Radiosensitivity index predicts for survival with adjuvant radiation in resectable pancreatic cancer. Issue 1 (October 2015)

• Record Type: Journal Article
• Authors: Strom, Tobin; Hoffe, Sarah E.; Fulp, William; Frakes, Jessica; Coppola, Domenico; Springett, Gregory M.; Malafa, Mokenge P.; Harris, Cynthia L.; Eschrich, Steven A.; Torres-Roca, Javier F.; Shridhar, Ravi
• Is Part Of: Radiotherapy and oncology. Volume 117:Issue 1(2015:Oct.)
• Page Start: 159
• Page End: 164
• Publication Date: 2015-10
• Subjects: Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2015.07.018
• Languages: English
• ISSNs: 0167-8140

Abstract

<abstract xml:lang="en" abstract-type="author" id="ab005"> <title id="st005">Abstract</title> <sec> <title id="st010">Background and purpose</title> <p id="sp0005">Adjuvant radiation therapy for resectable pancreatic cancer remains controversial. Sub-populations of radiosensitive tumors might exist given the genetic heterogeneity of pancreatic cancers. We evaluated whether RSI is predictive of survival in pancreatic cancer treated with radiation.</p> </sec> <sec> <title id="st015">Materials and methods</title> <p id="sp0010">We identified 73 genomically-profiled pancreas cancer patients treated with upfront surgery between 2000 and 2011 (48 radiation, 25 no radiation). Briefly, RSI score is derived from the expression of 10 specific genes and a linear regression algorithm modeled on SF2 of 48 cancer cells. The primary endpoint was to assess the association of RSI with overall survival.</p> </sec> <sec> <title id="st020">Results</title> <p id="sp0015">Median follow-up was 67 months for surviving patients. On multivariate analysis, patients with radioresistant tumors had a trend toward worse survival (Hazard ratio [HR] 2.1 [95% CI 1.0–4.3], <italic>p</italic> = 0.054). Among high-risk, irradiated patients (positive margins, positive lymph nodes, or a post-operative CA19-9 >90; <italic>n</italic> = 31), radiosensitive patients had significantly improved survival compared with radioresistant patients (median 31.2 vs. 13.2 months; HR 0.42 [0.19, 0.94], <italic>p</italic> = 0.04). Among irradiated patients (<italic>n</italic> = 48), low-risk patients lived longer than both high-risk patients with radiosensitive tumors and radioresistant tumors (HR 2.7 [1.0, 7.2], <italic>p</italic> = 0.04 and HR 6.3 [2.3, 17.0], <italic>p</italic> < 0.001, respectively).</p> </sec> <sec> <title id="st025">Conclusions</title> <p id="sp0020">Integrating RSI with standard high-risk variables has the potential to refine the classification of high-risk resected pancreatic cancer patients treated with radiation therapy.</p> </sec> </abstract>