Association of adjuvant chemotherapy with clinical outcomes in patients treated with neoadjuvant chemoradiation for locally advanced rectal cancer.
2014; Lippincott Williams & Wilkins; Volume: 32; Issue: 15_suppl Linguagem: Inglês
10.1200/jco.2014.32.15_suppl.3628
ISSN1527-7755
AutoresMichael M. Vickers, Jamison Mercer, Aalok Kumar, Gillian Gresham, Rachel Goodwin, Di Jiang, Patricia A. Tang, Soundouss Raissouni, Erin Powell, Julie A. Price Hiller, Jose Gerard Monzon, Winson Y. Cheung, Daniel Yick Chin Heng,
Tópico(s)Colorectal Cancer Treatments and Studies
Resumo3628 Background: Clinical trial data does not support the routine use of adjuvant chemotherapy (ACT) following neoadjuvant chemoradiation (nCRT) and surgery (Sx) in rectal cancer (Ca). Few studies have included oxaliplatin-based ACT or assessed the benefit in specific pathologic stage (Pstage) subgroups. Methods: Data from patients (pts) with locally advanced rectal Ca who received nCRT and had curative intent Sx from 2005 to 2012 were collected from Tom Baker Cancer Center, Cross Cancer Institute, BC Cancer Agency, Ottawa Hospital Cancer Centre and Dr. H. Bliss Murphy Cancer Centre. The effect of ACT on Time Free of Recurrence (TFR – death without recurrence censored), Disease Free Survival (DFS) and Overall Survival (OS) was assessed using cox proportional hazards model, controlling for age, sex, performance status (PS), circumferential resection margin (CRM), location of tumor, RT dose, Clinical stage (Cstage), Pstage. Results: 1172 pts were included, with a mean age of 61.6 (± 0.33) and a mean follow-up time of 3.8 years (± 0.05). 303 (25.9%) pts received oxaliplatin-based ACT, while 328 (28%) did not receive any ACT and these pts were more likely to be older (65.8 v 65 yrs, p<0.0001), have worse PS (p=0.009), receive lower doses of RT (p=0.0003) and have earlier Cstage (p=0.004) on univariate analysis compared with ACT pts. Univariate analyses for Pstage 0-II were non-significant (NS) for effect of ACT on TFR and DFS. See Table for all pts and Pstage III outcomes controlling for covariates above. Assessment of ACT in high risk v low risk stage II (as in colon Ca) was NS for TFR (p=0.47), DFS (p=0.7) and OS (p=0.7) adjusting for age, PS and CRM. Conclusions: ACT improved clinical outcomes in our retrospective database, however the benefits may be limited to those with Pstage III. Studies are needed to clarify if factors used to stratify stage II colon Ca into high vs. low risk may be applied to estimate recurrence risk in Pstage II rectal Ca. Population TFR (95% CIs) p-value DFS (95% CIs) p-value OS (95% CIs) p-value All pts ACT v no ACT 0.84 (0.59 – 1.18) 0.31 0.63 (0.47 –0.85) 0.002 0.52 (0.36 – 0.75) 0.0004 Pstage III ACT v no ACT 0.6 (0.39 – 0.93) 0.02 0.53 (0.35 – 0.8) 0.002 0.48 (0.29 – 0.79) 0.004
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