Staging and Survival of Colorectal Cancer (CRC) in Octogenarians: Nationwide Study of U.S. Veterans: 2017 Presidential Poster Award

Abstract

Introduction: USPSTF recommends against continuing screening for colorectal cancer past 75 years in adequately screened individuals. Research has shown that one time screening for elderly who have never been screened appears to be cost effective until 86 years of age. Risk stratification should be made based on life expectancy and risk to benefit ratio. Survival and staging data that compares elderly vs younger populations has not been published. Objective:1)To compare staging(0-4) of CRC in groups of 60-69, 70-79 and 80-89 year olds. 2)To compare survival outcomes(5-10 years) in stages 0-2 for these age groups after treatment i.e. surgery. 3)To compare surgical and no treatment (i.e. no surgery) survival outcomes in these age groups.Figure: Image 1.Figure: Image 2.Figure: Image 3.Methods: In a retrospective study, male veterans were selected from Veterans Affairs National Cancer Cube Registry. 22,735 patients within 60-69, 18,390 within 70-79 and 10,057 within 80-89 years were diagnosed with CRC from year 2000-2015 with majority being stage 1& 2[Image1]. Surgical and survival data were obtained only for stage 0-2 as surgery is the current standard of treatment for these stages. Results: After surgery, 5-10 year survival for 60-69 age group averaged about 34.4%[95%CI 31.94, 36.85] for stage 0-2. Similarly, for 70-79 and 80-89 age group it was 30.86%[95%CI 29.54, 32.19] and 25.45%[95% CI 24.77, 25.69] respectively[Image2]. The 5-10 year survival data for patients without treatment i.e. not undergoing surgery was 1.03%[95%CI 0.32, 1.74], 0.81%[95% CI -0.10, 1.73], and 0.95%[95%CI 0.33, 1.56] for age groups 60-69, 70-79 and 80-89 respectively[Image3]. When compared to surgery vs. no treatment there was significant difference( P<0.05) in all age groups for survival 5-10 years. Conclusion: Highest number of CRC cases diagnosed across each age group were stage 1 with stage 2 being second. In the surgical treatment group survival was statistically different for 80-89 age group as compared to 60-69 and 70-79, though octogenarians did have a surprisingly high mean of 25.45% suggesting early detection and treatment will help survival. Survival data from surgery and no-treatment cases showed an immense drop in survival for non-treated patients suggesting these candidates may have other reasons or comorbid conditions leading to their demise. Overall data showing early stage at cancer diagnosis and comparable surgical survival in octogenarians suggest those who have life expectancy 5-10 years could benefit from continued screening and treatment.