Conditional Survival Estimates Improve Over Time for Patients with Hepatocellular Carcinoma: An Analysis for Nationwide Korea Cancer Registry Database / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Conditional survival estimates (CSE) can provide additional useful prognostic information on the period of survival after diagnosis, which helps in counseling patients with cancer on their individual prognoses. This study aimed to analyze conditional survival (CS) for hepatocellular carcinoma (HCC) using a Korean national registry. MATERIALS AND METHODS: Patients with HCC, registered in the Korean cancer registry database, were retrospectively reviewed. Overall survival (OS) was calculated using the Kaplan-Meier method. The 1-year CS at X year or month after diagnosis were calculated as CS₁=OS((X+1))/OS((X)). CS calculations were performed in each Barcelona Clinic Liver Cancer stage, after which patients at stage 0, A, and B underwent subgroup analysis using initial treatment methods. RESULTS: A total of 4,063 patients diagnosed with HCC from January 2008 to December 2010, and 2,721 who were diagnosed from January 2011 to December 2012, were separately reviewed. In 2008-2010, the 1-year CS of 1, 2, 3, 4, and 5-year survivors was 82.9%, 85.1%, 88.3%, 88.0%, and 88.6%, respectively. Patients demonstrated an increase in CSE over time in subgroup analysis, especially in the advanced stages. In 2011-2012, the 1-year CS of 6, 12, 18, 24, 30, and 36 months was 81.5%, 83.8%, 85.3%, 85.5%, 86.5%, and 88.8%, respectively. The subgroup analysis showed the same tendency towards increased CSE in the advanced stages. CONCLUSION: Overall, the CS improved with each additional year after diagnosis in both groups. CSE may therefore provide a more accurate prognosis and hopeful message to patients who are surviving with or after treatment.

A National Study of Survival Trends and Conditional Survival in Nasopharyngeal Carcinoma: Analysis of the National Population-Based Surveillance Epidemiology and End Results Registry / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Conditional survival (CS) provides important information on survival for a period of time after diagnosis. Currently, information on CS patterns of patients with nasopharyngeal carcinoma (NPC) is lacking. We aimed to analyze survival rate over time and estimate CS for NPC patients using a national population-based registry. MATERIALS AND METHODS: Patients diagnosed with NPC between 1973 and 2007 with at least 5-year follow-up were identified from the Surveillance Epidemiology End Results registry. Traditional survival rates and crude CS estimateswere calculated using Kaplan-Meier analysis. Risk-adjusted survival curves were plotted from the proportional hazards model using the correct group prognosis method. RESULTS: For 7,713 patients analyzed, adjusted baseline 5-year overall survival improved significantly from 36.0% in patients diagnosed in 1973-1979, 41.7% in 1980-1989, 46.6% in 1990-1999, to 54.7% in 2000-2007 (p < 0.01). CS analysis demonstrated that for every additional year survived, adjusted probability of surviving the next 5 years increased from 66.7% (localized), 54.0% (regional), and 35.3% (distant) at the time of diagnosis, to 83.7% (localized), 75.0% (regional), and 62.2% (distant) for patients who had survived 5 years. Adjusted 5-year CS differed among age, sex, tumor histology, ethnicity, and stage subgroups initially, but converged with time. CONCLUSION: Treatment outcomes of NPC patients have greatly improved over the decades. Increases in CS become more prominent in patients with distant disease than in those with localized or regional disease as patients survive longer. CS provides more dynamic prognostic information for patients who have survived a period of time after diagnosis.