596P - Adverse events (AEs) associated with bevacizumab (BV) in older patients (pts) with metastatic colorectal cancer (mCRC)

Date 01 October 2012
Event ESMO Congress 2012
Session Poster presentation III
Topics Complications of Treatment
Geriatric Oncology
Colon Cancer
Rectal Cancer
Presenter Veena Shankaran
Authors V. Shankaran1, D. Mummy2, L. Koepl2, D. Blough3, Y.M. Yim4, E. Yu4, S. Ramsey2
  • 1Dept. Medical Oncology, Fred Hutchinson Cancer Research Center, 98109 - seattle/US
  • 2Cancer Prevention, Fred Hutchinson Cancer Research Center, 98109 - seattle/US
  • 3Pharmacy, University of Washington, 98195 - Seattle/US
  • 4Health Economics And Outcomes Research, Genentech, Inc., 94080 - San Francisco/US

Abstract

Background

The relative safety of BV in older mCRC pts is understudied. The objectives of this analysis are to investigate treatment-related AE incidence and to determine factors associated with AEs in a population-based sample of older mCRC pts.

Methods

Pts age ≥ 65 diagnosed (Dx) with mCRC in 2001-7 were identified from SEER-Medicare. First-line (1L) chemotherapy (CTx) was identified by claims within 3 months of Dx; pts were categorized as receiving no 1L CTx, 1L CTx alone, or 1L CTx + BV. Pts were also categorized by Dx period (2001-3 vs. 2005-7); pts Dx in 2004 were excluded as BV use could not be reliably identified in that year. Preexisting conditions (PCs) identified in the year prior to Dx were grouped into 5 categories (cardiovascular (CV), cerebrovascular (CNS), gastrointestinal (GI), tissue integrity (TI), and pulmonary (Pulm). Claims for these conditions between start of 1L CTx and end of follow-up were identified as AEs. AE incidence rates were determined by Dx year and 1L CTx cohort. We used a competing risks regression model to compare time to 1st AE for pts who received 1L CTx + BV in 2005-7 to pts who received 1L CTx alone in 2001-7. Similar models were constructed for specific serious AEs (stroke, DVT/PE, GI bleed, GI perforation).

Results

6,899 pts (median age 77) were identified. In 2001-3, 37% of pts received 1L CTx alone; in 2005-7, 21% and 19% of pts received 1L CTx alone and 1L CTx + BV. AE incidence was similar between pts receiving 1L CTx alone in 2001-3 (135 AEs / 100,000 person-days (PD)) and 1L CTx + BV in 2005-7 (140 AEs / 100,000 PD). Time to 1st AE was not shorter in pts receiving 1L CTx + BV in 2005-7 compared with 1L CTx alone in 2001-7 (HR 0.99, p = 0.90). Similarly, receipt of 1L CTx + BV was not associated with a shorter time to specific AE. (Table)

Conclusions

Older pts who received 1L CTx + BV had neither increased AE incidence nor decreased time to 1st AE compared with pts who received 1L CTx alone. BV utilization may not increase AE risk among elderly mCRC pts.

Time to 1st AE: BV vs. 1L CTx alone

AE Type HR 95% CI
Any AE 0.99 0.90-1.10
Stroke 1.04 0.95-1.15
DVT/PE 1.03 0.94-1.14
GI bleed 1.03 0.94-1.14
GI perforation 1.05 0.95-1.15

Models adjusted for: age, comorbidity, race, gender, CTx backbone, PC

Disclosure

V. Shankaran: This research activity received industry funding from Genentech, Inc.

D. Mummy: This research activity received industry funding from Genentech, Inc.

L. Koepl: This research activity received industry funding from Genentech, Inc.

D. Blough: This research activity received industry funding from Genentech, Inc.

Y.M. Yim: Financial interests include employment at Genentech, Inc. as as health economist and ownership in Genentech stocks.

E. Yu: Financial interests include employment at Genentech, Inc. as Associate Director and stock ownership in Roche.

S. Ramsey: This research activity received industry funding from Genentech, Inc.