Minyong Kang1, Jae Young Park2, Chang Wook Jeong3, Eu Chang Hwang4, Cheryn Song5, Sung-Hoo Hong6, Cheol Kwak3, Jinsoo Chung7, Hyun Hwan Sung1, Hwang Gyun Jeon1, Byong Chang Jeong8, Se Hoon Park9, Seong Soo Jeon1, Hyun Moo Lee1, Han Yong Choi10, Seong Il Seo11. 1. Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. 2. Department of Urology, Korea University College of Medicine, Seoul, Republic of Korea. 3. Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea. 4. Department of Urology, Chonnam National University Hwasun Hospital, Hwasun, Republic of Korea. 5. Department of Urology, Asan Medical Center, Seoul, Republic of Korea. 6. Department of Urology, Seoul St. Mary's Hospital, Seoul, Republic of Korea. 7. Department of Urology, National Cancer Center, Goyang, Republic of Korea. 8. Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea. 9. Division of Hematology-Oncology, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. 10. Department of Urology, Kangbuk Samsung Hospital, Seoul, Republic of Korea. 11. Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: siseo@skku.edu.
Abstract
PURPOSE: In this study we evaluated conditional survival probabilities in patients with metastatic renal cell carcinoma who underwent first line tyrosine kinase inhibitor therapy. We also identified predictors of conditional survival with time. MATERIALS AND METHODS: We retrospectively reviewed clinical data on 1,659 individuals with metastatic renal cell carcinoma in the Korean Renal Cancer Study Group database, of whom the records of 1,131 were finally analyzed. The primary end point was conditional overall survival. Kaplan-Meier survival analysis was used to calculate conditional overall survival probabilities using the formula, conditional survival (α│β) = S(α + β)/S(β), indicating the likelihood of additional α years survivorship in person who has already survived for β years after initial therapy. S(χ) represents the actual survival rate. Multivariate Cox regression model was used to identify predictors of conditional survival with time. RESULTS: Six, 12, 18, 24 and 36-month conditional overall survival gradually increased in patients at all additional survival times after initial treatment compared to patient baseline survival estimations. While the actual overall survival rate decreased with time, the 36-month conditional overall survival rate was calculated as 7.3% higher in patients who had already survived 36 months compared to baseline estimations at the time of initial tyrosine kinase inhibitor treatment. Furthermore, predictors of conditional overall survival changed with time. Only previous metastasectomy remained a key prognosticator of conditional overall survival until 36 months of survival following initial tyrosine kinase inhibitor treatment. CONCLUSIONS: Conditional survival improved with time after initial tyrosine kinase inhibitor treatment in patients with metastatic renal cell carcinoma. Our study offers valuable information for practical survival estimations and relevant prognosticators in patients with metastatic renal cell carcinoma who receive first line tyrosine kinase inhibitor.
PURPOSE: In this study we evaluated conditional survival probabilities in patients with metastatic renal cell carcinoma who underwent first line tyrosine kinase inhibitor therapy. We also identified predictors of conditional survival with time. MATERIALS AND METHODS: We retrospectively reviewed clinical data on 1,659 individuals with metastatic renal cell carcinoma in the Korean Renal Cancer Study Group database, of whom the records of 1,131 were finally analyzed. The primary end point was conditional overall survival. Kaplan-Meier survival analysis was used to calculate conditional overall survival probabilities using the formula, conditional survival (α│β) = S(α + β)/S(β), indicating the likelihood of additional α years survivorship in person who has already survived for β years after initial therapy. S(χ) represents the actual survival rate. Multivariate Cox regression model was used to identify predictors of conditional survival with time. RESULTS: Six, 12, 18, 24 and 36-month conditional overall survival gradually increased in patients at all additional survival times after initial treatment compared to patient baseline survival estimations. While the actual overall survival rate decreased with time, the 36-month conditional overall survival rate was calculated as 7.3% higher in patients who had already survived 36 months compared to baseline estimations at the time of initial tyrosine kinase inhibitor treatment. Furthermore, predictors of conditional overall survival changed with time. Only previous metastasectomy remained a key prognosticator of conditional overall survival until 36 months of survival following initial tyrosine kinase inhibitor treatment. CONCLUSIONS: Conditional survival improved with time after initial tyrosine kinase inhibitor treatment in patients with metastatic renal cell carcinoma. Our study offers valuable information for practical survival estimations and relevant prognosticators in patients with metastatic renal cell carcinoma who receive first line tyrosine kinase inhibitor.