Real‐world data on microsatellite instability status in various unresectable or metastatic solid tumors

Abstract

Microsatellite instability‐high (MSI‐H) is an important biomarker for predicting the effect of immune checkpoint inhibitors (ICIs) on advanced solid tumors. Microsatellite instability‐high is detected in various cancers, but its frequency varies by cancer type and stage. Therefore, precise frequency is required to plan ICI therapy. In this study, the results of MSI tests actually carried out in clinical practice were investigated. In total, 26 469 samples of various cancers were examined between December 2018 and November 2019 to determine whether programmed cell death‐1 blockade was indicated. The results of MSI tests were obtained for 26 237 (99.1%) of these samples. The male : female ratio was 51:49 and mean age was 64.3 years. In all samples, the overall frequency of MSI‐H was 3.72%. By gender, the frequency of MSI‐H was higher in female patients (4.75%) than in male patients (2.62%; P < .001). A comparison by age revealed that the frequency of MSI‐H was significantly higher in patients younger than 40 years of age (6.12%) and 80 years or older (5.77%) than in patients aged between 60 and 79 years (3.09%; P < .001). Microsatellite instability‐high was detected in 30 cancer types. Common cancer types were: endometrial cancer, 16.85%; small intestinal cancer, 8.63%; gastric cancer, 6.74%; duodenal cancer, 5.60%; and colorectal cancer, 3.78%. Microsatellite instability‐high was detected in cancer derived from a wide variety of organs. The frequency of MSI‐H varied by cancer type and onset age. These data should prove especially useful when considering ICI treatment.

Precision medicine for hereditary tumors in gynecologic malignancies

“…Figure 2 shows the frequency of MSI‐H by primary site in Japanese patients with various unresectable or metastatic solid tumors. The frequency of endometrial cancer was the highest at 17%, followed by small intestine, gastric, duodenal, and colon cancer, and the rate of ovarian cancer was 2.2% 47 . This frequency is almost the same as in Europe and the United States 44 .…”

“…Akagi et al reported that the overall frequency of MSI‐H was 3.72% in the results of 26 237 MSI tests in Japanese patients with various unresectable or metastatic solid tumors 47 . Figure 2 shows the frequency of MSI‐H by primary site in Japanese patients with various unresectable or metastatic solid tumors.…”

Chemotherapy for Biliary Tract Cancer in 2021

“…Only a few biliary tract cancer patients were included in these studies, owing to the rarity of these alterations. MSI-high biliary tract cancer was reported in 2.22% and 1.50% of Japanese cholangiocarcinoma and gallbladder cancer patients, respectively [ 71 ]. NTRK fusion positivity was reported in only 0.18% of biliary tract cancers [ 72 ].…”

An Investigator-Initiated Phase 2 Study of Nivolumab Plus Low-Dose Ipilimumab as First-Line Therapy for Microsatellite Instability—High Advanced Gastric or Esophagogastric Junction Cancer (NO LIMIT, WJOG13320G/CA209-7W7)

“…Among them, MSI-H has been an established biomarker for ICIs across tumor types. The prevalence of MSI-H was found to be~5% in Japanese patients with metastatic or recurrent GC [5]. The clinicopathologic profile of MSI-H tumors includes a local and systemic antitumoral immune response.…”

“…Not amenable to curative approaches such as definitive chemoradiation or surgery (5). No prior systemic anticancer treatment given as primary therapy for advanced or metastatic disease.…”