TY - JOUR
T1 - Circumferential Resection Margin as Predictor of Nonclinical Complete Response in Nonoperative Management of Rectal Cancer
AU - Chin, Re I.
AU - Schiff, Joshua P.
AU - Shetty, Anup S.
AU - Pedersen, Katrina S.
AU - Aranha, Olivia
AU - Huang, Yi
AU - Hunt, Steven R.
AU - Glasgow, Sean C.
AU - Tan, Benjamin R.
AU - Wise, Paul E.
AU - Silviera, Matthew L.
AU - Smith, Radhika K.
AU - Suresh, Rama
AU - Byrnes, Kathleen
AU - Samson, Pamela P.
AU - Badiyan, Shahed N.
AU - Henke, Lauren E.
AU - Mutch, Matthew G.
AU - Kim, Hyun
N1 - Publisher Copyright:
© 2023 Lippincott Williams and Wilkins. All rights reserved.
PY - 2023/7
Y1 - 2023/7
N2 - BACKGROUND: Short-course radiation therapy and consolidation chemotherapy with nonoperative intent has emerged as a novel treatment paradigm for patients with rectal cancer, but there are no data on the predictors of clinical complete response. OBJECTIVE: Evaluate the predictors of clinical complete response and survival. DESIGN: Retrospective cohort. SETTINGS: National Cancer Institute-designated cancer center. PATIENTS: Patients with stage I to III rectal adenocarcinoma treated between January 2018 and May 2019 (n = 86). INTERVENTIONS: Short-course radiation therapy followed by consolidation chemotherapy. MAIN OUTCOME MEASURES: Logistic regression was performed to assess for predictors of clinical complete response. The end points included local regrowth-free survival, regional control, distant metastasis-free survival, and overall survival. RESULTS: A positive (+) circumferential resection margin by MRI at diagnosis was a significant predictor of nonclinical complete response (OR: 4.1, p = 0.009) when adjusting for CEA level and primary tumor size. Compared to patients with a negative (-) pathologic circumferential resection margin, patients with a positive (+) pathologic circumferential resection margin had inferior local regrowth-free survival (29% vs 87%, p < 0.001), regional control (57% vs 94%, p < 0.001), distant metastasis-free survival (43% vs 95%, p < 0.001), and overall survival (86% vs 95%, p < 0.001) at 2 years. However, the (+) and (-) circumferential resection margin by MRI subgroups in patients who had a clinical complete response both had similar regional control, distant metastasis-free survival, and overall survival of more than 90% at 2 years. LIMITATIONS: Retrospective design, modest sample size, short follow-up, and the heterogeneity of treatments. CONCLUSIONS: Circumferential resection margin involvement by MRI at diagnosis is a strong predictor of nonclinical complete response. However, patients who achieve a clinical complete response after short-course radiation therapy and consolidation chemotherapy with nonoperative intent have excellent clinical outcomes regardless of the initial circumferential resection margin status.
AB - BACKGROUND: Short-course radiation therapy and consolidation chemotherapy with nonoperative intent has emerged as a novel treatment paradigm for patients with rectal cancer, but there are no data on the predictors of clinical complete response. OBJECTIVE: Evaluate the predictors of clinical complete response and survival. DESIGN: Retrospective cohort. SETTINGS: National Cancer Institute-designated cancer center. PATIENTS: Patients with stage I to III rectal adenocarcinoma treated between January 2018 and May 2019 (n = 86). INTERVENTIONS: Short-course radiation therapy followed by consolidation chemotherapy. MAIN OUTCOME MEASURES: Logistic regression was performed to assess for predictors of clinical complete response. The end points included local regrowth-free survival, regional control, distant metastasis-free survival, and overall survival. RESULTS: A positive (+) circumferential resection margin by MRI at diagnosis was a significant predictor of nonclinical complete response (OR: 4.1, p = 0.009) when adjusting for CEA level and primary tumor size. Compared to patients with a negative (-) pathologic circumferential resection margin, patients with a positive (+) pathologic circumferential resection margin had inferior local regrowth-free survival (29% vs 87%, p < 0.001), regional control (57% vs 94%, p < 0.001), distant metastasis-free survival (43% vs 95%, p < 0.001), and overall survival (86% vs 95%, p < 0.001) at 2 years. However, the (+) and (-) circumferential resection margin by MRI subgroups in patients who had a clinical complete response both had similar regional control, distant metastasis-free survival, and overall survival of more than 90% at 2 years. LIMITATIONS: Retrospective design, modest sample size, short follow-up, and the heterogeneity of treatments. CONCLUSIONS: Circumferential resection margin involvement by MRI at diagnosis is a strong predictor of nonclinical complete response. However, patients who achieve a clinical complete response after short-course radiation therapy and consolidation chemotherapy with nonoperative intent have excellent clinical outcomes regardless of the initial circumferential resection margin status.
KW - Circumferential resection margin
KW - Clinical complete response
KW - Nonoperative management
KW - Rectal cancer
KW - Short-course radiation therapy
UR - http://www.scopus.com/inward/record.url?scp=85162854791&partnerID=8YFLogxK
U2 - 10.1097/DCR.0000000000002654
DO - 10.1097/DCR.0000000000002654
M3 - Article
C2 - 36876988
AN - SCOPUS:85162854791
SN - 0012-3706
VL - 66
SP - 973
EP - 982
JO - Diseases of the Colon and Rectum
JF - Diseases of the Colon and Rectum
IS - 7
ER -