Conclusions
Inoue et al. reported that the 5-year survival rate of their 53-patient series of AFP-GC was 34%, although 53% of them had synchronous or metachronous hepatic metastases. They suggested that the prognosis of AFP-GC was not as poor as previously believed, and that multimodality treatment may be useful to improve survival. Adachi et al. analyzed 270 cases of AFP-GC reported in the Japanese literature from 1982 to 2001, including one of their patients, and they reported that 5-year survival rates were 42% and 22%, and the median survival periods were 29 months and 14 months in patient with curative gastrectomy and in all patients, respectively. Kochi et al. reported a significantly better response (70% vs. 31.9%, respectively), and a better conversion to surgery rate (40% vs. 12.8%) of stage IV AFP-CG by combination therapy with 5-fluorouracil, leucovorin, etoposide, and cisplatin was shown compared to Stage IV non-AFP-CG. The disappearance of PVTT in the current AFP-GC by chemotherapy with S-1 plus cisplatin conferred operability on this case, resulting a long-term tumor-free survival after the curative operation. Based on the current case and the previous reports, salvage surgery for AFP-GC should be done to prolong survival when curative surgery could be performed after chemotherapy.
The current AFP-GC with PVTT had the elevated level of serum AFP and the poorly differentiated adenocarcinoma cells stained with anti-AFP antibody immunohistochemically. Although the incidence of PVTT in AFP-GC has not been elucidated, a few reports suggested a relatively high incidence of PVTT in AFP-GC. Araki et al. reported that, among four patients with gastric cancer and PVTT, three patients showed elevated serum AFP levels, and two patients were proven immunohistochemically to be producing AFP in the primary tumor. Lee et al. found that 50% (4/8) of hepatoid adenocarcinomas of the stomach had PVTT in retrospective analyses of CT findings.
The prognosis of AFP-GC with PVTT has been thought to be miserable. However, Saitoh et al. reported a case of AFP-GC with PVTT as a recurrent lesion after gastrectomy and following various kinds of chemotherapy for liver and lymph node metastases. The PVTT lesion showed partial response to irinotecan plus cisplatin as the 5 line chemotherapy and S-1 monotherapy as the 6 line chemotherapy, and the patient lived for more than 5 years after the initiation of systemic chemotherapy against recurrence involving the liver and lymph nodes. Contrary to the case reported by Saitoh et al, the PVTT occurred simultaneously with primary tumor and completely disappeared after chemotherapy in the current case. Both of the current and their cases demonstrated that chemotherapies for AFP-GC with PVTT were effective and contributed to the long survival. Yamaguchi et al. reported 17 cases of AFP-GC with PVTT through a literature search from 1980 to 2002, including one of their own cases. They suggested that complete resection of AFP-GC with PVTT may lead to long-term survival based on their analysis of the literature data. The elimination of PVTT was an important factor for long term survival both in the current report and the case reported by Yamaguchi et al, although the removal methods of PVTT were quite different: chemotherapy and extirpation, respectively.
Recently, S-1 plus cisplatin for unresectable/recurrent gastric cancer has been recognized as a standard therapy in Japan. A few phase II studies of neoadjuvant chemotherapy with S-1 plus cisplatin for advanced gastric cancer have been conducted. Following the promising results of these phase II studies, a phase III study (JCOG0501) of S-1 plus cisplatin as neoadjuvant chemotherapy for type 4 and large type 3 gastric cancer has been ongoing. The current case was expected to have a very poor prognosis at the time of diagnosis of AFP-GC with PVTT. However, chemotherapy with S-1 plus cisplatin was effective to decrease PVTT, and the primary lesion was curatively resected. This is the first report suggesting that salvage surgery following chemotherapy may contribute to curative resection of AFP-GC with PVTT.