CA-125: an inaccurate surveillance tool immediately after cytoreductive surgery and hyperthermic intraoperative chemotherapy (CRS-HIPEC)?

<p><b>Objective:</b> This study seeks to evaluate pre and post-operative CA-125 in patients undergoing complete cytoreduction surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), and understand the time frame before values normalise allowing use as a surveillance tool to resume.</p> <p><b>Methods:</b> A retrospective review was carried out of 94 patients undergoing CRS-HIPEC to compare pre-operative CA-125 values, measured within one week prior to surgery to post-operative readings within the first 30 d. Raised CA-125 was defined using as a value >35 U/ml.</p> <p><b>Results:</b> Of 63 (67%) patients with normal pre-operative CA-125, 22 (35%) had raised post-operative CA-125, and consisted of patients with colorectal (<i>n</i> = 8), appendiceal (<i>n</i> = 6), ovarian (<i>n</i> = 4) or other (<i>n</i> = 4) cancers. The average peak CA-125 was 80 U/ml occurring on median 10th post-operative day (POD) (range 7–30). The median day of normalisation for patients with normal pre-operative and raised post-operative CA-125 was 57 (range 28–115). The median day of normalisation for patients with raised pre-operative CA-125 was POD 41 (range 1–114). Notably 10 patients had initial normalisation (median POD 1, range 1–6), followed by subsequent raised value (median POD 10, range 5–40) and re-normalisation (median POD 47, range 19–104).</p> <p><b>Discussion:</b> For patients with raised pre-operative CA-125 an immediate post-operative CA-125 within 3 d may be useful to assess normalisation following surgery. Aside from immediate measurement CA-125 is misleading and should not be measured post-operatively within the first 3 months after surgery following which its use as a surveillance marker can resume.</p