(116) Evaluation of the Management of Chemotherapy Induced Neutropenia and the Impact on Outcomes in Veterans Receiving Adjuvant FOLFOX for Colon Cancer within the South Texas Veterans Health Care System

Poster Abstract:

Background:

Patients with resected stage III and stage II colon cancer with high-risk features for recurrence receiving adjuvant chemotherapy with FOLFOX (fluorouracil (5-FU), leucovorin, and oxaliplatin) in 14-day cycles have improved disease free survival (DFS) and overall survival (OS).1 As with many cytotoxic chemotherapy regimens, FOLFOX is associated with an array of dose-limiting toxicities including neuropathy, gastrointestinal disturbances, and cytopenias, including Chemotherapy Induced Neutropenia (CIN). In the landmark trial evaluating adjuvant FOLFOX, 78.9% of patients experienced CIN with 28.8% of patients experiencing grade 3 and 12.3% of patients experiencing grade 4 CIN. Only 1.8% of patients experienced febrile neutropenia. Rather than introducing granulocyte colony stimulating factors (GCSF) to maintain dose intensity, patients experiencing CIN received chemotherapy dose reductions and chemotherapy dose delays.2 Real-world retrospective studies have evaluated the impact of CIN on patients receiving adjuvant FOLFOX and have found that GCSF is often initiated in conjunction with chemotherapy dose decreases.3 Addition of GCSF in this setting has not been shown to impact survival.4 Of note, chemotherapy dose reductions and dose delays can be detrimental, as suboptimal treatment intensity may be associated with poorer survival outcomes in comparison with full dose treatment without delays.5,6

Objective(s):

The objective of this single-center, retrospective study was to evaluate the impact of CIN on overall survival (OS) and disease free survival (DFS) in Veterans receiving adjuvant FOLFOX for colon cancer. The impact of CIN on chemotherapy dose delays, dose decreases, and initiation of GCSF were also evaluated.

Methods:

For this analysis, patients were included if they had a diagnosis of high-risk stage II or stage III colon cancer with receipt of at least one cycle of adjuvant FOLFOX at the South Texas Veterans Health Care System between January 1, 2010 and December 31, 2021. A patient list was determined using international classification of disease (ICD) codes for colon cancer with data collection via Microsoft Structured Query Language (SQL) and electronic medical record retrospective chart review. Patients with additional malignancies, metastatic disease, baseline neutrophil count < 1,000 cells/mm3, or microsatellite instability-high (MSI-H) disease were excluded. The survival cut-off date was December 27, 2023. Baseline characteristics and outcomes will be summarized with descriptive statistics. Chi-square test will be used to compare percent OS and DFS at 2 years, while Wilcoxon Rank Sum will be used to compare OS and DFS (in months).

Results:

Pending.

Conclusions/

Discussion:

Pending.

References (must also be included in final poster): 1. Andre T, Boni C, Navarro M, et al. Improved overall survival with oxaliplatin, fluorouracil and leucovorin as adjuvant treatment in stage II or III colon cancer in the MOSAIC trial. J Clin Oncol. 2009 Jul 1;27(19):3109-16
2. Andre T, Boni C, Mounedji-Boudiaf L, et al. Oxaliplatin, fluorouracil and leucovorin as adjuvant treatment for colon cancer. N Engl J Med. 2004 Jun 3;350(23):2343-51
3. Gotfrit J, Marginean H, Maroun JA, et al. Chemotherapy-induced neutropenia with FOLFOX in the adjuvant treatment of colorectal cancer. J Clin Oncol 38, no.4_suppl (February 01, 2020) 38-38 doi:10.1200/jco.2020.38.4_suppl.38
4. Trincao-Batra S, Goodwin RA, Marginean H, et al. Survival outcomes associated with chemotherapy-induced neutropenia in the adjuvant treatment of colorectal cancer with FOLFOX. J Clin Oncol, no. 4_suppl (February 01, 2022) 81-81doi: 10.1200/JCO.2022.40.2_suppl.081
5. Zhang X, Zheng H, Cai C, et al. Retrospective analysis of the impact of dose delay and reduction on outcomes of colorectal cancer patients treated with FOLFIRI‑based treatment. PeerJ. 2023;11:e15995. Published 2023 Sep 12. doi:10.7717/peerj.15995
6. Nielson CM, Bylsma LC, Fryzek JP, Saad HA, Crawford J. Relative Dose Intensity of Chemotherapy and Survival in Patients with Advanced Stage Solid Tumor Cancer: A Systematic Review and Meta-Analysis. Oncologist. 2021;26(9):e1609-e1618. doi:10.1002/onco.13822