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
3902 - The efficacy of preoperative breast cancer chemotherapy without anti-HER2-targeted treatment – single center experience in setting of no reimbursement in Poland (2011-2015)
Presenter: Agnieszka Badora-Rybicka
Session: Poster Display session 2
Resources:
Abstract
4733 - A Multicentre, International Neoadjuvant (NA), Randomized, Double-blind Phase III Trial comparing FULVESTRANT to a combination of FULVESTRANT and PALBOCICLIB in patients with operable Luminal Breast Cancer (SAFIA Trial)
Presenter: Jean-Marc Nabholtz
Session: Poster Display session 2
Resources:
Abstract
5227 - Outcome of Non-metastatic Male Breast Cancer: 222 patients
Presenter: Ulku Yalcintas Arslan
Session: Poster Display session 2
Resources:
Abstract
5943 - Effects of delayed initiation of adjuvant trastuzumab for non-metastatic, Her2 positive breast cancer in a limited resources setting: ML25232 study final results
Presenter: Samir Beslija
Session: Poster Display session 2
Resources:
Abstract
1725 - Final results of scalp cooling for hair preservation: A single- institution prospective study.
Presenter: Dario Loparco
Session: Poster Display session 2
Resources:
Abstract
3713 - Adjuvant Systemic Therapy in Women with Early Breast Cancer and Intermediate Prosigna ROR Scores: Is Chemotherapy Use Declining? Evidence From a Large Practice
Presenter: Lowell Hart
Session: Poster Display session 2
Resources:
Abstract
818 - Management of early breast cancer in women over 90: A 10 year experience
Presenter: Emily Coffey
Session: Poster Display session 2
Resources:
Abstract
1141 - Evolution in the risk of adverse events of adjuvant endocrine therapy in postmenopausal women with early- stage breast cancer.
Presenter: Daniel Reinhorn
Session: Poster Display session 2
Resources:
Abstract
2277 - Hepatitis B screening and incidence of flare among non-metastatic breast cancer patients treated with anthracyclines
Presenter: Zewen Zhang
Session: Poster Display session 2
Resources:
Abstract
2781 - Effect of denosumab on low bone mineral density in postmenopausal Japanese early breast cancer patients receiving aromatase nhibitors : 36-month results
Presenter: Koichi Sakaguchi
Session: Poster Display session 2
Resources:
Abstract