Survival Outcomes After Surgical Management of the Primary Tumor With and Without Radiotherapy for Metastatic Rectal Adenocarcinoma: A National Cancer Database (NCDB) Analysis

• Published in: Clinical colorectal cancer 2019-06, Vol.18 (2), p.e237-e243
• Main Authors: Renz, Paul, Wegner, Rodney E., Hasan, Shaakir, Brookover, Robert, Finley, Gene, Monga, Dulabh, Raj, Moses, McCormick, James, Kirichenko, Alexander
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - mortality; Adenocarcinoma - pathology; Adenocarcinoma - therapy; Adolescent; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Chemoradiotherapy, Adjuvant - methods; Databases, Factual - statistics & numerical data; Datasets as Topic; Female; Fluorouracil - therapeutic use; Follow-Up Studies; Humans; Kaplan-Meier Estimate; Leucovorin - therapeutic use; Local therapy; Male; Middle Aged; Neoplasm Staging; Organoplatinum Compounds - therapeutic use; Proctectomy; Proportional Hazards Models; Radiation therapy; Rectal cancer; Rectal Neoplasms - mortality; Rectal Neoplasms - pathology; Rectal Neoplasms - therapy; Rectum - pathology; Rectum - radiation effects; Rectum - surgery; Stage IV; Time Factors; Treatment Outcome; Young Adult
• ISSN: 1533-0028; 1938-0674
• DOI: 10.1016/j.clcc.2018.12.005

With advances in systemic therapies, the role of primary tumor resection may be of increased importance in patients with metastatic rectal cancer. The role of combining pelvic radiotherapy with surgical resection in the metastatic setting is unknown. We utilized the National Cancer Database to examine outcomes in patients with metastatic rectal adenocarcinoma with primary tumor resection with and without pelvic radiotherapy. We queried the National Cancer Database from 2004 to 2014 for patients with stage IV rectal adenocarcinoma receiving chemotherapy. We identified 4051 patients in that group that had primary tumor resection. Patients were then stratified by receipt of pelvic radiotherapy (yes = 1882; no = 2169) Univariable and multivariable analyses identified characteristics predictive of overall survival. Propensity-adjusted Cox proportional hazard ratios for survival were used to account for indication bias. The median patient age was 63 years (range, 18-90 years) with a median follow-up of 32.3 months (range, 3.02-151.29 months). There were proportionately more patients with T3/T4 disease or N1 disease in the surgery plus radiotherapy arm. The median survival was 46.3 months versus 35.3 months in favor of addition of radiotherapy (P < .001). The 2- and 5-year overall survival was 68.4% and 24.8% for surgical resection alone compared with 77.2% and 39.6% for surgery + radiotherapy. On propensity-adjusted multivariable analysis, radiotherapy was associated with a statistically significant reduction in risk of death (hazard ratio, 0.722; 95% confidence interval, 0.0665-0.784). This analysis indicates that in patients with metastatic rectal adenocarcinoma receiving chemotherapy, pelvic radiotherapy in addition to primary tumor resection may be of significant benefit. The present study examines outcomes in patients with stage IV rectal cancer receiving some form of local therapy. That local therapy was either surgery alone or chemoradiation followed by surgery. The authors’ analysis showed a benefit to the addition of chemoradiation to surgery, even in the metastatic setting highlighting the need for multidisciplinary management in this patient population.