SOX Chemotherapy is Effective Treatment for Gastric Cancer with Liver Metastases: A Case Report

Background: Gastric cancer is a malignant tumor of global signicance. Many patients have been shown to have advanced gastric cancer (AGC) with liver metastases, and thus are not surgical candidates. However, there is not report about hepatic metastasis disappearing. Case presentation: Herein we report a patient of AGC with liver metastases who received SOX (tegafur gimeracil, oteracil, and oxaliplatin) chemotherapy and the liver metastases regressed. Conclusions: SOX is effective in the treatment of AGC.


Background
Gastric cancer ranks third as a malignant tumor in men and fth in women worldwide [1]. Gastric cancer has a high incidence and mortality rate in eastern Asia [2]. The incidence of gastric cancer ranks third among cancers in China [3]. Late stage gastric cancer is the main reason Chinese patients are not surgical candidates [4]. The present case involves a 66-year-old male patient who was diagnosed with gastric adenocarcinoma and liver metastases. After therapy with SOX (tegafur gimeracil, oteracil, and oxaliplatin), the liver metastases regressed and the patient was suitable for surgery.

Case Presentation
The patient sought evaluation in the Oncology Department for a gastric cancer of 1-month duration. The pathology of the gastroscopic biopsy showed an adenocarcinoma and immunohistochemistry (IHC) was signi cant for Her-2(++) and Ki-67(+50%). Enhanced magnetic resonance imaging (EMRI) revealed a gastric tumor with metastases to the tumor ( Figure 1). Therefore, a diagnosis of gastric adenocarcinoma with liver metastases ( cTxNxM1) was made. Laboratory testing was normal, except the CA19-9 was > 700 U/ml. Fluorescence in situ hybridization (FISH) revealed a HER2/CEP17 = 1.05; there was no ampli cation. There was no contraindication for chemotherapy therefore a therapy of SOX (tegafur gimeracil and oteracil potassium capsules, TS-1: 60 mg d 1-14 bid po; and oxaliplatin, L-OHP: 200 mg d 1 ivgtt, Q21d). During chemotherapy, the patient was administered hepatoprotectives and symptomatic treatment. In the third chemotherapy session, the CA19-9 level was 208 U/ml and EMRI revealed a small liver metastatic lesion ( Figure 2). During the present chemotherapy session, because of myelosuppression, a single-drug chemotherapy regimen of TS-1 was performed. In the fourth chemotherapy session with SOX (tegafur gimeracil and oteracil potassium capsules, TS-1: 40 mg d 1-14 bid po; and oxaliplatin, L-OHP: 200 mg d 1 ivgtt, Q21d), the CA19-9 level was normal. In the fth chemotherapy session, a single-drug chemotherapy regimen of TS-1 (40 mg) was performed. In the sixth chemotherapy session with SOX (tegafur gimeracil and oteracil potassium capsules, TS-1: 40 mg d 1-14 bid po; and oxaliplatin, L-OHP: 200 mg d 1 ivgtt, Q21d) was performed. During the seventh chemotherapy session, due to poor liver function and myelosuppression, chemotherapy was not performed. EMRI ( Figure 3) and color ultrasound showed few liver metastases and the patient was transferred to general surgery for a laparoscopic radical gastrectomy. The pathology of the tissue specimen revealed poorly differentiated adenocarcinoma, Lauren type (intestine). IHC revealed the following: CD 10 (−); HEPA (−); CK (+); Ki67 (80% +); EGFR (++); HER2 (0); PGP (++); CD 44V6 (++); and TOPO II α(++). Post-operatively, the patient received SOX chemotherapy 2 times and there were no recurrences in the ensuing 5 months.

Discussion And Conclusions
Gastric cancer includes early gastric cancer and advanced gastric cancer (AGC). Many patients are shown to have a late stage of AGC at the time of diagnosis, and thus are not surgical candidates.
Systemic chemotherapy is usually the treatment of choice for AGCs. A combination of uorouracil and platinum is now the rst-line treatment for AGC, which is often based on the expression of human epidermal growth factor receptor 2 (HER2) [4]. In HER2-positive cases, trastuzumab plus chemotherapy is thought to be an effective therapy strategy for AGC [5].
S-1 is an oral anti-cancer medication which includes tegafur gimeracil and oteracil [6]; cisplatin plus S-1 is thought to be better for S-1 [7]. Currently, the SOX (S-1+oxaliplatin) chemotherapy project has been shown to have a therapeutic effect as rst-line chemotherapy for AGC [6].
Some studies have reported that SOX chemotherapy treatment for gastric cancer with liver metastases is effective [8][9][10][11]; however, these studies have not clearly indicated that patients with gastric cancer and liver metastases could undergo radical, curative surgery for carcinoma of the stomach.
In the present case, the patient was diagnosed with gastric adenocarcinoma based on a gastroscopic biopsy and the IHC was signi cant for Her-2(++); however, FISH illustrated no ampli cation for the Her2 gene. Therefore, trastuzumab plus chemotherapy was not used and the SOX strategy was utilized for the patient. After the sixth chemotherapy session liver metastases were not detected on EMRI. Thus, SOX treatment was effective, after which the patient was suitable for surgery. A laparoscopic radical gastrectomy was then performed. The patient recovered without complication 5 months post-operatively.
CD44v6 is the rst adhesive molecule of CD44 which showed the metastatic potential of human tumors [12]. PGP illustrates the invasive ability of gastric cancer [13]. CD 44V6 (++) and PGP (++) indicated metastases and invasion in the present patient. TOPO II α overexpression is related to the location of the tumor, depth of invasion, and TNM stage [14]. In the present patient, IHC of the pathologic specimen illustrated TOPO II α (++), which was consistent with lymphatic metastases.

Conclusion
Although cancer-targeted drugs are more and more prevalent, the SOX chemotherapy regimen is a reasonable treatment strategy for AGC, and offers more possibilities for gastric cancer. The study has been approved by the Ethics Committee of The third people's hospital of Dalian; and the consent has been get from the patient.

Availability of data and materials
Data could be founded from the corresponding author.

Con ict of Interests
The authors declare that they have no competing interests.

Consent
Written informed consent was obtained from the patient for publication of this case report and the accompanying images.