Abstract 71P
Background
Insight in real-world treatment patterns and sequences of systemic treatment (ST) in daily clinical practice of patients with metastatic colorectal cancer (mCRC) is not readily available. The aim of this population-based study is to provide an overview of treatment and overall survival (OS) of patients with mCRC in a nationwide cohort.
Methods
All patients with mCRC of whom the primary tumour was diagnosed in the first half of 2015 were selected from the Netherlands Cancer Registry. Data regarding subsequent treatments was collected in 2019. Treatment patterns were compared between patients with synchronous and metachronous mCRC. Differences in OS were analysed using Kaplan Meier method and log-rank test.
Results
In total, 1508 patients with synchronous mCRC and 875 patients with metachronous mCRC were included. Approximately one fifth of all patients did not receive any anticancer treatment. Among patients with synchronous mCRC 43% received ST without local treatment of metastases (LTM) as initial treatment. Of these patients 50% continued with 2nd-line ST, with 38% of the patients who started 2nd-line ST progressing to 3rd-line ST. Among patients with metachronous mCRC 33% received ST without LTM as initial treatment and 48% and 47% continued with 2nd-line and 3rd-line, respectively. Administered ST differed between patients with synchronous and metachronous mCRC (Table). OS of patients starting 1st-line ST and of those starting 2nd-line ST was slightly lower for patients with synchronous mCRC compared to patients with metachronous mCRC (median OS 12.6 vs. 14.9 months, p=0.05 and median OS 7.5 vs. 8.7 months, p=0.04, respectively). No difference in OS between patients with synchronous and metachronous mCRC was found for those initiating 3rd-line ST. Table: 71P
Top 3 of most frequently administered systemic treatment per treatment line
| Synchronous mCRC (% of patients who started treatment line) | Metachronous mCRC (% of patients who started treatment line) | |
| 1st-line | 1. CAPOX + antiVEGF (47%) 2. CAPOX (22%) 3. cap (13%) | 1. cap + antiVEGF (28%) 2. CAPOX + antiVEGF (27%) 3. CAPOX (13%) 3. cap (13%) |
| 2nd-line | 1. iri (72%) 2. antiEGFR (9%) 3. CAPOX (5%) | 1. iri (44%) 2. antiEGFR (24%) 3. CAPOX + antiVEGF (8%) |
| 3rd-line | 1. antiEGFR (46%) 2. iri (22%) 3. ftd/tpi (17%) | 1. ftd/tpi (31%) 2. antiEGFR (24%) 3. iri (18%) |
CAPOX = CAPOX/FOLFOX/S1-oxaliplatin; cap = capecitabine/5-FU/S-1; iri = irinotecan-based regimen; ftd/tpi = trifluridine/tipiracil
Conclusions
Data from a population-based registry provide insight into treatment patterns in daily practice, showing small differences in treatments and OS between patients with synchronous and metachronous mCRC.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
L.B. Valkenburg-van Iersel: Non-Financial Interests, Personal, Advisory Role: Amgen, BMS, Pierre Fabre, Servier. J.M.L. Roodhart: Financial Interests, Institutional, Advisory Board: GSK, Servier, Amgen, BMS; Financial Interests, Institutional, Invited Speaker: Servier, Pierre Fabre, GSK, Amgen, BMS, Pfizer; Financial Interests, Institutional, Research Grant: GSK, Xilis, Cleara, HUB Organoids BV; Non-Financial Interests, Member of Board of Directors: Board Member Foundation Hubrecht Organoid Biobank; Non-Financial Interests, Advisory Role: ONCODE clinical advisory board, KWF scientific board; Non-Financial Interests, Other, member guideline committee: Member national guideline committee lower digestive track Netherlands; Non-Financial Interests, Institutional, Other, organoids: HUB Organoids. All other authors have declared no conflicts of interest.