Prognostic Impact of Early Treatment and Oxaliplatin Discontinuation in Patients With Stage III Colon Cancer: An ACCENT/IDEA Pooled Analysis of 11 Adjuvant Trials

PURPOSE

Oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer (CC) for 6 months remains a standard in high-risk stage III patients. Data are lacking as to whether early discontinuation of all treatment (ETD) or early discontinuation of oxaliplatin (EOD) could worsen the prognosis.

MATERIALS AND METHODS

We studied the prognostic impact of ETD and EOD in patients with stage III CC from the ACCENT/IDEA databases, where patients were planned to receive 6 months of infusional fluorouracil, leucovorin, and oxaliplatin or capecitabine plus oxaliplatin. ETD was defined as discontinuation of treatment and EOD as discontinuation of oxaliplatin only before patients had received a maximum of 75% of planned cycles. Association between ETD/EOD and overall survival and disease-free survival (DFS) were assessed by Cox models adjusted for established prognostic factors.

RESULTS

Analysis of ETD and EOD included 10,447 (20.9% with ETD) and 7,243 (18.8% with EOD) patients, respectively. Compared with patients without ETD or EOD, patients with ETD or EOD were statistically more likely to be women, with Eastern Cooperative Oncology Group performance status ≥ 1, and for ETD, older with a lower body mass index. In multivariable analyses, ETD was associated with a decrease in disease-free survival and overall survival (hazard ratio [HR], 1.61, P < .001 and HR, 1.73, P < .001), which was not the case for EOD (HR, 1.07, P = .3 and HR, 1.13, P = .1). However, patients who received < 50% of the planned cycles of oxaliplatin had poorer outcomes.

CONCLUSION

In patients treated with 6 months of oxaliplatin-based chemotherapy for stage III CC, ETD was associated with poorer oncologic outcomes. However, this was not the case for EOD. These data favor discontinuing oxaliplatin while continuing fluoropyrimidine in individuals with significant neurotoxicity having received > 50% of the planned 6-month chemotherapy.

Using T stage to predict outcomes of adjuvant oxaliplatin (OX)-based chemotherapy (CT) in stage III colon cancer (CC): An ACCENT pooled analysis

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Background: Standard adjuvant CT for stage III CC are FOLFOX and CAPOX. Recently, IDEA study separated stage III patients (pts) into low risk (T1 to 3, N1) and high risk (T4 or N2). We recently confirmed benefit of OX in both risk groups. However, we observed a difference in the two high-risk subgroups, with benefit in N2 but not in T4 (Margalit O et al; Clin Colorectal Cancer 2021). This prompted us to compare outcomes (OS/TTR) between treatment with OX vs. without OX within sub-stage III CC groups defined by T and N. Methods: We pooled 4941 stage III CC pts from the three studies evaluating 6 months of CT with fluoropyrimidine (FP) ± OX: MOSAIC, C-07 and XELOXA. Baseline characteristics were compared using χ2 and t-test. OS was compared between OX and no OX in T and N subgroups. Kaplan-Meier analyses, adjusted and unadjusted Cox models stratified by study were used. Sub-groups classification was done according to OX benefit and verified by interaction test (Int) considered as significant with a P<0.1. We considered for recommendation of using OX-based adjuvant CT, 1) significant benefit in OS, 2) significant Int between substage and adjuvant therapy, and 3) the three individual trials showing similar results (benefit or non-benefit of OX). Results: In stage III population, T3 pts were 74.9%, T1-2 12.4%, T4 13.1%, while N stage was N1 64.7% and N2 35.3%. Population was well balanced according to treatment allocation in most subgroups. A significant benefit of OX was only observed in T3N1 and T3N2 (OS HR 0.76). Whatever N stage, there was no significant benefit of OX in the T1-2 and T4 subgroups. The effect of OX+FP vs FP alone in OS of the three studies differed between T3 and T1-2 subgroups (P = 0.047). Interaction was borderline between T3 and T4 subgroups (P = 0.10) but there was no interaction between T1-2 and T4 subgroups (P = 0.429). A benefit of OX in TTR remained in the T4 population. Discrepancy between advantage in time to relapse (TTR) and no advantage in OS was not explained by survival post relapse. Conclusions: Our analysis suggested that pts with T1-2N1-2 and T4N1-2 disease had no OS benefit of addition of OX to FP. The good survival achieved with FP alone in T1-2N1-2 pts (5-yr OS 89%) question the addition of OX. In the T4 population our results suggested that benefit of OX was limited and that further studies should assess this issue or at least stratify pts on T stage in the future adjuvant trials in CC. [Table: see text]

Prognostic impact of early treatment discontinuation and early oxaliplatin discontinuation in patients treated with 6 months of oxaliplatin-based adjuvant chemotherapy for stage III colon cancer: an ACCENT/IDEA pooled analysis of 11 trials

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Background: Six months of oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer (CC) remains a standard in high-risk stage III patients. Early treatment discontinuation (ETD) could worsen the prognosis. In addition, there is current lack of data on the prognostic impact of early oxaliplatin only discontinuation (EOD). Methods: We studied the prognostic impact of ETD and EOD in patients with stage III CC who participated in 11 relevant clinical trials of the ACCENT and IDEA databases, where patients were planned to receive 6 months of adjuvant fluoropyrimidine plus oxaliplatin (FOLFOX or CAPOX). ETD was defined as discontinuation of treatment before 75% of cycles of chemotherapy. EOD was defined as discontinuation of oxaliplatin only, while continuing the fluoropyrimidine, before 75% of cycles of oxaliplatin. Association between ETD/EOD and overall survival (OS) and disease-free survival (DFS) was assessed by Cox model adjusted for prognostic factors. Results: ETD analysis included 10,444 patients (FOLFOX n = 7,033; CAPOX n = 3,411), with 20.9% of patients with ETD (17.8% with FOLFOX and 27.2% with CAPOX, p < 0.001). Out of 7,243 patients, 18.8% experienced EOD (17.4% FOLFOX versus 21.4% with CAPOX, p < 0.001). Compared to patients without ETD or EOD, patients with ETD or EOD were statistically more likely to be women, older, with higher ECOG-PS ≥ 1, and in addition for ETD, a Body Mass Index (BMI) < 18.5 kg/m2. In multivariate analyses, ETD was associated with a decrease in DFS and OS in the overall population (HR: 1.40 95%CI 1.23-1.58, p < 0.001 and HR: 1.51 95%CI 1.31-1.74, p < 0.001, respectively). The same pattern was present with FOLFOX and CAPOX regimen, and also in low-risk and high-risk groups for each regimen with the exception of the CAPOX regimen in the low-risk group for DFS and OS. By contrast, EOD was not associated with reduced DFS or OS in the overall population (HR: 1.10 95%CI 0.77-1.58, p = 0.6 and HR: 0.97 95%CI 0.62-1.52, p = 0.9, respectively), in the low-risk group (HR: 0.97 95%CI 0.56-1.66, p = 0.9 and HR: 0.97 95%CI 0.51-1.82, p = 0.9, respectively) and high-risk group (HR: 1.22 95%CI 0.74-2.02, p = 0.4 and HR: 1.05 95%CI 0.53-2.08, p = 0.9, respectively) and for all subgroups of regimen. Conclusions: In patients treated with 6 months of oxaliplatin-based adjuvant chemotherapy for stage III CC, ETD was associated with a decrease in DFS and OS. By contrast, EOD was not significantly associated with poorer outcomes. In case of relevant neurotoxicity during a 6 months schedule, these data are not in favor of continuing oxaliplatin beyond 75% of planned cycles of adjuvant chemotherapy, and demonstrate that fluoropyrimidines remain the cornerstone of adjuvant chemotherapy in localized CC.

Pharmacogenetic study in gastric cancer patients treated with adjuvant fluorouracil/leucovorin or epirubicin/cisplatin/fluorouracil before and after chemoradiation on CALGB 80101 (Alliance)

There is a lack of pharmacogenetic predictors of outcome in gastric cancer patients. The aim of this study was to assess previously identified candidate genes associated with 5-fluorouracil (5-FU), cisplatin, or epirubicin toxicity or response in a cohort of resected gastric cancer patients treated on CALGB (Alliance) 80101. Gastric or gastroesophageal cancer patients randomized to adjuvant 5-FU/leucovorin or epirubicin/cisplatin/5-FU before and after 5-FU chemoradiation were genotyped for single nucleotide polymorphisms (SNPs) in GSTP1 (rs1695), ERCC1 (rs11615 and rs3212986), XRCC1 (rs25487), UGT2B7 (rs7439366) and the 28 base-pair tandem repeats in TYMS (rs34743033). Logistic regression and log rank tests were used to assess the association between each SNP and incidence of grade 3/4 neutropenia and leukopenia, overall (OS) and progression-free survival (PFS), respectively. Toxicity endpoint analyses were adjusted for the treatment arm, while OS and PFS were also adjusted for performance status, sex, age, lymph node involvement, and primary tumor site and size. Of 281 subjects with successful genotyping results and available clinical (toxicity and efficacy) data, 166 self-reported non-Hispanic White patients were included in the final analysis. There was a lack of evidence of an association among any SNPs tested with grade 3/4 neutropenia and leukopenia or OS and PFS. Age, lymph node involvement, and primary tumor size were significantly associated with OS and PFS. This study failed to confirm results of previous gastric cancer pharmacogenetic studies.

Characteristics of patients (pts) and prognostic factors across treatment lines (TL) in metastatic colorectal cancer (mCRC): An analysis from the Analysis and Research in Cancers of the Digestive System (ARCAD) database

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Background: Pts with mCRC frequently receive ≥1 sequential treatment TL. Approximately 50%-60% of pts receive second-line (L2) and 20%-30% third-line (L3) regimens in routine practice. We investigated the pts clinical/tumor characteristics and their prognostic impact across TL. Methods: Data from 37,560 pts enrolled in 48 randomized trials (34 in first (L1), 9 in L2, and 5 in L3) were analyzed. Candidate variables (VAR) measured at enrollment were sex, age, body mass index, performance status (PS), bilirubin, hemoglobin (Hb), platelets (Pl), derived white blood cells-to-absolute neutrophil counts ratio (WBC/ANC), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), primary tumor location, and number and location of metastatic sites (MS). Missing data were imputed. VAR with significant value at all TL were selected to construct a prognostic score of overall survival (OS) in training set (TS, n=30,050; 80%). For each TL, the score was calculated as the sum on the estimations of the VAR’ coefficients from the common multivariate model; Cox’s model was used to define risk groups. The discrimination capability was assessed using the Harrell’s C-index. External validation was done in the validation set (VS, n=7,510; 20%). Results: A total of 26,974 pts in L1, 7,693 pts in L2 and 2,893 pts in L3 were analyzed. The following characteristics increased continuously over TL: ≥2 MS (57%, 72%, 82%), lung metastases (50%, 74%, 91%), lymph nodes metastases (51%, 61%, 80%), KRAS mutation (37%, 47%, 51%) and elevated ALP (46%, 52%, 61%). BRAF mutation decreased (9%, 7%, 5%). In L1 vs L3 trials, 70% vs 89% of patients had primary tumor resection, 10% vs 80% had at least one metastasectomy and 31% vs 78% had a late metachronous (>12 months) metastasis. 7 independent VAR were retained in the prognostic score (PS, Hb, Pl, WBC/ANC, LDH, ALP, and the number of MS); four pt groups with significantly different prognoses were defined (table). This score remained valid when excluding pts with PS 2. Third-line oral drugs (vs placebo) and subsequent line (L2/L1 or L3/L2) were effective in all prognostic groups. Conclusions: Clinical/tumor pt characteristics significantly varied over subsequent TL in patients included in randomized trials. The same prognostic model using practical clinical and biological variables can be used in all TL.[Table: see text]

Clinicopathological and molecular characteristics of early-onset stage III colon adenocarcinoma: An analysis of 25 studies with 35,713 patients in the Adjuvant Colon Cancer End Points (ACCENT) database

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Background: Colon cancer (CC) incidence and mortality have decreased since the 1970s, but the incidence in young adults (20-49 years) is increasing. There are limited data suggesting that, as a group, patients with early onset CRC (eoCC) may have different phenotypic characteristics compared to those with late onset CRC (loCC, age ≥ 50 years). Methods: Individual patient data on 35,713 subjects with stage III CC from 25 randomized studies (recruiting between 1987 and 2009) in the ACCENT database were pooled. The distributions of demographics, clinicopathological features, biomarkers, and outcome data were summarized by age group. Overall survival (OS), disease-free survival (DFS), recurrence free rate (RFR), and survival after recurrence (SAR) were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for gender, race, body mass index, performance status, disease stage, grade, risk group, number of lymph nodes examined, disease sidedness and molecular markers. Results: Using a 5% difference between age groups as the clinically meaningful cutoff, patients with stage III eoCC (n = 6246) had similar distributions according to gender, race, PS, risk group, tumor sidedness and T/N stage compared to those with loCC (n = 29467). Patients with eoCC were significantly less likely to be overweight (30.2% vs 36.2%) but more commonly had ≥ 12 lymph nodes resected (69.5% vs 58.7%). The eoCC tumors were more frequently mismatch repair deficient (16.4% vs 11.5%), and less likely to have BRAFV600E (5.6% vs 14.0%), suggesting a higher frequency of Lynch syndrome in eoCC. In univariate analysis, patients with stage III eoCC had significantly better OS, DFS, and SAR; the difference between 3-year DFS and RFR strongly suggests the OS/DFS difference between these the eoCC and loCC may be due to increased competing risks and comorbidities in patients with loCC. In multivariate analysis, age at onset lost its prognostic value when outcome was adjusted for molecular markers. The clear relation between age of onset and KRAS/BRAF status was confirmed in the interaction analysis. Conclusions: Tumor biology was an important determinant of prognosis regardless of patient age. In multivariate analysis age of onset was not a statistically significant determinant of outcome.[Table: see text]

Benefit of Oxaliplatin in Stage III Colon Cancer According to IDEA Risk Groups: Findings from the ACCENT Database of 4934 Patients

BACKGROUND

The International Duration Evaluation of Adjuvant Chemotherapy (IDEA) pooled analysis compared 3 to 6 months of adjuvant chemotherapy for stage III colon cancer. Patients were classified into low risk and high risk, suggesting low-risk patients may be offered only 3 months of treatment. In this study, we aimed to assess the benefit of oxaliplatin in the adjuvant setting per IDEA risk groups, using data from 3 large adjuvant phase III studies, namely Multicenter International Study of Oxaliplatin/Fluorouracil/ Leucovorin in the Adjuvant Treatment of Colon Cancer (MOSAIC), C-07, and XELOXA.

METHODS

Using the MOSAIC, C-07, and XELOXA previously published studies, we identified 2810 low-risk and 2124 high-risk patients with stage III colon cancer. We used Cox regression model to evaluate the magnitude of survival differences between IDEA risk groups, according to oxaliplatin use. Based on design similarity and equivalent follow-up data, MOSAIC and C-07 were pooled, whereas XELOXA was analyzed separately. Subgroup analyses were also performed for T4 and/or N2 patients.

RESULTS

Individuals with IDEA low and high risk derived overall survival benefit from the addition of oxaliplatin to adjuvant chemotherapy, with adjusted hazard ratios of 0.79 (0.66-0.95) and 0.84 (0.71-0.99), respectively. Among individuals with IDEA high risk, those with T4 disease did not gain overall survival benefit from addition of oxaliplatin with hazard ratio of 0.95 (0.71-1.27). Similar results were demonstrated using data from the XELOXA study.

CONCLUSION

IDEA risk classification per se does not predict benefit from addition of oxaliplatin to adjuvant chemotherapy in stage III colon cancer. T4 disease may predict lack of benefit from oxaliplatin addition.

Sex and Adverse Events of Adjuvant Chemotherapy in Colon Cancer: An Analysis of 34 640 Patients in the ACCENT Database

BACKGROUND

Adjuvant chemotherapy is a standard treatment option for patients with stage III and high-risk stage II colon cancer. Sex is one of several factors responsible for the wide inter-patient variability in drug responses. Amalgamated data on the effect of sex on the toxicity of current standard adjuvant treatment for colorectal cancer are missing.

METHODS

The objective of our study was to compare incidence and severity of major toxicities of fluoropyrimidine- (5FU or capecitabine) based adjuvant chemotherapy, with or without oxaliplatin, between male and female patients after curative surgery for colon cancer. Adult patients enrolled in 27 relevant randomized trials included in the ACCENT (Adjuvant Colon Cancer End Points) database, a large, multi-group, international data repository containing individual patient data, were included. Comparisons were conducted using logistic regression models (stratified by study and treatment arm) within each type of adjuvant chemotherapy (5FU, FOLFOX, capecitabine, CAPOX, and FOLFIRI). The following major toxicities were compared (grade III or IV and grade I-IV, according to National Cancer Institute Common Terminology Criteria [NCI-CTC] criteria, regardless of attribution): nausea, vomiting, nausea or vomiting, stomatitis, diarrhea, leukopenia, neutropenia, thrombocytopenia, anemia, and neuropathy (in patients treated with oxaliplatin).

RESULTS

Data from 34 640 patients were analyzed. Statistically significant and clinically relevant differences in the occurrence of grade III or IV nonhematological {especially nausea (5FU: odds ratio [OR] = 2.33, 95% confidence interval [CI] = 1.90 to 2.87, P < .001; FOLFOX: OR = 2.34, 95% CI = 1.76 to 3.11, P < .001), vomiting (5FU: OR = 2.38, 95% CI = 1.86 to 3.04, P < .001; FOLFOX: OR = 2.00, 95% CI = 1.50 to 2.66, P < .001; CAPOX: OR = 2.32, 95% CI = 1.55 to 3.46, P < .001), and diarrhea (5FU: OR = 1.35, 95% CI = 1.21 to 1.51, P < .001; FOLFOX: OR = 1.60, 95% CI = 1.35 to 1.90, P < .001; FOLFIRI: OR = 1.57, 95% CI = 1.25 to 1.97, P < .001)} as well as hematological toxicities (neutropenia [5FU: OR = 1.55, 95% CI = 1.37 to 1.76, P < .001; FOLFOX: OR = 1.96, 95% CI = 1.71 to 2.25, P < .001; FOLFIRI: OR = 2.01, 95% CI = 1.66 to 2.43, P < .001; capecitabine: OR = 4.07, 95% CI = 1.84 to 8.99, P < .001] and leukopenia [5FU: OR = 1.74, 95% CI = 1.40 to 2.17, P < .001; FOLFIRI: OR = 1.75, 95% CI = 1.28 to 2.40, P < .001]) were observed, with women being consistently at increased risk.

CONCLUSIONS

Our analysis confirms that women with colon cancer receiving adjuvant fluoropyrimidine-based chemotherapy are at increased risk of toxicity. Given the known sex differences in fluoropyrimidine pharmacokinetics, sex-specific dosing of fluoropyrimidines warrants further investigation.

Clinicopathological and molecular biological characteristics of early-onset stage II/III colorectal adenocarcinoma: An analysis of 25 studies with 47,184 patients (pts) in the adjuvant colon cancer end points (ACCENT) database

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Background: Colorectal cancer (CRC) incidence and mortality has decreased since the 1970s but the incidence is increasing in young adults (age 20-49). The incidence of early onset CRC (eoCRC) will keep increasing significantly based on the trends of the SEER CRC registry data. There is limited data suggesting eoCRC may have different behaviors compared to traditional CRC (tCRC, age ≥ 50). Methods: Individual pt data of 47184 stage II/III CRC pts from 25 randomized studies in the ACCENT database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and treatment-related data were summarized by age group. Overall survival (OS), disease-free survival (DFS), recurrence-free rate (RFR), and survival after recurrence (SAR) were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for stage, performance status (PS), BMI and grade. Results: Using 5% difference between age groups as clinically meaningful cutoff, eoCRC had similar gender, race, ethnicity, PS, risk group, disease sidedness and T stage as tCRC. eoCRC were less likely overweight (30 vs 36%) and more pts had ≥ 12 lymph nodes resected (63 vs 51%). eoCRC had more frequent dMMR status (18 vs 12%), less BRAF mutations (5 vs 13%), and more dMMR/BRAF wild type (WT) status (17 vs 7%). Overall, eoCRC had better OS, DFS, and SAR, with the most significant differences between the < 30 and > = 70 age groups. Similar results were observed within pMMR pts. eoCRC experienced less hematological side effects, diarrhea, and stomatitis, but had more nausea and/or vomiting. Conclusions: eoCRC have unique characteristics; although statistically significant, the clinical differences in outcomes between eoCRC and tCRC are potentially due to the difference seen in extremely young and old pts. eoCRC have a different adverse events panel compared to tCRC. [Table: see text]

Update on optimal treatment for metastatic colorectal cancer from the AGITG expert meeting: ESMO congress 2019

Introduction: Outcomes in metastatic colorectal cancer are improving, due to the tailoring of therapy enabled by better understanding of clinical behavior according to molecular subtype.Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of systemic treatment of metastatic colorectal cancer. This review summarizes expert discussion of the current evidence for therapies in metastatic colorectal cancer (mCRC) based on molecular subgrouping.Expert opinion: EGFR-targeted and VEGF-targeted antibodies are now routinely incorporated into treatment strategies for mCRC. EGFR-targeted antibodies are restricted to patients with extended RAS wild-type profiles, with evidence that they should be further restricted to patients with left-sided tumors. Clinically distinct treatment pathways based on tumor RAS, BRAF, HER2 and MMR status, are now clinically applicable. Evidence suggests therapy for additional subgroups will soon be defined; the most advanced being for patients with KRAS G12 C mutation and gene TRK fusion defects.

Intergroup Randomized Phase III Study of Postoperative Oxaliplatin, 5-Fluorouracil, and Leucovorin Versus Oxaliplatin, 5-Fluorouracil, Leucovorin, and Bevacizumab for Patients with Stage II or III Rectal Cancer Receiving Preoperative Chemoradiation: A Trial of the ECOG-ACRIN Research Group (E5204)

BACKGROUND

The addition of bevacizumab to chemotherapy improved outcomes for patients with metastatic colon cancer. E5204 was designed to test whether the addition of bevacizumab to mFOLFOX6, following neoadjuvant chemoradiation and definitive surgery, could improve overall survival (OS) in patients with stage II/III adenocarcinoma of the rectum.

SUBJECTS, MATERIALS, AND METHODS

Patients with stage II/III rectal cancer who had completed neoadjuvant 5-fluorouracil-based chemoradiation and had undergone complete resection were enrolled. Patients were randomized to mFOLFOX6 (Arm A) or mFOLFOX6 with bevacizumab (Arm B) administered every 2 weeks for 12 cycles.

RESULTS

E5204 registered only 355 patients (17% of planned accrual goal) as it was terminated prematurely owing to poor accrual. At a median follow-up of 72 months, there was no difference in 5-year overall survival (88.3% vs. 83.7%) or 5-year disease-free survival (71.2% vs. 76.5%) between the two arms. The rate of treatment-related grade ≥ 3 adverse events (AEs) was 68.8% on Arm A and 70.7% on Arm B. Arm B had a higher proportion of patients who discontinued therapy early as a result of AEs and patient withdrawal than did Arm A (32.4% vs. 21.5%, p = .029).The most common grade 3-4 treatment-related AEs were neutropenia, leukopenia, neuropathy, diarrhea (without prior colostomy), and fatigue.

CONCLUSION

At 17% of its planned accrual, E5204 did not meet its primary endpoint. The addition of bevacizumab to FOLFOX6 in the adjuvant setting did not significantly improve OS in patients with stage II/III rectal cancer.

IMPLICATIONS FOR PRACTICE

At 17% of its planned accrual, E5204 was terminated early owing to poor accrual. At a median follow-up of 72 months, there was no significant difference in 5-year overall survival (88.3% vs. 83.7%) or in 5-year disease-free survival (71.2% vs. 76.5%) between the two arms. Despite significant advances in the treatment of rectal cancer, especially in improving local control rates, the risk of distant metastases and the need to further improve quality of life remain a challenge. Strategies combining novel agents with chemoradiation to improve both distant and local control are needed.

Targeted therapy for metastatic colorectal cancer

INTRODUCTION

Outcomes in metastatic colorectal cancer are improving, with better understanding and use of targeted therapies. Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of systemic treatment of metastatic colorectal cancer. This article reviews the current evidence for targeted therapies in advanced colorectal cancer, including up-to-date data regarding anti-epidermal growth factor receptor (EGFR) and anti-vascular endothelial growth factor (VEGF) agents, the relevance of primary tumor location and novel subgroups such as BRAF mutated, HER2 amplified, and mismatch-repair-deficient cancers. Expert commentary: EGFR-targeted and VEGF-targeted antibodies are now routinely incorporated into treatment strategies for metastatic colorectal cancer (mCRC). The use of EGFR-targeted antibodies should be restricted to patients with extended RAS wild-type profiles, and there is evidence that they should be further restricted to patients with left-sided tumors. Clinically, mCRC can be divided into subgroups based on RAS, BRAF, HER2, and MMR status, each of which have distinct treatment pathways.

Adjuvant Chemoradiotherapy With Epirubicin, Cisplatin, and Fluorouracil Compared With Adjuvant Chemoradiotherapy With Fluorouracil and Leucovorin After Curative Resection of Gastric Cancer: Results From CALGB 80101 (Alliance)

Purpose After curative resection of gastric or gastroesophageal junction adenocarcinoma, Intergroup Trial 0116 (Phase III trial of postoperative adjuvant radiochemotherapy for high risk gastric and gastroesophageal junction adenocarcinoma: Demonstrated superior survival for patients who received postoperative chemoradiotherapy with bolus fluorouracil (FU) and leucovorin (LV) compared with surgery alone. CALGB 80101 (Alliance; Phase III Intergroup Trial of Adjuvant Chemoradiation After Resection of Gastric or Gastroesophageal Adenocarcinoma) assessed whether a postoperative chemoradiotherapy regimen that replaced FU plus LV with a potentially more active systemic therapy could further improve overall survival. Patients and Methods Between April 2002 and May 2009, 546 patients who had undergone a curative resection of stage IB through IV (M0) gastric or gastroesophageal junction adenocarcinoma were randomly assigned to receive either postoperative FU plus LV before and after combined FU and radiotherapy (FU plus LV arm) or postoperative epirubicin, cisplatin, and infusional FU (ECF) before and after combined FU and radiotherapy (ECF arm). Results With a median follow-up duration of 6.5 years, 5-year overall survival rates were 44% in the FU plus LV arm and 44% in the ECF arm ( P_logrank = .69; multivariable hazard ratio, 0.98; 95% CI, 0.78 to 1.24 comparing ECF with FU plus LV). Five-year disease-free survival rates were 39% in the FU plus LV arm and 37% in the ECF arm ( P_logrank = .94; multivariable hazard ratio, 0.96; 95% CI, 0.77 to 1.20). In post hoc analyses, the effect of treatment seemed to be similar across all examined patient subgroups. Conclusion After a curative resection of gastric or gastroesophageal junction adenocarcinoma, postoperative chemoradiotherapy using a multiagent regimen of ECF before and after radiotherapy does not improve survival compared with standard FU and LV before and after radiotherapy.

Update on optimal treatment for metastatic colorectal cancer from the ACTG/AGITG expert meeting: ECCO 2015

The treatment of metastatic CRC (mCRC) has evolved over the last 20 years, from fluoropyrimidines alone to combination chemotherapy and new biologic agents. Median overall survival is now over 24 months for RAS mutated (MT) patients and over 30 months for RAS wild-type (WT) patients. However, there are subgroups of patients with BRAF V600E MT CRC who have a significantly poorer outlook. Newer treatment options are also being explored in select subgroups of patients (anti-HER 2 in HER2 positive mCRC and immunotherapy in patients with defective mismatch repair (dMMR)). The best use of these systemic treatment options, as well as surgery in well-selected patients requires careful consideration of predictive biomarkers and importantly, the optimal sequence in which therapies should be given to derive maximal benefit. A group of colorectal subspecialty medical oncologists from Australia, USA, The Netherlands and Germany met during ECCO 2015 in Vienna to review current practice.

Treatment sequence of synchronously (liver) metastasized colon cancer

No standards for staging, systemic therapy or the timing of an operation are defined for patients newly diagnosed with synchronous metastases and a primary in the colon. An expert group of radiologists, medical, radiation and surgical oncologists therefore came together to discuss staging and treatment sequence for these patients and came up with a recommendation based on current evidence of potential therapeutic options. The discussion was organized to debate recommendations centred on 5 topics and therefore the position paper is built upon these titles and their subtitles.

Determinants of Early Mortality Among 37,568 Patients With Colon Cancer Who Participated in 25 Clinical Trials From the Adjuvant Colon Cancer Endpoints Database

PURPOSE

Factors associated with early mortality after surgery and treatment with adjuvant chemotherapy in colon cancer are poorly understood. We aimed to characterize the determinants of early mortality in a large cohort of colon cancer trial participants.

METHODS

A pooled analysis of 37,568 patients in 25 randomized trials of adjuvant systemic therapy was conducted. Multivariable logistic regression models with several definitions of early mortality (30, 60, and 90 days, and 6 months) were constructed, adjusting for clinically and statistically significant variables. A nomogram for 6-month mortality was developed and validated.

RESULTS

Median age among patients was 61 years, patient demographics included 54% men and 90% White, 29% and 71% had stage II and III disease, respectively, and 79%, 20%, and 1% had an Eastern Cooperative Oncology Group performance status (PS) of 0, 1, and ≥ 2, respectively. Early mortality was low: 0.3% at 30 days, 0.6% at 60 days, 0.8% at 90 days, and 1.4% at 6 months. Of those patients who died by 6 months post-random assignment, 40% had documented disease recurrence prior to death. Early disease recurrence was associated with a markedly increased risk of death during the first 6 months post-treatment (hazard ratio, 82.6; 95%CI, 66.9 to 102.1). In prognostic analyses, advanced age, male sex, poorer PS, increasing ratio of positive to examined lymph nodes, earlier decade of enrollment, and higher tumor stage and grade predicted a greater likelihood of early mortality, whereas treatment received was not strongly predictive. A multivariable model for 6-month mortality showed strong optimism-adjusted discrimination (concordance index, 0.73) and calibration.

CONCLUSION

Early mortality was infrequent but more prevalent in patients with advanced age and a PS of ≥ 2, underscoring the need to carefully consider the risk-to-benefit ratio when making treatment decisions in these subgroups.

Impact of Patient Factors on Recurrence Risk and Time Dependency of Oxaliplatin Benefit in Patients With Colon Cancer: Analysis From Modern-Era Adjuvant Studies in the Adjuvant Colon Cancer End Points (ACCENT) Database

PURPOSE

Fluorouracil plus leucovorin (FU + LV) adjuvant chemotherapy reduced the risk of recurrence and death across all time points in a pooled analysis of 20,898 patients with colon cancer from 18 randomized studies. The impact of oxaliplatin added to FU + LV on the time course of recurrence and survival remains unknown.

PATIENTS AND METHODS

A total of 12,233 patients enrolled to the randomized trials C-07, C-08, N0147, MOSAIC (Adjuvant Treatment of Colon Cancer), and XELOXA (Adjuvant XELOX) were pooled to examine the impact of oxaliplatin and tumor-specific factors on the time course of recurrence and death. For each end point, continuous-time risk was modeled over 6 years post treatment in all oxaliplatin-treated patients and patients concurrently randomized to FU + LV with or without oxaliplatin; the latter analyses supported time-dependent treatment comparisons.

RESULTS

Addition of oxaliplatin significantly reduced the risk of recurrence within the first 14 months post treatment for patients with stage II disease and within the first 4 years for patients with stage III disease. Oxaliplatin also significantly reduced risk of death from 2 to 6 years post treatment for patients with stage III disease, with no differences in timing of outcomes between treatment groups (ie, oxaliplatin did not simply postpone recurrence or death compared with FU + LV alone). Patients with stage II disease receiving oxaliplatin did not exhibit a significant reduction in risk of death in the first 6 years post treatment. Recurrence risk peaked near 14 months for both treatments, and risk of recurrence and death increased with increased tumor and nodal burden.

CONCLUSIONS

These analyses support the addition of oxaliplatin to fluoropyrimidine-based adjuvant therapy in patients with stage III disease and underscore the need for adequate surveillance of patients with colon cancer during the first 3 years after adjuvant therapy.

Capecitabine Plus Oxaliplatin Compared With Fluorouracil/Folinic Acid As Adjuvant Therapy for Stage III Colon Cancer: Final Results of the NO16968 Randomized Controlled Phase III Trial

PURPOSE

To report the final efficacy findings and biomarker analysis from the NO16968 trial comparing bolus fluorouracil/folinic acid (FU/FA) with capecitabine plus oxaliplatin (XELOX) in resected stage III colon cancer.

PATIENTS AND METHODS

After curative resection, patients were randomly assigned to receive XELOX, as oxaliplatin 130 mg/m(2) on day 1 and capecitabine 1,000 mg/m(2) twice daily on days 1 to 14 every 3 weeks, or bolus FU/FA, as the Mayo Clinic or Roswell Park regimens, for 6 months. The primary end point was disease-free survival (DFS). Secondary end points included overall survival (OS).

RESULTS

The intention-to-treat population comprised 1,886 patients (XELOX, n = 944; FU/FA, n = 942). Seven-year DFS rates were 63% and 56% in the XELOX and FU/FA groups, respectively (hazard ratio [HR], 0.80; 95% CI, 0.69 to 0.93; P = .004). Seven-year OS rates were 73% and 67% in the XELOX and FU/FA groups, respectively (HR, 0.83; 95% CI, 0.70 to 0.99; P = .04). A total of 68% and 77% of patients who experienced relapse or a new colorectal cancer in the XELOX and FU/FA groups, respectively, received drug treatment for metastatic disease. Four hundred ninety-eight patients consented to the biomarker analysis: 242 in the XELOX group and 256 in the FU/FA group. Low tumor expression of dihydropyrimidine dehydrogenase may be predictive for XELOX efficacy; in the XELOX group, for high versus low dihydropyrimidine dehydrogenase expression levels, DFS HR was 2.45 (95% CI, 1.55 to 3.86; P < .001), and OS HR was 2.75 (95% CI, 1.65 to 4.59; P < .001). In the FU/FA group, no statistically significant associations were observed between any tumor biomarker and outcomes.

CONCLUSION

XELOX improved OS compared with bolus FU/FA in patients with resected stage III colon cancer after a median follow-up of almost 7 years. XELOX should be considered a standard adjuvant treatment option in patients with stage III disease. Tumoral dihydropyrimidine dehydrogenase expression is a promising predictive, and potentially, highly clinically relevant, biomarker for XELOX efficacy requiring further prospective evaluation.

Impact of age and medical comorbidity on adjuvant treatment outcomes for stage III colon cancer: a pooled analysis of individual patient data from four randomized, controlled trials

BACKGROUND

Adjuvant oxaliplatin plus capecitabine or leucovorin/5-fluorouracil (LV/5-FU) (XELOX/FOLFOX) is the standard of care for stage III colon cancer (CC); however, there is disagreement regarding oxaliplatin benefit in patients aged >70. In most analyses, the impact of medical comorbidity (MC) has not been assessed. Efficacy and safety of adjuvant XELOX/FOLFOX versus LV/5-FU were compared with respect to age and MC using pooled data from four randomized, controlled trials, selected for access to patient-level MC data and including commonly endorsed and utilized regimens.

PATIENTS AND METHODS

Individual data from patients with stage III CC in NSABP C-08, XELOXA, X-ACT, and AVANT were pooled, excluding bevacizumab-treated patients. Patients were grouped by treatment, MC (low versus high), or age (<70 versus ≥70), and compared for disease-free survival (DFS), overall survival (OS), and adverse events (AEs). Multivariable Cox proportional hazards regression controlled for gender, T stage, and N stage.

RESULTS

DFS benefits were shown for XELOX/FOLFOX versus LV/5-FU regardless of age or MC, although benefits were modestly attenuated for patients aged ≥70. Hazard ratios were 0.68 (P < 0.0001) and 0.77 (P < 0.014) for <70 and ≥70 age groups; 0.69 (P < 0.0001) and 0.59 (P < 0.0001) for Charlson Comorbidity Index ≤1 and >1 groups; and 0.70 (P < 0.0001) and 0.58 (P < 0.0001) for National Cancer Institute Combined Index ≤1 and >1 groups. OS was also significantly improved in all groups. Grade 3/4 serious AE rates were comparable across cohorts and MC scores and higher in patients aged ≥70. Oxaliplatin-relevant grade 3/4 AEs, including neuropathy, were comparable across ages and MC scores.

CONCLUSIONS

Results further support consideration of XELOX or FOLFOX as standard treatment options for the adjuvant management of stage III CC in all age groups and in patients with comorbidities, consistent with those who were eligible for these clinical trials.

Survival following early-stage colon cancer: an ACCENT-based comparison of patients versus a matched international general population†

BACKGROUND

Post-treatment survival experience of early colon cancer (CC) patients is well described in the literature, which states that cure is probable for some patients. However, comparisons of treated patients' survival versus that expected from a matched general population (MGP) are limited.

PATIENTS AND METHODS

A total of 32 745 patients from 25 randomized adjuvant trials conducted from 1977 to 2012 in 41 countries were pooled. Observed long-term survival of these patients was compared with expected survival matched on sex, age, country, and year, both overall and by stage (II and III), sex, treatment [surgery, 5-fluorouracil (5-FU), 5-FU + oxaliplatin], age (<70 and 70+), enrollment year (pre/post 2000), and recurrence (yes/no). Comparisons were made at randomization and repeated conditional on survival to 1, 2, 3, and 5 years. CC and MGP equivalence was tested, and observed Kaplan-Meier survival rates compared with expected MGP rates 3 years out from each landmark. Analyses were also repeated in patients without recurrence.

RESULTS

Within most cohorts, long-term survival of CC patients remained statistically worse than the MGP, though conditional survival generally improved over time. Among those surviving 5 years, stage II, oxaliplatin-treated, elderly, and recurrence-free patients achieved subsequent 3-year survival rates within 5% of the MGP, with recurrence-free patients achieving equivalence.

CONCLUSIONS

Conditional on survival to 5 years, long-term survival of most CC patients on clinical trials remains modestly poorer than an MGP, but achieves MGP levels in some subgroups. These findings emphasize the need for access to quality care and improved treatment and follow-up strategies.

Current opinion on optimal systemic treatment for metastatic colorectal cancer: outcome of the ACTG/AGITG expert meeting ECCO 2013

The treatment of metastatic colorectal cancer has evolved greatly in the last 15 years, involving combined chemotherapy protocols and, in more recent times, new biologic agents. Clinical benefit from the use of targeted therapy with bevacizumab, aflibercept, cetuximab, panitumumab and regorafenib in the treatment of metastatic colorectal cancer is now well established with median overall survival accepted as over 24 months, and with super selection for extended RAS patients higher again. The optimal timing of treatment options requires careful consideration of predictive biomarkers, and importantly the potential for interactions, to derive the maximal benefit. A group of colorectal subspecialty medical oncologists from Australia, the USA, the Netherlands and Germany met during ECCO 2013 to discuss current practice. Subsequent new data from the American Society of Clinical Oncology were also reviewed. This article reviews the evidence discussed in support of modern treatments for colorectal cancer and the decision-making behind the treatment choices, with their benefits and risks.

Current opinion on optimal treatment for colorectal cancer

The medical treatment of colorectal cancer (CRC) has evolved greatly in the last 10 years, involving complex combined chemotherapy protocols and, in more recent times, new biologic agents. Advances in adjuvant therapy have been limited to the addition of oxaliplatin and the substitution of oral fluoropyrimidine (e.g., capecitabine) for intravenous 5-fluorouracil with no evidence for improved outcome with biological agents. Clinical benefit from the use of the targeted monoclonal antibodies, bevacizumab, cetuximab and panitumumab, in the treatment of metastatic CRC is now well established, but the optimal timing of their use requires careful consideration to derive the maximal benefit. Evidence to date suggests potentially distinct roles for bevacizumab and EGF receptor-targeted biological agents (cetuximab and panitumumab) in the treatment of metastatic CRC. This article reviews the evidence in support of modern treatments for CRC and the decision-making behind the treatment choices, their benefits and toxicities.

Comparison of outcomes after fluorouracil-based adjuvant therapy for stages II and III colon cancer between 1978 to 1995 and 1996 to 2007: evidence of stage migration from the ACCENT database

PURPOSE

With improved patient care, better diagnosis, and more treatment options after tumor recurrence, outcomes after fluorouracil (FU) -based treatment are expected to have improved over time in early-stage colon cancer. Data from 18,449 patients enrolled onto 21 phase III trials conducted from 1978 to 2002 were evaluated for potential differences in time to recurrence (TTR), time from recurrence to death (TRD), and overall survival (OS) with regard to FU-based adjuvant regimens.

METHODS

Trials were predefined as old versus newer era using initial accrual before or after 1995. Outcomes were compared between patients enrolled onto old- or newer-era trials, stratified by stage.

RESULTS

Within the first 3 years, recurrence rates were lower in newer- versus old-era trials for patients with stage II disease, with no differences among those with stage III disease. Both TRD and OS were significantly longer in newer-era trials overall and within each stage. The lymph node (LN) ratio (ie, number of positive nodes divided by total nodes harvested) in those with stage III disease declined over time. TTR improved slightly, with larger number of LNs examined in both stages.

CONCLUSION

Improved TRD in newer trials supports the premise that more aggressive intervention (oxaliplatin- and irinotecan-based chemotherapy and/or surgery for recurrent disease) improves OS for patients previously treated in the adjuvant setting. Lower recurrence rates with identical treatments in those with stage II disease enrolled onto newer-era trials reflect stage migration over time, calling into question historical data related to the benefit of FU-based adjuvant therapy in such patients.

Impact of age on the efficacy of newer adjuvant therapies in patients with stage II/III colon cancer: findings from the ACCENT database

PURPOSE

Prior studies have suggested that patients with stage II/III colon cancer receive similar benefit from intravenous (IV) fluoropyrimidine adjuvant therapy regardless of age. Combination regimens and oral fluorouracil (FU) therapy are now standard. We examined the impact of age on colon cancer recurrence and mortality after adjuvant therapy with these newer options.

PATIENTS AND METHODS

We analyzed 11,953 patients age < 70 and 2,575 age ≥ 70 years from seven adjuvant therapy trials comparing IV FU with oral fluoropyrimidines (capecitabine, uracil, or tegafur) or combinations of fluoropyrimidines with oxaliplatin or irinotecan in stage II/III colon cancer. End points were disease-free survival (DFS), overall survival (OS), and time to recurrence (TTR).

RESULTS

In three studies comparing oxaliplatin-based chemotherapy with IV FU, statistically significant interactions were not observed between treatment arm and age (P interaction = .09 for DFS, .05 for OS, and .36 for TTR), although the stratified point estimates suggested limited benefit from the addition of oxaliplatin in elderly patients (DFS hazard ratio [HR], 0.94; 95% CI, 0.78 to 1.13; OS HR, 1.04; 95% CI, 0.85 to 1.27). No significant interactions by age were detected with oral fluoropyrimidine therapy compared with IV FU; noninferiority was supported in both age populations.

CONCLUSION

Patients age ≥ 70 years seemed to experience reduced benefit from adding oxaliplatin to fluoropyrimidines in the adjuvant setting, although statistically, there was not a significant effect modification by age, whereas oral fluoropyrimidines retained their efficacy.

Adjuvant therapy of stage III colon cancer

The decision for adjuvant therapy of colon cancer by both physicians and patients requires many factors, including knowledge of the risk for recurrence (prognosis), the likelihood of significant clinical benefit (prediction), toxicity of treatment, comorbidities, and the patient's understanding and acceptance of both the relative and absolute benefit of therapy. To predict the risk of recurrence, clinicopathologic features have typically been used such as the number of positive and negative nodes, T stage, tumor differentiation, obstruction and lymphovascular invasion. More recent quantitative prognostic markers include microsatellite instability, with MSI-H conferring better prognosis. In addition, in combination with MSI, gene expression profiles have been developed which may be especially helpful in stage II disease, and in some low risk stage III patients to decide on whether they should receive combination chemotherapy, capecitabine or no adjuvant treatment. The standard treatment for most stage III patients is a combination of oxaliplatin with infusional and bolus 5-FU (FOLFOX) or with an oral agent such as capecitabine (XELOX), with equivalent results. Although irinotecan is active in advanced colorectal cancer, two trials of this drug with 5-FU failed to show improvement over the fluoropyrimidines alone. The antiangiogenic agent bevacizumab also failed to improve treatment compared to FOLFOX alone, as did the EGFR agent, cetuximab. Studies are currently underway to compare the standard 6 months of FOLFOX with 3 months of therapy, to reduce the risk of neurotoxocity associate with oxaliplatin, while maintaining treatment efficacy.

Phase II Trial of Paclitaxel/Cisplatin Followed by Surgery and Adjuvant Radiation Therapy and 5-Fluorouracil/Leucovorin for Gastric Cancer (ECOG E7296)

BACKGROUND

Randomized trials have shown an increase in survival with perioperative chemotherapy as well as with postoperative chemoradiation. It was hypothesized that combining induction chemotherapy with postoperative chemoradiation would be well tolerated and improve pathologic complete response.

METHODS

Patients with resectable cancers of the stomach/gastroesophageal junction were eligible. Neoadjuvant chemotherapy consisted of 3 cycles of paclitaxel and cisplatin. Adjuvant therapy consisted of 1 cycle of 5-fluorouracil (FU) and leucovorin (LV) followed by chemoradiation (45 Gy with concurrent 5-FU/LV). Chemoradiation was followed by 2 additional cycles of 5-FU/LV. Response to neoadjuvant therapy was based on pathology.

RESULTS

From 1999 to 2002, 38 eligible patients were enrolled; 35 completed induction chemotherapy, and 29 went on to surgery. Sixteen patients did not develop metastatic progression, 10 developed metastatic disease, and 12 were unevaluable. There were no pathologic complete responses after induction therapy. Twenty-five of 38 patients suffered grade 3-4 toxicities during induction paclitaxel/cisplatin. Six of the 7 patients who received postoperative therapy suffered grade 3-4 toxicities. Only 3 of 38 (7.9%) eligible patients completed all assigned treatment. The median overall survival was 1.6 years, and the 2-year survival was 40%.

CONCLUSIONS

This regimen of neoadjuvant paclitaxel/cisplatin followed by postoperative 5-FU/LV-based chemoradiation did not have a high enough response rate and proved to be too toxic for further development.

Impact of age and medical comorbidity (MC) on adjuvant treatment outcomes for stage III colon cancer (CC): A pooled analysis of individual patient data from four randomized controlled trials

3522

Background: Studies show significantly improved disease-free and overall survival (DFS, OS) for oxaliplatin (Ox)-based vs. leucovorin/5-fluorouracil (LV/5-FU) adjuvant therapy in CC, with conflicting reports of Ox benefit in patients > 70 years old. The impact of MC on Ox benefit has not been assessed. We assessed the impact of age and MC on adjuvant treatment outcomes for stage III CC. Methods: N = 4,819 patients from NSABP C-08, XELOXA, X-ACT, and AVANT were analyzed by Ox therapy (XELOX/FOLFOX) vs. LV/5-FU, MC, and age; patients treated with bevacizumab were excluded. Endpoints were DFS (primary), OS, and safety. MC was assessed (except NSABP C-08) by adapted Charlson Comorbidity and NCI Combined Indices (CCI, NCI): Low (≤ 1) vs. high (> 1). Hazardratios (HR) were estimated by Cox regression analyses. Multivariate Cox regression analyses (MVA) tested for independent effects of age and MC on Ox benefit, controlling for gender, T, and N stage. Results: Patient demographics, MC, and disease characteristics (except lymph nodes examined) were well balanced across groups. Median follow-up was shorter in NSABP C-08 and AVANT (36 and 50 months) vs. XELOXA and X-ACT (83 and 74 months). MVA-confirmed DFS/OS benefit was consistently shown for XELOX/FOLFOX vs. LV/5-FU, regardless of age or MC. Grade 3/4 serious adverse event (AE) rates were comparable across cohorts and CCI scores, and higher in patients aged ≥ 70. Grade 3/4 AEs of interest, including peripheral sensory neuropathy, were comparable across ages and CCI scores, and higher with XELOX/FOLFOX. Conclusions: Ox benefit is modestly attenuated in patients aged ≥ 70; however, significant benefit is observed regardless of age or MC in this analysis. Our results further support XELOX or FOLFOX as standard options for the adjuvant management of stage III CC in all age groups. [Table: see text]

Effect of oxaliplatin-based adjuvant therapy on post-relapse survival (PRS) in patients with stage III colon cancer: A pooled analysis of individual patient data from four randomized controlled trials

3523

Background: Oxaliplatin-based adjuvant therapy is the standard of care for stage III colon cancer; however, its impact on PRS in these patients is unclear. We therefore compared PRS in trials of patients with stage III colon cancer treated with oxaliplatin plus capecitabine (XELOX) or 5-flourouracil (5-FU; FOLFOX) vs. leucovorin/5-FU (LV/5-FU). Methods: Individual patientdata (N = 4,819) from NSABP C-08, XELOXA, X-ACT, and AVANT were pooled and analyzed by XELOX/FOLFOX vs. LV/5-FU; patients treated with bevacizumab were excluded. Hazard ratios (HR) were estimated by Cox regression analyses and multivariate Cox regression analyses controlled for age, gender, T, and N stage. Post-relapse treatment data were collected when available. Results: Patient demographics and disease characteristics (except lymph nodes examined) were well balanced across analytic groups. Median follow-up was shorter in NSABP C-08 and AVANT (36 and 50 months) than in XELOXA and X-ACT (83 and 74 months). PRS was very similar for XELOX/FOLFOX and LV/5-FU (HR 0.94, 95% CI, 0.82–1.07; P = .33). Multivariate analyses supported these findings, but showed that PRS was associated with younger age and lower N stage at diagnosis after controlling for gender and T stage. PRS was also comparable for capecitabine or XELOX vs. LV/5-FU or FOLFOX (N = 5,819, HR 1.07, 95% CI, 0.95–1.20; P = .26). Post-relapse therapies were comparable across the two cohorts. Conclusions: Adjuvant chemotherapy regimen did not impact on PRS in patients with stage III colon cancer; however, both N stage and age demonstrated independent effects on PRS. Studies have demonstrated significantly improved disease-free and overall survival for oxaliplatin-based therapy, and our data show that survival is not compromised by worsened PRS at subsequent relapse. [Table: see text]

The role of TP, TS, and DPD as potential predictors of outcome following capecitabine plus oxaliplatin (XELOX) versus bolus 5-fluorouracil/leucovorin (5-FU/LV) as adjuvant therapy for stage III colon cancer: Biomarker findings from study NO16968 (XELOXA)

3578

Background: In NO16968, XELOX was superior in terms of disease-free survival (DFS) and overall survival (OS) to bolus 5-FU/LV as adjuvant therapy for stage III colon cancer (Schmoll et al. ASCO GI 2012). Three key enzymes appear to have the potential to predict efficacy and/or safety of fluoropyrimidine-based treatment: thymidine phosphorylase (TP), thymidylate synthase (TS), and dihydropyrimidine dehydrogenase (DPD). We evaluated the association between baseline TP, TS and DPD and outcome (DFS and OS). Methods: Pts with stage III colon cancer received either XELOX (8 cycles, 24w) or bolus 5-FU/LV (Mayo Clinic, 6 cycles, 24w; Roswell Park, 4 cycles, 32w). The primary study endpoint was DFS; secondary endpoints included OS. TP, TS and DPD expression levels were determined in formalin-fixed, paraffin-embedded tissues by RT-PCR, and the median used as a cut-off point: high (above median) vs. low (below median). Results: The biomarker population included 498 (26%) of 1886 pts entered (XELOX, n=242; 5-FU/LV, n=256). Baseline demographics, tumor characteristics, cancer history and efficacy (DFS and OS) were similar to those in the main study population. Cox regression analysis for DFS (Table). In the XELOX group pts with low DPD and TP levels and a high TP/DPD ratio appeared to have significantly better DFS; this effect was not observed with 5-FU/LV. Subgroup analysis shows that the difference between XELOX and 5-FU/LV was also higher in pts with low DPD levels. Conclusions: These exploratory findings suggest that tumor DPD and TP RNA levels could be used to predict outcomes of adjuvant treatment with fluoropyrimidine/oxaliplatin combinations, and should be validated prospectively. Analysis of the current dataset is ongoing and further details on potential biomarkers will be available. [Table: see text]

Comparative evaluation of capecitabine or infusional leucovorin/5-fluorouracil (LV/5-FU) with or without oxaliplatin (Ox) for stage III colon cancer (CC): A pooled analysis of individual patient data from four randomized controlled trials

3525

Background: A fluoropyrimidine + Ox is the standard of care for stage III CC but a fluoropyrimidine alone is recommended for selected patients in several practice guidelines. We assessed efficacy and safety of adjuvant capecitabine ± Ox vs. LV/5-FU ± Ox across a population of stage III CC patients enrolled in four trials. Methods: N = 5,819 patients from NSABP C-08, XELOXA, X-ACT, and AVANT were pooled and analyzed; bevacizumab-treated patients were excluded. Endpoints were disease-free survival (DFS, primary), relapse-free survival (RFS), overall survival (OS), and safety. Multivariate Cox regression analyses (MVA) controlled for age, gender, T, and N stage. Results: Patient demographics and disease characteristics (except lymph nodes examined) were well balanced across groups. The number of patients receiving capecitabine and LV/5-FU were 1,942 and 3,877, respectively. Median follow-up was shorter in NSABP C-08 and AVANT (36 and 50 months) vs. XELOXA and X-ACT (83 and 74 months). Five-year DFS was 62.8% for capecitabine ± Ox and LV/5-FU ± Ox. The capecitabine by Ox interaction was significant for OS with a trend for DFS and RFS; likely due to improved outcomes with capecitabine alone and similar outcomes for capecitabine or LV/5-FU + Ox. Serious adverse event (AE) rates were similar for LV/5-FU- and capecitabine-based therapy (16% vs. 20%, respectively). Overall, treatment-related grade 3/4 AEs were more common with LV/5-FU (59% vs. 47%). Treatment-related grade 3/4 AEs of interest included peripheral sensory neuropathy (5% vs. < 1%), diarrhea (12% vs. 15%), febrile neutropenia (2% vs. < 1%), and hand–foot syndrome (< 1% vs. 12%). Conclusions: Adjuvant capecitabine ± Ox and LV/5-FU ± Ox show comparableefficacy benefits for the treatment of stage III CC; further supporting capecitabine or LV/5-FU-based regimens as standard options for the adjuvant therapy of stage III CC. [Table: see text]

Updated analysis of SWOG-directed intergroup study 0116: a phase III trial of adjuvant radiochemotherapy versus observation after curative gastric cancer resection

PURPOSE

Surgical resection of gastric cancer has produced suboptimal survival despite multiple randomized trials that used postoperative chemotherapy or more aggressive surgical procedures. We performed a randomized phase III trial of postoperative radiochemotherapy in those at moderate risk of locoregional failure (LRF) following surgery. We originally reported results with 4-year median follow-up. This update, with a more than 10-year median follow-up, presents data on failure patterns and second malignancies and explores selected subset analyses.

PATIENTS AND METHODS

In all, 559 patients with primaries ≥ T3 and/or node-positive gastric cancer were randomly assigned to observation versus radiochemotherapy after R0 resection. Fluorouracil and leucovorin were administered before, during, and after radiotherapy. Radiotherapy was given to all LRF sites to a dose of 45 Gy.

RESULTS

Overall survival (OS) and relapse-free survival (RFS) data demonstrate continued strong benefit from postoperative radiochemotherapy. The hazard ratio (HR) for OS is 1.32 (95% CI, 1.10 to 1.60; P = .0046). The HR for RFS is 1.51 (95% CI, 1.25 to 1.83; P < .001). Adjuvant radiochemotherapy produced substantial reduction in both overall relapse and locoregional relapse. Second malignancies were observed in 21 patients with radiotherapy versus eight with observation (P = .21). Subset analyses show robust treatment benefit in most subsets, with the exception of patients with diffuse histology who exhibited minimal nonsignificant treatment effect.

CONCLUSION

Intergroup 0116 (INT-0116) demonstrates strong persistent benefit from adjuvant radiochemotherapy. Toxicities, including second malignancies, appear acceptable, given the magnitude of RFS and OS improvement. LRF reduction may account for the majority of overall relapse reduction. Adjuvant radiochemotherapy remains a rational standard therapy for curatively resected gastric cancer with primaries T3 or greater and/or positive nodes.

Capecitabine plus oxaliplatin (XELOX) versus bolus 5-fluorouracil/leucovorin (5-FU/LV) as adjuvant therapy for stage III colon cancer: Survival follow-up of study NO16968 (XELOXA)

388

Background: The MOSAIC trial demonstrated that adding oxaliplatin to 5-FU/LV (FOLFOX4) improved 3-year disease-free survival (DFS) compared to infusional and bolus 5-FU/LV as adjuvant therapy in patients (pts) with stage II/III colon cancer [André et al. NEJM 2004]. A significant survival advantage for FOLFOX4 versus 5-FU/LV was not evident until after median duration of follow-up had exceeded 6 years [André et al. JCO 2009]. Study NO16968 demonstrated that XELOX was superior to bolus 5-FU/LV as adjuvant therapy in pts with stage III colon cancer in terms of DFS at 57 months median follow-up (HR 0.80; 95% CI 0.69–0.93; p=0.0045) [Haller et al. JCO 2011]. The difference between treatment groups in overall survival (OS) was not significant at 59 months median follow-up (HR=0.87; p=0.1486). Data from the planned final analysis of NO16968 are presented.

Methods: Pts with resected stage III colon cancer were randomized to receive XELOX (8 cycles, 24w) or bolus 5-FU/LV (Mayo Clinic, 6 cycles; 24w or Roswell Park, 4 cycles; 32w). The primary study endpoint was DFS. Secondary endpoints included OS.

Results: The ITT population included 1886 pts (XELOX, n=944; 5-FU/LV, n=942). After a median follow-up of 74 months, the HR (XELOX vs 5-FU/LV) for DFS was 0.80 (95% CI 0.69–0.93; p=0.0038). Seven-year DFS rates were 63% for XELOX and 56% for 5-FU/LV. After a median follow-up of 83 months, the HR for OS was 0.83 (95% CI 0.70–0.99; p=0.0367). Absolute 7-year OS rates were 73% with XELOX and 67% with 5-FU/LV. After adjusting for stratification and prognostic variables, HRs remained essentially unchanged for both DFS (0.79; 95% CI 0.68–0.91; p=0.0016) and OS (0.84; 95% CI 0.71–1.00; p=0.0477). Locoregional / systemic treatments after recurrence were given in 230 (24%) XELOX pts and 308 (33%) 5-FU/LV pts.

Conclusions: The combination of oxaliplatin and capecitabine improves OS significantly compared with 5-FU/LV in the adjuvant treatment of stage III colon cancer after a median follow-up of 83 months; these data are comparable to those achieved with FOLFOX4 in the MOSAIC trial. XELOX is an effective adjuvant therapy option for pts with resected stage III colon cancer.

Resection status, age and nodal involvement determine survival among patients receiving adjuvant chemoradiotherapy in pancreatic adenocarcinoma

CONTEXT

Pancreas cancer can potentially be cured by resection, but the role of adjuvant chemotherapy and/or chemoradiation has been controversial.

OBJECTIVES

To better define clinicopathological factors that may serve as predictive and/or prognostic variables.

PATIENTS

Between 1984 and 2006, we retrospectively analyzed 91 patients with pancreas cancer treated with pancreaticoduodenectomy or total pancreatectomy followed by adjuvant 5-fluorouracil-based chemoradiation at the University of Pennsylvania. Final pathological coding including margin status was confirmed by a pathologist.

INTERVENTIONS

Patients were treated with 48.6 to 63.0 Gy, and 96.7% completed their prescribed radiation dose.

MAIN OUTCOME MEASURES

The prognostic significance of demographic factors, stage, year of surgery, tumor location, grade, resection status, and number of positive lymph nodes on overall survival were examined.

RESULTS

With a median follow-up of 6.5 years, the overall median survival was 2.3 years (95% CI 1.5-3.2 years), and the 5-year overall survival was 28.9%. In multivariate analysis, completeness of resection (P<0.001), fewer number of positive lymph nodes (0 vs. 1-2 vs. 3 or more) (P=0.004), and age less than, or equal to, 60 years (P=0.006) were all independently associated with improved overall survival. The overall survival reported in this study compares favorably with the results of other single-institution studies and with the RTOG 97-04 trial.

CONCLUSIONS

Adjuvant 5-FU-based chemoradiation following radical pancreatectomy can be delivered safely and results in comparatively good overall survival. The results of this analysis underscore the importance of resection status, number of involved lymph nodes and patient age as prognostic characteristics. These factors may be considered stratification variables for future post-pancreatectomy adjuvant therapy trials.