Limitations
Our study has limitations. Patients included were mostly non-Hispanic White with high levels of education; they do not represent the entire US population. The k-means algorithm is sensitive to outliers in the clustering variables, although all clustering variables ranged from 0 to 4. Euclidean distances might be distorted by the potential collinearity among the clustering variables. We only included PRO-CTCAE severity attributes; future analyses should expand to other attributes. Additionally, our k-means algorithm needs external validation.