In multivariate analysis, age ≤50 years (OR = 2.94, 95% CI 1.23–7.02, P = 0.015), grade III tumor (OR = 47.45, 95% CI 3.14–716.88, P = 0.005), lymph vascular invasion (OR = 13.00, 95% CI 1.95–86.47, P = 0.008), PR <20% (OR = 5.18, 95% CI 2.00–13.41, P = 0.001), Ki-67 ≥14% (OR = 4.56, 95% CI 1.98–10.53, P < 0.001), and RS (P < 0.001) were still significantly associated with chemotherapy recommendation (Table S4). Here, MKI67 is linked to neoplasm.