We read with great interest a recent research article by Mallouh and colleagues1 demonstrating that the COVID-19 pandemic did not precipitate stage migration at presentation of breast and lung cancer in Massachusetts. We would like to show the data from Japan.

The hospital-based cancer registries operated by the National Cancer Center, Japan, accumulated newly diagnosed cancer cases from 875 facilities, covering more than 70% of cancer cases in Japan.2 For us, the registry provided data from 2016 to 2021, including 2 years of the COVID-19 pandemic era (2020 to 2021). Each case was registered with the first treatment provided soon after the diagnosis, such as surgery alone, endoscopic therapy alone, radiation alone, medication alone, or a combination of them.