Conditional survival in Canada: adjusting patient prognosis over time

Conditional survival to assess prognosis in patients with chronic lymphocytic leukemia

Biomarkers in chronic lymphocytic leukemia (CLL) allow assessment of prognosis. However, the validity of current prognostic biomarkers based on a single assessment point remains unclear for patients who have survived one or more years. Conditional survival (CS) studies that address how prognosis may change over time, especially in prognostic subgroups, are still rare. We performed CS analyses to estimate 5-year survival in 1-year increments, stratified by baseline disease characteristics and known risk factors in two community-based cohorts of CLL patients (Freiburg University Hospital (n = 316) and Augsburg University Hospital (n = 564)) diagnosed between 1984 and 2021. We demonstrate that 5-year CS probability is stable (app. 75%) for the entire CLL patient cohort over 10 years. While age, sex, and stage have no significant impact on CS, patients with high-risk disease features such as non-mutated IGHV, deletion 17p, and high-risk CLL-IPI have a significantly worse prognosis at diagnosis, and 5-year CS steadily decreases with each additional year survived. Our results confirm that CLL patients have a stable survival probability with excess mortality and that the prognosis of high-risk CLL patients declines over time. We infer that CS-based prognostic information is relevant for disease management and counseling of CLL patients.

Conditional Relative Survival and Competing Mortality of Patients with Prostate Cancer in Korea: A Nationwide Cohort Study

BACKGROUND

Conditional relative survival (CRS) and competing mortality are important survivorship issues after cancer treatment. We aimed to investigate them among patients with prostate cancer treated by various modalities.

METHODS

Using a nationwide population-based database, we calculated 5-year CRS conditioned on 1 through 5 years survival after diagnosis. These rates were stratified by age, sex, socioeconomic status, comorbidities, and treatment received. Cause of death and estimated cause-specific mortality were also described and considered with competing risks.

RESULTS

A total of 81,773 patients newly diagnosed with primary prostate cancer from 2007 to 2013 were identified. The 5-year CRS was 81.1% at baseline, but increased gradually up to 95.4% at 4 years and exceeded 100% at 5 years after diagnosis, suggesting no excess mortality compared with the general population. However, this pattern differed by treatment received. Patients who underwent androgen deprivation therapy showed 5-year CRS of only 88.4% at 5 years after diagnosis, implying persistent excess mortality. Prostate cancer constituted around one-third of deaths, while other cancers were the main cause of death within <2 years after diagnosis. Noncancer-related deaths, including cardiovascular disease and respiratory disease, increased with time since diagnosis.

CONCLUSIONS

CRS rates for patients with prostate cancer improved over time and exceeded that of the general population at 5 years. Other cancers were the main cause of death in the earlier survivorship phase, and deaths from noncancer causes gradually increased over time.

IMPACT

Our findings will help patients and clinicians make evidence-based decisions on the basis of a patient's dynamic risk profile.

Conditional Survival of Patients Who Underwent Curative Resection for Esophageal Squamous Cell Carcinoma

Objective:

To analyze conditional survival estimates of patients with esophageal cancer who underwent curative resection.

Summary Background Data:

Conditional survival reflects dynamic prognosis updated to the current status and is a more relevant indicator for current healthcare and life decisions.

Methods:

This study included 1883 patients who underwent complete resection for esophageal squamous cell carcinoma at a tertiary cancer center from 1994 to 2016. We calculated 5-year (5Y) conditional overall survival (COS), conditional recurrence-free survival (CRFS), and conditional relative survival (CRS) estimates from diagnosis to 5 years of survival.

Results:

The 5Y COS, CRFS, and CRS increased from 63.7%, 65.2%, and 70.2% at diagnosis to 75.8%, 91.9%, and 86.4 at 5 years after diagnosis, respectively. While there were large differences with different stages (stage I, II, III) at diagnosis (81.2%, 64.9%, and 37.3% for COS; 85.1, 65.1%, and 67.9% for CRFS; 89.2%, 72.1%, and 41.1% for CRS), the gap decreased with time; rates were similar after 5 years (77.1%, 75.7%, and 72.6% for COS; 91.7%, 90.6%, and 94.5% for CRFS, and 89.3%, 85.4%, and 78.3% in CRS, respectively). The 5Y COS, CRFS, and CRS were persistently lower in older patients even after 5 years.

Conclusions:

Conditional survival estimates generally increase over time, and the largest improvements were observed for patients with advanced stage. Availability of updated prognosis at various time points allows clinicians to better guide their patients. Our results also imply substantial residual risk of recurrence and sustained excess mortality compared to the general population even after 5 years.

One-year conditional survival of dogs and cats with invasive mammary carcinomas: A concept inspired from human breast cancer

Numerous studies have described the prognostic factors of canine and feline mammary carcinomas (MCs), that is, variables that predict patient survival after diagnosis. But how does survival estimation evolve in patients that escaped early death from their cancer? In human oncology, conditional survival (CS), the probability of surviving X further years when cancer patients have already survived Y years, is used to analyse cancer outcomes in a long‐term perspective. In this cohort of 344 dogs and 342 cats with surgically removed stage I to III invasive MCs, with a minimal follow‐up of 2 years, we calculated the 1‐year CS, that is, the probability for patients that have survived 1 year, to survive or to die from cancer during the subsequent year. The 1‐year conditional specific survival probabilities were 59% and 48% at diagnosis of invasive MC respectively in dogs and cats, and 80% and 52% in 1‐year surviving dogs and cats respectively, suggesting that 1‐year surviving dogs were relatively protected from cancer‐related death, whereas feline MCs remained life‐threatening cancers for longer periods of time. Among the most significant parameters associated with CS in surviving dogs and cats were the nodal stage and lymphovascular invasion, as well as patient age, cancer stage and margin status in surviving dogs. By comparison, tumour size and the histological grade did not significantly alter CS probabilities in surviving dogs and cats. Conditional survival may be considered a very interesting tool for veterinary practitioners to estimate the likely outcome of cancer survivors.

Conditional relative survival and competing mortality in patients who underwent surgery for lung cancer: A nationwide cohort study

We aimed to investigate the conditional relative survival (CRS) and competing mortality in patients who underwent surgery for newly diagnosed lung cancer. Using a nationwide population-based database, we calculated 5-year CRS on 1 to 5 years survival after surgery. These rates were reported according to age, sex, socioeconomic status, comorbidities and treatment received. We also estimated cause-specific mortality with the consideration of competing risk. We identified 34 349 patients newly diagnosed with primary lung cancer from 2007 to 2013. The 5-year CRS after surgery was 71.7% at baseline improving steadily to 85.4% by 5 years, suggesting evidence of persistent excess mortality risk. Throughout the period, lung cancer was the most common cause of death, contributing to 83.6% mortality 1 year after surgery and 66.3% 5 years after surgery. Other causes of death included cardiovascular disease and respiratory disease, which increased continuously with time after surgery. CRS rates for patients with lung cancer improved over time but did not reach the level of the general population even 5 years after surgery. Although the main cause of death continues to be lung cancer, death from noncancer causes increased with time after surgery. Evidence-based decisions could be made on the dynamic risk profiles of the patients.

Stage-specific conditional survival in renal cell carcinoma after nephrectomy

OBJECTIVES

Conditional survival (CS) represents the probability that a cancer patient will survive some additional number of years, given that the patient has already survived for a certain period of time. CS estimates, therefore, serve as better measures of survival probability compared to standard estimates as they incorporate patient survivorship. Stage-specific CS has not been widely investigated in the context of renal cell carcinoma (RCC) after nephrectomy. We aimed to examine this phenomenon.

MATERIALS AND METHODS

We analyzed retrospective data on a population-based cohort of 87,225 surgically-treated RCC patients extracted from the Surveillance, Epidemiology, and End Results database (2004-2015) and on a similar validation cohort of 1,642 patients from our institution (1995-2015). 5-year cancer-specific CS estimates stratified by stage were obtained using the Kaplan-Meier method. Multivariable Cox regression analyses were performed to evaluate the possible variation in risk of cancer-specific mortality by stage at nephrectomy and with increasing postoperative survivorship.

RESULTS

5-year cancer-specific survival rates at time of nephrectomy for stage I, II, III, and IV patients in the population-based cohort were 97.4%, 89.9%, 77.9%, and 26.7%, respectively. Improvement in 5-year CS was mainly observed in surviving patients with advanced-stage disease; given 1, 2, 3, 4, and 5 years of survivorship after nephrectomy, the subsequent 5-year cancer-specific survival rates were, respectively, 79.3% (+1.8% increase over previous survival probability), 81.3% (+2.5%), 83.3% (+2.5%), 84.3% (+1.2%), and 85.1% (+1.0%) for stage III, and 34.6% (+29.6%), 42.5% (+22.8%), 49.0% (+15.3%), 55.7% (+13.7%), and 58.6% (+5.2%) for stage IV. A similar trend was established in the validation cohort. Findings were confirmed upon multivariable analyses.

CONCLUSIONS

CS after nephrectomy for RCC varies dramatically by stage of disease. Gains in CS over time occur primarily among patients with advanced-stage disease. Stage-specific CS estimates can help urologists better plan postoperative surveillance for RCC patients.

Conditional Disease-free Survival After Radical Prostatectomy: Recurrence Risk Evolution Over Time

OBJECTIVE

To assess changes in conditional disease-free survival (DFS) rates after radical prostatectomy (RP) and how the impact of well-known prognostic factors evolves over time.

MATERIALS AND METHODS

There were 2813 patients treated with RP and postoperatively followed with clinical and prostate-specific antigen assessments. Estimation of conditional survival (CS) probabilities used the Kaplan-Meier method. Multivariable Cox regression model was used to calculate proportional hazard ratios for prediction of DFS after stratification by prognostics characteristics.

RESULTS

The 5-year DFS rate was 71.2%. The DFS rate 5 years after RP increased to 77.4% (+8.7%), 82.1% (+15.3%), 88.0% (+23.6%), and 94.0% (+32.0%) for patients surviving without recurrence 1, 2, 3, and 4 years after RP, respectively. This represented a relatively stable survival gain per survived year ranging from 5.6% to 8.7%. The conditional 5-year DFS improves mainly for disease-free surviving patients with adverse pathologic factors. Among patients with pT3b-4 disease, the probability of surviving without recurrence to year 5 increased from 20.7% at the time of presentation to 78.9% for patients surviving 4 years without recurrence (+281%) as compared to +12.5% in pT2 disease. The impact of Gleason score and pT stage on CS estimates remained stable over time. Findings were confirmed upon multivariable analyses.

CONCLUSION

The period elapsed from RP is associated with DFS. The risk of recurrence decreases with increasing survivorship, mainly in patients with adverse pathologic factors. CS can provide relevant information for clinicians and patients giving an update of their risk of subsequent recurrence.

Provincial rates and time trends in pancreatic cancer outcomes

Pancreatic cancer, often called the “silent killer,” is the twelfth most common cancer in Canada, with an estimated 4600 new cases in 2012. [...]

Conditional survival after radical cystectomy for bladder cancer: evidence for a patient changing risk profile over time

BACKGROUND

Standard survival statistics do not take into consideration the changes in the weight of individual variables at subsequent times after the diagnosis and initial treatment of bladder cancer.

OBJECTIVE

To assess the changes in 5-yr conditional survival (CS) rates after radical cystectomy for bladder cancer and to determine how well-established prognostic factors evolve over time.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed data from 8141 patients treated with radical cystectomy at 15 international academic centers between 1979 and 2012.

INTERVENTIONS

Radical cystectomy and pelvic lymph node dissection.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Conditional cancer-specific survival (CSS) and overall survival (OS) estimates were calculated using the Kaplan-Meier method. The multivariable Cox regression model was used to calculate proportional hazard ratios for the prediction of mortality after stratification by clinical characteristics (age, perioperative chemotherapy status) and pathologic characteristics (pT stage, grade, lymphovascular invasion, pN stage, number of nodes removed, margin status). The median follow-up was 32 mo.

RESULTS AND LIMITATIONS

The 5-yr CSS and OS rates were 67.7% and 57.5%, respectively. Given a 1-, 2-, 3-, 5- and 10-yr survivorship, the 5-yr conditional OS rates improved by +5.6 (60.7%), +8.4 (65.8%), +7.6 (70.8%), +3.0 (72.9%), and +1.9% (74.3%), respectively. The 5-yr conditional CSS rates improved by +5.6 (71.5%), +9.8 (78.5%), +7.9 (84.7%), +7.2 (90.8%), and 5.6% (95.9%), respectively. The 5- and 10-yr CS improvement was primarily noted among surviving patients with advanced stage disease. The impact of pathologic parameters on CS estimates decreased over time for both CSS and OS. Findings were confirmed on multivariable analyses. The main limitation was the retrospective design.

CONCLUSIONS

CS analysis demonstrates that the patient risk profile changes over time. The risk of mortality decreases with increasing survivorship. The CS rates improve mainly in the case of advanced stage disease. The impact of prognostic pathologic features decreases over time and can disappear for long-term CS.

Conditional survival for longer-term survivors from 2000-2004 using population-based cancer registry data in Osaka, Japan

Background

We usually report five-year survival from population-based cancer registries in Japan; however these survival estimates may be pessimistic for cancer survivors, because many patients with unfavourable prognosis die shortly after diagnosis. Conditional survival can provide relevant information for cancer survivors, their family and oncologists.

Methods

We used the period approach to estimate the latest 10-year survival of 38,439 patients with stomach, colorectal, lung, breast and prostate cancer diagnosed between 1990 and 2004 and followed-up from 2000–04 in Osaka, Japan. Conditional survival is an estimate, with the pre-condition of having already survived a certain length of time. Conditional five-year relative survival of one to five years after diagnosis was calculated by site, age and stage for survivors under the age of 70.

Results

Five-year relative survival for stomach cancer was 60%. Conditional five-year relative survival was 77% one year after diagnosis and 97% five years after diagnosis. This means that 97% of patients who survive five years after diagnosis can survive a further five years. Conditional five-year relative survival improved successively with each additional year that patients lived after diagnosis for stomach, colorectal and lung cancer. These figures for breast and prostate cancer were stable at high survival. Liver cancer did not show an increase in conditional five-year survival.

Conclusion

Conditional five-year survival is a relevant figure for long-term cancer survivors in Japan. It is important for population-based cancer registries to provide figures which cancer patients and oncologists really need.