TY - JOUR
T1 - Adjuvant Chemotherapy Is Associated With Improved Overall Survival in Locally Advanced Rectal Cancer After Achievement of a Pathologic Complete Response to Chemoradiation
AU - Shahab, Danish
AU - Gabriel, Emmanuel
AU - Attwood, Kristopher
AU - Ma, Wen Wee
AU - Francescutti, Valerie
AU - Nurkin, Steven
AU - Boland, Patrick M.
N1 - Publisher Copyright:
© 2017 The Authors
PY - 2017/12
Y1 - 2017/12
N2 - Micro-Abstract Patients with rectal cancer and a complete response (pCR) to chemoradiation have an excellent prognosis. Adjuvant chemotherapy is controversial and used only in a few cases. The results of the present study have demonstrated associations between survival and age, comorbidities, carcinoembryonic antigen, and chemotherapy use in this population. Thus, chemotherapy appears to be underused in the pCR setting. Background In locally advanced rectal adenocarcinoma, 15% to 20% of patients treated with neoadjuvant chemoradiation (nCRT) achieve a pathologic complete response (pCR). The benefit of adjuvant chemotherapy is controversial in rectal cancer. Our objective was to evaluate the effect of clinical risk factors and adjuvant chemotherapy usage on the outcomes of the pCR patient population. Patients and Methods We performed a retrospective study using the National Cancer Data Base from 2006 to 2013. The primary outcome was overall survival (OS). The association between OS and patient characteristics (demographics, tumor variables, and treatment) was examined using multivariable Cox regression modelling. Results A total of 2891 patients were identified who had achieved a pCR. Of these 2891 patients, 2102 received nCRT and 789 received nCRT followed by adjuvant chemotherapy. The median follow-up duration was 43.2 months. The factors significantly associated with OS included age (P <.001), gender (P =.011), Charlson-Deyo comorbidity score (P <.001), grade (P =.029), clinical T stage (P =.030), carcinoembryonic antigen negativity (P =.002), and receipt of adjuvant chemotherapy (P <.001). Nodal status was not significantly associated with survival. The 5-year OS rate was 94% in the nCRT plus adjuvant group compared with 84% in the nCRT-alone group. Adjuvant chemotherapy was more likely to be given to younger patients (aged < 60 years), higher grade, lower Charlson-Deyo comorbidity score, elevated carcinoembryonic antigen level, higher clinical T stage, and higher clinical N stage. Conclusion Our findings showed a significant improvement in OS for patients who received nCRT plus adjuvant chemotherapy compared with those who received nCRT alone. The nCRT plus adjuvant patients were more likely to be younger, have a lower comorbidity score, have clinical ≥ T3 disease, and have clinical node-positive disease. Thus, a selection bias could have been present. Nonetheless, even in the setting of already excellent outcomes, for patients with locally advanced rectal adenocarcinoma who achieve a pCR, the additional benefit of adjuvant chemotherapy should be weighed against the potential for toxicity.
AB - Micro-Abstract Patients with rectal cancer and a complete response (pCR) to chemoradiation have an excellent prognosis. Adjuvant chemotherapy is controversial and used only in a few cases. The results of the present study have demonstrated associations between survival and age, comorbidities, carcinoembryonic antigen, and chemotherapy use in this population. Thus, chemotherapy appears to be underused in the pCR setting. Background In locally advanced rectal adenocarcinoma, 15% to 20% of patients treated with neoadjuvant chemoradiation (nCRT) achieve a pathologic complete response (pCR). The benefit of adjuvant chemotherapy is controversial in rectal cancer. Our objective was to evaluate the effect of clinical risk factors and adjuvant chemotherapy usage on the outcomes of the pCR patient population. Patients and Methods We performed a retrospective study using the National Cancer Data Base from 2006 to 2013. The primary outcome was overall survival (OS). The association between OS and patient characteristics (demographics, tumor variables, and treatment) was examined using multivariable Cox regression modelling. Results A total of 2891 patients were identified who had achieved a pCR. Of these 2891 patients, 2102 received nCRT and 789 received nCRT followed by adjuvant chemotherapy. The median follow-up duration was 43.2 months. The factors significantly associated with OS included age (P <.001), gender (P =.011), Charlson-Deyo comorbidity score (P <.001), grade (P =.029), clinical T stage (P =.030), carcinoembryonic antigen negativity (P =.002), and receipt of adjuvant chemotherapy (P <.001). Nodal status was not significantly associated with survival. The 5-year OS rate was 94% in the nCRT plus adjuvant group compared with 84% in the nCRT-alone group. Adjuvant chemotherapy was more likely to be given to younger patients (aged < 60 years), higher grade, lower Charlson-Deyo comorbidity score, elevated carcinoembryonic antigen level, higher clinical T stage, and higher clinical N stage. Conclusion Our findings showed a significant improvement in OS for patients who received nCRT plus adjuvant chemotherapy compared with those who received nCRT alone. The nCRT plus adjuvant patients were more likely to be younger, have a lower comorbidity score, have clinical ≥ T3 disease, and have clinical node-positive disease. Thus, a selection bias could have been present. Nonetheless, even in the setting of already excellent outcomes, for patients with locally advanced rectal adenocarcinoma who achieve a pCR, the additional benefit of adjuvant chemotherapy should be weighed against the potential for toxicity.
KW - Adjuvant chemotherapy
KW - Chemoradiotherapy
KW - Colorectal cancer
KW - nCRT
KW - pCR
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U2 - 10.1016/j.clcc.2017.03.005
DO - 10.1016/j.clcc.2017.03.005
M3 - Article
C2 - 28420585
AN - SCOPUS:85017478811
SN - 1533-0028
VL - 16
SP - 300
EP - 307
JO - Clinical colorectal cancer
JF - Clinical colorectal cancer
IS - 4
ER -