Abstract 3291
Background
Microsatellite instability (MSI) is thought to be a marker of immunogenicity and better prognosis in colorectal cancer (CRC). However, the mechanism by which MSI confers a survival advantage is not well known and there is a range of results reported in the literature.
Methods
A systematic literature search of original studies was performed on Ovid searching Medline, Embase, Cochrane Library, CINAHL, Clinical Trials databases from inception of database to current. Data extracted included age, stage, MSI-H, MSS and MSI-L, proximal (right) vs. distal (left), colon vs. rectal, BRAF status, type of MSI or IHC test used, incidence of Lynch within cohort. The primary endpoint was survival (overall survival (OS), disease/relapse free survival (DFS) and disease (cancer) specific survival DSS). Statistical analysis was performed using RevMan Ver 5.3 Cochrane Collaboration.
Results
From 11,747 studies, 117 met the inclusion criteria (n = 100,257; MSI-H n = 12,263, (MSI-H 12.2%). Overall, MSI was associated with improved OS (OR 0.80 (0.71, 0.91). When stratified by stage, there was no difference in OS in stage I and IV, but a protective effect in stage II (OR 0.69 (0.51, 0.92)) and III (0.70 (0.54, 0.91)) CRC. By age, there was benefit in studies where reported median age < 60 (OR 0.66 (0.54,0.82)) but not ≥ 60. There was no difference in OS between MSI-L and MSS. In studies including only mucinous/signet cell/poor differentiation, there was no difference in OS. In both right and left colon, MSI status was associated with improved OS, but not in the rectum. MSI status was associated with improved DFS (HR 0.75 (0.66, 0.84)), but there was no difference in DSS (HR 0.78 (0.60, 1.03)), and this was seen in all stages (I-IV).
Conclusions
MSI is associated with improved overall survival in stage II and III colorectal cancer. Improved prognosis is seen in younger patients, in both right and left sided colon cancer, but evidence is limited in rectal cancer. MSI was associated with less relapse, but was not associated with cancer specific survival at any stage.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5124 - STAR_PAC: Phase I clinical trial repurposing all trans retinoic acid (ATRA) as stromal targeting agent in a novel drug combination for pancreatic cancer.
Presenter: Hemant Kocher
Session: Poster Display session 2
Resources:
Abstract
5257 - Outcomes of First Line FOLFIRINOX (FFX) Versus Gemcitabine and Nab-Paclitaxel (GN) in Patients with Advanced Pancreatic Cancer: Multi-Institutional Canadian Sites Experience
Presenter: Neha Papneja
Session: Poster Display session 2
Resources:
Abstract
1166 - Effect of prior cancer on survival outcomes for patients with pancreatic adenocarcinoma
Presenter: Chaobin He
Session: Poster Display session 2
Resources:
Abstract
1169 - Association of combination of irreversible electroporation ablation and chemotherapy with outcomes of locally advanced pancreatic cancer: a large cohort study
Presenter: Chaobin He
Session: Poster Display session 2
Resources:
Abstract
1222 - Results from phase I study of the oncolytic viral immunotherapy agent Canerpaturev (C-REV) in combination with gemcitabine plus nab-paclitaxel as first-line treatment of unresectable pancreatic cancer
Presenter: Yusuke Hashimoto
Session: Poster Display session 2
Resources:
Abstract
1698 - Multicenter retrospective study of gemcitabine plus nab-paclitaxel for elderly patients with advanced pancreatic cancer
Presenter: Masato Ozaka
Session: Poster Display session 2
Resources:
Abstract
2424 - Irinotecan Combined with Oxaliplatin and S1 in Patients with Metastatic Pancreatic Adenocarcinoma
Presenter: Keke Nie
Session: Poster Display session 2
Resources:
Abstract
2885 - Cancer-associated thrombosis in patients with pancreatic cancer and its correlation with plasma tissue factor level: A Japanese prospective cohort study
Presenter: Satoshi Kobayashi
Session: Poster Display session 2
Resources:
Abstract
3702 - A Phase I/Ib, multi-center trial of ARQ-761 (Beta-Lapachone) with gemcitabine/nab-Paclitaxel in patients with advanced pancreatic cancer
Presenter: Muhammad Beg
Session: Poster Display session 2
Resources:
Abstract
5185 - Systemic administration of the hyaluronidase-expressing oncolytic adenovirus VCN-01 in patients with advanced or metastatic pancreatic cancer: first-in-human clinical trial
Presenter: Rocio Garcia-Carbonero
Session: Poster Display session 2
Resources:
Abstract