Haller, Daniel G.

PURPOSE Several lines of treatment can be used sequentially in patients with metastatic colorectal cancer. We investigated the evolution of patient/tumor characteristics and their prognostic impact across treatment lines to develop an overall prognostic score (OPS). PATIENTS AND METHODS Individual patient data from 48 randomized trials were analyzed. The end point was overall survival (from random assignment to death). Missing data were imputed. The complete data set was then separated into construction (80%) and validation sets (20%). The Cox's model was used to define risk groups for survival using the OPS. The discrimination capability was assessed in each treatment-line via bootstrapping to obtain optimism-corrected calibration and discrimination C-indices. Internal validation was done in the validation set. RESULTS A total of 37,560 patients (26,974 in first-line [1L], 7,693 in second-line [2L], and 2,893 in third-line [3L]) were analyzed. Some clinical, biological, and molecular characteristics of patients/tumors included in therapeutic trials evolve over the lines. Seven independent prognostic variables were retained in the final multivariate model common to all lines: Eastern Cooperative Oncology Group performance status, hemoglobin, platelet count, WBC/absolute neutrophil count ratio, lactate dehydrogenase, alkaline phosphatase, and the number of metastatic sites. The OPS was used to define four patient subgroups with significantly different prognoses in 1L, 2L, and 3L, separately, with adequate C-indices: 0.65, 0.66, and 0.69 in the construction set and 0.65, 0.66, and 0.68 in the validation set, respectively. The OPS was not predictive, with 3L drugs ( v placebo) or subsequent line (2L/1L or 3L/2L) extending survival in all prognostic groups. CONCLUSION The same prognostic model using practical variables can be used before all treatment lines. The OPS could better stratify patients in future clinical trials and help to therapeutic decision in routine practice.

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.

3606 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]

11 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.

Abstract Background Colon cancer (CC) incidence in young adults (age 20-49 years), termed early-onset CC (EO-CC), is increasing. Methods Individual patient data on 35 713 subjects with stage III colon cancer from 25 randomized studies in the Adjuvant Colon Cancer ENdpoint database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and outcome data were summarized by age group. Overall survival, disease-free survival, time to recurrence, and survival after recurrence were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for sex, race, body mass index, performance status, disease stage, grade, risk group, number of lymph nodes examined, disease sidedness, and molecular markers. All statistical tests were 2-sided. Results Using a 5% difference between age groups as the clinically meaningful cutoff, patients with stage III EO-CC had similar sex, race, performance status, risk group, tumor sidedness, and T stage compared with patients with late-onset CC (age 50 years and older). EO-CC patients were less likely to be overweight (30.2% vs 36.2%) and more commonly had 12 or more lymph nodes resected (69.5% vs 58.7%). EO-CC 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 rate of Lynch syndrome in EO-CC. Patients with EO-CC had statistically significantly better overall survival (hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.74 to 0.89; P &lt; .001), disease-free survival (HR = 0.91, 95% CI = 0.84 to 0.98; P = .01), and survival after recurrence (HR = 0.88, 95% CI = 0.80 to 0.97; P = .008) in the analysis without molecular markers; however, age at onset of CC lost its prognostic value when outcome was adjusted for molecular markers. Conclusion Tumor biology was found to be a more important prognostic factor than age of onset among stage III colon cancer patients in the Adjuvant Colon Cancer ENdpoint database.

3597 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]

3575 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]

PURPOSE: In patients with stage III colon cancer (CC) whose tumors demonstrate microsatellite instability (MSI), the efficacy of adjuvant fluoropyrimidine (FP) with or without oxaliplatin has not been clearly demonstrated and the prognostic value of MSI remains uncertain. MATERIALS AND METHODS: Individual patient data from the ACCENT database were used to evaluate the effect of FP with or without oxaliplatin on disease-free survival (DFS) and overall survival (OS) among patients with MSI stage III CC and the prognostic value of MSI in patients treated with FP plus oxaliplatin, by stratified Cox models adjusted for demographic and clinicopathological factors. RESULTS: MSI status was available for 5,457 patients (609 MSI, 11.2%; 4848 microsatellite stable [MSS], 88.8%) from 12 randomized clinical trials (RCTs). Oxaliplatin significantly improved OS of MSI patients from the two RCTs testing FP with or without oxaliplatin (n = 185; adjusted hazard ratio [aHR] = 0.52, 95% CI, 0.28 to 0.93). Among the 4,250 patients treated with FP plus oxaliplatin (461 MSI and 3789 MSS), MSI was associated with better OS in the N1 group compared with MSS (aHR = 0.66; 95% CI, 0.46 to 0.95) but similar survival in the N2 population (aHR = 1.13; 95% CI, 0.86 to 1.48; P interaction = .029). The main independent prognosticators of MSI patients treated with FP plus oxaliplatin were T stage (aHR = 2.09; 95% CI, 1.29 to 3.38) and N stage (aHR = 3.57; 95% CI, 2.32 to 5.48). Similar results were observed for DFS in all analyses. CONCLUSION: Adding oxaliplatin to FP improves OS and DFS in patients with MSI stage III CC. Compared with MSS, MSI patients experienced better outcomes in the N1 group but similar survival in the N2 group.

4515 Background: INT0116 (SWOG 9008) was a prospectively randomized phase III trial of postoperative adjuvant therapy utilizing 5-FU/leucovorin plus external beam radiation in 582 eligible cases of resected stage IB-IV(M0) stomach and gastroesophageal junction cancers. Initial results (NEJM 345: 725, 2001) showed both overall and disease free survivals improved by chemoradiation. Methods:We now report INT0116 results with >10years median follow-up. Exploratory subset outcomes are also reported. Results: INT0116 continues to show benefit for chemoradiation with hazard ratios (HR) for survival (HR=1.32, p=.004) and disease free survival (HR=1.51, p<.001) favoring chemoradiation. Subset analyses were performed for sex, race, T and N stage, D-level of surgical resection, tumor location (proximal or other), histology (intestinal or diffuse) and Maruyama index. Chemoradiation benefited all subsets with the exceptions of women and diffuse histology. In women the HR for therapy was 1.0(0.68–1.45). The HR for therapy in diffuse histology cases was 0.97(0.62–1.40). Interaction between these factors is suggested as women were significantly more likely to have diffuse histology than men (56% versus 33%). A multivariate analysis of sex and histology did not detect an effect of sex once histology was included. These data suggest that sex may not be an independent variable for lack of response to chemoradiation but that diffuse histology may be. Long term toxicities were examined. Thirty-five second tumors occurred in 31 cases. Twenty-two occurred in chemoradiation cases and 9 in surgery only cases. Second tumors represented a spectrum of types of neoplasms commonly occurring in this age group (median age 60 years). Excessive numbers of tumors known to be caused by radiation and/or chemotherapy were not noted. More tumors may have occurred in the treated patients since their death rates were less than surgery only cases. Conclusions: With >10 years median follow-up, survival remains improved in stage IB-IV (M0) gastric cancer cases treated with post-operative chemoradiaiton. All subsets benefit from this treatment with the exception of cases with diffuse histology. Women may be more likely to have diffuse histology gastric cancers. No increases in late toxic effects were noted. No significant financial relationships to disclose.

Abstract 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 &lt; .001; FOLFOX: OR = 2.34, 95% CI = 1.76 to 3.11, P &lt; .001), vomiting (5FU: OR = 2.38, 95% CI = 1.86 to 3.04, P &lt; .001; FOLFOX: OR = 2.00, 95% CI = 1.50 to 2.66, P &lt; .001; CAPOX: OR = 2.32, 95% CI = 1.55 to 3.46, P &lt; .001), and diarrhea (5FU: OR = 1.35, 95% CI = 1.21 to 1.51, P &lt; .001; FOLFOX: OR = 1.60, 95% CI = 1.35 to 1.90, P &lt; .001; FOLFIRI: OR = 1.57, 95% CI = 1.25 to 1.97, P &lt; .001)} as well as hematological toxicities (neutropenia [5FU: OR = 1.55, 95% CI = 1.37 to 1.76, P &lt; .001; FOLFOX: OR = 1.96, 95% CI = 1.71 to 2.25, P &lt; .001; FOLFIRI: OR = 2.01, 95% CI = 1.66 to 2.43, P &lt; .001; capecitabine: OR = 4.07, 95% CI = 1.84 to 8.99, P &lt; .001] and leukopenia [5FU: OR = 1.74, 95% CI = 1.40 to 2.17, P &lt; .001; FOLFIRI: OR = 1.75, 95% CI = 1.28 to 2.40, P &lt; .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.