Study populations for period analyses of cancer survival

Background:

Period analysis is increasingly used to compute long-term cancer survival, as it provides better prediction of survival of newly diagnosed patients than traditional cohort analysis. However, the patient population to which period survival estimates best pertain to and which should be described in a study is less obvious.

Methods:

Using Finnish Cancer Registry data on 23 common cancer sites, age-standardized period estimates of 5-, 10-, 15-, and 20-year relative survival were computed for each 2-, 5-, and 10-year calendar period in 1954–2003 and compared with survival estimates for two cohorts by means of mean, mean absolute and mean squared differences: a full cohort of all patients potentially contributing some data to the survival analysis and a restricted cohort of patients diagnosed in the period of interest.

Results:

In most computations, survival estimates for the full cohorts were on average closer to the period estimates for the majority of cancer sites. For 10-year survival, results were less obvious with respect to the mean difference. However, mean squared and mean absolute differences were smaller for the majority of cancers when using the full cohort.

Conclusion:

Our results suggest that the full cohort should be described in reports of period survival analysis.     

Updating long-term childhood cancer survival trend with period and mixed analysis: good news from population-based estimates in Italy

An empirical evaluation of long-term period survival analysis was performed using data from the Childhood Cancer Registry of Piedmont, Italy. The aim was to update survival time trends and provide 25-year projections for children currently diagnosed with cancer. The observed survival experiences up to 15 years after diagnosis of five quinquennial cohorts (cohort analysis) were compared to the corresponding estimates obtained by period analysis. The two methods generally produced very similar findings, although period analysis estimates were slightly lower than those obtained from cohort analysis. We then used mixed analysis to assess time trends in long-term survival. This showed that the probability of surviving 25 years after a cancer in childhood has more than doubled compared to cohort analysis estimates from patients diagnosed more than 25 years ago (73% vs. 32%), providing further evidence of an ongoing improvement in prognosis.     

Cancer survival in Qidong, China, 1992-2000

The Qidong cancer registry was established in 1972, and registration of cases is done by active and passive methods. The registry contributed data on 33 cancer sites or types registered during 1992-2000 for this survival study. Data on 22 cancers registered during 1972-2000 were utilized to elicit the survival trend by period and cohort approaches. Follow-up was done by a mixture of active and passive methods, with median follow-up ranging from 2-25 months. The proportion of cases with histologically verified cancer diagnosis ranged from 9-100%, and 87-100% of total registered cases were included for survival analysis. The top-ranking cancers on 5-year age-standardized relative survival (%) were thyroid (78%), breast (58%), corpus uteri (54%), larynx (51%) and urinary bladder (42%). The corresponding survival rates for common cancers were liver (6%), lung (7%) and stomach (18%). The 5-year relative survival by age group fluctuated and showed no distinct pattern or trend. The comparison of 5-year relative survival trend by cohort and period approaches revealed that period survival closely predicted the survival experience of cancer cases diagnosed in that period for most cancers.     

Survival in patients with primary liver cancer,gallbladder and extrahepatic biliary tract cancer and pancreatic cancer in Europe 1999–2007: Results of EUROCARE-5

BackgroundThe EUROCARE study collects and analyses survival data from population-based cancer registries (CRs) in Europe in order to provide data on between-country differences in survival and time trends in survival.MethodsThis study analyses data on liver cancer, gallbladder and extrahepatic biliary tract cancers (“biliary tract cancers”), and pancreatic cancer diagnosed in 2000–2007 from 88 CRs in 29 countries. Relative survival (RS) was estimated overall, by region, sex, age and period of diagnosis using the complete approach. Time trends in 5-year RS over 1999–2007 were also analysed using the period approach.ResultsThe prognosis of the studied cancers was poor. Age-standardised 5-year RS was 12% for liver cancer, 17% for biliary tract cancers and 7% for pancreatic cancer. There were some between-country differences in survival. In general, RS was low in Eastern Europe and high in Central and Southern Europe. For all sites, 5-year RS was similar in men and women and decreased with advancing age. No substantial changes in survival were reported for pancreatic cancer over the period 1999–2007. On average, there was a crude increase in 5-year RS of 3 percentage points between the periods 1999–2001 and 2005–2007 for liver cancer and biliary tract cancers.ConclusionsThe major changes in imaging techniques over the study period for the diagnosis of the three studied cancers did not result in an improvement in the prognosis of these cancers. In the near future, new innovative treatments might be the best way to improve the prognosis in these cancers.     

Survival analysis of cancer cases from Qidong cancer registry

Thispaperdescribesthesurvivalexperiencefrom15selectedsitesofcancersaccordingtodatafromapopulation--basedcancerregistryduringtheperiodof1982--1991forevaluationofcancersurvivalaswellasdifferentcancercontrolmeasures.MATERIALSANDMETHODSDataCollectionCanc...     

A comparison of relative and cause‐specific survival by cancer site,age and time since diagnosis

Relative survival (RS) estimates are widely used by cancer registries, mainly because they do not rely on the well‐documented deficiencies of cause of death information. The aim of our study was to compare 5‐year cause‐specific survival (CSS) estimates and 5‐year RS estimates for different cancer sites by age and time since diagnosis, and discuss possible reasons for observed differences. Using data from the Cancer Registry of Norway, we identified 200,008 patients diagnosed with cancer at one of the 48 sites included in this analysis during the period 1996–2005, and followed them up until the end of 2010. CSS estimates were calculated (i) considering cause of death to be the cancer that was originally diagnosed and (ii) considering the cause of death to be a cancer within the same organ system. For most cancer sites the difference between CSS and RS estimates was small (<5%). The greatest differences were seen for rarer cancers such as mediastinum and Kaposi sarcoma. Including deaths from the same organ system in the calculation of CSS further reduced the differences for many sites. For younger age groups and shorter time since diagnosis, RS and CSS estimates tended to be similar, whereas CSS estimates tended to be lower than RS estimates with longer time since diagnosis in the oldest age groups. When compared to RS estimates CSS estimates were reliable for most of the cancer sites included in our analysis. There are, however, some exceptions where CSS estimates may not be recommended, including for rarer cancers and for patients aged 85 and above.     

Up-to-date monitoring of childhood cancer long-term survival in Europe: methodology and application to all forms of cancer combined.

BACKGROUND: The Automated Childhood Cancer Information System (ACCIS) provides a unique database for monitoring and comparing long-term prognosis of children with cancer in Europe. The 'period' method has been shown particularly useful for that purpose. PATIENTS AND METHODS: The ACCIS database was used for comparative analyses of up-to-date long-term survival in four regions and 19 countries of Europe by period analysis. Overall, follow-up data on 49,503 children diagnosed between 1985 and the end of the 1990s were included. Period estimates of 10-year survival were derived for the 1995-99 period and compared with estimates obtained by cohort and complete analysis. In this article, the methodology is described and the approach is illustrated for all forms of childhood cancer combined. RESULTS: Long-term childhood cancer survival achieved in Europe by the end of the twentieth century is much higher than previous estimates indicated. The overall period estimate of 10-year survival was 71% for all countries combined, but it varied between 45% for Estonian children and 79% for Swedish and Finnish children with cancer. CONCLUSION: Period analysis is the method of choice to monitor population-based survival. Despite major improvement during the past decades, tremendous variation in childhood cancer survival between European countries has persisted.     

启东市1972～2000年主要恶性肿瘤生存率分析

[目的]评价启东1972～2000年基于全人群的恶性肿瘤登记病例的预后。[方法]55496例登记病例的生存（死亡）情况随访截止于2001年12月31日，用Hakulinen等编制的SURV3．00bl软件计算5年观察生存率（OS）及5年相对生存率（RS）。[结果]女性乳腺癌的5年生存率最高（OS：55．92％，RS：58．44％），其次为宫颈癌（OS：39．06％，RS：42．40％）。原发性肝癌的5年生存率在男性（OS：3．26％，RS：3.46％）和女性（0S：4．11％，RS：4．31％）中均为最低。食管癌（OS：4．09％，RS：4．76％），肺癌（OS：4．79％，RS：5．48％），白血病（OS：5．48％，RS：5．79％）和胰腺癌（OS：6．56％．RS：7．45％）的预后也较差。与1972～1976年的生存率比较，男性胃癌、肝癌、前列腺癌等，以及女性鼻咽癌、直肠癌、肝癌、膀胱癌等生存率有所改善。[结论]启东市癌症总体生存率较低．与国内大城市相比有较大的葺距．与国外发达国家相比差距更大。     

Long-term cancer patient survival achieved by the end of the 20th century: most up-to-date estimates from the nationwide Finnish cancer registry

A new method of survival analysis, denoted period analysis, has recently been developed, which has been shown to provide more up-to-date estimates of long-term survival rates than traditional methods of survival analysis. We applied period analysis to data from the nationwide Finnish cancer registry to provide up-to-date estimates of 5-, 10-, 15- and 20-year relative survival rates (RSR) achieved by the end of the 20th century. For most forms of cancer, period estimates of long-term survival are much higher than corresponding traditional survival estimates which suggests that for these cancers there has been ongoing major progress in survival rates in recent years which so far has remained undisclosed by traditional methods of survival analysis. For example, period analysis reveals that 10 year RSR have come close to (or even exceed) 80% for cancer of the corpus uteri and melanoma, 75% for breast cancer, 70% for bladder cancer, 65% for cancer of the cervix uteri, and 55% for cancer of the colon and prostate. Period analysis further reveals that 20 year RSR have now come close to (or even exceed) 75% for endometrial cancer and melanoma, 60% for breast cancer and cervical cancer, 55% for colon cancer and bladder cancer, and 40%-50% for cancer of the rectum, the ovaries, kidneys and nervous system.     

Long-term survival expectations of cancer patients in Europe in 2000–2002

Period analysis has been shown to provide more up-to-date estimates of long-term cancer survival rates than traditional cohort-based analysis. Here, we provide detailed period estimates of 5- and 10-year relative survival by cancer site, country, sex and age for calendar years 2000–2002. In addition, pan-European estimates of 1-, 5- and 10-year relative survival are provided. Overall, survival estimates were mostly higher than previously available cohort estimates. For most cancer sites, survival in countries from Northern Europe, Central Europe and Southern Europe was substantially higher than in the United Kingdom and Ireland and in countries from Eastern Europe. Furthermore, relative survival was also better in female than in male patients and decreased with age for most cancer sites.     

Survival for oesophageal,stomach and small intestine cancers in Europe 1999–2007: Results from EUROCARE-5

BackgroundEuropean regional variation in cancer survival was reported in the EUROCARE-4 study for patients diagnosed in 1995–1999. Relative survival (RS) estimates are here updated for patients diagnosed with cancer of the oesophagus, stomach and small intestine from 2000 to 2007. Trends in RS from 1999–2001 to 2005–2007 are presented to monitor and discuss improvements in patient survival in Europe.Materials and methodsEUROCARE-5 data from 29 countries (87 cancer registries) were used to investigate 1- and 5-year RS. Using registry-specific life-tables stratified by age, gender and calendar year, age-standardised ‘complete analysis’ RS estimates by country and region were calculated for Northern, Southern, Eastern and Central Europe, and for Ireland and United Kingdom (UK). Survival trends of patients in periods 1999–2001, 2002–2004 and 2005–2007 were investigated using the ‘period’ RS approach. We computed the 5-year RS conditional on surviving the first year (5-year conditional survival), as the ratio of age-standardised 5-year RS to 1-year RS.ResultsOesophageal cancer 1- and 5-year RS (40% and 12%, respectively) remained poor in Europe. Patient survival was worst in Eastern (8%), Northern (11%) and Southern Europe (10%). Europe-wide, there was a 3% improvement in oesophageal cancer 5-year survival by 2005–2007, with Ireland and the UK (3%), and Central Europe (4%) showing large improvements.Europe-wide, stomach cancer 5-year RS was 25%. Ireland and UK (17%) and Eastern Europe (19%) had the poorest 5-year patient survival. Southern Europe had the best 5-year survival (30%), though only showing an improvement of 2% by 2005–2007.Small intestine cancer 5-year RS for Europe was 48%, with Central Europe having the best (54%), and Ireland and UK the poorest (37%). Five-year patient survival improvement for Europe was 8% by 2005–2007, with Central, Southern and Eastern Europe showing the greatest increases (⩾9%).ConclusionsSurvival for these cancer sites, particularly oesophageal cancer, remains poor in Europe with wide variation. Further investigation into the wide variation, including analysis by histology and anatomical sub-site, will yield insights to better monitor and explain the improvements in survival observed over time.     

Disclosing progress in cancer survival with less delay

Cancer registration plays a key role in monitoring the burden of cancer. However, cancer registry (CR) data are usually made available with substantial delay to ensure best possible completeness of case ascertainment. Here, we investigate empirically with routinely available data whether such a delay is mandatory for survival analyses or whether data can be used earlier to provide more up-to-date survival estimates. We compared distributions of prognostic factors and period relative survival estimates for three population-based CRs in Germany (Schleswig-Holstein (SH), Rhineland-Palatinate (RP), Saarland (SA)) computed on datasets extracted one (DY+1) to 5 years after the year of diagnosis (DY+5; reference). Analyses were conducted for seven cancer sites and various survival analyses scenarios. The proportion of patients registered in the datasets at a given time varied strongly across registries with 57% (SH), 2% (RP) and 26% (SA) registered in DY+1 and >93% in all registries in DY+3. Five-year survival estimates for the most recent three-year period were comparable to estimates from the reference dataset already in DY+1 (mean absolute deviations = 0.2–0.6% units). Deviations >1% units were only observed for pancreatic and lung cancer in RP and leukemia in SA (all ≤1.5% units). For estimates of 1-year survival based on the most recent 1-year period only, slightly longer delays were required, but reasonable estimates were still obtained after 1–2 years, depending on the CR and cancer site. Thus, progress in cancer survival could be disclosed in a more timely manner than commonly practiced despite delays in completeness of registration.     

Cancer survival in Tianjin, China, 1991-1999

The Tianjin cancer registry was established in 1978, and registration of cases is done by the active method. The registry contributed data on 51 cancer sites or types registered during 1991-1999 for this survival study. Follow-up has been a mixture of both active and passive methods, with median follow-up ranging from 5-77 months. The proportion with histologically verified diagnosis for various cancers ranged from 21-95% and 97-100% of total registered cases were included for survival analysis. The top-ranking cancers by 5-year age-standardized relative survival (%) were renal pelvis (101%), lip (99%), corpus uteri (91%), penis and nonmelanoma skin (90%) and thyroid (89%). The corresponding survival for common cancers were lung (31%), stomach (41%), Liver (25%) and breast (82%). The 5-year relative survival by age group reveals an inverse relationship for a few cancers and fluctuated for most cancers. Period survival closely predicted the survival experience of cancer cases diagnosed in that period, with the 5-year relative survival in 1991-1995 by period approach being more or less similar to survival by cohort approach in 1996-1999 for most cancers.     

On-going improvement and persistent differences in the survival for patients with colon and rectum cancer across Europe 1999–2007 – Results from the EUROCARE-5 study

BackgroundPrevious population-based studies revealed major variation in survival for patients with colorectal cancer (CRC) in Europe by age and between different countries and regions, but also a sustained improvement in survival for patients with CRC in recent years. This EUROCARE-5 paper aims to update available knowledge from previous studies and to provide the latest survival estimates for CRC patients from Europe.MethodsThe study analysed data of patients diagnosed with CRC from population-based cancer registries diagnosed in 29 European countries. Estimates of 1-year and 5-year relative survival (RS) were derived for patients diagnosed in 2000–2007 by European region, country and age at diagnosis. Additionally to these cohort estimates, time trends in 5-year RS were obtained for the calendar periods 1999–2001 and 2005–2007, using the period analysis methodology.ResultsEuropean average 5-year RS for patients diagnosed with colon and rectum cancer was 57% and 56%, respectively. The analyses showed persistent differences in cancer survival across Europe with lowest survival for CRC patients observed in Eastern Europe. The analyses further showed a strong gradient in age-specific survival. Even though the study revealed sustained improvement in patient survival between 1999–2001 and 2005–2007 (absolute increase of 4 and 6 percentage points for colon and rectum, respectively), the differences in the survival for CRC patients observed at the beginning of the millennium persisted over time.ConclusionAlthough survival for CRC patients in Europe improved markedly in the study period, significant geographic variations and a strong age gradient still persisted. Enhanced access to effective diagnostic procedures and treatment options might be the keys to reducing the existing disparities in the survival of CRC patients across Europe.     

Up-to-date estimates of cancer patient survival even with common latency in cancer registration.

In an era of ongoing improvement in cancer patient survival, available long-term survival figures from cancer registries are often outdated and too pessimistic for two reasons: first, delay in availability of cancer registry data, typically in the order of a few years, and, second, application of cohort-based methods of survival analysis, which provide survival estimates for patients diagnosed many years ago. We developed a model-based period analysis approach aimed to overcome both problems. We provide extensive empirical evaluation of our approach by comparing its performance with that of previously available methods for monitoring of 5- and 10-year relative survival, with the use of data from the nationwide Finnish Cancer Registry of 490,279 patients ages >/=15 years and diagnosed with one of 20 common forms of cancer between 1953 and 1997. We show that, in most cases, the model-based approach predicts 5- and 10-year relative survival expectations of newly diagnosed patients quite closely and much better than any of the previously available methods, including standard period analysis. We conclude that the model-based approach may enable deriving up-to-date cancer survival rates even with the common latency in availability of cancer registry data.     

Survival of 86,690 patients with thyroid cancer: A population-based study in 29 European countries from EUROCARE-5

BackgroundIncidence rates of thyroid cancer (TC) increased in several countries during the last 30 years, while mortality rates remained unchanged, raising important questions for treatment and follow-up of TC patients. This study updates population-based estimates of relative survival (RS) after TC diagnosis in Europe by sex, country, age, period and histology.MethodsData from 87 cancer registries in 29 countries were extracted from the EUROCARE-5 dataset. One- and 5-year RS were estimated using the cohort approach for 86,690 adult TC patients diagnosed in 2000–2007 and followed-up to 12/31/2008. RS trends in 1999–2007 and 10-year RS in 2005–2007 were estimated using the period approach.ResultsIn Europe 2000–2007, 5-year RS after TC was 88% in women and 81% in men. Survival rates varied by country and were strongly correlated (Pearson ρ = 75%) with country-specific incidence rates. Five-year RS decreased with age (in women from >95% at age 15–54 to 57% at age 75+), from 98% in women and 94% in men with papillary TC to 14% in women and 12% in men with anaplastic TC. Proportion of papillary TC varied by country and increased over time, while survival rates were similar across areas and periods. In 1999–2007, 5-year RS increased by five percentage points for all TCs but only by two for papillary and by four for follicular TC. Ten-year RS in 2005–2007 was 89% in women and 79% in men.ConclusionsThe reported increasing TC survival trend and differences by area are mainly explained by the varying histological case-mix of cases.     

Cancer survival in Singapore, 1993-1997

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 nonmelanoma 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.     

上海人群胃癌生存率研究

背景与目的：我国胃癌的发病率和死亡率呈逐年上升趋势,以人群为基础的胃癌生存率资料反映了胃癌诊治效果,也可以为评价胃癌人群综合防治效果提供参考。方法：根据上海市肿瘤登记处收集的2002—2006年胃癌登记和生存随访报告资料,采用寿命表法和EdererⅡ法计算胃癌患者的观察生存率(observed survival,OS)和相对生存率(relative survival,RS)。结果：上海市2002—2006年共诊断胃癌病例28243例,患者5年OS和RS分别为32.15%和45.81%。35~54岁年龄段患者生存率高于其他年龄组;Ⅰ期患者的生存率明显高于其他分期患者;管状腺癌的胃癌患者生存率显著高于其他类型;郊区患者5年OS高于市区患者。不同性别患者的生存率差异无统计学意义。2002—2006年与1972—1976年相比,男、女性胃癌患者的生存率均显著上升。结论：不同年龄、居住区域、诊断时期别、肿瘤组织学类型和病理学类型的患者生存率差异有统计学意义。上海地区胃癌的5年OS和RS在过去30年中显著升高,但仍低于发达国家。应提高胃癌患者早期诊断率,以改善胃癌患者的生存及预后情况。     

Long-term survival of cancer patients in Germany achieved by the beginning of the third millenium.

BACKGROUND: Over the last decades, long-term survival rates have substantially increased for many forms of cancer. However, these improvements have often been detected with substantial delay by traditional methods of survival analyses. PATIENTS AND METHODS: Using data of the population-based Saarland Cancer Registry, 5- and 10-year relative survival rates were derived for patients with 24 common forms of cancer in Saarland/Germany for the years 2000-2002 by period analysis and compared with conventional cohort estimates of 5- and 10-year relative survival rates pertaining to patients diagnosed in 1990-1992. RESULTS: For many forms of cancer, the 2000-2002 period survival estimates were substantially higher than the corresponding estimates for the cohorts of patients diagnosed in 1990-1992. For example, 10-year relative survival rates achieved in 2000-2002 were close to 100% for patients with testis and thyroid cancer, >85% for patients with melanomas of the skin, approximately 80% for patients with endometrial cancer and prostate cancer, close to 70% for patients with breast cancer and kidney cancer, and close to 60% for patients with colon cancer and lymphomas. CONCLUSIONS: Survival expectations of patients diagnosed with cancer at the beginning of the third millenium are substantially higher than previously available survival statistics have suggested.     

恶性肿瘤16 922例生存率分析

目的对启东１９８２～１９９１年以人群为基础的１５个部位的１６９２２例恶性肿瘤患者进行生存率分析,为全人群恶性肿瘤的生存率评价提供依据。方法据ＫａｐｌａｎＭｅｉｅｒ法,采用ＥＧＲＥＴ软件计算观察生存率（ＯＳ）;并用观察生存率与启东寿命表中期望生存率之比计算相对生存率（ＲＳ）。结果５种主要恶性肿瘤肝癌、胃癌、肺癌、食道癌及直肠癌的５年ＯＳ分别为１．８％、１１．６％、３．０％、３．３％及１９．９％,５年ＲＳ分别为１．９％、１４．０％、３．６％、４．２％、２３．７％。肝癌、胃癌、肺癌、食道癌、直肠癌的５年ＲＳ在男性分别为１．７％、１４．８％、３．４％、４．２％、２６．０％,在女性分别为２．７％、１２．７％、４．１％、４．０％、２２．０％。女性乳腺癌、宫颈癌的５年ＲＳ分别为５４．６％、３３．０％。结论人群各部位癌症的生存率均较低,其中以肝癌为最低,乳腺癌预后相对较好。肺癌、食道癌及胰腺癌的生存率与发达国家的结果大致相当,而乳腺癌、宫颈癌、白血病等的生存率差异较大