers, it was intended that a minimum of 150 cases be randomly selected. For cervix and breast cancers and Kaposi sarcoma, the number intended is 300. For breast cancer, it is equally distributed among minority (white) and African (black) races. For the rest of cancers, the inclusion of the minority races (other than white) is only by chance[4].



Data quality indices


The proportion of cases with histological confirmation of cancer diagnosis in this series is 65%, varying between 20% for liver cancer and 100% for Hodgkin lymphoma. The proportion of cases registered on a death certificate only is 10%, ranging from nil to 34%. The exclusion of cases without any follow-up information or other inconsistencies ranged from 1–8%. Thus, 58–97% in the series among different cancers are included in the estimation of the survival probability.











Cancer survival in Riyadh, Saudi Arabia, 1994-1996


Abstract

The national cancer registry in Saudi Arabia has functioned since 1994, collecting population-based incidence data on malignant and in situ tumours. Cancer registration is carried out by both passive and active methods. The registry contributed data on survival from cancer of the breast registered in 1994–1996 from Riyadh province. Follow-up was carried out predominantly by active methods, and the median follow-up was 57 months. The proportion of cases with a histological confirmation of breast cancer diagnosis was almost 100%; there were no cases registered based on death certificate only (DCO); 93% of total cases registered were included in the survival analysis. Complete follow-up at five years was 80%. Relative survival rates at one, three and five years were 96%, 83% and 65%, respectively. Five-year age-standardized relative survival was 65%. Five-year relative survival by age group did not show any pattern and was fluctuating. Five-year absolute survival by extent of disease was localized (70%), regional (56%), distant metastasis (57%) and unknown (62%).


National cancer registry


The national cancer registry in Saudi Arabia has functioned since 1994, collecting population-based incidence data on malignant and in situ tumours. It is based at Gulf Centre for cancer registration, King Faisal Specialist Hospital, Riyadh. Cancer registration is carried out by both passive and active methods. Cancer care services are provided predominantly by the Ministry of Health, which includes cancer centres with all diagnostic and treatment facilities and other hospitals with some participation from private sector. Data are collected from all these sources by scrutiny of records or linkage with data in computer systems maintained at these places. The registry covers an area of 3 855 000 km2 and caters to a mixed urban and rural estimated population of about 20.7 million in 1998 with a sex ratio of 1264 males to 1000 females; the corresponding Saudi population is 15.1 million with 1020 males to 1000 females. The average annual age-standardized incidence rate among Saudis was 65 per 100 000 among males and 68 per 100 000 among females, with a lifetime cumulative risk of one in 13 of developing cancer for both sexes in the period 1997–1998. The top-ranking cancers among males are liver, followed by non-Hodgkin lymphoma and leukaemia. Among females, the order is breast, thyroid and leukaemia[1].






Cancer survival in Bhopal, India, 1991-1995

Abstract

The Bhopal population-based cancer Registry was established in 1986 under the national cancer registry programme to investigate the after-effect of a gas leak in 1984. Cancer registration is done entirely by active methods. The registry is contributing data on survival for 16 cancer sites or types registered during 1991–1995. Follow-up of cases was done by active methods with median follow-up time ranging between 8–44 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged between 61–100%; death certificates only (DCOs) comprised 0–2%; 50–92% of total registered cases were included for survival analysis. The 5-year age-standardized relative survival rates for common cancers were mouth (34%), cervix (31%), breast (25%), tongue (12%), oesophagus (3%) and lung (1%). The 5-year relative survival by age group showed that survival was the highest in the younger age group (45 years and below) for a majority of cancers. A decreasing survival with increasing clinical extent of disease was noted for most cancers studied.



Bhopal Cancer Registry

The Bhopal Population-Based Cancer Registry is the only one of its kind in the central part of India. It was established in 1986 as a special purpose registry at the Gandhi Medical College, Bhopal, under the National Cancer Registry Programme, to investigate the after-effect of the gas leak in 1984. Data from the registry have been regularly published by the Indian Council of Medical Research[1]. The method of cancer registration is entirely done by active methods. The registry staff visits the various medical institutions in and around Bhopal city for data collection by direct interview of cases and/or from medical records[2]. The registry covers an area of 285 km2 and caters to an entirely urban population of about 1.4 million in 2001 with a sex ratio of 893 females to 1000 males. The average annual age-standardized incidence rate is 114 per 100 000 among males and 104 per 100 000 among females with a lifetime cumulative risk of one in 10 of developing cancer for both sexes in the period 1999–2001. The leading site of cancer among males is the lung followed by oral cavity and oesophagus. The ranking among females is breast followed by cervix and oral cavity[1].






Cancer survival in Chiang Mai, Thailand, 1993-1997


Abstract

The Chiang Mai tumour registry was established in 1978 as a hospital-based cancer registry, and population-based cancer registration started in 1986, with retrospective data collection on cancer incidence and mortality since 1983. Registration of cases is done by active method. Data on survival for 36 cancer sites or types registered during 1993–97 are reported here. Follow-up has been carried out predominantly by active methods, with median follow-up ranging between 1–39 months for different cancers. The proportion of histologically verified diagnosis for various cancers ranged between 28–100%; death certificate only (DCOs) cases comprised 0–56%; 33–92% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 59–100% for different cancers. The 5-year age-standardized relative survival rates was the highest for Hodgkin lymphoma (70%) followed by thyroid (65%), cervix (57%), breast (56%) and corpus uteri (49%). The 5-year relative survival by age group showed either an inverse relationship or was fluctuating. An overwhelmingly high proportion of cases were diagnosed with a regional spread of disease, ranging between 44–82% for different cancers and survival decreased with increasing extent of disease for all cancers studied.









Cancer survival in Singapore, 1993-1997

Abstract

The Singapore cancer registry is a national registry established in 1968. Cancer registration is done by passive methods. The registry contributed survival data on 45 cancer sites or types registered during 1993–1997. Data on 34 cancers registered during 1968–1997 were utilized for survival trend by period and cohort approaches. Follow-up was done by passive methods, with median follow-up ranging between 2–72 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged between 27–100%; death certificates only (DCOs) comprised 0–7%; 76–100% of total registered cases were included for the survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were non-melanoma skin (96%), thyroid (90%), testis (88%), corpus uteri (77%), breast (74%), Hodgkin lymphoma (73%) and penis (70%). Five-year relative survival by age group showed either a decreasing trend with increasing age groups or was fluctuating. Localized stage of disease ranged between 18–65% for various cancers and survival decreased with increasing extent of disease. Period survival closely predicted survival experience of cancers diagnosed in that period, and an increasing trend in period survival over different periods indicated an improved prognosis for cancers diagnosed in those calendar periods.

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