The influence of seminal events on the transition from adjuvant to neoadjuvant chemoradiation in the treatment of locally advanced rectal adenocarcinoma (LARC).

Abstract

631 Background: Factors leading to uptake of new oncology treatment innovations are poorly understood. In particular, the degree to which seminal events, such as report of pivotal phase III trials, influence practice is unclear. For example, preoperative (pre-op) 5-fluorouracil + radiation (5-FU + RT) is the current standard of care for definitive treatment of LARC. However, postoperative (post-op) 5-FU + RT was standard before the seminal German Rectal Cancer Study Group (GRCSG) results were published. We investigated the impact of seminal events on the change in practice pattern from pre- to post-op 5-FU + RT at our institution. Methods: Patients with LARC (T2N+; any T3; any T4) treated at our institution between 1994-2010 were identified from the cancer registry. The date of diagnosis was compared to the dates of three seminal events: A) JAMA meta-analysis publication; B) publication of GRCSG results; C) founding of a multidisciplinary clinic at our institution. Pearson Chi square was used for univariate analysis. Results: 334 patients were evaluable. RT +/- 5-FU was delivered pre-op for 207 patients, post-op for 127 patients. The unadjusted odds ratio (OR) for receiving pre-op treatment after vs. before each seminal event was similar: (A) 4.16; (B) 4.08; (C) 3.91. When patients diagnosed prior to (A) or after (C) were excluded, (B) appeared to have a smaller effect, OR 2.07 (p = .053) (Table). Conclusions: All seminal events had similar associated OR, indicating that the process of uptake of the innovation of pre-op 5-FU + RT was gradual. The seminal GRCSG publication, when temporally isolated, had only modest effect. This suggests that report of seminal results is necessary but not sufficient for uptake of a new therapy innovation in LARC at our institution. Whether this pattern of uptake is generalizable is worthy of further investigation. [Table: see text]