Incidence, clinicopathological features, and clinical outcomes of low HER2 expressed, inoperable, advanced, or recurrent gastric/gastroesophageal junction adenocarcinoma

BACKGROUND

According to the DESTINY-Breast04 trial, treating patients with breast cancer and low human epidermal growth factor receptor 2 expressions (HER2-low) varies from that of those with no HER2 expression. However, it is interesting to know if HER2-low indicates for anti-HER2 therapy in the gastric or gastroesophageal junction (G/GEJ) adenocarcinoma. Hence we conducted this study to assess the incidence, clinicopathological features, and treatment outcomes of patients with HER2-low G/GEJ adenocarcinoma.

PATIENTS AND METHODS

This was a single-center, retrospective observational study. Patients with previously untreated G/GEJ adenocarcinoma were classified based on their HER2 status using immunohistochemistry (IHC) with or without in situ hybridization (ISH) as follows: HER2 negative (IHC 0), HER2-low (IHC 1+ or 2+/ISH-), and HER2-positive (IHC2+/ISH+ or 3+).

RESULTS

In total, 734 patients with G/GEJ adenocarcinoma were divided into three groups (HER2-negative, n = 410; HER2-low, n = 154, and HER2-positive, n = 170). The intestinal-type histology, peritoneal metastasis, and higher serum carcinoembryonic antigen (CEA) levels differed significantly among patients with negative, low, and positive HER2 statuses: intestinal-type histology (21.0%, 44.2%, and 59.8%, respectively), peritoneal metastasis (56.3%, 44.8%, and 21.8%, respectively), and higher serum CEA level (32.2%, 41.6%, and 56.5%, respectively). Improved survival was observed in the HER2-positive group than in the HER2-negative G/GEJ adenocarcinoma group [hazard ratio (HR) = 0.73, 95% confidence interval (CI) 0.59-0.89; P = 0.002]. However, the prognoses of the HER2-low and HER2-negative groups were similar (HR = 1.01, 95% CI 0.82-1.23; P = 0.843).

CONCLUSIONS

Patients with HER2-low G/GEJ adenocarcinoma exhibited intermediate and distinct characteristics than those in the HER2-negative group. Similarly, the HER2-low group's prognosis was worse than that of the HER2-positive group. Therefore developing novel therapeutic strategies targeting HER2-low G/GEJ adenocarcinoma is required.

Failure of neoadjuvant chemotherapy for resectable esophageal squamous cell carcinoma

Neoadjuvant treatment has become standard care for patients with resectable esophageal cancer. However, some patients cannot undergo surgery or curative resection because of disease progression during neoadjuvant treatment. The aim of this study is to identify the pretreatment characteristics of patients in whom neoadjuvant treatment failed. The study enrolled 231 patients who underwent chemotherapy with cisplatin and 5-fluorouracil (CF) as neoadjuvant therapy for T1N1-3 or T2-3 any-N esophageal squamous cell carcinoma (ESCC). Of these patients, 201 (87.0%) underwent curative resection (R0) and 30 (13.0%) could not undergo curative resection; 19 patients (8.2%) underwent incomplete resection (R1 or R2), and 11 patients (4.8%) could not undergo surgery because of disease progression. We compared clinical characteristics and survival between patients who underwent curative resection (curative group) and those who could not undergo curative resection (noncurative group) to determine the factors predicting noncurative treatment. The noncurative group had significantly worse disease-specific survival than the curative group (P < 0.001). All patients in the noncurative group had cT3 tumors. In 141 patients with cT3 tumors, those in the noncurative group were more likely to have higher serum SCC antigen concentration (P = 0.021), location of the main tumor in the upper to the middle third of the esophagus (P = 0.071), intramural metastases (P < 0.001), advanced N category (P = 0.016), and bulky lymph node metastases (P = 0.060). Multivariate logistic regression analysis identified location of the main tumor in the upper to the middle third of the esophagus (P = 0.047), intramural metastases (P = 0.002), and nodal metastases (N1, P = 0.014; N2, P = 0.015, respectively) as independent predictors of treatment failure in patients with cT3 tumors. Neoadjuvant CF therapy alone may not be effective for patients with cT3 tumors accompanied by these risk factors, and the efficacy of alternative strategies, such as triplet chemotherapy or chemoradiotherapy, should be evaluated.

Combination chemotherapy with bevacizumab and S-1 for elderly patients with metastatic colorectal cancer (BASIC trial)

BACKGROUND

Chemotherapeutic regimens for elderly patients with metastatic colorectal cancer (mCRC), such as bevacizumab combined with 5-fluorouracil (5-FU) and leucovorin, often exclude oxaliplatin and irinotecan owing to the risk of toxicity. However, treatment with infusional 5-fluorouracil and leucovorin requires percutaneous port-catheter placement and other precautions, causing unnecessary stress for patients as well as healthcare workers.

METHODS

We conducted a phase II study to evaluate the efficacy and safety of bevacizumab plus S-1 in elderly patients with previously untreated mCRC. Bevacizumab was given intravenously every two weeks, and S-1 was administered orally on days 1-28 of a 42-day cycle. The primary end-point was progression-free survival (PFS). The secondary end-points were time to treatment failure, response rate (RR), overall survival (OS), treatment completion status and safety.

RESULTS

From October 2007 through March 2010, 56 patients were enroled. The median PFS was 9.9months, the median OS was 25.0months, and the RR was 57%. The main adverse events of grade 3 or higher were hypertension (11%), diarrhoea (9%) and neutropenia (7%).

CONCLUSION

Our results suggest that combination chemotherapy with S-1 and bevacizumab can be administered safely and continuously on an outpatient basis and is therapeutically effective in elderly patients with mCRC.

BRAF mutation is a powerful prognostic factor in advanced and recurrent colorectal cancer

Background:

Activating mutation of KRAS and BRAF are focused on as potential prognostic and predictive biomarkers in patients with colorectal cancer (CRC) treated with anti-EGFR therapies. This study investigated the clinicopathological features and prognostic impact of KRAS/BRAF mutation in advanced and recurrent CRC patients.

Method:

Patients with advanced and recurrent CRC treated with systemic chemotherapy (n=229) were analysed for KRAS/BRAF genotypes by cycleave PCR. Prognostic factors associated with survival were identified by univariate and multivariate analyses using the Cox proportional hazards model.

Results:

KRAS and BRAF mutations were present in 34.5% and 6.5% of patients, respectively. BRAF mutated tumours were more likely to develop on the right of the colon, and to be of the poorly differentiated adenocarcinoma or mucinous carcinoma, and peritoneal metastasis. The median overall survival (OS) for BRAF mutation-positive and KRAS 13 mutation-positive patients was 11.0 and 27.7 months, respectively, which was significantly worse than that for patients with wild-type (wt) KRAS and BRAF (40.6 months) (BRAF; HR=4.25, P<0.001, KRAS13; HR=2.03, P=0.024). After adjustment for significant features by multivariate Cox regression analysis, BRAF mutation was associated with poor OS (HR=4.23, P=0.019).

Conclusion:

Presence of mutated BRAF is one of the most powerful prognostic factors for advanced and recurrent CRC. The KRAS13 mutation showed a trend towards poor OS in patients with advanced and recurrent CRC.

Evaluation of the seventh TNM classification system in patients with esophageal cancer receiving chemoradiotherapy

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Background: The new 7th edition of the TNM classification system is based on pathologic data of esophageal cancer underwent surgery alone. No report is available on the prognostic evaluation of the new staging system in patients treated with chemoradiotherapy (CRT). The objective of this study was to evaluate the prognostic impact of the 7th edition of the TNM staging system in esophageal cancer patients treated with CRT.

Methods: A retrospective review was performed of 301 consecutive patients who met the following inclusion criteria: (1) squamous cell carcinoma of thoracic esophagus; (2) total radiation dose ≥ 50 Gy; (3) concomitant chemotherapy consisting of 5-fluolouracil and platinum; (4) no previous thoracic radiotherapy or surgery. We compared the prognostic impact of the 6th and 7th editions of the TNM staging systems. Also, we compared the prognostic impact of stage group and prognostic group, which was newly defined in the 7th edition. Survival analysis was performed by using log-rank and Cox regression testing.

Results: Patients with stage I/II/III/IV were 52/42/54/153 and 57/46/128/70 according to 6th and 7th edition, respectively. Eighty-four patients were shifted to a lower stage in 7th edition compared with 6th edition, and most of these were from stage IV to III (n = 74). There were significant differences among stages I to III (p < 0.01, respectively) according to each edition. However, 7th edition poorly distinguishes between stages III and IV (p = 0.43). The survival curve of stage IV (lymph) almost completely overlapped with stage III (p = 0.69), although there were significant differences between stages IV (lymph) and IV (organ) (p = 0.04). Among the factors included in prognostic group in 7th edition, the histological grade and cancer site had no significant influence on patient survival, and T factor was only independent prognostic factors in multivariate analysis (p < 0.01).

Conclusions: Our study suggested several pitfalls in 7th TNM classification as prognostic factor in patients who received CRT.

No significant financial relationships to disclose.

Phase I study of cediranib in combination with cisplatin plus fluoropyrimidine (S-1 or capecitabine) in Japanese patients (pts) with untreated advanced gastric cancer (AGC)

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Background: Cediranib (AZD2171) is an oral, highly potent inhibitor of VEGF signalling with activity versus all three VEGFRs and c-Kit. Combination therapy with cisplatin + oral fluoropyrimidine is commonly used as first-line treatment for AGC. This phase I study assessed cediranib in combination with cisplatin/S-1 or cisplatin/capecitabine in Japanese pts with previously untreated AGC.

Methods: Eligible pts received cediranib 20 mg/day and either cisplatin 60 mg/m2 iv, day 1 + S-1 40–60 mg bd, days 1–21, q5w (Arm A) or cisplatin 80 mg/m2 iv, day 1 + capecitabine 1000 mg/m2 bd, days 1–14, q3w (Arm B). The primary endpoint was safety and tolerability. Secondary endpoints included assessment of steady-state pharmacokinetics (PK) of cediranib and chemotherapy alone and in combination. Preliminary efficacy was an exploratory objective. Adverse events (AEs) were evaluated according to CTCAE v3.0.

Results: Between Aug–Dec 2009, 14 pts (median age, 60.5 [27–72] years; male, n = 9; PS 0/1, n = 7/7) were recruited to Arm A (n = 6) or Arm B (n = 8). The safety profile in both arms was consistent with that of the individual agents. There were no unexpected toxicities. All pts experienced ≥1 AE. Dose-limiting toxicities were reported in 1 pt in Arm A (decreased appetite) and 1 pt in Arm B (decreased appetite, fatigue, hyponatremia). The most common AEs in Arm A were decreased appetite, fatigue, nausea, diarrhoea, decreased weight and neutropenia (all n = 5; 83%), and decreased appetite, fatigue, nausea (all n = 8; 100%) and constipation (n = 7; 88%) in Arm B. Five (83%) pts in Arm A and 6 (75%) in Arm B experienced grade ≥ 3 AEs. Grade 3 AEs in > 1 pt were neutropenia (n = 3) in Arm A and hypokalaemia (n = 3), neutropenia, hyponatraemia and fatigue (all n = 2) in Arm B. Grade 4 syncope was reported in 1 pt in Arm A; this resolved on the same day it was observed. Preliminary efficacy and PK data will be presented.

Conclusions: Cediranib 20 mg plus cisplatin/S-1 or cisplatin/capecitabine was generally well tolerated and considered suitable for further evaluation in pts with AGC. The safety profile of each regimen was comparable with the individual agents. No new toxicities were identified.

[Table: see text]

Multicenter feasibility study of 5-FU, leucovorin, plus paclitaxel (FLTAX) for peritoneal disseminated gastric cancer with massive ascites or inadequate oral intake

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Background: Oral fluoropyrimidine plus cisplatin is widely used as a standard treatment for advanced gastric cancer, but patients (pts) with severe peritoneal metastasis often cannot tolerate this regimen. The aim of this study was to assess the feasibility of fluorouracil (5-FU), leucovorin (LV), plus paclitaxel (PTX) for peritoneal disseminated gastric cancer with massive ascites or inadequate oral intake.

Methods: Peritoneal disseminated gastric cancer with massive ascites or inadequate oral intake were enrolled in Part I (Level 1 (n=6): 5-FU bolus/l- LV div 2hr/PTX div 1hr = 500/250/60, Level 2 (n=6): 600/250/80 mg/m2 (day1, 8, 15, q4w) to determine dose-limiting toxicity (DLT) and recommended dose (RD). In Part II (n=19), primary endpoint was completion rate of 2 cycles to evaluate the feasibility of this regimen at RD level.

Results: One of Level 1 pts had DLT with grade 4 gastrointestinal perforation. Two of Level 2 pts had DLT (grade 3 febrile neutropenia and grade 3 infection with normal neutrophils) and treatment-related death (TRD) was observed in one patient due to pneumonia with grade 4 neutropenia. The RD was determined to be Level 1. Twenty-five patients were enrolled at RD level: first-line/second-line=18/7, performance status 0/1/2=1/19/5. The completion rate of 2 cycles was 92% and objective response rate of ascites was 45%. Grade 3 or 4 neutropenia was observed in 12% (febrile neutropenia in 8%). Five patients out of 7 second-line patients died within 30 days after last administration of FLTAX (TRD: 1 and disease progression: 4).

Conclusions: RD of FLTAX regimen was 5-FU/l-LV/PTX=500/250/60 mg/m2. This regimen was feasible as the first-line treatment against peritoneal disseminated gastric cancer patients with massive ascites or inadequate oral intake.

[Table: see text]

Progression-free survival and time to progression as surrogate markers of overall survival in patients with advanced gastric cancer: Literature-based analysis of 36 randomized trials

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Background: We evaluated the potential of progression-free survival (PFS) and time to progression (TTP) to act as surrogates of overall survival (OS) in clinical trial settings by a comprehensive literature-based analysis.

Methods: Randomized trials of systemic chemotherapy for advanced gastric cancer were identified by comprehensive electronic and manual search. Correlations between PFS/TTP and OS were evaluated.

Results: Thirty-six trials with a total of 83 treatment arms and 10,484 patients were selected for analysis. The nonparametric Spearman rank correlation coefficient (p) between median PFS/TTP and OS was 0.70 (95% CI, 0.59 to 0.82) and the correlation coefficient between hazard ratios in PFS/TTP and OS was 0.80 (95% CI, 0.68 to 0.92). Correlation tended to be higher in non-Asian (p = 0.80; 0.61-0.98) than Asian trials (p = 0.67; 0.39-0.94), higher in trials reporting PFS (p = 0.85; 0.72-0.97) than in those reporting TTP (p = 0.60; 0.24-0.97), and higher in trials in patients with measurable lesions only (p = 0.91; 0.77-1.00) than in those including non-measurable lesions (p = 0.71; 0.50-0.93), albeit that none of these differences was significant.

Conclusions: Our results indicate that improvements in PFS/TTP in advanced gastric cancer strongly correlate with improvements in OS. PFS/TTP may be an appropriate surrogate for OS in clinical trials for advanced gastric cancer.

No significant financial relationships to disclose.

Evaluation of BRAF mutation as a powerful prognostic factor in advanced and recurrent colorectal cancer

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Background: Alterations in the RAS/RAF/ERK signaling pathways frequently occur in colorectal cancer (CRC). KRAS mutations preclude responsiveness to EGFR-targeted therapies for CRC patients. However, prognostic significance of KRAS mutation is still controversial. The aim of this study is to investigate clinicopathological features of KRAS mutation in codon 12 and 13 as well as of BRAF mutation, and to validate prognostic impact of KRAS/BRAF mutation in advanced and recurrent CRC.

Methods: The population consisted of 230 unselected patients who had undergone first-line chemotherapy for advanced and recurrent CRC between November 2002 and June 2010. Cycleave PCR was performed to detect a point mutation at codon 12, 13 or 61 in KRAS, and the V600E mutation in BRAF. Prognostic factors associated with survival were identified using univariate and multivariate logistic and/or Cox proportional hazards analyses.

Results: KRAS mutations were present in 34.8% (n= 80) of patients, including 23.5% (n = 54) in codon 12, 11.3% (n = 26) in codon 13, and 0% in codon 61. 6.5% (n = 15) of patients had BRAF mutation. None of the CRC patients carried both KRAS and BRAF mutations. The primary tumor lesions were located on the right side of the colon in 60% of the BRAF mutant patients (p=0.0371). Furthermore, BRAF mutant was significantly associated with the pathological subtypes of poorly differentiated adenocarcinoma/mucinous carcinoma (p<0.0001) and peritoneal metastasis (p=0.0059). The median overall survival for BRAF mutant and KRAS 13 mutant patients was 11.0 and 27.7 months, respectively, which was significantly worse than that for KRAS wild-type (wt)/BRAF wt (40.6 months) (BRAF; HR=3.89, 95% CI 1.83-8.24, p<0.001, KRAS13; HR=2.03, 95% CI 1.10-3.74, p=0.024). After adjustment for significant features by multivariate Cox regression analysis, BRAF mutation was associated with poor overall survival (HR, 3.70, 95% CI, 1.48-9.28; p=0.005), together with performance status 2.

Conclusions: This retrospective analysis shows that clinicopathological features of CRC patients with BRAF mutations seem to be distinct from those with wild type BRAF. BRAF mutation is one of the most powerful prognostic factors in advanced and recurrent CRC.

No significant financial relationships to disclose.

Phase II study of combination chemotherapy with biweekly cetuximab and irinotecan for wild-type KRAS metastatic colorectal cancer refractory to irinotecan, oxaliplatin, and fluoropyrimidines

561

Background: Weekly cetuximab and irinotecan is a standard regimen in heavily pretreated patients with metastatic colorectal cancer (MCRC). The aim of this study was to prospectively evaluate the efficacy of combination chemotherapy with biweekly cetuximab and irinotecan in patients with pretreated MCRC harboring wild-type KRAS.

Methods: Patients with wild- type KRAS MCRC that had progressed after chemotherapy with irinotecan, oxaliplatin, and fluoropyrimidine were included in this study. Cetuximab was administered at 500 mg/m2 biweekly with irinotecan. The primary endpoint was response rate. The secondary endpoints included adverse events, progression-free survival, and overall survival. The pharmacokinetics of cetuximab was also evaluated in five patients.

Results: From May, 2009 to February, 2010, a total of 31 patients were enrolled from five institutions. One patient was not eligible. Among the 30 assessable patients, ECOG PS was 0 in 12, 1 in 16, and 2 in two patients. The objective response rate was 30.0% (95% confidence interval [CI], 14.7-49.4), and the disease control rate (complete response, partial response, or stable disease) was 76.7% (95%CI, 61.4-92.3). The median progression-free survival was 5.3 months (95%CI, 3.4-7.3). Grade 3 skin toxicity was observed in 3 patients (10%), and treatment related death due to pneumonia occurred in one patient.

Conclusions: The efficacy data are similar to those of standard dose of cetuximab plus irinotecan. Combination chemotherapy with biweekly cetuximab and irinotecan is effective for pretreated metastatic wild-type KRAS MCRC.

No significant financial relationships to disclose.

Feasibility study of adjuvant chemotherapy with S-1 plus cisplatin for gastric cancer

PURPOSE

To evaluate the feasibility of S-1 plus cisplatin as adjuvant chemotherapy for stage III gastric cancer after curative resection.

METHODS

Japanese patients with stage III gastric cancer who underwent gastrectomy with D2 lymph node resection were enrolled. Treatment consisted of 3 cycles of S-1 (80 mg/m(2)/day, b.i.d.) for 21 days followed by a 14-day rest, and cisplatin (60 mg/m(2) iv) on day 8. After that, S-1 monotherapy was given on days 1-28 every 6 weeks until 1-year postsurgery. After protocol amendment, the first chemotherapy cycle consisted of S-1 monotherapy; cisplatin was added to cycles 2, 3, and 4, followed by S-1 monotherapy up to 1-year postsurgery. The primary endpoint was the completion rate of three cycles of S-1 plus cisplatin.

RESULTS

A total of 63 enrolled patients have been evaluated. Grade 3/4 toxicities included neutropenia (40%), anorexia (28%), and febrile neutropenia (4%) before protocol amendment (n = 25), and neutropenia (37%), anorexia (8%), and febrile neutropenia (3%) after amendment implementation (n = 38). Excluding ineligible cases, treatment completion rates were 57% (12/21) before and 81% (30/37) after the protocol amendment.

CONCLUSIONS

The amended S-1 plus cisplatin is more feasible than the original protocol because of early dose reduction of S-1 prior to cisplatin addition and greater recovery time from surgery prior to cisplatin. This treatment should be considered as a feasible experimental arm for the next postoperative adjuvant phase III trial.

Neutropenia as a prognostic factor in advanced gastric cancer patients undergoing second-line chemotherapy with weekly paclitaxel

BACKGROUND

Neutropenia during chemotherapy has been reported to be a predictor of better survival in patients with several types of cancers, although there are no reports in pretreated patients.

METHODS

We retrospectively analyzed 242 patients with advanced gastric cancer (AGC) who received weekly paclitaxel (Taxol) as second-line chemotherapy. Background characteristics and neutropenia as time-varying covariates (TVCs) were analyzed as prognostic factors.

RESULTS

Of the 242 patients, mild neutropenia (grades 1-2) occurred in 101 patients (41.7%) and severe neutropenia (grades 3-4) occurred in 63 patients (26.0%). The other 78 patients (32.2%) did not experience neutropenia. According to a multivariate Cox model with neutropenia as a TVC, hazard ratios of death were 0.61 [95% confidence interval (CI) 0.43-0.85; P = 0.004] for patients with mild neutropenia and 0.61 (95% CI 0.41-0.88; P = 0.009) for those with severe neutropenia. Among the patients in landmark analysis (landmark of 2.5 months; median time to treatment failure of paclitaxel), mild and severe neutropenia remained significant prognostic factors.

CONCLUSIONS

Our results indicate that neutropenia during chemotherapy is associated with improved survival in patients with AGC who received weekly paclitaxel as second-line chemotherapy. Prospective trials are required to assess whether dosing adjustments based on neutropenia may improve chemotherapy efficacy.