A pan-cancer study on characteristic of CDK4/6 amplification between Chinese and Western patients.

Abstract

e15074 Background: CDK4/6 kinases associate with cyclin D proteins during transition from G1 to S phase of the cell cycle. Amplification of CDK4/6 may elicit the activity of cyclin D, which hyperphosphorylates RB, ultimately leading to uncontrolled cell proliferation. Currently, three CDK4/6 inhibitors are used in breast cancer, ovarian cancer and sarcoma. Herein, we investigate the prevalence of CDK4/6 amplification in Chinese and Western cancer patients, hope to find more cancer subtypes with CDK4/6 amplification. Methods: Next-generation sequencing data and clinical data were collected from 10828 TCGA pan-cancer patients (Western cohort). A 539-gene panel targeted sequencing assay was performed on FFPE tumor samples from 4181 Chinese pan-cancer patients (Chinese cohort). CDK4 and CDK6 amplification were calculated on the two cohorts following the same criteria. Results: In total, 182 (4.4%) of the 4181 Chinese patients and 529 (4.9%) of the 10828 Western patients had CDK4 amplification, 133 (3.2%) of the 4181 Chinese patients and 475 (4.4%) of the 10828 Western patients had CDK6 amplification. In Western cohort, the top 5 CDK4 amplification-associated cancer types were sarcoma, glioblastoma multiforme, lung adenocarcinoma, ovarian carcinoma, and adrenocortical carcinoma, and the top 5 CDK6 amplification-associated cancer types were esophageal carcinoma, ovarian carcinoma, lung squamous cell carcinoma, stomach adenocarcinoma, sarcoma. In Chinese cohort, the top 5 CDK4 amplification-associated cancer types were lung adenocarcinoma, melanoma, sarcoma, stomach carcinoma, liver cancer, and the top 5 CDK6 amplification-associated cancer types were lung adenocarcinoma, stomach carcinoma, liver cancer, melanoma, glioma. In addition, CDK4 amplification in Chinese cohort, 22 (11%) of the 203 Chinese bone and soft tissue sarcoma patients had CDK4 amplification, and 4 (2%) of the 203 had CDK6 amplification. Bone and soft tissue sarcoma types with CDK4 / 6 amplification including soft tissue sarcoma, bone cancer, fibrosarcoma, chondrosarcoma, rhabdomyosarcoma, liposarcoma, synovial sarcoma. Conclusions: Our study provided a characteristic of CDK4/6 amplification in Chinese and Western pan-cancer patients. Analysis revealed frequent CDK4 / 6 amplification in lung cancer, sarcoma, stomach carcinoma, ovarian carcinoma and liver cancer. It is suggested patient with these cancer types may potentially benefit from CDK4/6 inhibitor.