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
3608 - Prognostic impact of Body Mass Index (BMI) on overall survival in patients with metastatic breast cancer
Presenter: Khalil SALEH
Session: Poster Display session 2
Resources:
Abstract
2686 - Clinicopathological characteristics, survival and prognostic factors of breast cancer-related microangiopathic haemolytic anemia: a multicenter study
Presenter: Marion Alhenc Gelas
Session: Poster Display session 2
Resources:
Abstract
1565 - Metabolic tumor volume by 18F-FDG PET/CT is an independent prognostic factor in metastatic breast cancer
Presenter: Heekyung Ahn
Session: Poster Display session 2
Resources:
Abstract
4498 - Patient Preferences for breast cancer treatments: A Discrete Choice Experiment from four European countries
Presenter: Thomais Konstantopoulou
Session: Poster Display session 2
Resources:
Abstract
1423 - Palbociclib plus fulvestrant as second- or later-line therapy for patients with locally advanced, inoperable or metastatic HR+/HER2- breast cancer in Germany: Interim results of the INGE-B phase 2 study
Presenter: Diana Lüftner
Session: Poster Display session 2
Resources:
Abstract
2284 - Ventriculoperitoneal Shunt for CNS Metastasis in Breast Cancer: Clinical Outcomes Based on Intrinsic Subtype
Presenter: Hee Kyung Kim
Session: Poster Display session 2
Resources:
Abstract
4598 - Administration of chemotherapy for metastatic breast cancer near the end of life: a population registry study
Presenter: Luisa Edman Kessler
Session: Poster Display session 2
Resources:
Abstract
5706 - Prognostic value of histological growth pattern in patients operated for breast cancer liver metastases
Presenter: Ali Bohlok
Session: Poster Display session 2
Resources:
Abstract
1697 - Illness perceptions, quality of life and mood in metastatic breast cancer patients
Presenter: Isabel Domingues
Session: Poster Display session 2
Resources:
Abstract
1935 - Multidisciplinary Treatments Increases Overall Survival in Patients with Newly Diagnosed Stage IV Breast Cancer:An Analysis of 2010–2014 SEER Data
Presenter: Jian Zhang
Session: Poster Display session 2
Resources:
Abstract