Adjuvant paclitaxel followed by oral fluoropyrimidines for gastric cancer: Safety data of the factorial phase III SAMIT trial

72

Background: Adjuvant chemotherapy with fluoropyrimidine (FP) with or without platinum for gastric cancer (GC) has become standard almost worldwide; however, there has been no comparison among concurrent, sequential, and monotherapy. Paclitaxel (PTX) is one of key drugs in GC widely used as 2nd-line chemotherapy in Japan.

Methods: SAMIT is a randomized, multicenter phase III study of FP (S1 or UFT) vs. PTX followed by FP in patients (pts) with gastric adenocarcinoma. Eligibility includes T3/T4, N0-2, M0 except for positive lavage cytology, chemotherapy- and radiotherapy- naive, being able to start chemotherapy 14 and 56 days after D2 gastrectomy. Pts received either UFT 267 mg/m2/day for 4w, q4w x 6 cycles (arm A); S1 80 mg/m2/day for 2w, q3w x 8 cycles (arm B); PTX 80 mg/m2 Day 1, 8 for the first 3w x 1 cycle, Day 1, 8, 15 q4w x 2 cycles, followed by UFT 267 mg/m2/day for 4w, q4w x 3 cycles (arm C); or PTX as in C, followed by S1 80 mg/m2/day for 2w, q3w x 4 cycles (arm D). The FP cycles was prolonged by 24w after ACTS-GC publication in 2007. Primary endpoint is disease-free survival and total number of patients was calculated to be1480 where 90% power for superiority of C+D group vs. A+B. The Independent Data Monitoring Committee undertook a review of the 1417 pts at the 2nd interim analysis in 2011.

Results: Arm A (n=353), arm B (n=359), arm C (n=352), arm D (n=353) were well balanced for baseline factors. The compliance with UFT in arm A and S1 in B was 74% and 76% in the first 12 weeks, and 89% and 90% between week 37 and 48; that in arm C and D was 83% and 80% in the second 12 weeks, and 94% and 84% between week 37 and 48. Numbers of grade 3/4 hematological and non-hematological adverse events (AEs) were 3 and 46, 0 and 64, 5 and 35, and 16 and 67 for arm A, B, C, and D, respectively. Anorexia was the most common AE observed in 5.8%, 6.8%, 1.7%, and 5.1% for arm A, B, C, and D, respectively. There were 363/1323 (27%) deaths and 762/1323 (58%) of pts survived disease free.

Conclusions: Adjuvant chemotherapy with sequential PTX and FP for GC was safe and the compliance of the FP part could be better than that of FP monotherapy. The final efficacy results will be formally assessed in 2012.

Macroscopic tumor size as an independent prognostic factor for patients with stage II/III gastric cancer who underwent D2 gastrectomy followed by adjuvant chemotherapy with S-1

56

Background: In patients with stage II/III gastric cancer, tumors often recur even after curative D2 gastrectomy followed by adjuvant S-1 chemotherapy. The objective of this retrospective study was to clarify the prognostic factors in these patients that might be useful for future patients.

Methods: Overall survival was examined in 82 gastric cancer patients who underwent curative D2 surgery, were diagnosed with stage IIA, II B, IIIA, IIIB, or IIIC pathologically, and received adjuvant S-1 after surgery between June of 2002 and March of 2010.

Results: When overall survival was compared by the log-rank test, a significant difference was observed with regard to macroscopic tumor diameter and the depth of tumor invasion. A macroscopic tumor diameter greater than 70mm was regarded as a critical point of classification considering the survival. Uni- and muliti-variate Cox’s proportional hazard analyses demonstrated that macroscopic tumor diameter was the only significant independent prognosticator. The five-year survival was 64.9% in patients with a macroscopic tumor diameter <70mm, and 33.1% in patients with a macroscopic tumor diameter ≥70mm (P=0.022).

Conclusions: The macroscopic tumor diameter was the most important prognostic factor for survival in patients with stage II/III gastric cancer who underwent D2 gastrectomy followed by adjuvant S-1 chemotherapy. Prognostic factors can be affected by adjuvant chemotherapy.

Infectious complication and recurrence after surgery for gastric cancer

85

Background: There are many known prognostic indicators following surgery for gastric cancer. However, the impact of infectious complication on prognosis is less clear. The aim of the present study was to evaluate the relationship between infectious complication and relapse-free survival in patients undergoing potentially curative resection of gastric cancer.

Methods: A consecutive series of 657 patients who underwent macroscopically curative resection between 2000 and 2005 in Kanagawa Cancer Center were retrospectively studied. Five-year relapse-free survival rates in each stages (TNM7th) were calculated. Infectious complications (≥Grage2 by Clavien-Dindo classification) were classified as pneumonia, anastomotic leakage, intra-abdominal abscess, septicaemia, colitis, pancreatic-fistula, and wound infection.

Results: Mean age was 61 years; male-female ration was 4:1; the number of patients in TNM7th stages were I :389, II :93, III :116, and IV :59. Infectious complications occurred in 57 patients (8.7%) including 8.5% in stage I, 3.2% in stage II, 12.1% in stage III, and 11.9% in stage IV, respectively. Five-year relapse-free survival rates in patients without infectious complications and with infectious complications were 93.1% vs 81.6% in stage I, 84.4% and 100% in stage II, 55.8% and 28.6% in stage III, and 9% and 0% in stage IV, respectively. In stage III, patients with infectious complication had significantly poorer outcome in relapse-free survival compared with those without one (p<0.05).

Conclusions: This study indicates a correlation between infectious complications and cancer recurrence in advanced but localized gastric cancer. Immunologic response of the host against postoperative infection could influence the viability of microscopic residual disease. Further clinical and basic study are needed to improve outcome for this category of patients.

Body weight loss after surgery as an independent risk factor for continuation of S-1 adjuvant chemotherapy for gastric cancer

125

Background: S-1 adjuvant chemotherapy improves survival of stage II/III gastric cancer, however, the compliance is not high. The aim of the present study is to clarify risk factors for continuation of S-1 after gastrectomy.

Methods: Patients were retrospectively selected according to the following criteria; (1) patients underwent curative D2 gastrectomy for gastric cancer during 2002 and 2010, (2) pathological stage II/III, (3) creatinine clearance more than 60 ml/min, and (4) S-1 was initiated at a dose of 80mg/m2 within 6 weeks after surgery. Clinical factors when starting S-1 chemotherapy were examined by uni- and multi-variate analyses.

Results: Seventy-five patients were eligible. Median age was 62 years (range: 36-80). Performance status was 0 in 65 patients and 1 in 10. Serum albumin level was >4.0 g/dl in 34 patients and <4.0 g/dl in 39. Operative procedure was total gastrectomy (TG) in 46 patients and distal one in 29. Median percentile of body weight loss to preoperative state (%BW loss) was 9.3 (range 0-21.1). Stage was II in 22 patients and III in 53. When %BW loss was classified to two groups; LOW (<15%, n=64) and HIGH (>15%, n=11), S-1 continuation rates were 82.8% in the LOW and 54.6% in the HIGH at 3 months and 73.2% in the LOW and 45.5% in the HIGH at 6 months, which were statistically significant (p=0.025). Among age, performance status, type of gastrectomy, %BW loss, serum albumin, and stage, only %BW loss was a significant independent risk factor for S-1continuation with hazard ratio of 2.437 by multi-variate Cox proportional hazard analyses (p=0.039).

Conclusions: To improve drug compliance which leads to survival, it is a key to maintain BW before starting adjuvant chemotherapy. Peri-operative nutritional therapy should be developed and be focused on chronic inflammatory phase after surgery and on starvation after gastrectomy. A randomized phase III trial is on-going to show efficacy of peri-operative nutritional support including eicosapentaenoic acid (EPA).

Safety and feasibility of S-1 adjuvant chemotherapy for gastric cancer in elderly patients

BACKGROUND

The safety and feasibility of administering S-1 adjuvant chemotherapy for gastric cancer has not been fully evaluated in elderly patients.

METHODS

This retrospective study selected patients who underwent curative D2 surgery for gastric cancer, were diagnosed with stage II or III disease, and received adjuvant S-1 at our institution. Patients were categorized into two groups; non-elderly patients (age <70 years: group A) and elderly patients (age ≥70 years: group B). The toxicity and S-1 continuation rates in the two groups were compared.

RESULTS

A total of 75 patients were evaluated in the study. There were no grade 4 toxicities. The incidences of grade 3 hematological and non-hematological toxicities were <5% in both groups, and the differences were not significant. The continuation rate at 6 months was 69% in group A and 70% in group B, and this difference was also not significant.

CONCLUSIONS

These results suggest that S-1 adjuvant chemotherapy for gastric cancer is safe and feasible, regardless of the age of the patient; especially for elderly patients who could be candidates for clinical trials.

[Adjuvant therapy for advanced gastric cancer]

The importance of surgery (gastrectomy plus lymph node dissection) for the treatment of advanced gastric cancer is unquestionable, although there has been a disparity in methods used to achieve local control in Asia and the West. The superiority of D2 dissection has not been confirmed in a large multiinstitutional trial, and the long-term follow-up results of a Dutch trial revealed that the recurrence rate was lower in the D2 group. Thus, the European Society for Medical Oncology and the US National Comprehensive Cancer Network guidelines recommend D2 dissection, leading to a worldwide consensus. Meanwhile, the focus of oncology should be on multimodality treatment for cure, and numerous large, randomized clinical trials have established effective adjuvant treatment. In gastric cancer, different evidence emerged first in the USA, followed by Europe, and Japan/the Republic of Korea to become the standard for each: adjuvant chemoradiation, perioperative adjuvant chemotherapy, and postoperative chemotherapy, respectively. The Japanese standard has become adjuvant S-1 chemotherapy for 1 year after surgery, and the optimal regimen for stage III should be further investigated in consideration of other robust results. Other issues include the role of surgery in local control with regard to adjuvant treatment such as radiation and molecular-targeted treatment to establish a worldwide standard.

Risk factors for peritoneal recurrence in stage II/III gastric cancer patients who received S-1 adjuvant chemotherapy after D2 gastrectomy

BACKGROUND

The peritoneum is still the most frequent site of recurrence in stage II/III gastric cancer patients, although the survival rate was improved by the introduction of S-1 adjuvant chemotherapy. The objective of this retrospective study was to clarify the risk factors for peritoneal recurrence in patients who received S-1 adjuvant chemotherapy.

METHODS

Peritoneal recurrence-free survival was examined in 100 gastric cancer patients who underwent curative D2 surgery, which were diagnosed with stage II or III disease pathologically, and received adjuvant S-1 between June 2002 and March 2011. The univariate and multivariate analyses were performed to identify risk factors by a Cox proportional hazards analysis.

RESULTS

The P-RFS was 64.3% at 3 years and 58.8% at 5 years. A total of 18 patients were diagnosed with peritoneal recurrence. The macroscopic tumor diameter, depth of tumor invasion, and lymph node metastasis were the significant factors identified by the univariate analysis, while the tumor diameter and lymph node metastasis were the only significant independent risk factors identified by the multivariate analysis.

CONCLUSIONS

The macroscopic tumor diameter and presence of lymph node metastasis were the most important risk factors for peritoneal recurrence. When patients had these risk factors, S-1 was not sufficient to inhibit peritoneal recurrence. A novel adjuvant chemotherapeutic agent targeting peritoneal metastasis in these patients should be developed.

A comparison of multimodality treatment: two and four courses of neoadjuvant chemotherapy using S-1/CDDP or S-1/CDDP/docetaxel followed by surgery and S-1 adjuvant chemotherapy for macroscopically resectable serosa-positive gastric cancer: a randomized phase II trial (COMPASS-D trial)

This randomized Phase II trial will compare the outcome of neoadjuvant chemotherapy using two and four courses of S-1 plus cisplatin or S-1 plus cisplatin plus docetaxel by a two-by-two factorial design for patients with macroscopically resectable serosa-positive gastric cancer. After neoadjuvant chemotherapy, patients will receive D2 gastrectomy followed by S-1 chemotherapy for 1 year postoperatively. The primary endpoint is the 3-year overall survival. The sample size is 120 for the two hypotheses: the superiority of four courses compared with two courses and the superiority of S-1 plus cisplatin plus docetaxel compared with S-1 plus cisplatin. This trial will be able to define the more suitable number of cycles and better regimen of neoadjuvant chemotherapy for gastric cancer.

[S-1/krestin immunochemotherapy for patients with advanced gastric cancer]

BACKGROUND

S-1 mono-therapy for advanced gastric cancer is hard to continue in some patients due to adverse events. We retrospectively examined the patients who received S-1/Krestin( PSK) immunochemotherapy for advanced gastric cancer.

METHODS

During September 2006 to August 2008, 3 patients had received S-1/PSK. S-1 was given for 6-week schedule or 3-week schedule, and PSK was for everyday during the S-1 treatment.

RESULTS

Cases 1 and 2 had lymph node metastases after surgery. Case 3 had peritoneal metastasis. The median treatment duration was 112 days. The median overall survival was 552 days. All patients stopped the treatment due to progression of disease. There were no patients who stopped the treatment due to adverse events.

CONCLUSIONS

PSK may increase the compliance of S-1.

[Randomized phase II trial to compare S-1 and S-1/PSK for advanced or recurrent gastric cancer-lessons from the results]

BACKGROUND

This is a randomized phase II trial to evaluate non-inferiority of progression-free surviva(l PFS) by comparing S-1 and S-1/PSK for advanced or recurrent gastric cancer. Sample size was calculated to be 120. However, the trial was terminated because of slow accrual. This exploratory analysis was done by collecting the minimum data.

RESULTS

Only 8 patients were enrolled. Four patients were randomly assigned to S-1 and the others to S-1/PSK. Performance status was 0 in all 8 patients. Median age was 64. Median overall survival was 13.7 months in all 8 patients, 8 . 9 months in S-1 group, and 13 . 7 months in S-1/PSK group.

CONCLUSION

When considering PS 0 in 8 patients enrolled, an overall survival was comparable to that observed in S-1 group of other phase III trials. Standard chemotherapy for advanced gastric cancer was changed to S-1/CDDP by SPIRITS phase III trial which was presented just after this trial was initiated, which would be a major cause of slow accrual. When conducting phase III trial, we should carefully determine design and standard arm by considering on-going phase III trial.

[Assessment of the cost of laparoscopy-assisted gastrectomy]

BACKGROUND

The cost of laparoscopic gastrectomy (LG) has not been fully clarified yet.

PATIENTS AND METHODS

The actual cost for the instruments used for surgery was examined between LG and conventional open gastrectomy( OG) by separating distant (l D-) and total (l T-) gastrectomy in a total of 20 patients(5 for each)during Oct 2010 and Feb 2011. The profit was defined as the difference of the actual cost and the operation fee including the instruments determined by the insurance and compared.

RESULTS

The fee for D-OG, T-OG, D-LG, and T-LG were 708, 700 yen, 856 , 400 yen, 783 , 600 yen and 922 , 300 yen, respectively. The mean profits of D-OG, T-OG, D-LG, and T-LG were 408 , 297 yen, 475 , 812 yen, 308, 681 yen and 269 , 478 yen, respectively.

CONCLUSION

Appropriate surgical and instrumental fees should be determined considering the actual cost.

[Prognosis and clinical course of gastric cancer with para-aortic lymph node metastasis after curative D2 gastrectomy and adjuvant chemotherapy with S-1]

BACKGROUND

Survival and clinical course were unknown in patients with recurrence of para-aortic lymph node after curative D2 gastrectomy and adjuvant S-1 chemotherapy.

METHODS

The study examined clinical characteristics and prognosis of 3 patients who had para-aortic nodal recurrence after curative D2 gastrectomy and S-1 adjuvant chemotherapy.

RESULTS

Initial stage was III C in all of the patients. Median treatment interval of S-1 was 8 . 8 months. Para-aortic nodal metastasis was single in 2 and multiple in 1 patient. Median survival time was 14 .3 months. Other recurrent sites than para- aortic node were not seen in all of the patients.

CONCLUSIONS

In the times of S-1 adjuvant chemotherapy, it is valuable to know whether para-aortic node should be resected prophylactically, or be treated after recurrence, or be treated by locally or systemically.

Intrinsic subtypes of gastric cancer, based on gene expression pattern, predict survival and respond differently to chemotherapy

BACKGROUND & AIMS

Gastric cancer (GC) is a heterogeneous disease comprising multiple subtypes that have distinct biological properties and effects in patients. We sought to identify new, intrinsic subtypes of GC by gene expression analysis of a large panel of GC cell lines. We tested if these subtypes might be associated with differences in patient survival times and responses to various standard-of-care cytotoxic drugs.

METHODS

We analyzed gene expression profiles for 37 GC cell lines to identify intrinsic GC subtypes. These subtypes were validated in primary tumors from 521 patients in 4 independent cohorts, where the subtypes were determined by either expression profiling or subtype-specific immunohistochemical markers (LGALS4, CDH17). In vitro sensitivity to 3 chemotherapy drugs (5-fluorouracil, cisplatin, oxaliplatin) was also assessed.

RESULTS

Unsupervised cell line analysis identified 2 major intrinsic genomic subtypes (G-INT and G-DIF) that had distinct patterns of gene expression. The intrinsic subtypes, but not subtypes based on Lauren's histopathologic classification, were prognostic of survival, based on univariate and multivariate analysis in multiple patient cohorts. The G-INT cell lines were significantly more sensitive to 5-fluorouracil and oxaliplatin, but more resistant to cisplatin, than the G-DIF cell lines. In patients, intrinsic subtypes were associated with survival time following adjuvant, 5-fluorouracil-based therapy.

CONCLUSIONS

Intrinsic subtypes of GC, based on distinct patterns of expression, are associated with patient survival and response to chemotherapy. Classification of GC based on intrinsic subtypes might be used to determine prognosis and customize therapy.

Macroscopic tumor size as an independent prognostic factor for stage II/III gastric cancer patients who underwent D2 gastrectomy followed by adjuvant chemotherapy with S-1

BACKGROUND

In patients with stage II/III gastric cancer, tumors often recur even after curative D2 gastrectomy followed by adjuvant S-1 chemotherapy. The objective of this retrospective study was to clarify the prognostic factors in these patients that might be useful for future patients.

METHODS

Overall survival (OS) was examined in 82 gastric cancer patients who underwent curative D2 surgery; were diagnosed with stage IIA, IIB, IIIA, IIIB, or IIIC pathologically; and received adjuvant S-1 after surgery between June 2002 and March 2010.

RESULTS

When length of OS was evaluated by the log-rank test, significant differences were observed with regard to macroscopic tumor diameter and the depth of tumor invasion. A macroscopic tumor diameter >70 mm was regarded as a critical point of classification considering survival. Univariate and multivariate Cox's proportional hazard analyses demonstrated that macroscopic tumor diameter was the only significant independent prognosticator. The 5-year survival was 64.9% in patients with a macroscopic tumor diameter <70 mm, and 33.1% in patients with a macroscopic tumor diameter ≥70 mm (P = 0.022).

CONCLUSIONS

The macroscopic tumor diameter was the most important prognostic factor for survival in patients with stage II/III gastric cancer who underwent D2 gastrectomy followed by adjuvant S-1 chemotherapy. Prognostic factors can be affected by adjuvant chemotherapy.

Survival and prognosticators of gastric cancer that recurs after adjuvant chemotherapy with S-1

BACKGROUND

Some patients experience a recurrence of cancer even after curative D2 gastrectomy followed by adjuvant S-1 chemotherapy. The objective of this retrospective study was to clarify the survival and prognosticators in these patients.

METHODS

The study selected patients who underwent curative D2 surgery, were diagnosed with stage II, IIIA, or IIIB cancer, received adjuvant S-1 for more than 4 weeks, and experienced recurrence confirmed by an imaging study.

RESULTS

A total of 34 patients were evaluated. The median overall survival (OS) was significantly longer in the 26 patients who received palliative chemotherapy than that in the 8 who did not (8.5 vs. 2.5 months, P = 0.002). Only 1 patient received S-1, 21 received taxane-containing regimens, and 4 received irinotecan plus cisplatin as the first-line chemotherapy. Univariate and multivariate analyses showed that the histological type was only independent significant prognosticator.

CONCLUSIONS

These results suggested that the survival did not reach the level expected for first-line chemotherapy. The histological type was a significant prognosticator in patients who experienced recurrence after adjuvant S-1 therapy and thereafter received palliative chemotherapy.

An integrated analysis of two phase II trials (JCOG0001 and JCOG0405) of preoperative chemotherapy followed by D3 gastrectomy for gastric cancer (GC) with extensive lymph node metastasis (ELM)

90

Background: GC with ELM (bulky N2 metastasis and / or para-aortic lymph node metastases [PAN]) is commonly regarded unresectable, while in JCOG combined modality treatment has been tested since 2000 (JCOG0001 and JCOG0405). Both trials met their primary endpoints (i.e., 3 year-survival of 27.3% in JCOG0001 and R0 resection of 82.4% in JCOG0405). The survival and the toxicity profile were quite different between the trials despite the similar eligibility with an outstanding 3-year survival of 58.8% in JCOG0405. This study is conducted to explore if survival is still better in JCOG0405 after adjusting baseline factors and if there is a subset of patients (pts) who benefit more from either treatment.

Methods: Eligibility criteria for both included histologically proven gastric adenocarcinoma; bulky nodal involvement around major branched arteries to the stomach and/or PAN; cM0 (except PAN); negative lavage cytology; not linitis plastica type; PS of 0 or 1. Pts received two or three cycles of induction chemotherapy of IP: irinotecan (70 mg/m2 on day 1 and day 15) and cisplatin (80 mg/m2 on day 1) in JCOG0001, or SP: S1 (80 mg/m2 from day 1 to 21) and cisplatin (60 mg/m2 on day 8) in JCOG0405, followed by D3 gastrectomy. Multivariate analysis for overall survival adjusting baseline factors and treatment (IP/SP) was performed with a Cox regression model. Interaction tests were also carried out between baseline factors and treatment.

Results: After adjusting baseline factors, SP was superior than IP for overall survival (HR=0.335: 0.184 – 0.612). There was only interaction effect between treatment and the status of lymph node metastases (bulkyN+/PAN- vs bulkyN-/PAN+ vs bulkyN+/PAN+; p=0.1306).

Conclusions: SP was shown to be the favorable treatment for GC with ELM by multivariate analysis, while poor prognosis in pts having both bulky N+ and PAN+ may necessitate further treatment improvement.

No significant financial relationships to disclose.

A phase II study of preoperative chemotherapy with S-1 (S) and cisplatin (P) followed by D3 gastrectomy for gastric cancer (GC) with extensive lymph node metastasis (ELM): Survival results of JCOG0405

70

Background: GC with ELM, especially in case of M1(LYM), is regarded unresectable in many countries, while challenge is ongoing in Japan to treat them by intensive chemotherapy followed by super extended surgery. In our previous phase II study (JCOG0001) for the same population, iritotecan plus P (IP) chemotherapy followed by surgery showed remarkable survival of 27.0% at 3 years but its toxicity led to rather high treatment related death (TRD). Development of safer and more effective treatment is urged.

Methods: Eligibility criteria included histologically proven gastric adenocarcinoma; bulky nodal involvement around major branched arteries to the stomach and/or para-aortic nodal metastases; cM0 (except para-aortic nodes); negative lavage cytology; not linitis plastica type; PS of 0 or 1. Patients (pts) received two or three 28- day cycles of induction chemotherapy of S (80 mg/m2 from day 1 to 21) and P (60 mg/m2 on day 8), and then underwent D3 gastrectomy. Primary endpoint was R0 resection and key secondary endpoint was 3-year survival. Other secondary endpoints included response rate and adverse events.

Results: Between 02/2005 and 06/2007, 53 pts were enrolled and 2 pts were ineligible. Only surrogate endpoints of efficacy and feasibility were reported in ASCO-GI 2008, which included clinical response of 64.7%, R0 of 82.4%, pathological response of 51.0%, and no TRD with low toxicities. The 3-year overall survival, which we first clarified in this report, was 58.8% (95% CI, 44.1-70.9%).

Conclusions: Preoperative SP followed by D3 gastrectomy demonstrated excellent 3-year survival with low mortality compared with preoperative IP, which was far better result than expected against this unresectable population. This multimodal treatment is highly promising for GC with ELM.

[Table: see text]

Impact of c-kit mutations, including codons 557 and/or 558, on the recurrence-free survival after curative surgery in patients with GIST

12

Background: Recently, c-kit exon 11 deletions, including codons 557 and/or 558, have been reported to predict a worse prognosis in GIST patients. However, it is difficult to prove the correlation between genotype and tumor aggressiveness in the imatinib- adjuvant era because exon 11 mutations respond well to imatinib. In this study, we evaluated the impact of c-kit mutational status on recurrence-free survival (RFS) after resection of primary GIST.

Methods: Clinical and pathological characteristics of 89 GIST patients in our single institution study were retrospectively analyzed. Tumors were categorized into 4 subgroups based on their mutational locations; A1: mutated codons including neither 557 nor 558, A2: either 557 or 558, B1: only 557 and 558, B2: both 557 and 558. All of the patients underwent curative surgery, and none received adjuvant imatinib. The median duration of follow-up was 49 months.

Results: Tumors originated from the stomach (n=75/89, 84%), small intestine (n=10), and colorectum (n=4). Mutation subgroup B was associated with both Fletcher and Miettinen high-risk categories. The 2-year recurrence free survival rate for A1, A2, B1, B2, was 84.9%, 85.7%, 50%, 57%, respectively. Group B2 had a significantly worse RFS than groups A1 (p=0.0004) and A2 (p=0.0014). Multivariate analysis for RFS indicated that only the mutational subgroup was a significant prognostic factor (p=0.03, HR=2.42).

Conclusions: C-kit mutations, including both 557 and 558, affected the RFS of GIST patients after curative surgery, but those including either 557 or 558 did not. Our results indicate that the locations of c-kit mutations are associated with PFS, and they may therefore affect the selection of candidates with GIST for adjuvant imatinib.

No significant financial relationships to disclose.

[Current status of treatment for elderly patients with gastric cancer]

In Japan, elderly gastric cancer(GC)patients have been rapidly increasing, and in 2020 when the babyboomers' GC incidence reaches its peak, the number of deaths due to GC will reach seventy thousand per year. Few clinical trials have been done for surgery and chemotherapy for GC so far, and little information is available on the risk benefit for elderly patients. Reports from single institutes described comparable efficacy and safety, while a large national database indicates age as an independent risk factor. Similarly, little study and information are available on chemotherapy for elderly with GC. In future, standardization of comprehensive geriatric assessment(CGA)and preoperative risk assessment in clinical trials with risk-stratified protocol treatment, and a large surgical database with similar standard risk assessment are warranted.

[Role of surgical resection for scirrhous gastric cancer with minimal peritoneal metastasis]

Prognosis of scirrhous gastric cancer with minimal peritoneal metastasis was poor, and the role of resection has not been clarified yet. Analysis 1: Overall survival was examined in 79 patients who underwent R0/R1 resection during 1970-1995 at Kanagawa Cancer Center (Group A), and in 47 patients who underwent R0/R1 resection and received S1 chemotherapy at the 30 hospitals of Japan Clinical Oncology Group (Group B). Hazard ratio (HR) of group B to group A was examined. HR was 0.64 at 1 year, 0.76 at 2-year, and 0.92 at 3-year. Analysis 2: HR of S1 group in SPIRITS phase III trial to FU group in JCOG 9205 phase III trial was examined. HR was 0.64 at 1 year and 0.84 at 2-year. Analysis 3: HR was compared each other including HR of ACTS-GC phase III trial. HR was ACTS<analysis 1=analysis 2 at 1 year, and was ACTS<analysis 1<analysis 2 at 2-year. In conclusion, these results suggested that the significance of resection increased by post-operative S1 chemotherapy.

A randomized phase II trial to test the efficacy of intra-peritoneal paclitaxel for gastric cancer with high risk for the peritoneal metastasis (INPACT trial)

Owing to its peculiar pharmacological characteristics, paclitaxel attains substantial intra-peritoneal concentration for a prolonged period when delivered intra-peritoneally, and is active against peritoneal metastasis of ovarian cancer. It is also considered promising against disseminated gastric cancer. However, the fact that the intra-peritoneal paclitaxel has not been approved in Japan has rendered its evaluation by a formal clinical trial impossible. The authors designed a randomized phase II trial using the Kodo Iryo Hyoka system, a new system to legally test an yet unapproved mode of treatment. It is hoped that this trial will result in a breakthrough in the treatment of peritoneal carcinomatosis from gastric cancer.

A feasibility study of postoperative chemotherapy with S-1 and cisplatin (CDDP) for gastric carcinoma (CCOG0703)

BACKGROUND

The outcome of stage III gastric cancer patients treated by D2 dissection followed by adjuvant chemotherapy with S-1 remains unsatisfactory. Moreover, some patients with a preoperative diagnosis of stage II/III turn out to be stage IV after surgical exploration, and a standard postoperative treatment for this population has not been established.

METHODS

A feasibility study of postoperative S-1/cisplatin (CDDP) was performed with patients who underwent gastrectomy for what turned out to be a stage IV gastric cancer. The primary endpoint of the trial was the relative dose intensity during five courses of S-1/CDDP. Several criteria to skip, postpone, or reduce the dose had been predetermined.

RESULTS

Between 2007 and 2009, 31 patients were accrued, including 19 patients who were positive for peritoneal washing cytology, 6 with peritoneal seeding, 5 with metastasis to the paraaortic nodes, and 4 with other distant metastases. Only 7 patients completed five cycles as planned (median, two cycles). The median relative dose intensities of S-1 and CDDP were 37% and 40%, respectively. Causes of treatment failure were failure to fulfill criteria for starting a new course within 5 weeks of the last administration of S-1 in 7, patient refusal in 6, disease recurrence/progression in 4, need to reduce dose by two levels in 4, and two successive skips of CDDP in 3 patients. The median progression-free survival time of all patients was 363 days.

CONCLUSIONS

Although promising in the neoadjuvant and advanced/metastatic setting, S-1/CDDP is too toxic as a postgastrectomy treatment for Japanese patients.