Adjuvant Oxaliplatin Research Articles

Phase II trial evaluating the long-term efficacy and peripheral sensory neuropathy of capecitabine plus oxaliplatin (XELOX) as adjuvant therapy in Japanese patients with operated stage III colon cancer

Adjuvant oxaliplatin plus capecitabine (XELOX) therapy is recommended for patients with curatively resected colon cancer. However, prospective data on its practical application in Japanese patients are limited. Therefore, we aimed to conduct a long-term clinical evaluation of the efficacy and safety of adjuvant XELOX in patients with curatively resected stage III colon cancer (MCSCO-1024). This prospective, multi-center, open-label, single-arm, phase II study enrolled patients with curatively resected stage III colon cancer. The treatment protocol consisted of a 120-minute intravenous infusion of oxaliplatin (130 mg/m2) on day 1 and two divided doses oral capecitabine (2000 mg/m2/day) for 14 days in a 3-week cycle, totaling eight cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS), and the secondary endpoints were 5-year overall survival and long-term prognosis of peripheral sensory neuropathy. A total of 196 patients were enrolled between November 2011 and August 2014 (34 months). The 3-year DFS rate was 73%, and the 5-year overall survival rate was 87%. The overall incidence of peripheral sensory neuropathy was 17%, with a 1% rate of grade 3 neuropathy after 5 years. Adjuvant XELOX demonstrated utility and safety in the clinical management of Japanese patients with stage III colon cancer.

A retrospective study of adjuvant albumin-bound paclitaxel plus S-1 after D2 gastrectomy versus oxaliplatin plus S-1 in gastric cancer

Adjuvant oxaliplatin plus S-1 (SOX) chemotherapy for gastric cancer (GC) after D2 gastrectomy has been proven effective. There has yet to be a study that evaluates adjuvant nanoparticle albumin-bound paclitaxel (nab-paclitaxel) plus S-1. In this single-center, retrospective study, GC patients after D2 gastrectomy received either nab-paclitaxel plus S-1 (AS group) or SOX group were recruited between January 2018 and December 2020 in The First Affiliated Hospital of Zhejiang University. Intravenous nab-paclitaxel 120 mg/m2 or 260 mg/m2 and oxaliplatin 130 mg/m2 were administered as eight 3 week cycle, especially in the AS and SOX group. Patients received S-1 twice daily with a dose of 40 mg/m2 in the two groups on days 1–14 of each cycle. The end points were disease-free survival (DFS) rate at 3 years and adverse events (AEs). There were 56 eligible patients, 28 in the AS group and 35 in the SOX group. The 3 year DFS rate was 78.0% in AS group versus 70.7% in SOX group (p = 0.46). Subgroup analysis showed that the patients with signet-ring positive in the AS group had a prolonged DFS compared with the SOX group (40.0 vs. 13.8 m, p = 0.02). The diffuse-type GC or low differentiation in the AS group was associated with numerically prolonged DFS compared with the SOX group, but the association was not statistically significant (p = 0.27 and p = 0.15 especially). Leukopenia (14.3%) were the most prevalent AEs in the AS group, while thrombocytopenia (28.5%) in the SOX group. Neutropenia (7.1% in AS group) and thrombocytopenia (22.8% in SOX group) were the most common grade 3 or 4 AEs. In this study analyzing past data, a tendency towards a greater 3 year DFS was observed when using AS regimen in signet-ring positive patients. AS group had fewer thrombocytopenia compared to SOX group. More studies should be conducted with larger sample sizes.

Study protocol: fish oil supplement in prevention of oxaliplatin-induced peripheral neuropathy in adjuvant colorectal cancer patients – a randomized controlled trial. (OxaNeuro)

BackgroundOxaliplatin-induced peripheral neuropathy (OIPN) in general and painful OIPN in particular is a debilitating late effect that severely affects cancer survivors’ quality of life and causes premature cessation of potentially lifesaving treatment. No preventive treatments and no effective treatment for chronic OIPN exist despite many attempts. One of several suggested mechanisms includes neuroinflammation as a contributing factor to OIPN. Fish oil containing long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFAs) are precursors to specialized proresolving mediators that mediate the resolution of inflammation. Our primary hypothesis is that a high supplementation of n-3 LCPUFAs will lower the prevalence and severity of OIPN.MethodsThe OxaNeuro project is an investigator-initiated, multicenter, double-blinded, randomized, placebo-controlled clinical study. We will include 120 patients eligible to receive adjuvant oxaliplatin after colorectal cancer surgery. Patients will receive fish oil capsules containing n-3 LCPUFAs or corn oil daily for 8 months.The primary endpoint is the prevalence of OIPN at 8 months defined as relevant symptoms, including one of the following: abnormal nerve conduction screening, abnormal vibration threshold test, abnormal skin biopsy, or abnormal pinprick test. Additional endpoints include the intensity and severity of OIPN-related neuropathic pain, patient-reported OIPN symptoms, quality of life, mental health symptoms, body composition, and cognitive evaluation. Furthermore, we will evaluate inflammatory biomarkers in blood samples and skin biopsies, including the potential OIPN biomarker neurofilament light protein (NfL) which will be measured before each cycle of chemotherapy.DiscussionIf readily available fish oil supplementation alleviates OIPN prevalence and severity, it will significantly improve the lives of both cancer survivors and palliative cancer patients receiving oxaliplatin; it will improve their quality of life, optimize chemotherapeutic treatment plans by lowering the need for dose reduction or premature cessation, and potentially increase survival.Trial registrationClinicalTrial.gov identifier: NCT05404230Protocol version: 1.2, April 25th. 2023

Real-world adoption of 3 months of adjuvant oxaliplatin chemotherapy in patients with stage III colorectal cancer (CRC).

83 Background: Based on the IDEA analysis, 3 months (mos) of adjuvant chemotherapy (ACT) with CAPOX has emerged as an option for both low-risk and high-risk stage III CRC. This has resource utilization, cost and toxicity benefits (particularly less neurotoxicity) without compromising efficacy. This study examines the patterns of uptake of CAPOX vs FOLFOX and duration of ACT in a contemporary post-COVID real-world cohort of patients (pts) in the province of British Columbia (BC), Canada. Methods: The provincial pharmacy database was used to identify pts with resected stage III CRC who received adjuvant CAPOX or FOLFOX between January 2021 and December 2022. Pts with rectal cancer requiring neoadjuvant chemotherapy or radiotherapy were excluded. Demographic, tumor, and treatment information was collected. “High-risk features” were defined as pT4 or pN2 tumors. “Urban” setting was defined based on the population size of the regional health authority. Descriptive statistical analyses were performed to examine baseline characteristics and Fisher’s exact test was used to examine univariate associations. Results: 452 pts were included, of which 234 (52%) and 218 (48%) were planned to receive 3 and 6 mos of ACT respectively (see table). Within the 3 mos group, 226 (97%) received CAPOX. Within the 6 mos group, there was a 51%/49% split between CAPOX/FOLFOX. By univariate analysis, factors associated with 3 mos of CAPOX vs 6 mos of ACT were age >70y (P=0.039), low/intermediate grade (P=0.005) and low-risk stage III disease (P<0.0001). 29% of pts planned for 6 mos of oxaliplatin ACT had low-risk disease, with 52% of these receiving CAPOX. Conclusions: 3 mos of adjuvant CAPOX is an accepted option for nearly all pts with stage III disease with consequent less neurotoxicity and fewer treatment visits. Yet, in this contemporary cohort, use of 3 mos of adjuvant CAPOX remains low and is associated with older age and low-risk disease. 6 mos of oxaliplatin is still being offered to pts with low-risk disease. Exploration of patient preferences, real-world treatment and time toxicities, and resource costs may improve more widespread adoption of 3 mos of adjuvant CAPOX in stage III CRC. [Table: see text]

LBA78 Overall survival of perioperative or postoperative adjuvant oxaliplatin with S-1 versus adjuvant oxaliplatin with capecitabine in locally advanced gastric or gastro-oesophageal junction adenocarcinoma undergoing D2 gastrectomy: An updated analysis of RESOLVE trial

LBA78 Overall survival of perioperative or postoperative adjuvant oxaliplatin with S-1 versus adjuvant oxaliplatin with capecitabine in locally advanced gastric or gastro-oesophageal junction adenocarcinoma undergoing D2 gastrectomy: An updated analysis of RESOLVE trial

Oxaliplatin causes increased offset analgesia during chemotherapy- a feasibility study.

Offset analgesia (OA) is the phenomenon where the perceived pain intensity to heat stimulation disproportionally decreases after a slight decrease in stimulation temperature. The neural mechanisms of OA are not fully understood, but it appears that both peripheral and central temporal filtering properties are involved. Chemotherapy with oxaliplatin often causes acute peripheral sensory neuropathy, and manifests primarily as a cold induced allodynia. The aim of this exploratory patient study was to investigate if OA was affected by the neurotoxic effects of adjuvant oxaliplatin treatment. OA was assessed in 17 colon cancer patients during 12 cycles of adjuvant oxaliplatin treatment. The OA response was estimated as the decrease in pain intensity caused by a temperature decrease from 46 °C to 45 °C. Changes in the OA during the treatment period was estimated using a mixed linear model and corrected for multiple comparisons by Sidak's test. OA was increased significantly when assessed before the 2nd, 3rd, 5th, 6th, 9th, and 10th treatment cycle compared to the first (baseline) treatment (p<0.05). OA is generally decreased in persons suffering from chronic pain or peripheral neuropathy as compared tohealthy controls. But in the present study, OA increased during chemotherapy with oxaliplatin. The underlying mechanism of this unexpected increase should be further explored.

The adjuvant oxaliplatin-irinotecan paradox.

e15655 Background: A pervasive pattern in oncology is that chemotherapeutic agents which achieve acceptance for adjuvant use are the ones that have shown superior efficacy in the treatment of metastatic disease. The greater the efficacy in metastatic disease, the greater the likelihood that adjuvant use will be statistically viable. Oxaliplatin is the exception to this, having paradoxically shown similar outcomes to irinotecan in metastatic colorectal cancer (CRC) but superiority in the adjuvant setting. In this study, the TriNetX research database was used to better evaluate the adjuvant efficacy of oxaliplatin use in real-world patients. Methods: The TriNetX research database was used for this study. The TriNetX platform provides access to anonymized medical record information on more than 91 million patients in 75 large healthcare organizations. Three cohorts of stage III colorectal patients were created for comparison, utilizing International Classification of Disease-10 (ICD-10) codes and medication codes provided in the TriNetX platform. All patients were required to have a diagnosis of colon cancer (C18) and lymph node involvement (C77), with the absence of any liver or lung metastases (C78.7 and C78.0, respectively). Adjuvant oxaliplatin use was identified by the presence of the oxaliplatin medication code within 9 months of CRC diagnosis. The adjuvant oxaliplatin cohort was compared to a cohort with no oxaliplatin exposure, identified by the exclusion of the oxaliplatin medication code for 12 months following CRC diagnosis. The cohorts were balanced for age, race, gender, and ethnicity. The endpoint of the comparisons was all-cause mortality at 5 years. Results: Adjuvant use of oxaliplatin was associated with a 2.3% absolute decrease in the risk of death at 5 years (risk ratio 0.88, 95% CI (0.79,0.97), p-value 0.01). See figure 1. Conclusions: This study shows that adjuvant use of oxaliplatin is associated with a 2.3% absolute survival advantage in stage III colorectal cancer patients. This small absolute benefit is likely why occasional retrospective analyses have been unable to replicate it. A controlled interrupted time series analysis from Huang, et. al. showed no benefit to adjuvant oxaliplatin in the stage III setting for Taiwanese patients. Such a small benefit may also explain why the ACHIEVE trial found three months of adjuvant oxaliplatin to be equivalent to six. When a benefit is very small, a shorter duration of treatment would be more likely to result in statistical equivalency than if the benefit was more substantial. [Table: see text]

Second-line bevacizumab plus FOLFOX in patients with metastatic colorectal cancer previously treated with adjuvant oxaliplatin-based chemotherapy.

157 Background: There is a rarity of evidence for retreatment with oxaliplatin for metastatic colorectal cancer (mCRC), especially in combination with bevacizumab. This is a retrospective study of second line bevacizumab (Bev) plus FOLFOX (oxaliplatin, 5-fluorouracil, and leucovorin) in patients with metastatic colorectal cancer previously treated with adjuvant oxaliplatin-containing chemotherapy. Methods: Patients with age older than 18 and histologically confirmed metastatic colorectal cancer treated with second line bevacizumab plus FOLFOX in a single institute between 2015 and 2020 were enrolled. History of previous adjuvant chemotherapy regimens in patients with metachronous metastatic colorectal cancer was analyzed. Progression-free survival (PFS) and overall survival (OS) of the second line treatment were calculated using Kaplan-Meier method and compared between patients pretreated with adjuvant oxaliplatin (ReOx) and oxaliplatin-naive patients (control) with the log rank test. Results: A total of 72 patients were included. 23 patients (ReOx) were pretreated with adjuvant oxaliplatin and 49 patients (control) were oxaliplatin-naive before the second line treatment. There was a tendency of younger age in the ReOx group, but not statistically significant. Liver metastasis was significantly more frequent in the control group. The median PFS and OS in the ReOx group and the control group were 4.3 months (95% confidence interval [CI], 3.67–21.50) versus 5.5 months (95% CI, 4.23–8.20, hazard ratio [HR] = 0.84), and 10.5 months (95% CI, 5.40–30.37) versus 9.4 months (95% CI, 6.00–14.9, HR = 1.01) respectively. There was no significant difference of PFS ( p= 0.523) and OS ( p= 0.9745) between two groups. Conclusions: This study suggests a potential survival benefit of bevacizumab plus FOLFOX for mCRC patients previously treated with adjuvant oxaliplatin-containing treatment comparable to oxaliplatin-naive patients. [Table: see text]

A phase II randomized therapeutic optimization trial for patients with refractory metastatic colorectal cancer using circulating tumor DNA (ctDNA): Rapid 1 trial.

TPS280 Background: Patients with advanced colorectal cancer after progressing through first line therapy, have several FDA-approved systemic therapies that are associated with clinical benefit for a substantive minority of patients. Current clinical practice is to trial these various treatments in a step-wise fashion using CT scans every 3 months to evaluate effectiveness. This process requires 3-4 months between therapeutic interventions from which the patient may ultimately derive no clinical benefit, may have a performance status decline; limiting the number of possible interventions and increases risk for physical and financial toxicity. An alternative to the traditional CT-scan guided approach for disease assessment is a circulating tumor DNA (ctDNA) intervention. The Signatera ctDNA assay which utilizes 16 truncal mutations derived from a patient’s tumor, can be assessed every 2 weeks for a rapid determination of the effectiveness of a systemic therapy. This may allow patients to be exposed to many treatments during a short time, limiting toxicity, allowing for a quicker determination of clinical benefit and personalization of treatment. The aim of this study will be to compare the traditional scan-driven approach vs an intervention guided by ctDNA assessments, both arms using a pre-specified order of chemotherapy treatments. Methods: This is a phase 2 randomized study of patients with refractory metastatic adenocarcinoma of the colon or rectum. Participants are eligible after progression or intolerance to first line chemotherapy or recurrence within 6 months of adjuvant oxaliplatin based chemotherapy. They must have RECIST measurable metastatic disease that is not eligible for definitive management. Tissue from the primary and/or metastatic deposit is required for Signatera NGS analysis and subjects must have measurable ctDNA at sampling. Participants must be ≥18 years old without major organ dysfunction and have an ECOG performance status of 0 to 2. Subjects with Microsatellite High, deficient in DNA mismatch repair genes, or BRAF V600E mutations are excluded. Subjects will be randomized 1:1 to Arm A (ctDNA guided intervention) or Arm B (scan-guided control group). Patients in both arms will undergo systemic treatments in a standardized pre-specified order. Arm A will have ctDNA assessments every 2 weeks until an intervention shows a significant decrease, then every 4 weeks until Progressive Disease (PD) by scan or significant ctDNA increase. CT imaging will be performed every 12 weeks. Those in Arm B, will have CT imaging every 12 weeks and blood collected for post-hoc analysis every 4 weeks until PD by scan. The primary endpoint is overall survival. Secondary endpoints include progression free survival and overall response. Exploratory analysis with be performed of the microbiome. Enrollment continues to a maximum of 78 patients. Clinical trial information: NCT04786600 .

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

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&lt;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]

The impact of adjuvant oxaliplatin and tumor sidedness on the overall survival of stage IIB colon cancer patients: a multicentre study

The aim of this multicentre retrospective study was to compare the efficacy of adjuvant chemotherapy regimens both with and without oxaliplatin and tumor sidedness in stage IIB (pT4aN0) colon cancer patients. This study included patients with stage IIB colon cancer who underwent curative surgery and received adjuvant chemotherapy. The patients were divided into two groups (one with and one without oxaliplatin) to compare the overall survival (OS) in right- and left-sided tumors. The study population included 298 patients with stage IIB colon cancer (median age: 57) of whom 69.1% were male. Forty-four per cent of these patients (n = 131) were diagnosed with right-sided colon cancer. The median follow-up duration was 35.9 months. In the entire population, a median OS was not reached, and the five-year OS was 83%. The median disease-free survival (DFS) was 12 months. There was no significant difference in terms of the five-year OS between right- (82%) and left-sided (84%) colon tumors (p = 0.67). In addition, the five-year OS of patients treated with and without oxaliplatin were 76% and 89%, respectively, and there was no statistically significant difference (p = 0.23). The five-year OS of the patients treated with and without oxaliplatin were 83% and 96.5%, respectively, (p = 0.8) in right-sided colon tumors, while it was 75% and 93% (p = 0.06), respectively, in left-sided colon tumors. Tumor sidedness and the addition of oxaliplatin to adjuvant chemotherapy were not found to be associated with the OS in stage IIB colon cancer patients in our study. Further large prospective studies that also include MSI, RAS and BRAF status data are warranted in colon cancer patients.

Adjuvant oxaliplatin and fall-related injury in patients with colorectal cancer.

78 Background: Adjuvant oxaliplatin improves colorectal cancer (CRC) survival but causes dose-dependent peripheral neuropathy, possibly increasing the risk of fall-related injuries (FRI) such as fractures. In this retrospective cohort study, we examined the impact of adjuvant oxaliplatin cycles on FRIs. Methods: All data were ascertained from linked health administrative and population databases. We included Ontarians aged 18-85 years at CRC diagnosis between January 1 2007 to December 31 2018 who underwent curative resection and received adjuvant oxaliplatin. We excluded those with a prior cancer diagnosis within 5 years, prior CRC diagnosis ever, non-adenocarcinoma histology, prior oxaliplatin, and &lt;2 years of Ontario health insurance prior to CRC diagnosis. Oxaliplatin dose was determined in the 382 days after resection and dichotomized (1-6 vs. 7-12 cycles). The outcome was FRI, defined by ICD10 codes W00-W19 for any injury caused by a fall requiring emergency or inpatient care. Follow-up began at the end of the treatment window and terminated at the first of FRI, death, loss of Ontario health insurance, or March 31 2020. To account for differences between groups, clinical and demographic characteristics at diagnosis (Table) were used to estimate propensity scores for treatment and calculate inverse probability of treatment weights. These weights were applied to a Fine &amp; Gray regression model to determine the subdistribution hazard ratio (sHR) estimating the association between FRI and 1-6 versus 7-12 cycles of oxaliplatin, with death as a competing risk. Standardized differences &lt;0.1 indicated negligible imbalance. An interaction term tested for effect modification by age at diagnosis. Results: 9,324 patients were included in the study; 1,870 received 1-6 cycles and 7,454 received 7-12 cycles of oxaliplatin. Those exposed to 1-6 cycles were older (61.0 vs. 59.1 years), had higher comorbidity scores (13.5 vs 12.3), and more often had rectal cancer (27.5 vs. 22.2%). Negligible imbalance remained after weighting. Median follow-up was 50.2 months. Total follow-up was 44,472 person-years. There were 1,223 FRIs and 1,913 deaths. The sHR for FRIs comparing 7-12 cycles against 1-6 cycles of oxaliplatin was 0.98 (95% CI 0.85-1.14). The interaction p-value for age and oxaliplatin dose was 0.24. Conclusions: In this population-based retrospective cohort study of 9,324 patients with CRC, the risk of FRIs was similar for 7-12 cycles compared with 1-6 cycles of adjuvant oxaliplatin. This finding was consistent across age at diagnosis. Future research should examine the relationship between oxaliplatin dose and falls not resulting in injury. [Table: see text]

Impact of previous adjuvant oxaliplatin combination therapy on survival in elderly colorectal cancer patients with recurrence.

48 Background: The benefit of adjuvant chemotherapy with oxaliplatin for elderly patients with colorectal cancer (CRC) remains controversial. Our study could not demonstrate the benefit of adding oxaliplatin for elderly CRC patients aged over 70 years as with the previous clinical trials. Here, we evaluated the prognosis after recurrence in the elderly patients who received adjuvant chemotherapy. Methods: This retrospective study included patients aged over 70 years who were diagnosed with high-risk stage II and stage III CRC and received adjuvant chemotherapy in our two hospitals (The Jikei University Hospital and Katsushika Medical Center) between January 2010 and December 2019. The patients were divided into two groups; patients who received fluoropyrimidine monotherapy were included in Fp group and those who received fluoropyrimidine plus oxaliplatin were included in Fp+OX group. Moreover, we evaluated patient characteristics, treatment, and survival in the patients with recurrence and compared them between two groups. Results: A total of 127 patients received adjuvant chemotherapy; 75 patients in Fp group and 52 patients in Fp+OX group. With a median follow-up time of 64.5 months, the 5-years disease-free survival and 5-years overall survival in Fp group/Fp+OX group were 70.6/67.1% (hazard ratio [HR] 1.10, 95% confidence interval [CI] 0.61–1.98) and 89.0/71.8% (HR 1.48, 95% CI 0.76–2.88), respectively. The benefit of adding oxaliplatin was not observed. Among them, 15 patients in Fp group and 14 patients in Fp+OX group were relapsed; median age was 78 (range: 72-83) and 78 (range: 72-86) years, male was 67% and 64%, PS of 0/1 was 67/33% and 86/14%, primary tumor site of right/left was 47/53% and 57/43%, and RAS mutation was 20% and 29%, respectively. Median relapse-free survival was 17.7 and 14.3 months (p = 0.453). There were no significant differences in treatment after recurrence; aggressive treatment (surgery/chemotherapy) was 73% (33/40%) and 86% (21/65%), best supportive care was 7% each, and unknown was 20% and 7%, respectively. However, the median overall survival from the date of relapse was significantly worse in Fp+OX group than Fp group (45.0 and 14.4 months, p = 0.011). Conclusions: Recurrence after receiving adjuvant oxaliplatin combination therapy was considered as one of the poor prognostic factors. It might attenuate the benefit of adding oxaliplatin in adjuvant setting in elderly patients.

A phase II randomized therapeutic optimization trial for subjects with refractory metastatic colorectal cancer using circulating tumor DNA (ctDNA): Rapid 1 trial.

TPS223 Background: Patients with advanced colorectal cancer after progressing through first line therapy, have several FDA-approved systemic therapies that are associated with clinical benefit for a substantive minority of patients. Current clinical practice is to trial these various treatments in a step-wise fashion using CT scans every 3 months to evaluate effectiveness. This process requires 3-4 months between therapeutic interventions from which the patient may ultimately derive no clinical benefit, may have a performance status decline; limiting the number of possible interventions and increases risk for physical and financial toxicity. An alternative to the traditional CT-scan guided approach for disease assessment is a circulating tumor DNA (ctDNA) intervention. The Signatera ctDNA assay which utilizes 16 truncal mutations derived from a patient’s tumor, can be assessed every 2 weeks for a rapid determination of the effectiveness of a systemic therapy. This may allow patients to be exposed to many treatments during a short time, limiting toxicity, allowing for a quicker determination of clinical benefit and personalization of treatment. The aim of this study will be to compare the traditional scan-driven approach vs an intervention guided by ctDNA assessments, both arms using a pre-specified order of chemotherapy treatments. Methods: This is a phase 2 randomized study of patients with refractory metastatic adenocarcinoma of the colon or rectum. Participants are eligible after progression or intolerance to first line chemotherapy or recurrence within 6 months of adjuvant oxaliplatin based chemotherapy. They must have RECIST measurable metastatic disease that is not eligible for definitive management. Tissue from the primary and/or metastatic deposit is required for Signatera NGS analysis and subjects must have measurable ctDNA at sampling. Participants must be ≥18 years old without major organ dysfunction and have an ECOG performance status of 0 to 2. Subjects with Microsatellite High, deficient in DNA mismatch repair genes, or BRAF V600E mutations are excluded. Subjects will be randomized 1:1 to Arm A (ctDNA guided intervention) or Arm B (scan-guided control group). Patients in both arms will undergo systemic treatments in a standardized pre-specified order. Arm A will have ctDNA assessments every 2 weeks until an intervention shows a significant decrease, then every 4 weeks until Progressive Disease (PD) by scan or significant ctDNA increase. CT imaging will be performed every 12 weeks. Those in Arm B, will have CT imaging every 12 weeks and blood collected for post-hoc analysis every 4 weeks until PD by scan. The primary endpoint is overall survival. Secondary endpoints include progression free survival and overall response. Exploratory analysis with be performed of the microbiome. Enrollment continues to a maximum of 78 patients. Clinical trial information: NCT04786600.

Sex hormones and sperm parameters after adjuvant oxaliplatin-based treatment for colorectal cancer

BackgroundThe incidence of colorectal cancer (CRC) in individuals of fertile age is increasing. Oxaliplatin is a cornerstone treatment in the adjuvant setting for stage III and high-risk stage II CRC. Limited data exist on possible side effects of oxaliplatin on fertility and gonadal function. More data is needed to guide possible fertility preservation procedures and aid evidence-based fertility counselling. Patients and methodsThe aim of this study (EudraCT2006-002832-10) was to prospectively investigate sex hormones and sperm parameters after oxaliplatin-based adjuvant chemotherapy to clarify the risk of infertility and hypogonadism. Twenty males aged ≤55 years and 16 females aged ≤40 years were recruited from five hospitals in the Nordic countries. All had undergone radical surgery due to CRC and were given adjuvant oxaliplatin in combination with 5-fluorouracil. Measurement of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, sex hormone binding globulin (SHBG) and semen analysis were done in males, while LH, FSH and oestradiol were measured in females. Measurements were done prior to chemotherapy, after completion of adjuvant treatment and at follow-up 1 and up to 5 years after end of treatment. ResultsFSH and testosterone levels increased in males after chemotherapy treatment but were restored at follow-up. No patients developed hypogonadism. There was a trend towards a decrease in sperm concentration during treatment (p = 0.063). When comparing sperm concentration and rapid progressive motility of sperms prior to chemotherapy and at follow-up, there were no differences, and no patients became permanently azoospermic by treatment. No distinct altering of gonadal function could be observed in females. ConclusionsOxaliplatin in combination with 5-fluorouracil seems to induce transient decrease in sperm concentration with recovery and a minor transient increase in FSH in males. No distinct altering of gonadal function was observed in females. The risk of infertility and hypogonadism in males and females after adjuvant oxaliplatin-based chemotherapy seems low.

Systematic review of long-term chemotherapy-induced peripheral neuropathy (CIPN) following adjuvant oxaliplatin for colorectal cancer.

Chemotherapy-induced peripheral neuropathy (CIPN) is the most common dose-limiting side effect of oxaliplatin. It often persists and can adversely affect quality of life of colorectal cancer (CRC) survivors. This systematic review explored the proportions of patients with persistent CIPN and the reporting methods used. MEDLINE, EMBASE, Web of Science and CINAHL were searched up to March 2021 for publications reporting CIPN outcomes following adjuvant oxaliplatin-containing chemotherapy at prespecified timepoints in participants with CRC. Secondary outcomes assessed the tools used to measure CIPN. Two authors reviewed full text publications for eligibility, data extraction and appraisal. Meta-analysis was performed where Common Terminology Criteria for Adverse Events (any grade) was reported at the most frequent timepoints. From 7895 citations identified, 27 studies met the eligibility criteria: six were randomised control trials, and 21 were non-randomised studies. Pooled prevalence of CIPN at 6, 12, 24 and 36months after chemotherapy were 58%, 45%, 32% and 24% respectively. The average prevalence of CIPN decreased by 26% per year after chemotherapy (pooled RR = 0.74; 95% CI 0.72-0.75). Across all studies, ten separate tools were used as the primary measure of CIPN. Quality appraisal identified open-label design and inadequate reporting of participants lost to follow-up as the main methodological limitations. Our summary of reported rates of persistent CIPN indicates substantial long-term toxicity affecting CRC survivors, and will help clinicians estimate CIPN risk and its change over time. The heterogeneity of CIPN measures identified in the review highlights the need for a standardised CIPN assessment.

Real-World Effectiveness of Adjuvant Oxaliplatin Chemotherapy in Stage III Colon Cancer: A Controlled Interrupted Time Series Analysis.

Background: The real-world effectiveness of oxaliplatin in stage III colon cancer has not been determined in a large-scale population. We aimed to assess the real-world impact of adjuvant oxaliplatin treatment on the survival of these patients. Methods: Based on Taiwan cancer registry, we evaluated 17,801 patients with resected stage III colon cancer, including 14,168 patients receiving adjuvant chemotherapy and 3,633 not receiving adjuvant chemotherapy as the control group between 2004 and 2014. We used the controlled interrupted time-series analysis to assess the three-year disease-free survival and five-year overall survival rates before (2004–2008) and after (2009–2014) the addition of oxaliplatin. Results: The introduction of oxaliplatin was associated with no significant improvement in the slopes (per half-year) of the three-year disease-free survival rate (0.2%, 95% CI: −1.7∼2.2%) and five-year overall survival rate (0.6%, 95% CI: −1.8∼3%). The patients receiving oxaliplatin-based chemotherapy also showed no significant increase in the slopes (per half-year) of the three-year disease-free survival rate (0.6%, 95% CI: −1.4∼2.6%) and five-year overall survival rate (1%, 95% CI: −1.5∼3.5%). The nonsignificant results were consistent across subgroup analyses of age (<70 vs. ≥70 years), recurrence risk (T1-3 or N1 vs. T4 or N2), and cycle of oxaliplatin use (≤6 vs. >6). However, oxaliplatin-based chemotherapy significantly increased the slope (per half-year) of the five-year OS (2%, 95% CI: 0.2∼3.8%) for patients in the high-risk group (T4 or N2). The present results were robust in several sensitivity analyses. Conclusion: Among real-world patients with stage III colon cancer, the introduction of oxaliplatin does not yield a significant improvement in survival. Future work should identify the subpopulation(s) of patients who benefit significantly from the addition of oxaliplatin.

The impact of socioeconomic status on stage at presentation, receipt of diagnostic imaging, receipt of treatment, and overall survival in colorectal cancer patients.

10565 Background: Socioeconomic factors have been identified to influence patterns of care in colorectal cancer yet current literature findings are sparse, conflicting, and often incomplete. As such, this study investigates the impact of socioeconomic status (SES) on stage at presentation, receipt of diagnostic imaging, receipt of treatment, and overall survival (OS) in a universal healthcare system. Methods: The Ontario Cancer Registry was accessed to identify a cohort of patients diagnosed with colorectal adenocarcinoma from 2007-2016 in Ontario, Canada. Linkage to administrative datasets allowed study of the impact of SES, measured by mean neighbourhood household income divided into quintiles (Q1-Q5; Q1 = lowest income), on stage, imaging, treatments, and OS. Multivariable regression analyses of all endpoints were adjusted for age, sex, comorbidity, and rurality with OS models also adjusting for imaging and treatment. Results: 39,802 colon and 13,164 rectal patients were identified. Lower SES patients were more likely to present at a higher stage in both cohorts. Lower SES colon patients were less likely to receive magnetic resonance imaging (MRI) of the abdomen, liver resection, adjuvant oxaliplatin, and all palliative systemic therapies studied. In rectal patients, lower SES was associated with decreased receipt of MRI pelvis, rectal cancer resection in early stages, adjuvant oxaliplatin, and most palliative chemotherapies studied. All OS models found that lower SES was associated with poorer OS. Conclusions: These findings suggest disparities across the continuum of cancer care persist even within a universal healthcare system. Further efforts should be directed towards temporal research, identifying barriers, and subsequently applying this information to actionable policies.

The impact of socioeconomic status on stage at presentation, receipt of diagnostic imaging, receipt of treatment and overall survival in colorectal cancer patients.

Socioeconomic factors influence patterns of care in colorectal cancer. Our study investigates the impact of socioeconomic status (SES) on stage at presentation, receipt of diagnostic imaging, receipt of treatment and overall survival (OS) in a universal healthcare system. The Ontario Cancer Registry (OCR) was accessed to identify a cohort of patients diagnosed with colorectal adenocarcinoma from 2007 to 2016 in Ontario, Canada. SES was measured using median neighborhood income divided into quintiles (Q1-Q5; Q1=lowest income). Logistic regression analyses were used to evaluate stage, imaging and treatment. Cox proportional hazards models were used to evaluate OS. All endpoints were adjusted for demographics and comorbidities with OS models also adjusting for stage, imaging and treatment. In total, 39 802 colon and 13 164 rectal patients were identified. Lower SES was associated with advanced stage at presentation in both cohorts (Q1 vs Q5: Colon odds ratio [OR]=1.08, P=.046, rectal OR=1.25, P < .0001). Lower SES colon patients were less likely to receive adjuvant oxaliplatin (Q1 vs Q5: OR=0.78, P < .001) and all palliative chemotherapies studied including oxaliplatin (Q1 vs Q5: OR=0.60, P < 0.0001), irinotecan (Q1 vs Q5: OR=0.65, P < .0001), bevacizumab (Q1 vs Q5: OR=0.70, P < .001), cetuximab (Q1 vs Q5: OR=0.40, P=.0053) and panitumumab (Q1 vs Q5: OR=0.54, P=.0036). In rectal patients, lower SES was associated with decreased receipt of rectal cancer resection for stages I-III (Q1 vs Q5: OR=0.78, P < .001), adjuvant oxaliplatin (Q1 vs Q5: OR=0.72, P=.0020) and palliative chemotherapies including oxaliplatin (Q1 vs Q5: OR=0.59, P < .001), irinotecan (Q1 vs Q5: OR=0.53, P < .001) and bevacizumab (Q1 vs Q5: OR=0.71, P=.046). All survival models identified poorer OS for lower SES patients (total colorectal; Q1 vs Q5: Hazard ratio [HR]=1.25, P < .0001). These findings suggest disparities persist even within universal healthcare.

Early-onset stage II/III colorectal adenocarcinoma in the IDEA database: Treatment adherence, toxicities, and outcomes from adjuvant fluoropyrimidine and oxaliplatin.

3517 Background: Incidence of early-onset colorectal cancer (eoCRC, age &lt; 50) is steadily increasing. Decisions on adjuvant treatment (adjTx) regimen and duration should consider tx adherence, toxicity (tox) and expected outcomes in a population with life-expectancy longer than late onset CRC (loCRC, age ≥ 50). Methods: Individual patient data from stage II/III patients (pts) from 6 randomised trials in the IDEA database were used to compare characteristics, tx adherence, and adverse events of eoCRC to loCRC. To reduce the confounder of non-cancer-related deaths due to age/co-morbidities, time-to-recurrence (TTR) and cancer-specific survival (CSS) were compared by stratified Gay k-sample test. 5-year cancer-specific mortality (CSM) rate were estimated by adjusted cumulative incidence function. 3-year relapse-free survival (RFS) rate were compared by stratified and adjusted COX models. Results: Out of 16,349 pts included, 1564 (9.6%) were eoCRC. Compared to loCRC, eoCRC had lower percent of male pts (51% vs 57%, p &lt; 0.01) better performance status (PS0 86% vs 80%, p &lt; 0.01), similar T stage distribution (% T1-3/T4: 76/24 vs 77/23, p = 0.97), higher rate of N2 disease (24% vs 22%, p &lt; 0.01), more likely to complete pre-planned duration of adjTx (83.2% vs 78.2%, p &lt; 0.01) and received a higher tx intensity especially with 6 month tx (mean oxaliplatin dose intensity 75% vs 72%, p &lt; 0.01; capecitabine 85% vs 78%, p &lt; 0.01; 5FU 85% vs 82% p &lt; 0.01). Gastrointestinal tox was more common in eoCRC (any grade nausea 58% vs 45%, p &lt; 0.01; any grade vomiting 22% vs 16%, p &lt; 0.01); haematological tox was more frequent in loCRC (62% vs, 69%, p = &lt; 0.01); any grade neuropathy rate was similar (75%). Significant interaction was found between age and T stage for TTR (p = 0.04). Clinical outcome estimates and comparisons are shown in Table. Notably, high risk stage III (T4/N2) eoCRC had significantly lower 3-y RFS rate (54% vs 64%, HRadj 0.74, p &lt; 0.01). Conclusions: eoCRC have better tx adherence than loCRC, as expected. While in high risk stage II and low risk stage III, cancer-specific outcomes are not different, in high risk stage III young age is negatively prognostic and associated with significantly higher relapse rate and risk of CRC death; this is despite a higher administered adjTx-intensity, suggesting a more aggressive disease biology. Clinical trial information: NCT00749450 (SCOT); NCT00646607 (TOSCA); NCT01150045 (CALGB/SWOG 80702); NCT00958737 (IDEA France) [Table: see text]