Successful treatment of advanced gastric cancer by surgical resection following combination chemotherapy with oral S-1 and biweekly paclitaxel

TRPM2 channel-mediated regulation of autophagy maintains mitochondrial function and promotes gastric cancer cell survival via the JNK-signaling pathway

A lack of effective treatment is one of the main factors contributing to gastric cancer-related death. Discovering effective targets and understanding their underlying anti-cancer mechanism are key to achieving the best response to treatment and to limiting side effects. Although recent studies have shown that the cation channel transient receptor potential melastatin-2 (TRPM2) is crucial for cancer cell survival, the exact mechanism remains unclear, limiting its therapeutic potential. Here, using molecular and functional assays, we investigated the role of TRPM2 in survival of gastric cancer cells. Our results indicated that TRPM2 knockdown in AGS and MKN-45 cells decreases cell proliferation and enhances apoptosis. We also observed that the TRPM2 knockdown impairs mitochondrial metabolism, indicated by a decrease in basal and maximal mitochondrial oxygen consumption rates and ATP production. These mitochondrial defects coincided with a decrease in autophagy and mitophagy, indicated by reduced levels of autophagy- and mitophagy-associated proteins (i.e. ATGs, LC3A/B II, and BNIP3). Moreover, we found that TRPM2 modulates autophagy through a c-Jun N-terminal kinase (JNK)-dependent and mechanistic target of rapamycin-independent pathway. We conclude that in the absence of TRPM2, down-regulation of the JNK-signaling pathway impairs autophagy, ultimately causing the accumulation of damaged mitochondria and death of gastric cancer cells. Of note, by inhibiting cell proliferation and promoting apoptosis, the TRPM2 down-regulation enhanced the efficacy of paclitaxel and doxorubicin in gastric cancer cells. Collectively, we provide compelling evidence that TRPM2 inhibition may benefit therapeutic approaches for managing gastric cancer.

Paclitaxel chemotherapy for the treatment of gastric cancer

A comprehensive review of phase I and phase II clinical trials of paclitaxel and paclitaxel-containing chemotherapy regimens for advanced gastric cancer was performed. Response rates, median progression-free survivals, and median overall survivals were examined, together with the treatment regimens and the numbers of patients registered in each trial. Although paclitaxel monotherapy produced considerable improvement in tumor response and prognosis, combination doublet or triplet chemotherapy with fluoropyrimidines and/or platinum compounds showed better results than the paclitaxel monotherapy. With regard to the schedule of paclitaxel administration, weekly injection seemed to show less toxicity and better results than administration every 3 weeks. Adjuvant therapies, chemoradiation therapies, and paclitaxel treatment for gastric ascites were also investigated and are discussed.

The number of metastatic lymph nodes is a significant risk factor for bone metastasis and poor outcome after surgery for linitis plastica-type gastric carcinoma

BACKGROUND

Linitis plastica-type gastric carcinoma remains a disease with poor prognosis despite an aggressive surgical approach. Although a prominent pattern of disease failure is peritoneal carcinomatosis, some patients experience rapid disease progression without signs of the peritoneal disease.

METHODS

Clinicopathologic data from 178 patients with linitis plastica-type gastric cancer operated on between 1991 and 2000 were analyzed. Survival stratified by curability of surgery, pN stage, and patterns of failure were evaluated by using the Kaplan-Meier method, and chi(2) test was used to evaluate correlation between the number of metastatic lymph nodes in terms of pN categories and the incidence of various patterns of metastasis and recurrence. Cox regression hazard model was used to identify independent prognostic factors.

RESULTS

R0 resection was performed only among 82 patients (46% of those who underwent laparotomy). Node metastasis was frequent with only 22 patients classified as pN0. Peritoneal carcinomatosis was observed in 131 patients and was the commonest pattern of recurrence. Bone metastasis, found in 13 patients, was associated with poor outcome, and its incidence was significantly correlated with the number of metastatic nodes. pT4 status and pN3 status were identified as significant independent prognostic determinants.

CONCLUSION

Treatment strategy for the linitis plastica should in general combine surgery with aggressive treatment directed toward peritoneal disease. However, patients with >16 metastatic nodes more often are associated with bone metastasis than those with modest nodal involvement and suffer from poor prognosis.

A multicenter phase II study of biweekly paclitaxel and S-1 combination chemotherapy for unresectable or recurrent gastric cancer

PURPOSE

This Phase II study assessed the activity and safety of biweekly paclitaxel and oral S-1 as treatment for unresectable and recurrent gastric cancer. The maximum tolerated dose for this regimen had been established previously in a Phase I study performed in Japanese patients.

PATIENTS AND METHODS

Chemotherapy was performed using two anticancer agents, S-1 and paclitaxel. Oral S-1 (80 mg/m(2)) was administered twice a day after meals for two consecutive weeks from Day 1 to 14, followed by a 2 week recovery period; paclitaxel (120 mg/m(2)) was administered intravenously, biweekly, on Days 1 and 15. The patient received cycles of this regimen every 4 weeks (q 28-day cycles). The primary end point was the response rate according to the Response Evaluation Criteria in Solid Tumors.

RESULTS

A total of 39 patients (median age, 65 years) were enrolled; 13 other patients were screened, but found to be ineligible. All patients had unresectable and recurrent gastric cancer. The most common treatment-related Grade 3/4 adverse events were neutropenia (37.5%), appetite loss, diarrhea, decreased sodium (each 5%), and anemia, increased alanine aminotransferase, general fatigue, and dizziness (each 2.5%). Almost all the patients experienced alopecia. Intent-to-treat analysis showed a response rate of 43.6%. With a median follow-up of 14 months (range 8-21 months), median survival was 256 days and the median time to progression was 4 months.

CONCLUSION

A combination regimen of biweekly paclitaxel and oral S-1 was well tolerated and showed promising activity against unresectable and recurrent gastric cancer.