Effect of Adjuvant Chemotherapy on Survival of Patients With Stage III Colon Cancer Diagnosed After Age 75 Years
ABSTRACT Few patients 75 years of age and older participate in clinical trials, thus whether adjuvant chemotherapy for stage III colon cancer (CC) benefits this group is unknown.
A total of 5,489 patients ≥ 75 years of age with resected stage III CC, diagnosed between 2004 and 2007, were selected from four data sets containing demographic, stage, treatment, and survival information. These data sets included SEER-Medicare, a linkage between the New York State Cancer Registry (NYSCR) and its Medicare programs, and prospective cohort studies Cancer Care Outcomes Research and Surveillance Consortium (CanCORS) and the National Comprehensive Cancer Network. Data sets were analyzed in parallel using covariate adjusted and propensity score (PS) matched proportional hazards models to evaluate the effect of treatment on survival. PS trimming was used to mitigate the effects of selection bias.
Use of adjuvant therapy declined with age and comorbidity. Chemotherapy receipt was associated with a survival benefit of comparable magnitude to clinical trials results (SEER-Medicare PS-matched mortality, hazard ratio [HR], 0.60; 95% CI, 0.53 to 0.68). The incremental benefit of oxaliplatin over non-oxaliplatin-containing regimens was also of similar magnitude to clinical trial results (SEER-Medicare, HR, 0.84; 95% CI, 0.69 to 1.04; NYSCR-Medicare, HR, 0.82, 95% CI, 0.51 to 1.33) in two of three examined data sources. However, statistical significance was inconsistent. The beneficial effect of chemotherapy and oxaliplatin did not seem solely attributable to confounding.
The noninvestigational experience suggests patients with stage III CC ≥ 75 years of age may anticipate a survival benefit from adjuvant chemotherapy. Oxaliplatin offers no more than a small incremental benefit. Use of adjuvant chemotherapy after the age of 75 years merits consideration in discussions that weigh individual risks and preferences.
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ABSTRACT: Given the paucity of information on dose intensity, the objective of this study is to describe the use of adjuvant chemotherapy for stage III colon cancer, focusing on relative dose intensity (RDI), overall survival (OS) and disease-free survival (DFS). Retrospective cohort of 367 patients diagnosed with stage III colon cancer in 2003-2008 and treated at 19 VA medical centers. Kaplan-Meier curves summarize 5-year OS and 3-year DFS by chemotherapy regimen and RDI, and multivariable Cox proportional hazards regression was used to model these associations. 5-fluorouracil/leucovorin (FU/LV) was the most commonly initiated regimen in 2003 (94.4%) and 2004 (62.7%); in 2005-2008, a majority of patients (60%-74%) was started on an oxaliplatin-based regimen. Median RDI was 82.3%. Receipt of >70% RDI was associated with better 5-year OS (p < 0.001) and 3-year DFS (P = 0.009) than was receipt of ≤70% RDI, with 5-year OS rates of 66.3% and 50.5%, respectively and 3-year DFS rates of 66.1% and 52.7%, respectively. In the multivariable analysis of 5-year OS, oxaliplatin + 5-FU/LV (versus 5-FU/LV) (HR = 0.55; 95% CI = 0.34-0.91), >70% RDI at the first year (HR = 0.58; 95% CI = 0.37-0.89) and married status (HR = 0.66; 95% CI = 0.45-0.97) were associated with significantly decreased risk of death, while age ≥75 (versus 55-64) (HR = 2.06; 95% CI = 1.25-3.40), Charlson Comorbidity Index (HR = 1.17; 95% CI = 1.06-1.30), T4 tumor status (versus T1/T2) (HR = 5.88; 95% CI = 2.69-12.9), N2 node status (HR = 1.68; 95% CI = 1.12-2.50) and bowel obstruction (HR = 2.32, 95% CI = 1.36-3.95) were associated with significantly increased risk. Similar associations were observed for DFS. Patients with stage III colon cancer who received >70% RDI had improved 5-year OS. The association between RDI and survival needs to be examined in studies of adjuvant chemotherapy for colon cancer outside of the VA.BMC Cancer 12/2015; 15(1):1038. DOI:10.1186/s12885-015-1038-y · 3.32 Impact Factor
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ABSTRACT: This evidence-based review will discuss the current standard of adjuvant chemotherapy for resected high-risk colon cancer and address existing controversies including strategies for risk-stratification, the status of targeted therapy, treatment of the elderly and the optimal duration of therapy.Indian journal of medical and paediatric oncology 07/2014; 35(3):197-202. DOI:10.4103/0971-5851.142032
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ABSTRACT: Colorectal cancer (CRC) is mainly a disease of the elderly. Our primary aim was to investigate if age had influence on treatment decisions in regards to surgery, referral to an oncologist and treatment by an oncologist. We identified patients with CRC in our department from 2004 through 2011 in the Danish Colorectal Cancer Group (DCCG) database. According to age ≤75 and >75 years multivariate logistic regression analysis was used on treatment decisions: surgery, referral to an oncologist and oncologic treatment. Independent variables were age, ASA score, tumorlocation, stage, gender and year of diagnosis. Additional analysis was performed for stage III and IV patients as a subgroup. 1701 patients were included of which 525 were >75 years of age. In multivariate analysis there was no association between age and chance of surgery. Older patients had a significantly lower odds ratio for referral to an oncologist (OR 0.624, p < 0.0001) and for oncological treatment if referred (OR 0.218, p < 0.0001). Being an elderly patient with stage III or IV CRC OR was 0.233 for referral- and for receiving treatment by an oncologist OR was 0.210 (p < 0.0001 for both), after adjusting for possible confounders. Based on age elderly patients are on a lesser extent referred to an oncologist and get oncologic treatment less frequently. Surgically the elderly are not undertreated. Copyright © 2014 Elsevier Ltd. All rights reserved.European Journal of Surgical Oncology 01/2015; 41(3). DOI:10.1016/j.ejso.2014.10.065 · 2.89 Impact Factor