Advanced ovarian cancer [advanced versus early, HR: 2.3 (95% CI 1.3–4.2), p = 0.004], ≥1 cm postoperative residual tumor [≥1 cm versus < 1 cm, HR: 2.1 (95% CI 1.4–2.9), p < 0.001], and detectable BTLA expression in cancerous tissue [detectable versus non-detectable, HR: 1.7 (95% CI 1.2–2.4), p = 0.002] were independent prognostic factors for poor DFS in the 254 patients by multivariate analysis. Here, BTLA is linked to neoplasm.