Biological aggressiveness of alpha-fetoprotein (AFP)-positive gastric cancer

Alpha-fetoprotein (AFP)-positive gastric cancer (APGC) which occupied well-defined gastric cancer entity, reportedly has an aggressive behavior with hematogenous metastasis. However, little information regarding the clinicopathological and biological behaviors of APGC is available due to the small size of reported series.

We retrospectively analyzed the clinical features of APGC in 556 patients with gastric cancer who underwent preoperative measurement of serum AFP levels and gastrectomy in Kagoshima University Hospital. APGC was regarded as any cancer with preoperative serum AFP levels above the cutoff level of 5 ng/mL. Clinicopathological features of APGC were assessed using the General Rules of Gastric Cancer. Of the 556 patients, 97 patients underwent immunohistochemical evaluation of AFP expression in the primary tumor. Both p53 and MIB-1 expression were examined at the same time and compared with AFP expression. Biological aggressiveness of APGC was estimated.

Serum AFP positivity was detected in 4.3% of cases (range, 0-2202 ng/mL). Patients were divided into 25 APGC patients and 531 non-APGC patients. APGC displayed deeper tumor invasion, increased nodal involvement, increased venous invasion, and increased CEA concentrations compared to gastric cancer in non-APGC. Surgical outcomes for APGC were significantly worse than those for non-APGC (p < 0.05). All recurrences in patients with APGC involved hepatic metastasis. Abnormalities of p53 were more frequent for APGC than for non-APGC (p < 0.05).

APGC was strongly associated with hematogenous factors such as venous invasion, hepatic metastasis and aggressive biological factors (p53 abnormalities). Considering the aggressive biological behavior of APGC, we must closely follow up for patients with such tumor, including postoperative adjuvant therapy.