Late phase II study of novel oral fluoropyrimidine anticancer drug S-1 (1 M tegafur-0.4 M gimestat-1 M otastat potassium) in advanced gastric cancer patients

A novel animal model of tegafur-induced hand-foot syndrome

Hand-foot syndrome (HFS) is a common side effect of fluoropyrimidine anticancer drugs and often becomes a dose-limiting manifestation of toxicity once it occurs. The precise mechanism of HFS remains unclear, and effective measures to prevent or relieve it are currently limited. To investigate the pathogenesis of HFS and effective measures for treating or preventing it, establishment of animal models is crucial. Here, we gave male SD rats 170 mg/kg of tegafur (prodrug of 5-FU) daily for 35 days and evaluated their clinical and histopathological characteristics and pain-related behavioral tests. TUNEL-positive apoptotic cells and 5-FU concentrations in the plantar skin were also evaluated to investigate the mode of toxicity. Tegafur treatment induced hypersensitivity to mechanical pressure on the plantar surface beginning in Week 3, with decreased locomotor activity. Focal desquamation of the plantar skin was observed almost concomitantly and gradually worsened to palmar and plantar skin thickening with severe desquamation, cracks, or both. Histopathological lesions in the plantar skin at treatment end included desquamation and thickening, with epidermal cell swelling and spongiosis and focal inflammation in the dermis. The time-course of development and the characteristics of the tegafur-induced skin lesions were highly similar to those in human fluoropyrimidine-induced HFS, indicating that a HFS rat model was successfully established. Localized high concentrations of 5-FU in the palmar and plantar skin, with increased apoptosis, are likely involved in the mode of toxicity. Our model should clarify the pathogenesis of HFS, providing new insights into the best supportive care and prevention.

S-1 maintenance therapy in advanced gastric cancer without disease progression after first-line chemotherapy: A retrospective analysis

For patients with advanced gastric cancer after chemotherapy, the optimal mode of maintenance therapy is not yet clear. This research aimed to compare the efficacy and adverse effects of S-1 maintenance therapy and follow-up observation in patients with advanced gastric cancer without disease progression after first-line combined chemotherapy. This study retrospectively analyzed 106 patients from January 2018 to December 2021. The primary endpoints were overall survival and progression-free survival, the secondary endpoint was chemotherapy-related toxicity, and the curative effects and baseline characteristics of the patients were analyzed. Longer progression-free survival and overall survival were observed in the S-1 maintenance treatment group than in the follow-up observation group (p < 0.001). No obvious differences existed in the subgroup results regarding progression-free survival or overall survival (p > 0.05). In the maintenance treatment group, the occurrence of thrombocytopenia and hand-foot syndrome was significantly increased (p < 0.001). No toxicity-related deaths occurred. The included patients without disease progression after first-line combined chemotherapy can achieve significant survival benefits by receiving S-1 maintenance therapy. The patient's tolerance to S-1 maintenance therapy was good.

Association of renal function with the safety and efficacy of cisplatin plus S-1 therapy and docetaxel plus cisplatin plus S-1 therapy in patients with advanced gastric cancer: an exploratory analysis of JCOG1013

BACKGROUND

Although cisplatin and 5-chloro-2,4-dihydropyrimidine (dihydropyrimidine dehydrogenase inhibitor contained in S-1) are excreted into the urine, it remains unknown how creatinine clearance (CrCl) affects the safety and efficacy of cisplatin plus S-1 and docetaxel plus cisplatin plus S-1 in patients with advanced gastric cancer.

METHODS

Among the 741 participants in JCOG1013 comparing cisplatin plus S-1 with docetaxel plus cisplatin plus S-1, 723 with serum creatinine levels ≤1.2 mg/dL were categorized into A1 (CrCl ≥ 80 mL/min), A2 (60 ≤ CrCl <80) and A3 (CrCl < 60) in the cisplatin plus S-1 arm and similarly B1, B2 and B3 in the docetaxel plus cisplatin plus S-1 arm. The initial dose modification by CrCl was pre-specified in the docetaxel plus cisplatin plus S-1 arm but not in the cisplatin plus S-1 arm.

RESULTS

The numbers of patients categorized as A1/A2/A3 and B1/B2/B3 were 169/136/57 and 170/138/53, respectively. In the cisplatin plus S-1 arm, a lower CrCl was associated with higher incidences of grade 4 leukopenia (P = 0.006), neutropenia (P = 0.002), and grade 3/4 anorexia (P = 0.004) and febrile neutropenia (P = 0.049), whereas there was no association in the docetaxel plus cisplatin plus S-1 arm. No significant differences were observed according to CrCl in the overall survival [median: 15.4/15.5/15.4 months in A1/A2/A3 (P = 0.886) and 15.3/13.7/13.7 months in B1/B2/B3 (P = 0.719)], progression-free survival [median: 7.1/6.8/6.2 months in A1/A2/A3 (P = 0.884) and 7.5/7.2/7.8 months in B1/B2/B3 (P = 0.851)] and response rates [58.9/57.8/46.9% in A1/A2/A3 (P = 0.311) and 62.0/61.5/51.5% in B1/B2/B3 (P = 0.362)].

CONCLUSIONS

Renal impairment was associated with severe adverse events in cisplatin plus S-1 therapy but not with the efficacy in cisplatin plus S-1 and docetaxel plus cisplatin plus S-1 therapy.

Phase I dose escalation study of sorafenib plus S-1 for advanced solid tumors

S-1, an oral pyrimidine fluoride-derived agent, is effective against various cancers. Sorafenib, an oral multikinase inhibitor, was found to prolong the survival of various cancers and enhance the cytotoxicity of chemotherapeutic agents. We conducted a phase I dose escalation study to determine dose-limiting toxicity (DLT) and maximal tolerated dose (MTD) of S-1 when combined with sorafenib for refractory solid tumors. Eligible patients received escalating doses (30, 35, and 40 mg/m² bid) of S-1 Day 1 (D1)-D14 and continuous sorafenib 400 mg bid from cycle 1 D8 every 21 days in a standard 3 + 3 study design. Primary endpoint was MTD. Thirteen patients were enrolled between May 2010 and Feb 2012. DLT developed in two (one grade 3 erythema and one prolonged grade 2 hand-foot-skin reaction) of the 6 patients at 35 mg/m² dose level. One pancreatic neuroendocrine tumor (pNET) patient achieved a durable partial response (27.9 months). Four colon cancer patients had stable disease and 3 of them had progression-free survival greater than 6 months. This study determined the recommended (MTD) S-1 dose of 30 mg/m² bid for this regimen. This result warrants further phase II studies for advanced pNET and colon cancer to evaluate the efficacy of this combination.

Maintenance Chemotherapy with S-1 Following SOX Regimen Chemotherapy Improves Prognosis of Stage 3 Gastric Cancer After D2 Gastrectomy: A 5-Year Analysis

Objective

To assess the effectiveness and safety of treatment consisting of maintenance chemotherapy (MCT) with S-1 following S-1 plus oxaliplatin (SOX) chemotherapy for stage 3 gastric cancer (GC) after D2 gastrectomy.

Methods

In this retrospective study, we enrolled 255 patients with stage 3 GC who underwent D2 gastrectomy between February 2011 and May 2014. The SOX regimen chemotherapy was administrated to all of the patients as adjuvant therapy. The SOX regimen consisted of S-1 (for patients with a body surface area [BSA] of less than 1.25 m², 80 mg/d; 100 mg/d for BSA=1.25 m²- <1.5 m², and 120 mg/d for BSA≥1.5 m², in 2 divided doses for 14 d) and oxaliplatin (130 mg/m² given on Day 1), repeated every 21 d for 8 cycles. Following SOX chemotherapy, 122 of these patients received maintenance chemotherapy (the MCT group) with S-1, whereas 133 patients (the control group) received no MCT. The MCT consisted of S-1 (80, 100, or 120 mg daily based on BSA, in 2 divided doses for 14 d), repeated every 21 d for 8 cycles at most. The chemotherapy was discontinued if unacceptable toxicity or disease progression occurred or upon the request of the patient. All cases were followed up, and overall survival (OS), recurrence-free survival (RFS), and toxicities were compared.

Results

The MCT group exhibited a distinctly higher 5-year OS (P=0.0425) and RFS (P=0.0479) than those of the control group. The incidence of hand-foot syndrome was markedly greater in the MCT group (P=0.0026). No toxicity-related death occurred.

Conclusion

Maintenance chemotherapy with S-1 following the SOX regimen chemotherapy provides significant survival benefit for stage 3 GC after D2 gastrectomy.

Phase I study of DFP-11207, a novel oral fluoropyrimidine with reasonable AUC and low Cmax and improved tolerability, in patients with solid tumors

5-fluorouracil (5-FU) and 5-FU derivatives, such as capecitabine, UFT, and S-1, are the mainstay of chemotherapy treatment for gastrointestinal cancers, and other solid tumors. Compared with other cytotoxic chemotherapies, these drugs generally have a favorable safety profile, but hematologic and gastrointestinal toxicities remain common. DFP-11207 is a novel oral cytotoxic agent that combines a 5-FU pro-drug with a reversible DPD inhibitor and a potent inhibitor of OPRT, resulting in enhanced pharmacological activity of 5-FU with decreased gastrointestinal and myelosuppressive toxicities. In this Phase I study (NCT02171221), DFP-11207 was administered orally daily, in doses escalating from 40 mg/m2/day to 400 mg/m2/day in patients with esophageal, colorectal, gastric, pancreatic or gallbladder cancer (n = 23). It was determined that DFP-11207 at the dose of 330 mg/m2/day administered every 12 hours was well-tolerated with mild myelosuppressive and gastrointestinal toxicities. The pharmacokinetic analysis determined that the 5-FU levels were in the therapeutic range at this dose. In addition, fasted or fed states had no influence on the 5-FU levels (patients serving as their own controls). Among 21 efficacy evaluable patients, 7 patients had stable disease (33.3%), of which two had prolonged stable disease of >6 months duration. DFP-11207 can be explored as monotherapy or easily substitute 5-FU, capecitabine, or S-1 in combination regimens.

Irinotecan combined with oxaliplatin and S-1 in patients with metastatic pancreatic adenocarcinoma: a single-arm, three-centre, prospective study

Objective

To study the efficacy and toxicity of irinotecan combined with oxaliplatin and S-1 in patients with metastatic pancreatic adenocarcinoma.

Patients and methods

Previously untreated patients with cytologically or histologically confirmed metastatic pancreatic adenocarcinoma underwent a treatment regimen consisting of an intravenous infusion of irinotecan 165 mg/m² and oxaliplatin 85 mg/m² on day 1, and oral S-1 40 mg/m² twice daily on days 1-14, repeating the regimen every 21 days until one of the following occurred: disease progression, intolerable toxicity, or patient death. The primary endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS), response rate, toxicity, and quality of life. This ongoing study had been registered on ClinicalTrials.gov, NCT03726021.

Results

A total of 41 patients were enrolled in this study, 18 men and 23 women. The median PFS was 4.33 months [95% confidence interval (CI): 2.83-5.88] and the median OS was 11.00 months (95% CI: 9.16-12.84). There were no instances of a complete response; the partial response, stable disease, and disease progression rates were 39.02% (16/41), 29.27% (12/41), and 31.71% (13/41), respectively.The most common adverse side effects were mild to moderate nausea, vomiting, neutropenia, and thrombocytopenia. Grade 3 or 4 neutropenia and thrombocytopenia were observed in 29.27% (12/41) and 12.20% (5/41) of the patients, respectively. No treatment-related death was observed.

Conclusion

Irinotecan combined with oxaliplatin and S-1 is a safe and effective treatment for metastatic pancreatic adenocarcinoma, and any toxicities are mild to moderate and tolerable. A larger study population is needed for further evaluation.

Neoadjuvant chemoradiotherapy for locally advanced gastric cancer with bulky lymph node metastasis: Five case reports

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) has not been accepted as a general therapy for gastric cancer because of its localized effect and toxicity for radiosensitive organs. However, if radiation therapy could compensate for the limited or inadequate treatment choices available for elderly patients and/or those at high risk, the available therapeutic options for advanced gastric cancer might increase. From this perspective, we present our experiences of five patients with advanced gastric cancer in whom we used NACRT therapy with interesting results.

CASE SUMMARY

We admitted five patients with clinical Stage III gastric cancer and bulky lymph node metastasis or adjacent organ invasion at the time of diagnosis. A total of 50 Gy of preoperative intensity modulated radiation therapy was delivered to the patients in doses of 2.0 Gy/d, together with a regimen of concomitant chemotherapy comprising two courses of oral tegafur/gimeracil/oteracil (S-1; 65 mg/m2 per day) for three consecutive weeks followed by two weeks of rest, starting at the same time as radiotherapy. All patients underwent no residual tumor resection and a pathological complete response of the primary tumors was achieved in two patients. The incidence of hematological toxicity was low, although the digestive toxicities of anorexia and diarrhea developed in three of the five patients, necessitating termination of radiation therapy at 30 Gy and S-1 at three weeks. However, even 30 Gy of irradiation and half the dose of S-1 resulted in sufficient downstaging, indicating that even a reduced amount of NACRT could confer considerable effects.

CONCLUSION

Slightly reduced NACRT might be useful and safe for patients with locally advanced gastric cancer.

Rapidly progressive glomerulonephritis caused by tegafur/gimeracil/oteracil resulted in diabetes nephropathy, in a patient with minor risk of diabetes nephropathy: a case report

A 79-year-old Japanese male with a history of type 2 diabetes mellitus (T2DM) for 16 years was admitted to evaluate possible renal disease. The T2DM was well controlled in this patient using nutrition therapy without the need for any diabetes medication, and both diabetes retinopathy and proteinuria were negative. At the age of 78 advanced colorectal cancer (stage IIIa) was diagnosed and laparoscopic-assisted colectomy was performed. Following this procedure, the patient began treatment with tegafur/gimeracil/oteracil (S-1), 80 mg twice daily for 28 days of 42-day cycle. The patient received S-1 for 6 months, during which time, serum albumin decreased from 3.0 g/dL to 1.1 g/dL, urinary protein increased from negative to 3.0 g/day, and serum creatinine increased from 0.9 mg/dL to 2.1 mg/dL. Treatment with S-1 was discontinued, and furosemide 180 mg and prednisolone 30 mg treatment was initiated; however, serum creatinine levels continued to increase to 7.2 mg/dL and proteinuria continued to increase reaching a nephrotic range. A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity was decreased to 27.0%. Renal biopsy showed Kimmelstiel-Wilson nodules, while immunofluorescence intensity of IgG subclass was IgG1 dominant, which was not compatible with diabetic nephropathy (DN). Plasma exchange was not affected. However, hemodialysis was initiated.The results of this investigation suggest that when S-1 monotherapy is performed in the case with DN, rapidly progressive glomerulonephritis (RPGN) may develop due to a condition similar to thrombotic microangiopathy, even in patients with a minor risk factor of DN.

Clinicopathological Characteristics and Prognosis of Upper Gastric Cancer Patients in China: A 32-Year Single-Center Retrospective Clinical Study

Purpose

Upper or proximal gastric cancer occurs in the upper third of the stomach between the cardia and a line connecting the greater and lesser curvatures. As it differs from other gastric cancers in pathology and prognosis, we evaluated patient and disease characteristics that might guide improved treatment and survival of upper gastric cancer.

Methods

We conducted a retrospective analysis of 649 patients with upper gastric cancer and 1551 patients with lower gastric cancer and R0 radical surgery at our institution between January 1980 and December 2012.

Results

Survival after radical surgery for upper gastric cancer was 77.8% at 1 year, 49.6% at 3 years, and 41.1% at 5 years. The corresponding rates for lower gastric cancer were 85.9%, 60.0%, and 57.2% (p < 0.001). Upper gastric cancer had a poor prognosis. Sex (p = 0.036), tumor diameter (p = 0.001), macroscopic type (p < 0.001), pTM stage (p < 0.001), tissue differentiation type (p = 0.003), and serosal invasion (p = 0.034) were independently associated with lymph node metastasis. The macroscopic type (p = 0.045), lymphovascular tumor emboli (p = 0.021), and pTNM stage were independently associated with recurrence and metastasis. Survival of 333 patients with D2 total gastrectomy was 81.3% at 1 year, 54.4% at 3 years, and 45.2% at 5 years. The corresponding rates for 316 proximal gastrectomy patients were 75.4%, 44.9%, and 36.7%. Radical total gastrectomy had better survival than radical proximal resection.

Conclusions

Upper gastric cancers were more aggressive, had a worse prognosis, and were more prone to recurrence and metastasis compared with lower gastric cancers. Survival was better after total gastrectomy than after proximal resection.

Curative-Intent Surgery for Stage IV Advanced Gastric Cancer: Who Can Undergo Surgery and What Are the Prognostic Factors for Long-Term Survival?

BACKGROUND

A retrospective study was performed to evaluate the predictive factors for performing curative-intent surgery and prognostic factors for long-term survival of patients undergoing surgery for stage IV gastric cancer.

PATIENTS AND METHODS

Between 2001 and 2017, 271 patients with stage IV gastric cancer with distant metastasis who underwent systemic chemotherapy were enrolled. Logistic regression analysis was performed to evaluate predictive factors for curative-intent surgery. Cox proportional hazards regression model was applied for patients who were subsequently treated with curative-intent surgery to identify prognostic factors for long-term survival.

RESULTS

Curative-intent surgery was performed in 48 patients (17.7%). Median survival time was significantly longer in the surgery group than in the nonsurgery group (53 vs. 11 months, p < 0.0001). R0 resection was performed in 35 patients (72.9%). The three-year overall survival (OS) rates of the R0, R1, and R2 surgery groups were 75.4%, 33.3%, and 25.0%, respectively (p = 0.0002). Logistic regression analysis revealed that lymphogenous distant metastasis alone (odds ratio = 3.276, p = 0.004), positive lavage cytology alone (6.394, 0.014), doublet or triplet chemotherapy (4.064, 0.034), and high Glasgow prognostic score (0.276, 0.001) were independent predictive factors for performing curative-intent surgery. Among patients undergoing surgery, the Cox proportional hazards regression model for OS showed that R0 surgery was an independent prognostic factor for favorable OS (hazard ratio 0.188, p = 0.022).

CONCLUSIONS

Patients with lymphogenous distant metastasis alone, P0CY1 alone, good immunonutritional status, and doublet/triplet chemotherapy are candidates for performing effective curative-intent surgery. R0 surgery is crucial for improving long-term survival after surgery.

S-1 salvage chemotherapy for stage IV thymic carcinoma: a study of 44 cases

Background

Thymic carcinoma (TC) is a rare mediastinal tumor, and patients with stage IV TC have a poor prognosis. No optimal chemotherapeutic regimen has yet been established. In this study, we evaluated the efficacy and safety of S-1 as a salvage mono-therapy in stage IV TC.

Methods

Patients with histologically confirmed stage IV TC were enrolled in this study when front-lined chemotherapy failed. S-1 capsules were orally taken twice a day. The daily dose was prescribed in three levels (80, 100, 120 mg) based on body surface area (BSA). One cycle of treatment consists of 4 weeks of drug use and 2 weeks of rest. The cycle was repeated until tumor progressed or intolerable toxicity occurred. The response rate, progression-free survival (PFS), overall survival (OS), and toxicity were evaluated.

Results

Forty-four patients with stage IV TC were included between January 2013 and July 2017. Squamous cell carcinoma accounted for 84% of cases (37/44). There were 22 males and 22 females with a median age of 57 years (27-78 years). S-1 was prescribed at a dose of 80 mg for 18 (41%) patients, 100 mg for 17 patients (38%), and 120 mg for 9 patients (21%). The median number of cycles of administrated per patient was 3 [1-32]. Among 44 patients, 13 (30%) achieved a partial response, 22 (50%) remained stable disease, and 9 (20%) showed a rapid progression. With a median follow-up time of 14 months, the median PFS and OS of the whole group were 6 (95% CI, 7.0-13.9) months and 15 (95% CI, 13.2-21.6) months, respectively. For the 13 patients who showed response to S-1, the median PFS was 22 (95% CI, 15.5-30) months. Anorexia was the most common side effect, but all cases were mild. Other toxicities of grade ≥3 were bone marrow suppression (n=6) and rash (n=1). No drug-related deaths occurred.

Conclusions

S-1 is a safe and effective treatment for stage IV TC as a salvage monotherapy. It is especially effective in disease control when the tumor shows response to S-1.

TS-1 add-on therapy in Japanese patients with triple-negative breast cancer after neoadjuvant or adjuvant chemotherapy: a feasibility study

Purpose We examined the feasibility, efficacy, and safety of TS-1 add-on therapy (TAT) in Japanese patients with triple-negative breast caner (TNBC). Methods TAT (TS-1, 80 mg/m²/day, BID, PO), consisting of the 21-day cycles of 14-day consecutive administration followed by 7-day drug holiday, was conducted for 365 days. The median follow-up was 75.2 months (range, 7.3–103.3 months). The primary endpoint was the feasibility of TAT. The secondary endpoints included relapse-free survival (RFS), overall survival (OS), and safety. Results 63 Japanese patients with TNBC (median age, 52.5 years; range, 23.7–68.6 years) were examined. Among them, 34 (54.0%) were postmenopausal, 54 (93.7%) had TNBC of common histological type, 51 (81.0%) had T1 to 3 tumors, 63 (100%) had undergone standardized surgery, and 44 (69.8%) and 19 (30.2%) had undergone neoadjuvant chemotherapy and adjuvant chemotherapy, respectively. The 365-day cumulative rate of TS-1 administration was 68.3% (95% confidence interval, 55.3–79.4), being comparable to 65.8% previously reported for gastric cancer. The 5-year RFS rates were 52.3% and 84.2% in the neoadjuvant and adjuvant chemotherapy groups, respectively, and the 5-year OS rates were 68.0% and 89.5%, respectively. The most common adverse events (AEs) were leucocyte count decreased (50.8%), total bilirubin decreased (44.4%), and pigmentation (42.9%). AEs were manageable clinically, and any grade 4 AEs did not develop. Conclusions The 365-day cumulative rate of TS-1 administration in TNBC patients was comparable to that in gastric cancer patients despite previous chemotherapy with anthracyclines and/or taxanes. TAT was feasible for TNBC patients after standard primary therapy.

The optimal neoadjuvant treatment of locally advanced esophageal cancer

Esophagectomy is the cornerstone of intentionally curative treatment in patients with locally advanced esophageal cancer. Neoadjuvant treatments have been introduced to minimize the risk of development of locoregional- and/or distant recurrences. Chemotherapy is used based on the results of the MAGIC- and the OEO2-trials and chemoradiotherapy became part of standard treatment after the publication of the CROSS-trial. Although several studies have compared the efficacy of neoadjuvant chemotherapy and chemoradiotherapy, no robust evidence on the optimal neoadjuvant treatment has been obtained as yet. Several studies indirectly comparing both modalities suggest a benefit for chemoradiotherapy in the number of pathologically complete responders, radical resection rate and possibly even in overall survival. Large randomized controlled trials like the Neo-AEGIS-, ESOPEC- and NeXT-trials are currently addressing this topic. A relatively new aspect of esophageal cancer treatment is the administration of monoclonal antibodies. Several monoclonal antibodies have been tested in, mostly, advanced esophageal cancer treatment. Cetuximab has also been tested as addition to neoadjuvant- and definitive treatment in patients with locally advanced esophageal cancer, showing mixed results. This review aims at providing an overview of the currently available neoadjuvant treatments in esophageal cancer.

Phase II Study of the Triple Combination Chemotherapy of SOXIRI (S-1/Oxaliplatin/Irinotecan) in Patients with Unresectable Pancreatic Ductal Adenocarcinoma

LESSONS LEARNED

The triple combination chemotherapy of SOXIRI (S-1/oxaliplatin/irinotecan) in patients with unresectable pancreatic ductal adenocarcinoma was an effective treatment that appeared to be better tolerated than the widely used FOLFIRINOX regimen.SOXIRI regimen may provide an alternative approach for advanced pancreatic cancer.

BACKGROUND

In our previous phase I study, we determined the recommended dose of a biweekly S-1, oxaliplatin, and irinotecan (SOXIRI) regimen in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). This phase II study was conducted to assess the safety and clinical efficacy in patients with unresectable PDAC.

METHODS

Patients with previously untreated metastatic and locally advanced PDAC were enrolled. The primary endpoint was response rate (RR). Secondary endpoints were adverse events (AEs), progression-free survival (PFS), and overall survival (OS). Patients received 80 mg/m² of S-1 twice a day for 2 weeks in alternate-day administration, 150 mg/m² of irinotecan on day 1, and 85 mg/m² of oxaliplatin on day 1 of a 2-week cycle.

RESULTS

Thirty-five enrolled patients received a median of six (range: 2-15) treatment cycles. The RR was 22.8% (95% confidence interval [CI]: 10.4-40.1); median OS, 17.7 months (95% CI: 9.8-22.0); and median PFS, 7.4 months (95% CI: 4.2-8.4). Furthermore, the median OS in patients with distant metastasis was 10.1 months, whereas that in patients with locally advanced PDAC was 22.6 months. Major grade 3 or 4 toxicity included neutropenia (54%), anemia (17%), febrile neutropenia (11%), anorexia (9%), diarrhea (9%), and nausea (9%). There were no treatment-related deaths.

CONCLUSION

SOXIRI is considered a promising and well-tolerated regimen in patients with unresectable PDAC.

Prognostic Factors for Advanced Pancreatic Cancer Treated with Gemcitabine Plus S-1: Retrospective Analysis and Development of a Prognostic Model

Gemcitabine plus S-1 (GS) is commonly used to treat advanced pancreatic cancer (APC) in Asia. Few clinical experiments have demonstrated the clinical efficacy of GS in routine clinical practice. We aimed to identify the prognostic factors and develop a prognostic model for survival prediction in patients with APC, treated with GS. Records of 111 patients with newly diagnosed APC who received first-line palliative GS chemotherapy during 2010⁻2016 in Taiwan were analyzed retrospectively. Univariate and multivariate analyses were performed for the identification of prognostic factors. A prognostic model using prognosticators from the multivariate analysis was developed for survival prediction. The median overall survival (OS) for the cohort was 9.3 months (95% confidence interval [CI], 8.0⁻10.6). The prognostic model was constructed based on four independent prognosticators: performance status, tumor stage, pre-treatment albumin level, and neutrophil-to-lymphocyte ratio. Patients were categorized by tertiles into good, intermediate, and poor prognostic groups. The median OS values for each of these groups were 21.1 (95% CI, 8.2⁻33.9), 9.2 (95% CI, 8.3⁻10.1), and 5.8 months (95% CI, 4.4⁻7.1; log-rank p < 0.001), respectively. The bootstrapped corrected C-index of this model was 0.80 (95% CI, 0.71⁻0.89). The developed model was robust and could accurately predict survival in this population, and can assist clinicians and patients in survival discrimination and the determination of appropriate medical care goals. Additional research is needed to externally validate the model's performance.

Surgery with curative intent for stage IV gastric cancer: Is it a reality of illusion?

Gastric cancer with metastases outside of the regional lymph nodes is deemed oncologically unresectable. Nevertheless, some metastatic lesions are technically resectable by applying established surgical techniques such as para-aortic lymphadenectomy and hepatectomy. At the time of compilation of the Japanese gastric cancer treatment guidelines version 4, systematic reviews were conducted to see whether it is feasible to make any recommendation to dissect both the primary and metastatic lesions with intent to cure, possibly as part of multimodality treatment. Long-term survivors were found among carefully selected groups of patients both in prospective and retrospective studies. In addition, there is a growing list of publications reporting encouraging outcomes of gastrectomy conducted after exceptionally good response to chemotherapy, usually among patients who underwent R0 resection. This type of surgery is often referred to as conversion surgery. It is sometimes difficult to define a clear borderline between curative surgery scheduled after neoadjuvant chemotherapy and the conversion surgery. This review summarizes what we knew after the literature reviews conducted at the time of compiling the Japanese guidelines and in addition reflects some new findings obtained thereafter through clinical trials and retrospective studies. Metastases were divided into three categories based on the major metastatic pathways: lymphatic, hematogenous, and peritoneal. In each of these categories, there were findings that could provide hope for patients with metastatic disease. These findings implied that the surgical technique that we already use could become more useful upon further developments in antineoplastic agents and drug delivery.

A phase II trial of capecitabine plus cisplatin (XP) for patients with advanced gastric cancer with early relapse after S-1 adjuvant therapy: XParTS-I trial

BACKGROUNDS

In Japan, standard regimens for advanced gastric cancer (AGC) include S-1 chemotherapy. The standard treatment for early relapse after adjuvant chemotherapy with fluoropyrimidine alone is platinum-based chemotherapy, while the standard treatment for early relapse after adjuvant chemotherapy with fluoropyrimidine plus platinum is second-line chemotherapy. To evaluate the efficacy and safety of capecitabine plus cisplatin (XP) treatment for AGC patients who relapse within 6 months after S-1-based therapy, we conducted a multicenter phase II trial (NCT01412294).

METHODS

HER2-negative gastric cancer patients treated with adjuvant chemotherapy including S-1 for more than 12 weeks and relapsed within 6 months were treated with capecitabine 1000 mg/m² bid for 14 days plus cisplatin 80 mg/m² on day 1 of a 3-week cycle. The primary endpoint was PFS; secondary endpoints were OS, time to treatment failure, overall response rate (ORR) and safety.

RESULTS

Forty patients (median age 64) were enrolled; of those, 37 (92.5%) received adjuvant S-1 monotherapy. Median PFS was 4.4 months (95% CI 3.6-5.1), which was longer than the 2-month protocol-specified threshold (p < 0.001). Median OS was 13.7 months (95% CI 9.0-17.7) and ORR was 8/30 (26.7%) (95% CI 14.2-44.4). Most common grade ≥ 3 adverse events were neutropenia (23%), anemia (18%), elevated serum creatinine (18%), fatigue (13%), diarrhea (7.5%), and anorexia (7.5%).

CONCLUSIONS

XP was safe and effective in patients with early relapse after S-1 adjuvant chemotherapy for curatively resected gastric cancers. XP may be a good option for the treatment of patients after early failure after adjuvant S-1.

TRIAL REGISTRATION

NCT01412294.

5-Chloro-2,4-dihydroxypyridine, CDHP, prevents lung metastasis of basal-like breast cancer cells by reducing nascent adhesion formation

A drug for metastasis prevention is necessary. The orally administered anticancer drug S‐1 contributes to cancer therapy. In a mouse xenograft model of metastatic breast cancer from our previous study, the administration of S‐1 inhibited lung metastasis. However, the mechanism of inhibition remains elusive. S‐1 contains 5‐chloro‐2,4‐dihydroxypyridine (CDHP), which does not have the antigrowth activity, but prevents the degradation of 5‐fluorouracil, an anticancer reagent. In this study, we found that CDHP treatment shrinks cell morphology in metastatic basal‐like breast cancer cell lines. Wound healing assays showed reduced cell migration in CDHP‐treated cells. At the molecular level, CDHP treatment reduced the number of nascent adhesions, whereas the number of mature focal adhesions was not changed. These findings indicate that CDHP impairs focal adhesion formation, which results in a reduction in cell migration. For the in vivo metastasis assay, we used a highly lung‐metastatic cell line. We xenografted them into immunodeficient mice, and administered CDHP. To determine whether CDHP prevents metastasis, we measured the weights of harvested lungs. The results showed that the lung weights of the CDHP‐treated animals were not significantly different compared to the no‐tumor controls, whereas the vehicle group showed a number of metastatic foci and an increase in lung weight. These observations indicate that CDHP administration prevents metastasis. This study reveals a novel effect of CDHP for lung metastasis prevention. Our findings may facilitate the establishment of future metastasis prevention therapies.

Genomic predictors of chemotherapy efficacy in advanced or recurrent gastric cancer in the GC0301/TOP002 phase III clinical trial

Recent gastric cancer clinical trials have aimed to establish the efficacy of combination therapy over monotherapy, however, the role for genomic biomarkers in these trials has remained largely unexplored. Here, using the NanoString expression platform, we analyzed 105 gastric tumors from a randomized phase III Japanese clinical trial (GC0301/TOP002) testing the efficacy of irinotecan plus S-1(IRI-S) versus S-1 therapy. We found that previously established proliferative subtype signatures, were associated with older patients (>65 years) and liver metastasis while mesenchymal subtype signatures were associated with younger patients (≤65 years) and peritoneal metastasis. Genes associated with tumor microenvironment (CD4, CD14, ADAMTS1, CCL5, CXCL12, CCL19), therapeutic implications (DPYD) and oncogenic signaling (Wnt5A, PTRF) were significantly associated with patient age, histology, tumor status, measurable lesions and metastasis. We identified Wnt5A downregulation as a candidate predictor of improved progression free survival (>8 weeks) in S-1 but not in IRI-S treatment. Although statistical significance was not achieved, mesenchymal subtype showed a trend for treatment interaction with IRI-S for efficacy. These findings highlight promising genomic markers that could be useful predictors of chemotherapy efficacy for better prognosis and survival outcome in gastric cancer.

Elevated neutrophil-to-lymphocyte ratio is associated with nutritional impairment, immune suppression, resistance to S-1 plus cisplatin, and poor prognosis in patients with stage IV gastric cancer

Gastric cancer continues to be a major cause of morbidity and mortality worldwide. Recently, there has been a growing interest in the host inflammatory response and there is increasing evidence that the neutrophil to lymphocyte ratio (NLR), which is a useful marker of systemic inflammation, can be an effective prognostic indicator in various types of malignant diseases. A total of 110 patients with stage IV gastric cancer who received chemotherapy of S-1 plus cisplatin were enrolled in this study. Eleven patients did not complete four cycles of the chemotherapy. The patients were divided into two groups with 3.0 of NLR. The percentage of patients with a partial response to chemotherapy was significantly higher in the group of patients with a lower NLR (<3) (19.1 vs. 38.5%, high vs. low NLR group, respectively; P<0.05). The percentage of patients with progressive disease was higher in the high vs. low NLR group (57.4 vs. 25.0%, respectively; P<0.05). NLR levels were significantly inversely correlated with serum levels of prealbumin (P<0.01) and retinol binding protein (P<0.05). NLR levels were also significantly correlated with c-reactive protein levels (P<0.05), white blood cell count (P<0.05) and inversely with the stimulation index (a marker of cell-mediated immune function; P<0.05). Overall survival was significantly longer in patients with a lower NLR (≤ 3.0) than in those with a higher NLR (>3.0). The present study demonstrated that the NLR is a useful marker for resistance to chemotherapy, malnutrition, systemic inflammation and immune suppression. Moreover, the NLR was demonstrated to be a strong prognostic indicator in these patients.

Effect of Sipjeondaebo-Tang on the Pharmacokinetics of S-1, an Anticancer Agent, in Rats Evaluated by Population Pharmacokinetic Modeling

S-1 (TS-1^®) is an oral fluoropyrimidine anticancer agent containing tegafur, oteracil, and gimeracil. Sipjeondaebo-tang (SDT) is a traditional oriental herbal medicine that has potential to alleviate chemotherapy-related adverse effects. The aim of the present study was to evaluate the effect of SDT on the pharmacokinetics of S-1. Sprague-Dawley rats were pretreated with a single dose or repeated doses of SDT for seven consecutive days (1200 mg/kg/day). After the completion of pretreatment with SDT, S-1 was orally administered and plasma concentrations of tegafur, its active metabolite 5-FU, and gimeracil were determined by liquid chromatography-tandem mass spectrometry (LC/MS/MS). A population pharmacokinetic model was developed to evaluate the effect of SDT on pharmacokinetics of tegafur and 5-FU. Although a single dose of SDT did not have any significant effect, the absorption rate of tegafur decreased, and the plasma levels of 5-FU reduced significantly in rats pretreated with SDT for seven days in parallel to the decreased gimeracil concentrations. Population pharmacokinetic modeling also showed the enhanced elimination of 5-FU in the SDT-pretreated group. Repeated doses of SDT may inhibit the absorption of gimeracil, an inhibitor of 5-FU metabolism, resulting in enhanced elimination of 5-FU and decrease its plasma level.

Therapeutic strategies with oral fluoropyrimidine anticancer agent, S-1 against oral cancer

Oral cancer has been recognized as a tumor with low sensitivity to anticancer agents. However, introduction of S-1, an oral cancer agent is improving treatment outcome for patients with oral cancer. In addition, S-1, as a main drug for oral cancer treatment in Japan can be easily available for outpatients. In fact, S-1 exerts high therapeutic effects with acceptable side effects. Moreover, combined chemotherapy with S-1 shows higher efficacy than S-1 alone, and combined chemo-radiotherapy with S-1 exerts remarkable therapeutic effects. Furthermore, we should consider the combined therapy of S-1 and molecular targeting agents right now as these combinations were reportedly useful for oral cancer treatment. Here, we describe our findings related to S-1 that were obtained experimentally and clinically, and favorable therapeutic strategies with S-1 against oral cancer with bibliographic considerations.

Phase II Study of Neoadjuvant Chemotherapy With S-1 and CDDP in Patients With Lymph Node Metastatic Stage II or III Gastric Cancer

OBJECTIVES

We conducted a phase II trial to investigate the efficacy and safety of neoadjuvant chemotherapy (NAC) comprising S-1 and cisplatin (CDDP) followed by extensive resection in the management of resectable locally advanced gastric cancer with lymph node (LN) metastases.

METHODS

Patients with LN metastases from stage II or III gastric cancer received S-1 and CDDP, as NAC criteria for LN metastases were the involvement of ≥4 nodes <2 cm or ≥1 nodes ≥2 cm as confirmed by a total body computed tomography scan. All patients underwent extensive resection including D2 gastrectomy. The primary endpoint was complete resection rate and the secondary endpoints were 3-year relapse-free and overall survival.

RESULTS

Fifty patients were assessable for the analysis. The complete resection rate was 87.8%. Three-year relapse-free survival was 44.9% and 3-year overall survival rate was 48.0%.

CONCLUSIONS

NAC with S-1 and CDDP is safe and may improve the complete resection rate in patients with metastatic LN gastric cancer. This suggests that LN metastases would provide good target lesions in future clinical trials of NAC.

Randomized phase II study of daily and alternate-day administration of S-1 for advanced gastric cancer (JFMC43-1003)

Purpose

Although S-1 based chemotherapy for patients with advanced gastric cancer has generally been accepted in Japan, discontinuations of treatment have been reported due to grade 3 or more adverse events. The present randomized phase II study was conducted to test whether alternate-day administration of S-1 would be comparably efficient and reduce adverse events compared with conventional daily administration in the first-line chemotherapy for advanced gastric cancer.

Methods

132 patients with advanced gastric cancer were randomly assigned to 1:2 ratios to receive treatment with daily at a standard dose of 80 mg/m²/day or alternate-day administration group received S-1 on 4 days a week. The primary end point was progression-free survival (PFS), and the secondary end points were safety, overall survival, time to treatment failure (TTF), disease control rate, and response rate.

Results

The 6-month PFS rate of the alternate-day administration group was 20.9% and failed to show significant difference from the pre-specified threshold at 15% (p = 0.117), whereas that of the daily administration group was 39.1% and significantly higher than the threshold (p = 0.001). The hazard ratio of the alternate-day administration group compared with the daily administration group was 1.753 (95% confidence interval (CI) 1.15–2.68, p = 0.010). With regard to OS, the hazard ratio of the alternate-day administration group compared with the daily administration group was 1.487 (95% CI 0.97–2.29, p = 0.072). The median TTF were 4.2 and 2.8 months in the daily and alternate-day administration group, respectively (p = 0.007).

Conclusion

The alternate-day administration of S-1 was not recommended as the first-line therapy for patients with advanced gastric cancer.

Hyperthermic intraperitoneal perfusion chemotherapy and response evaluation in patients with gastric cancer and malignant ascites

The present study describes the use of bidirectional chemotherapy in the treatment of patients with gastric cancer and peritoneal carcinomatosis (PC), using newly developed response criteria for the treatment of malignant ascites. In addition, the association between effusion response and survival was analyzed. Between June 2010 and May 2014, patients affected by malignant ascites secondary to unresectable PC of gastric origin were treated with a combination of systemic and loco-regional chemotherapy. Cisplatin (75 mg/m²) at an inflow temperature of 43°C was infused intraperitoneally, and docetaxel (75 mg/m²) was infused simultaneously via a peripheral vein, on day 1 every 3 weeks. The primary endpoint was overall survival rate, and the secondary endpoint was efficacy against malignant ascites using new response criteria. In total, 41 patients were enrolled, the majority of whom received 6 cycles of intraperitoneal chemotherapy in combination with hyperthermia. The majority of patients exhibited clinical regression of ascites and relief of associated symptoms. Malignant ascites disappeared [complete response (CR)] or decreased by 50% [partial response (PR)] in 73.2% of patients. No mortalities associated with the procedures occurred. The median survival time was 8.6 months, and the 1-year survival rate was 24.4%. As these new response criteria for the treatment of malignant ascites were found to be feasible, bidirectional chemotherapy may be the preferred strategy for the treatment of gastric cancer with PC. The CR, PR and non-PR groups showed significant differences in overall survival, indicating that decreased effusion was associated with improved patient survival.

Multicenter, randomized, open-label Phase II study comparing S-1 alternate-day oral therapy with the standard daily regimen as a first-line treatment in patients with unresectable advanced pancreatic cancer

PURPOSE

Non-inferiority for overall survival (OS) following alternate-day treatment with the oral anticancer drug S-1 compared with standard daily treatment was assessed in Japanese patients with unresectable advanced pancreatic cancer in a multicenter, randomized, phase II study. This trial was registered at the UMIN Clinical Trials Registry (no. 000008604).

METHODS

Chemotherapy-naïve patients with locally advanced or metastatic pancreatic cancer were randomly assigned 2:1 to treatment with alternate-day (twice daily on alternate days from days 1 through 42 of a 42-day cycle) or daily (twice daily on days 1 through 28 of a 42-day cycle) treatment with S-1. The primary endpoint was OS. Secondary endpoints were progression-free survival (PFS), time to treatment failure, response rate, quality of life assessments, and safety.

RESULTS

A total of 190 patients were enrolled, of which 185 were included in the final analysis (alternate-day: 121; daily: 64). Median OS was 9.4 for the alternate-day group and 10.4 months for the daily group [hazard ratio (HR), 1.19; 95% credible interval, 0.86 to 1.64], indicating that non-inferiority of alternate-day treatment to daily treatment was not demonstrated. Median PFS was 3.0 for the alternate-day group and 4.2 months for the daily group (HR, 1.65; 95% credible interval, 1.20-2.29). The incidence of anorexia, fatigue, neutrophils, pigmentation, and pneumonitis was lower in alternate-day treatment compared with daily treatment.

CONCLUSION

S-1 for advanced pancreatic cancer should be taken daily as recommended, based on the decreased OS and PFS and marginal improvement in safety observed in the alternate-day group.

Phase I study of orally administered S-1 in combination with epirubicin and oxaliplatin in patients with advanced solid tumors and chemotherapy-naïve advanced or metastatic esophagogastric cancer

BACKGROUND

This phase I study investigated the safety and the maximum tolerated dose (MTD) of the oral fluoropyrimidine S-1 when combined with epirubicin and oxaliplatin (EOS).

METHODS

Patients aged ≥18 years with advanced or metastatic solid tumors were enrolled in a 3 + 3 design with S-1 dose escalation (two planned cohorts) performed according to the occurrence of dose-limiting toxicity (DLT). On day 1 of each 21-day cycle, patients received epirubicin 50 mg/m² followed by oxaliplatin 130 mg/m² (maximum 8 cycles) and then S-1 [20 mg/m² (cohort 1) or 25 mg/m² (cohort 2), twice daily]: first dose, evening of day 1; subsequent administration on days 2-14, twice daily; last dose, morning of day 15 (unlimited number of S-1 cycles). After protocol amendment, enrollment in a third cohort was restricted to patients with chemotherapy-naïve advanced or metastatic esophagogastric cancer.

RESULTS

DLT was reported for two of the five patients in cohort 2, defining 20 mg/m² twice daily as the MTD of S-1 combined with epirubicin and oxaliplatin in heavily pretreated patients. Thirteen patients with chemotherapy-naïve advanced or metastatic esophagogastric cancer were subsequently enrolled and treated at an S-1 dose level of 25 mg/m² twice daily; no DLTs were reported; median overall survival was 13.1 months. Of the 11 evaluable patients, three (27 %) had partial responses and seven (64 %) had stable disease. The safety profile was in line with expectations.

CONCLUSIONS

The promising activity of EOS (S-1 dose level, 25 mg/m² twice daily) and acceptable safety profile support further clinical development of this combination for the first-line treatment of patients with advanced or metastatic esophagogastric cancer.

Clinical Observation of Bevacizumab Combined with S-1 in the Treatment of Pretreated Advanced Esophageal Carcinoma

Objective To investigate the clinical effects and safety of bevacizumab combined with S-1 as the second-line treatment of recurrent and/or metastatic esophageal cancer after chemoradiation. Methods Patients with recurrent or metastatic esophageal cancer after chemoradiation were treated with bevacizumab and S-1. Bevacizumab was used by intravenous infusion, 7.5mg/kg body weight on day 1; S-1 was used by oral at 80mg/m²·d on day 1-14, 21 days as a cycle of treatment and repeated until either pro- gressive disease or intolerable toxicity occurred. Chest CT were performed and RECIST 1.1 was used for response evaluation. Kaplan-Meier method was used for survival analysis. Side effects were recorded and analyzed. Results Totally 78 patients were enrolled in the study, including 67 squamous cell carcinoma and 11 adenocarcinoma histologically. The overall response (CR+PR) rate was 22.4% (17/76) and disease control (CR+PR+SD) rate was 61.8% (47/76) respectively. The median follow-up time was 20 months (range from 9 to 44 months). The median progression-free survival (PFS) was 4.9 months (95% CI 4.4-5.5) and the median overall survival (OS) was 8.1 months (95% CI 7.6-9.2). The median PFS and OS of patients with metastasis diseases were 6.2 months (95% CI 3.3 to 6.3) and 8.5 months (95% CI 5.8 to 11.2), where PFS was longer than that of patients with local regional recurrence (median 5.0 months, 95% CI 3.0 to 5.5, P=0.017) and OS was longer than that of patients with regional disease and metastasis (median 8.0 months, 95% CI 4.6 to 9.5, P=0.010). The common adverse effects were mild to moderate neutropenia (84.2%), grade I-II hand and foot syndrome (51.3%), grade I-II nausea (48.7%), mild epistaxis (30.1%) and mild vomiting (14.5%). Esophageal bleeding occurred in 7.9% of patients. One patient (1.3%) died from massive bleeding which was caused by esophageal perforation. Conclusion Bevacizumab combined with S-1 was effective and safe for esophageal cancer patients who had recurrent or metastatic diseases after chemoradiation.

Improvement of intratumor microdistribution of PEGylated liposome via tumor priming by metronomic S-1 dosing

The efficient delivery of nanocarrier-based cancer therapeutics into tumor tissue is problematic. Structural abnormalities, tumor vasculature heterogeneity, and elevated intratumor pressure impose barriers against the preferential accumulation of nanocarrier-based cancer therapeutics within tumor tissues and, consequently, compromise their therapeutic efficacy. Recently, we have reported that metronomic S-1, orally available tegafur formulation, dosing synergistically augmented the therapeutic efficacy of oxaliplatin (l-OHP)-containing PEGylated liposome without increasing the toxicity in animal model. However, the exact mechanism behind such synergistic effect was not fully elucidated. In this study, therefore, we tried to shed the light on the contributions of metronomic S-1 dosing to the enhanced accumulation and/or spatial distribution of PEGylated liposome within tumor tissue. Tumor priming with metronomic S-1 treatment induced a potent apoptotic response against both angiogenic endothelial cells and tumor cells adjacent to tumor blood vessels, resulting in enhanced tumor blood flow via transient normalization of tumor vasculature, along with alleviation of intratumor pressure. Such a change in the tumor microenvironment imparted by S-1 treatment allows efficient delivery of PEGylated liposome to tumor tissue and permits their deep penetration/distribution into the tumor mass. Such a priming effect of S-1 dosing can be exploited as a promising strategy to enhance the therapeutic efficacy of nanocarrier-based cancer therapeutics suffering from inadequate/heterogeneous delivery to tumor tissues.

S-1 monotherapy in a patient with cholangiolocellular carcinoma: A case report

A 71-year-old man with alcoholic cirrhosis was found to have multiple hypervascular lesions in the liver on enhanced computed tomography. An ultrasound-guided biopsy of the lesion was performed. Immunohistochemical analysis for hepatocyte paraffin 1 expression was negative; cytokeratin (CK) 7, CK19, epithelial cell adhesion molecule and epithelial membrane antigens were positive; mucicarmine staining was negative. The tumor was thus histologically diagnosed as cholangiolocellular carcinoma (CoCC). The tumor was inoperable due to the associated advanced liver disease. In addition, the patient preferred systemic chemotherapy using only orally administered agents. Thus, S-1 monotherapy was recommended. S-1 was initially administered orally at a dose of 80 mg/day. Although the levels of tumor marker (prothrombin induced by vitamin K absence/antagonist-II and carbohydrate antigen 19-9) levels were marginally elevated, their values did not change over the entire course. The patient achieved a partial response according to the Response Evaluation Criteria In Solid Tumors (RECIST) and modified RECIST 1 year after chemotherapy initiation. In conclusion, S-1 monotherapy exhibited promising efficacy against unresectable CoCC.

Capecitabine for the treatment of gastric cancer

Capecitabine is an orally administered prodrug of 5-fluorouracil (5-FU) and was designed to specifically affect tumor cells more than normal tissues. Capecitabine is as effective and well tolerated as infusional 5-FU in the treatment of advanced gastric cancer (AGC). Following the REAL-2 and ML17032 studies, capecitabine has replaced infusional 5-FU for treating GC. Capecitabine plus platinum is one of the most widely used regimens for the first-line treatment of AGC, regardless of HER2 status. The adjuvant capecitabine/oxaliplatin regimen is one therapeutic option for resectable gastric cancer, especially after D2 resection. Compared with S-1, capecitabine has been shown to have a similar efficacy, but is associated with fewer ethnic differences than S-1, which accounts for the more widespread usage of capecitabine worldwide.

Randomised phase III study of S-1 alone versus S-1 plus lentinan for unresectable or recurrent gastric cancer (JFMC36-0701)

BACKGROUND

Lentinan (LNT) is a purified β-1, 3-glucan that augments immune responses. The present study was conducted to assess the efficacy of LNT in combination with S-1 as a first-line treatment for unresectable or recurrent gastric cancer.

PATIENTS AND METHODS

Eligible patients were randomly assigned to receive S-1 alone or S-1 plus LNT. The primary end-point was overall survival (OS). Secondary end-points were time-to-treatment failure (TTF), overall response rate (ORR), safety, quality of life (QOL), and biomarker. The percentages of LNT-binding monocytes in peripheral blood prior to treatment were analysed for the biomarker assessment.

RESULTS

One hundred and fifty-four and 155 patients were randomly assigned to receive S-1 alone or S-1 plus LNT, respectively. The median OS was 13.8 and 9.9 months (P = 0.208), the median TTF was 4.3 and 2.6 months (P < 0.001), the ORR was 22.3% and 18.7% for the S-1 and S-1 plus LNT groups, respectively. The incidences of haematologic and non-haematologic adverse events were similar, and no significant changes in QOL scores were observed during the treatment in both groups. In a subpopulation of patients with LNT-binding monocytes ≥2%, patients who received more than two cycles of chemotherapy showed a longer survival time in the S-1 plus LNT group.

CONCLUSIONS

OS did not improve and TTF was significantly worse in the S-1 plus LNT group as compared with the S-1-only group. This study showed no efficacy of LNT when combined with S-1 treatment in patients with unresectable or recurrent gastric cancer.

CLINICAL TRIAL REGISTRATION ID NUMBER

UMIN 000000574.

Current adjuvant treatment modalities for gastric cancer: From history to the future

The discrepancy between the surgical technique and the type of adjuvant chemotherapy used in clinical trials and patient outcomes in terms of overall survival rates has led to the generation of different adjuvant treatment protocols in distinct parts of the world. The adjuvant treatment recommendation is generally chemoradiotherapy in the United States, perioperative chemotherapy in the United Kingdom and parts of Europe, and chemotherapy in Asia. These options mainly rely on the United States Intergroup-0116, United Kingdom British Medical Research Council Adjuvant Gastric Infusional Chemotherapy, and the Asian Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer and Capecitabine and Oxaliplatin Adjuvant Study in Stomach Cancer trials. However, the benefits were evident for only certain patients, which were not very homogeneous regarding the type of surgery, chemotherapy regimens, and stage of disease. Whether the dissimilarities in survival are attributable to surgical technique or intrinsic biological differences is a subject of debate. Regardless of the extent of surgery, multimodal therapy may offer modest survival advantage at least for diseases with lymph node involvement. Moreover, in the era of individualized treatment for most of the other cancer types, identification of special subgroups comprising those who will derive more or no benefit from adjuvant therapy merits further investigation. The aim of this review is to reveal the historical evolution and future reflections of adjuvant treatment modalities for resected gastric cancer patients.

The association between the duration of fluoropyrimidine-based adjuvant chemotherapy and survival in stage II or III gastric cancer

Background

This study was conducted to propose the optimal duration of fluoropyrimidine-based adjuvant chemotherapy consisting of fluoropyrimidine derivatives alone or combined with intravenous platinum for stage II or III gastric cancer (GC).

Methods

We analyzed retrospectively the data from 2219 patients with histologically confirmed adenocarcinoma in the stomach, who underwent a curative gastrectomy with lymphadenectomy from 2005 to 2012. Five-year overall survival (OS) and 3-year relapse-free survival (RFS) were analyzed according to the duration of fluoropyrimidine-based adjuvant chemotherapy.

Results

Data from 617 patients with stage II or III GC were analyzable; 187 patients (30.3 %) were treated with surgery alone, while 430 patients (69.7 %) were treated with postoperative adjuvant chemotherapy. The duration of adjuvant chemotherapy was less than 6 months [group 1] in 147 patients (34.2 %), 6 months to less than 12 months [group 2] in 94 patients (21.9 %), 1 year to less than 2 years [group 3] in 139 patients (32.3 %), and over 2 years [group 4] in 50 patients (11.6 %). The 5-year OS in groups 1, 2, 3, and 4 was 75.7, 87, 90.3, and 93.4 %, respectively, while 3-year RFS was 52.5, 58.8, 81.4, and 94.0 %, respectively.

Conclusions

In this retrospective study, we did not demonstrate any significant improvement in OS and RFS by longer periods of fluoropyrimidine-based adjuvant chemotherapy in stage II or III GCs. Further prospective randomized studies are needed.

Clinical Benefit and Health-Related Quality of Life Assessment in Patients Treated with Cisplatin/S-1 Versus Cisplatin/5-FU: Secondary End Point Results From the First-Line Advanced Gastric Cancer Study (FLAGS)

PURPOSE

Patient-reported outcomes (PRO) of health-related quality of life (HRQoL) and time to worsening of clinical benefit parameters were evaluated as secondary end points in the phase 3 first-line advanced gastric cancer study (FLAGS) trial of cisplatin/S-1 versus cisplatin/5-fluorouracil (5-FU) in patients with previously untreated advanced gastric cancer.

METHODS

The primary PRO end point was the Trial Outcome Index of the Functional Assessment of Cancer Therapy-Gastric (FACT-Ga). FACT-Ga was completed at the beginning of the first 4 cycles, cycle 6, and then every 3 cycles thereafter. The Chemotherapy Convenience and Satisfaction Questionnaire (CCSQ) was administered before the first 4 cycles; clinical benefit parameters (performance status, weight loss, and anorexia) were assessed at baseline, prior to study drug administration on day 1 of each cycle after cycle 1, and at the end of study treatment.

RESULTS

Compliance to questionnaire fulfillment was more than 80 % through cycle 9. Significantly, fewer patients treated with cisplatin/S-1 reported worsened physical well-being (PWB) scores (45.1 versus 51.7 %, p = 0.044) and experienced significantly longer time to worsening in PWB scores, with a median of 4.5 months (95 % confidence interval (CI), 3.1-5.1) compared to 3.0 months (2.8-4.6) with cisplatin/5-FU (CF) (p = 0.01). Patients receiving cisplatin/S-1 also reported significantly higher best and worst score of PWB as well as CCSQ scores and a longer median time to worsening in clinical benefit parameters.

CONCLUSIONS

Differences in secondary end points of PWB, CCSQ scores, and clinical benefit parameters favoring the cisplatin/S-1 arm provide further evidence for considering this combination a standard therapeutic option for first-line treatment of advanced gastric cancer.

Emerging role of S-1 in gastric cancer

Gastric cancer remains one of the most important malignancies worldwide in terms of incidence and mortality. The treatment is based on the combination of local surgery and radiation therapy as well as systemic chemotherapy and targeted molecules. Fluoropyrimidines and particularly 5-fluorouracil (FU) represent still the backbone for gastric cancer chemotherapy and new molecular versions of this molecule have been brought to clinical practice in order to improve benefits and reduce adverse effects. S-1 is an oral prodrug of 5-FU, which has demonstrated high effectiveness for gastric cancer treatment and a favorable safety profile. Currently, there are geographic differences in the treatment of gastric cancer and in the use of S-1, which is a mainstay of gastric cancer management in Eastern countries, but is not part of the standard care in the rest of the world. In this review, we gathered data from phase I, II, and III trials of S-1 in gastric cancer, in order to define its real benefit-risk ratio and assess whether geographic differences in S-1 use are justified by unchangeable factors.

Evaluation of Thymidylate Synthase Expression in Prostate Cancer

Thymidylate synthase (TS), a key enzyme in DNA synthesis, is over-expressed in a variety of cancer cells. 5-Fluorouracil, an anticancer agent clinically used against various cancers, including prostate cancer, inhibits DNA synthesis by binding TS. In this study, we investigated expression of TS in prostate cancer and its prognostic significance. Seventy-five prostatic tissue specimens were obtained from patients who had undergone prostate biopsy for diagnosis of prostate cancer. We analyzed the cancerous tissue specimens for TS expression using immunohistochemistry. TS expression was significantly increased in patients with bone metastasis. No relationship was found between expression of TS and the other clinicopathological findings. Because TS expression could be used as a prognostic parameter in patients with prostate cancer, an accurate prediction of prognosis might help to select patients for more intensive surgical, hormonal, or chemotherapeutic approaches, including 5-fluorouracil. Additional prospective studies are warranted to define the role of TS in selecting patients for adjuvant therapy for prostate cancer.

S-1 combined with cisplatin versus cisplatin alone for the treatment of advanced gastric cancer: a pilot randomized-controlled trial

We aimed to assess the efficacy and safety of S-1 combined with cisplatin (SC) over cisplatin alone (C) for the treatment of advanced gastric cancer in China. Between July 2009 and June 2011, 72 eligible patients with advanced gastric cancer were selected and divided randomly into two groups. Thirty-six patients received SC, with S-1 on days 1 through 14 of a 21-day cycle and cisplatin (60 mg/m on day 1) every 4 weeks for two cycles. The other 36 patients were administered only cisplatin (in the same manner as SC). The primary outcome was overall survival. The secondary outcomes were progression-free survival and adverse events. The 2-year overall response rate was 51.5 and 42.3% for the SC and C groups, respectively, and the difference was statistically significant, whereas the median overall survival was 9.4 months (range, 1.9-24.4 months) and 7.6 months (range, 1.7-21.4 months), respectively (P=0.039). The median progression-free survival was 7.7 months for SC (range, 1.8-19.4 months), whereas it was 6.5 months (range, 1.5-16.4 months) for C (P=0.047). The toxicity profile was similar in both groups. In summary, we have shown that S-1 combined with cisplatin is more effective, with acceptable toxicity in comparison with cisplatin alone in Chinese patients with advanced gastric cancer. Chinese Clinical Trials Register: ChiCTR-TRC-13003993.

Phase II Trial of S-1 and Oxaliplatin Plus Cetuximab for Colorectal Cancer Patients with Initially Unresectable or Not Optimally Resectable Liver Metastases (KSCC1002)

BACKGROUND

The Kyushu Study Group of Clinical Cancer (KSCC) conducted phase II trials of KSCC1002 (UMIN000001308) concerning liver resectability after first-line treatment of initially unresectable or not optimally resectable colorectal liver metastases in a prospective, multicenter study.

METHODS

Patients with wild-type KRAS received 4-6 cycles of S-1 and oxaliplatin (SOX) plus cetuximab. Liver resectability was evaluated subsequently with the liver resection rate as the primary endpoint.

RESULTS

Of the 33 patients enrolled between March 2010 and July 2013, the median number of administration cycles was 4 (range 0-10). The overall response rate was 63.6 % (95 % confidence interval [CI] 45.1-79.6 %). Liver resection was possible in 16 of 33 (48.5 %) patients, and there were 13 R0 cases (39.4 %). We conducted a central review of liver resectability evaluated by five liver surgeons, and the resectability increased from 18.2 to 66.7 % after chemotherapy, based on imaging. The median overall survival for all 33 cases was 31.6 months (95 % CI 14.8-not reached). The median progression-free survival was 9.7 months (95 % CI 6.2-11.8).

CONCLUSIONS

SOX plus cetuximab is safe and effective for advanced colorectal cancer with limited liver metastasis, and may lead to high liver resectability.

Trastuzumab in combination with docetaxel/cisplatin/S-1 (DCS) for patients with HER2-positive metastatic gastric cancer: feasibility and preliminary efficacy

PURPOSE

We previously reported that a triplet combination of docetaxel, cisplatin, and S-1 (DCS) is active against metastatic gastric cancer with a very high response rate of 87.1 % in a phase II study. Recently, the efficacy of trastuzumab (T-mab) for the treatment of HER2-positive gastric cancer has been reported. Therefore, we investigated the feasibility and preliminary efficacy of DCS + T-mab (DCS-T) for unresectable HER2-positive metastatic gastric cancer.

METHODS

Patients received oral S-1 (40 mg/m(2) b.i.d.) on days 1-14, intravenous cisplatin (60 mg/m(2)), docetaxel (50 mg/m(2)), and T-mab (8 mg/kg in the first cycle and 6 mg/kg in the second cycle and thereafter) on day 8 every 3 weeks.

RESULTS

The study included 16 patients: median age, 60 (34-76) years; males/females, 11:5; intestinal-type/diffuse-type histology, 11:5; and HER2 3+/2+(FISH+), 13:3. The completion rate until the third cycle was 87.5 % (14/16) (95 %CI 71.3-103.7 %). Adverse events of grade 3/4 severity during the first 3 cycles were: leukopenia/neutropenia, 50.0:75.0 %; febrile neutropenia, 12.5 %; diarrhea, 12.5 %; and stomatitis, 12.5 %. All of these side effects were manageable and well controlled. There were no treatment-related deaths. The overall response rate was 93.8 % (15/16), and the response rate in patients with measurable lesions was 100 % (15/15). The median cycle to response was only 1 (1-3 cycles). Non-curative factors disappeared in 56.3 % (9/16) of patients, and conversion surgery (R0 resection) was performed in all these cases. Pathological response rates in primary and metastatic lesions were 88.9 % (8/9) and 100 % (9/9), respectively. The median PFS and OS were not reached during the median follow-up time of 18.3 months ranged from 11.0 to 34.3 months.

CONCLUSIONS

DCS-T was feasible in patients with unresectable HER2-positive metastatic gastric cancer. The observed response was very promising and warrants further investigation.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000005603.

A phase II study of biweekly S-1 and paclitaxel (SPA) as first-line chemotherapy in patients with metastatic or advanced gastric cancer

PURPOSE

Paclitaxel and S-1 are both effective antitumor chemotherapeutic agents for advanced gastric cancer. However, the continuous administration of S-1 for 3 weeks or more can result in unacceptable toxicities, particularly hematological toxicities. Therefore, an alternative treatment schedule (1-week administration followed by 1-week rest) is warrant for testing in order to allow continuation of the therapy. We evaluate the efficacy and safety of biweekly S-1 and paclitaxel (SPA) as first-line chemotherapy in patients with metastatic or advanced gastric cancer.

METHODS

Patients with previously untreated advanced or relapsed gastric cancer who had measurable lesion(s) were enrolled. Paclitaxel was administered intravenously at a dose of 120 mg/m(2) on day 1 and oral S-1 was given twice daily (BSA < 1.25 m(2), 80 mg/day; 1.25 ≤ BSA < 1.50 m(2), 100 mg/day; 1.50 m(2) ≤ BSA, 120 mg/day) on days 1-7 followed by a drug-free interval of 1 week every 14-day cycle.

RESULTS

Forty-four patients (M/F = 33/11) were enrolled. A total of 277 chemotherapy cycles were administered, with a median of six cycles per patient (range 1-12), and 19 (43.2 %) patients received up to seven cycles. The assessed overall response rate was 38.6 with 38.6 % partial response in 17 patients, 45.4 % stable disease in 20 patients, and 13.6 % progressive disease in six patients. Thirty-four patients (77.3 %) received second-line chemotherapy. The estimated median progression-free survival and median overall survival times were, respectively, 5.2 months (95 % CI 4.08-6.39 months) and 12.2 months (95 % CI 8.81-15.60 months). The major hematological toxicities were included grade 3 leucocytopenia in two patients (4.5 %), grade 3 neutropenia in 14 patients (40.9 %), and grade 4 neutropenia in four patients (9.0 %). Two patients (4.5 %) suffered grade 1 febrile neutropenia. All grade of the non-hematological toxicities, such as nausea, vomiting, alopecia, and diarrhea, held the proportion of 54.5 % (grade 3/4, 4.5 %), 31.8, 95.4, and 18.1 % (grade 3/4, 2.2 %), respectively.

CONCLUSIONS

Biweekly S-1 and paclitaxel (SPA regimen) combination therapy had promising activity with acceptable adverse toxicities. SPA regimen was easily implemented, and more patients received second-line chemotherapy. It deserved to conduct a well-designed randomized phase III study to compare this regimen with S-1-based combination treatment.

The SOFT trial: a Phase III study of the dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine S-1 and oxaliplatin (SOX) plus bevacizumab as first-line chemotherapy for metastatic colorectal cancer

ABSTRACT 

A combination of oxaliplatin, leucovorin and 5-fluorouracil (FOLFOX) plus bevacizumab has been widely used for the first-line chemotherapy of metastatic colorectal cancer (mCRC). S-1 is an oral fluoropyrimidine preparation that combines tegafur, a prodrug of 5-fluorouracil, with two modulators. Several studies of combination chemotherapy with oxaliplatin plus S-1 (SOX) conducted in Asia have reported promising efficacy and safety in patients with mCRC, suggesting the potential to replace mFOLFOX6. The SOFT trial (JapicCTI-090699) was a randomized Phase III trial designed to evaluate the noninferiority of SOX plus bevacizumab to mFOLFOX6 plus bevacizumab in patients with mCRC. This review summarizes the drug concept of S-1 and the results of clinical trials of S-1 and SOX in CRC and presents an overview of the SOFT trial.

Feasibility study of alternate-day S-1 as adjuvant chemotherapy for gastric cancer: a randomized controlled trial

BACKGROUND

The Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer established oral S-1 administration for 1 year as the standard postoperative adjuvant chemotherapy for gastric cancer in Japan. We conducted a multicenter cooperative prospective study comparing daily and alternate-day S-1 administration as postoperative adjuvant therapy for gastric cancer.

METHODS

Patients with Stage II or III gastric cancer who underwent curative surgery were randomly assigned to receive standard daily S-1 administration [group A: 80-120 mg/day S-1 depending on body surface area (BSA); days 1-28 every 6 weeks for 1 year] or alternate-day administration (group B: 80-120 mg/day S-1 depending on BSA; alternate days for 15 months). Treatment completion rate was the primary endpoint, and relative dose intensity and safety, overall survival, and relapse-free survival (RFS) were secondary endpoints.

RESULTS

Seventy-three patients were enrolled. The treatment completion rate was 72.2 % in group A and 91.8 % in group B; the relative dose intensity was 67.5 % in group A and 81.2 % in group B; and compliance was better in group B. Digestive system adverse effects were less frequent in group B than in group A. Median follow-up time was 2.8 years; 3-year survival rate was 69.6 % in group A and 87.3 % in group B; and 3-year RFS rate was 76.4 % in group A and 73.1 % in group B.

CONCLUSIONS

Our data show improved compliance and fewer adverse effects with alternate-day S-1 administration, which appears to be a more sustainable option for adjuvant chemotherapy for Stage II or III gastric cancer.

Feasibility of oral administration of S-1 as adjuvant chemotherapy in gastric cancer: 4-week S-1 administration followed by 2-week rest vs. 2-week administration followed by 1-week rest

In 2006, the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) demonstrated that S-1 is an effective adjuvant therapy for gastric cancer. Following that study, S-1 has been used as the standard adjuvant therapy for gastric cancer in Japan. However, the 1-year completion rate was only 65.8% in the ACTS-GC study and feasibility remains a critical issue. We conducted a study to evaluate the feasibility of 2 weekly administration regimens of S-1 as adjuvant chemotherapy in gastric cancer. The criteria for eligibility included histologically proven stage II (excluding T1), IIIA or IIIB gastric cancer with D2 lymph-node dissection. The patients were randomly assigned to either arm A (S-1 administration for 4 weeks followed by 2 weeks of rest) or arm B (S-1 administration for 2 weeks followed by 1 week of rest). In each arm, treatment was continued for 12 months unless recurrence or severe adverse events were observed. The primary endpoint was feasibility (protocol treatment completion rate). The secondary endpoints were safety, relapse-free survival and overall survival. A total of 47 patients were assigned to arms A or B between May, 2008 and February, 2010. During the first interim analysis, the protocol treatment completion rates in arms A and B were 83 and 100%, respectively at 6 months and 49 and 89%, respectively, at 12 months (P=0.0046). Therefore, S-1 administration for 2 weeks followed by 1 week rest was more feasible as adjuvant chemotherapy in gastric cancer. Grade 3 adverse events in arm A included fatigue (8.0%), anorexia (8.0%), nausea (4.0%), vomiting (4.0%) and hand-foot syndrome (4.0%), whereas none were observed in arm B. There were no reported grade 4 adverse events in either arm. In conclusion, the 2-week S-1 administration followed by 1-week rest regimen appears to be a more feasible oral administration regimen for S-1 as adjuvant chemotherapy in gastric cancer.