Recurrence-free and overall survival among elderly stage III colon cancer patients treated with CAPOX or capecitabine monotherapy: Adjuvant Chemotherapy Regimen

Estimating Treatment Effect of Adjuvant Chemotherapy in Elderly Patients With Stage III Colon Cancer Using Bayesian Networks

PURPOSE

While adjuvant therapy with capecitabine and oxaliplatin (CAPOX) has been proven to be effective in stage III colon cancer, capecitabine monotherapy (CapMono) might be equally effective in elderly patients. Unfortunately, the elderly are under-represented in clinical trials and patients included may not be representative of the routine care population. Observational data might alleviate this problem but is sensitive to biases such as confounding by indication. Here, we build causal models using Bayesian Networks (BNs), identify confounders, and estimate the effect of adjuvant chemotherapy using survival analyses.

METHODS

Patients 70 years and older were selected from the Netherlands Cancer Registry (N = 982). We developed several BNs using constraint-based, score-based, and hybrid algorithms while precluding noncausal relations. In addition, we created models using a limited set of recurrence and survival nodes. Potential confounders were identified through the resulting graphs. Several Cox models were fitted correcting for confounders and for propensity scores.

RESULTS

When comparing adjuvant treatment with surgery only, pathological lymph node classification, physical status, and age were identified as potential confounders. Adjuvant treatment was significantly associated with survival in all Cox models, with hazard ratios between 0.39 and 0.45; CIs overlapped. BNs investigating CAPOX versus CapMono did not find any association between the treatment choice and survival and thus no confounders. Analyses using Cox models did not identify significant association either.

CONCLUSION

We were able to successfully leverage BN structure learning algorithms in conjunction with clinical knowledge to create causal models. While confounders differed depending on the algorithm and included nodes, results were not contradictory. We found a strong effect of adjuvant therapy on survival in our cohort. Additional oxaliplatin did not have a marked effect and should be avoided in elderly patients.

Does adjuvant chemotherapy improve outcomes in elderly patients with colorectal cancer? A systematic review and meta-analysis of real-world studies

BACKGROUND

Elderly patients are frequently excluded from randomized trials. It is unclear if adjuvant chemotherapy improves outcomes of colorectal cancer in such patients. The current study aimed to review evidence on the impact of adjuvant chemotherapy on overall survival (OS) and disease-free survival (DFS) in elderly patients with stage II/III colorectal cancer by pooling data from real-world studies.

METHODS

PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched for observational studies reporting adjusted data on OS and DFS in elderly (≥70 years) colorectal cancer patients based on receipt of adjuvant chemotherapy.

RESULTS

Thirteen studies included. The meta-analysis demonstrated statistically significant improved OS in elderly patients receiving adjuvant chemotherapy (p < 0.00001). Results were similar for sub-group analysis based on cancer stage and definition of elderly. Improvement in OS was noted in only Western population studies with no difference in Asian patients. The meta-analysis also revealed no statistically significant difference in DFS in elderly patients receiving adjuvant chemotherapy vs surgery alone (p = 0.14).

CONCLUSION

Real-world evidence indicates that adjuvant chemotherapy significantly improved OS but not DFS in elderly colorectal cancer patients. Scarce evidence suggests a limited role of adjuvant chemotherapy in Asian patients which needs confirmation by further studies.

New diagnostic measures of oxaliplatin-induced peripheral sensory neuropathy

OBJECTIVE

Oxaliplatin-induced peripheral neuropathy (OIPN) is an unwanted side effect of oxaliplatin chemotherapy treatment. OIPN manifests in an acute phase that lasts a few days after injection and a persistent phase that may become chronic. Currently, there is no consensus about a clinically applicable, quantitative, and objective measure of OIPN.

METHODS

Seventeen patients treated with oxaliplatin containing adjuvant chemotherapy for stage III colon cancer, but otherwise healthy, were tested with six quantitative sensory tests (QST) and five large fibre perception threshold tracking (PTT) measures (quantified by, e.g., rheobase and electrotonus threshold) one hour before each of the 12 chemotherapy cycles given at two weeks' intervals. These measures were repeated at 3, 6, and 12-month follow-ups. The temporal development of OIPN assessed by the Common Terminology Criteria for Adverse Events (CTCAE) scale, QST, and PTT measures was calculated by linear regression.

RESULTS

The CTCAE score showed a tri-phasic increase during the treatment and remained increased during the follow-up. The vibration threshold (R = 0.25, p<0.001), the cold pain threshold (R = 0.17, p = 0.02), and the rheobase (R = 0.28, p < 0.001) increased during treatment, whereas the cold detection threshold (R=-0.16, p = 0.002) decreased. The cold pain threshold and the rheobase remained increased, and the cold detection and heat pain threshold remained decreased during follow-up.

CONCLUSIONS

Increased cold pain sensitivity and decreased large fibre sensitivity (increased rheobase) correlate to the persistent OIPN, whereas the CTCAE score assesses both acute and persistent OIPN. Furthermore, the novel PTT method assessed the nerve excitability changes caused by the oxaliplatin.

Effect of the duration of the capecitabine regimen following colon cancer surgery in an elderly population: a retrospective cohort study

Background

Only 50–70% of elderly colon cancer patients could complete the recommended 6 months of postoperative chemotherapy. It is unknown whether a shorter duration of postoperative capecitabine-alone chemotherapy would compromise survival. We thus conducted this study to analyze the association between postoperative chemotherapy duration of a capecitabine-alone regimen and cancer-specific survival (CSS) and disease-free survival (DFS) of surgery-treated elderly colon cancer patients.

Methods

We performed a retrospective cohort study of surgically treated stage III and high-risk stage II colon cancer patients aged ≥ 70 treated at two medical centers. Cox proportional hazard regression models were utilized to calculate crude and adjusted hazard ratios (HRs). The nonlinear relationship between postoperative chemotherapy duration and survival was analyzed through restricted cubic spline regression analysis, and the threshold effect was calculated by the two-piecewise Cox proportional hazard model.

Results

A total of 1217 surgery-treated colon cancer patients between August 1, 2013, and September 1, 2019, were reviewed, and 257 stage III and high-risk stage II patients aged ≥ 70 were enrolled. Postoperative chemotherapy with capecitabine was administered to 114 patients, and 143 patients only received surgery. As the duration of chemotherapy increased by 1 week, the risk of cancer-specific death was reduced by 11% (HR = 0.89, 95% confidence interval (CI) 0.82–0.96), and the risk of recurrence was reduced by 10% (HR = 0.90, 0.82–0.96). Nonlinearity exploration suggested a threshold effect of capecitabine duration on CSS in stage III disease. The HR for death was 0.79 (95% CI, 0.68–0.92) with duration ≤ 16 weeks and 1.34 (95% CI, 0.91–1.97) with duration > 16 weeks.

Conclusions

The postoperative capecitabine duration was significantly associated with a decrease in death risk and recurrence risk in elderly colon cancer patients. However, the threshold effect of capecitabine duration on survival suggests that short-term chemotherapy may improve survival in elderly stage III colon cancer patients.

Suboptimal Completion Rates, Adverse Events, Costs, Resource Utilization, and Cost Impact of Noncompletion in Oral Adjuvant Capecitabine-Based Chemotherapy in Patients With Early-Stage Colon Cancer

BACKGROUND

Suboptimal completion of chemotherapy, which may involve reduced patient adherence, remains a serious issue and leads to reduced treatment efficacy. This study assessed the completion rates, risk factors for noncompletion, and cost impact for noncompletion in patients on capecitabine monotherapy (Cape) or capecitabine with oxaliplatin (CAPOX) for the adjuvant treatment of early-stage colon cancer.

METHODS

Patients with a diagnosis of early-stage colon cancer between April 2013 and March 2017 were retrospectively identified. Treatment completion was evaluated. Multivariate logistic regressions analyses were used to assess the baseline factors associated with noncompletion. Adverse events, costs, healthcare resource utilization, and cost impact for noncompletion were investigated.

RESULTS

A total of 673 patients met the eligibility criteria, of which 382 (57%) were treated with Cape and 291 (43%) with CAPOX. The overall completion rate for adjuvant therapy was 40% (Cape 46%; CAPOX 33%). Noncompletion was associated with CAPOX treatment and higher healthcare costs within 6 months prior to chemotherapy. The 6-month unadjusted total healthcare costs were $44,444 for Cape and $71,247 for CAPOX. The nonchemotherapy costs were 41% higher for noncompleters than completers in both treatment groups (P = .002).

CONCLUSIONS

The real-world completion rates for adjuvant capecitabine-based chemotherapy in early-stage colon cancer patients are low. Noncompletion of therapy is associated with higher baseline healthcare costs. The nonchemotherapy costs are significantly higher in noncompleters than completers, highlighting the financial burden of managing adverse events and preexisting comorbidities, which may lead to early discontinuation of therapy. Effective strategies to optimize completion of oral chemotherapy may consider adherence monitoring.

Survival benefit of adjuvant chemotherapy in elderly patients with colon cancer: a systematic review and meta-analysis

BACKGROUND

Adjuvant chemotherapy after curative resection is established as a standard therapy for colon and rectal cancer. Although the efficacy of adjuvant chemotherapy has been shown by pooled analyses from randomized controlled trials, elderly patients still receive adjuvant chemotherapy less frequently than younger patients. In this systematic review and meta-analysis, we aimed to assess the survival benefit of adjuvant chemotherapy in elderly patients based on observational studies in which the elderly patients would likely be representative of those encountered in real-world clinical settings.

METHODS

A comprehensive literature search was conducted using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. Observational studies that investigated the survival benefit of adjuvant chemotherapy after curative resection in elderly patients (age ≥ 70 years) with colon or rectal cancer were included. The 5-year overall survival (OS) rate and OS were assessed. Risk of bias was assessed using the ROBINS-I tool.

RESULTS

Eleven studies in elderly patients with colon cancer were included. No relevant study was identified for rectal cancer. Elderly patients who received adjuvant chemotherapy had a significantly higher 5-year OS rate than those who did not (risk ratio 1.51, 95% confidence interval 1.29-1.76, P < 0.001). There was also a significant improvement in OS in elderly patients who received adjuvant chemotherapy (hazard ratio 0.59, 95% confidence interval 0.53-0.66, P < 0.001). The overall risk of bias was judged to be critical for both outcomes.

CONCLUSION

Adjuvant chemotherapy provides a survival benefit for elderly patients with colon cancer, although the quality of evidence is low.

Adjuvant Chemotherapy in Elderly Colorectal Cancer Patients

The value of adjuvant chemotherapy in elderly patients has been the subject of many overviews, with opinions varying from “not effective”, since randomized trials have not been performed, to “as effective as in young individuals”, based upon many retrospective analyses of randomized trials that have included patients of all ages. In the absence of randomized trials performed specifically with elderly patients, retrospective analyses demonstrate that the influence on the time to tumour recurrence (TTR) may be the same as in young individuals, but that endpoints that include death for any reason, such as recurrence-free survival (RFS), disease-free survival (DFS), and overall survival (OS), are poorer in the elderly. This is particularly true if oxaliplatin has been part of the treatment. The need for adjuvant chemotherapy after colorectal cancer surgery in elderly patients is basically the same as that in younger patients. The reduction in recurrence risks may be similar, provided the chosen treatment is tolerated but survival gains are less. Adding oxaliplatin to a fluoropyrimidine is probably not beneficial in individuals above a biological age of approximately 70 years. If an oxaliplatin combination is administered to elderly patients, three months of therapy is in all probability the most realistic goal.

Safety and efficacy of a modified XELOX adjuvant regimen for patients with operated stage III colon cancer: a Chinese single-center experience

Background

A fixed 8-cycle oxaliplatin and capecitabine (XELOX) regimen has been the standard adjuvant therapy for patients with stage III colon cancer. However, completing the full-cycle of oxaliplatin is often associated with severe neurotoxicity. To spare patients from the toxic effects, without comprising the required efficacy, we evaluated the safety and efficacy of a modified XELOX (mXELOX) adjuvant chemotherapy regimen with 6 cycles of oxaliplatin and a full cycle of capecitabine.

Methods

We retrospectively analyzed 330 eligible patients with stage III colon cancer who underwent curative tumor resection followed by mXELOX, standard XELOX or unfinished XELOX adjuvant chemotherapy between December 2007 and April 2015. Associated prognostic factors were investigated and their disease-free survival (DFS) and overall survival (OS) rates were also determined and compared among the different regimen groups.

Results

Compared with the standard XELOX group, the mXELOX group had lower total incidence rates of neurotoxicity (39.3% vs. 76.2%, P < 0.001), leucopenia (53.6% vs. 69.8%, P = 0.017) and thrombocytopenia (38.1% vs. 56.3%, P = 0.011). The standard XELOX and mXELOX adjuvant chemotherapy regimens presented with comparable 3-year DFS rates (86.3% vs. 89.2%; P = 0.838) and 3-year OS rates (92.7% vs. 97.6%; P = 0.227). Compared to unfinished XELOX chemotherapy, the oncologic benefits of the mXELOX regimen were greater for patients with T4 tumors (3-year DFS: Hazard ratio [HR], 2.184; 95% confidence interval [CI], 1.051–4.540; P = 0.036; 3-year OS: HR, 4.529; 95% CI 1.245–16.479; P = 0.022) and for high-risk patients (3-year DFS: HR, 1.962; 95% CI 0.964–3.993; P = 0.044; 3-year OS: HR, 4.193; 95% CI 1.182–14.874; P = 0.026).

Conclusions

The mXELOX adjuvant chemotherapy presented a comparable survival benefit and lower incidence of toxicity than standard XELOX chemotherapy. It could be an alternative treatment for high-risk patients with operated stage III colon cancer.

Association Between Adjuvant Chemotherapy Duration and Survival Among Patients With Stage II and III Colon Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

The results from the recent International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration have led some clinicians to adopt shorter durations of adjuvant chemotherapy for patients with stage III colon cancer. The extent to which these findings are supported by other data is unknown.

OBJECTIVE

To conduct a systematic review and meta-analysis of randomized and observational studies investigating the association between the duration of adjuvant chemotherapy and survival among individuals diagnosed as having stage II and III colon cancer (PROSPERO protocol CRD42018108711]).

DATA SOURCES

Abstracts published in English between 2003 and 2018 within the MEDLINE, Embase, CENTRAL, and CINAHL databases were reviewed by 2 authors. Also searched were conference proceedings and the indexes of high-impact oncology journals.

STUDY SELECTION

Studies were excluded if they did not present original data; focused on animal populations, on cancers in sites other than the colon, or on patients with stage 0, I, or IV disease; did not examine a 5-flourouracil-based monotherapy or combination therapy; or did not evaluate the association between treatment duration and survival. The search identified 2341 articles, from which 2 randomized trials and 20 observational studies were included in the meta-analysis.

DATA EXTRACTION AND SYNTHESIS

This study followed the PRISMA and MOOSE reporting guidelines. The risk of bias was assessed by 2 authors using the Cochrane and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tools. The results were synthesized using a random-effects model.

MAIN OUTCOMES AND MEASURES

The primary and secondary outcomes were overall survival and disease-free survival, respectively. It was hypothesized a priori that 3 months of chemotherapy would be as effective as 6 months of chemotherapy.

RESULTS

Twenty-two studies were included in the meta-analysis, representing 43 671 patients. The inclusion of patients with stage II disease or with rectal cancer was identified as a source of heterogeneity. After restricting the analysis to patients with stage III colon cancer, there was no association between the duration of chemotherapy and overall survival among studies involving FOLFOX (leucovorin calcium [folinic acid], fluorouracil, and oxaliplatin) or CAPOX (capecitabine plus oxaliplatin) regimens (hazard ratio [HR], 0.80; 95% CI, 0.58-1.09). Among studies focused exclusively on monotherapy, the standard 6-month regimen relative to a 3-month regimen was associated with improved survival (HR, 0.59; 95% CI, 0.52-0.68).

CONCLUSIONS AND RELEVANCE

Shortened durations of chemotherapy may reduce survival among patients with stage III colon cancer prescribed monotherapy but not a combination regimen.

Age-related inequalities in colon cancer treatment persist over time: a population-based analysis

Background

Older people experience poorer outcomes from colon cancer. We examined if treatment for colon cancer was related to age and if inequalities changed over time.

Methods

Data from the UK population-based Northern and Yorkshire Cancer Registry on 31 910 incident colon cancers (ICD10 C18) diagnosed between 1999–2010 were obtained. Likelihood of receipt of: (1) cancer-directed surgery, (2) chemotherapy in surgical patients, (3) chemotherapy in non-surgical patients by age, adjusting for sex, area deprivation, cancer stage, comorbidity and period of diagnosis, was examined.

Results

Age-related inequalities in treatment exist after adjustment for confounding factors. Patients aged 60– 69, 70–79 and 80+ years were significantly less likely to receive surgery than those aged <60 years (multivariable ORs (95% CI) 0.84(0.74 to 0.95), 0.54(0.48 to 0.61) and 0.19(0.17 to 0.21), respectively). Age-related differences in receipt of surgery and adjuvant chemotherapy (but not chemotherapy in non-surgical patients) narrowed over time for the ’younger old’ (aged <80 years) but did not diminish for the oldest patients.

Conclusions

Age inequality in treatment of colon cancer remains after adjustment for confounders, suggesting age remains a major factor in treatment decisions. Research is needed to better understand the cancer treatment decision-making process, and how to influence this, for older patients.

Use of adjuvant chemotherapy in patients with stage III colon cancer in Puerto Rico: A population-based study

Objective

This study aims to examine factors associated with the use of adjuvant chemotherapy and the use of oxaliplatin after curative resection in stage III colon cancer patients and assesses the effect of their use in three-year survival.

Methods

This retrospective cohort study was conducted using Puerto Rico Central Cancer Registry-Health Insurance Linkage Database. The study cohort consisted of stage III colon cancer patients with a curative surgery in the period 2008–2012. Multivariate logistic regression was used to estimate adjusted odds ratios. Kaplan-Meier methods and Cox proportional hazards models were used to assess the association between adjuvant chemotherapy and oxaliplatin use and overall survival and risk of death, respectively.

Results

Overall, 75% of the study population received adjuvant chemotherapy during the study period. Factors statistically associated with receiving adjuvant chemotherapy within four months after resection included being married (adjusted odds ratio [AOR] 1.64; 95% CI 1.18–2.28; p = 0.003), and being enrolled in Medicare (AOR 1.68; 95% CI: 1.03–2.75; p = 0.039) or Medicaid and Medicare dual eligible (AOR 1.66; 95% CI: 1.06–2.60; p = 0.028). However, patients aged ≥70 years were less likely to receive adjuvant chemotherapy (AOR 0.22; 95%CI 0.14–0.36; p<0.001).

Discussion

We observed a significant reduction in mortality in adjuvant chemotherapy treated patients. Similarly, patients <70 years treated with oxaliplatin had significantly lower risk of death than those who did not, although for patients ≥70 years no statistical significance was achieved. Future studies should assess effective interventions to reduce barriers to access guideline-based recommended colon cancer treatment.

Impact of timing of adjuvant chemotherapy on survival in stage III colon cancer: a population-based study

Background

There is no consensus regarding the optimal time to initiate adjuvant chemotherapy after surgery for stage III colon cancer, and the relevant postoperative complications that cause delays in adjuvant chemotherapy are unknown.

Methods

Eligible patients aged ≥66 years who were diagnosed with stage III colon cancer from 1992 to 2008 were identified using the linked Surveillance, Epidemiology, and End Results-Medicare database. Kaplan-Meier analysis and a Cox proportional hazards model were utilized to evaluate the impact of the timing of adjuvant chemotherapy on overall survival (OS).

Results

A total of 18,491 patients were included. Delayed adjuvant chemotherapy was associated with worse OS (9–12 weeks: hazard ratio [HR] = 1.222, 95% confidence interval [CI] = 1.063–1.405; 13–16 weeks: HR = 1.252, 95% CI = 1.041–1.505; ≥ 17 weeks: HR = 1.969, 95% CI = 1.663–2.331). The efficacies of adjuvant chemotherapy within 5–8 weeks and ≤4 weeks were similar (HR = 1.045, 95% CI = 0.921–1.185). Compared with the non-chemotherapy group, chemotherapy initiated at ≥21 weeks did not significantly improve OS (HR = 0.882, 95% CI = 0.763–1.018). Patients with postoperative complications, particularly cardiac arrest, ostomy infection, shock, and septicemia, had a significantly higher risk of a 4- to 11-week delay in adjuvant chemotherapy (p < 0.05).

Conclusions

Adjuvant chemotherapy initiated within 8 weeks was acceptable for patients with stage III colon cancer. Delayed adjuvant chemotherapy after 8 weeks was significantly associated with worse OS. However, adjuvant chemotherapy might still be useful even with a delay of approximately 5 months. Moreover, postoperative complications were significantly associated with delayed adjuvant chemotherapy.

Side-effects related to adjuvant CAPOX treatment for colorectal cancer are associated with intermuscular fat area, not with total skeletal muscle or fat, a retrospective observational study

AbstractBackground: Chemotherapeutic treatment is regularly accompanied by side-effects. Hydrophilic chemotherapeutics such as capecitabine and oxaliplatin (CAPOX), often used in colorectal cancer treatment, predominantly accumulate in non-adipose tissues. From this we hypothesized that body composition and fat infiltration in the muscle (muscle attenuation and intermuscular-adipose-tissue [IMAT] content) are associated with chemotherapy-induced toxicities.Methods: In this retrospective observational study, we collected data from 115 colorectal cancer patients receiving adjuvant CAPOX chemotherapy between 2006 and 2015. Information on cancer characteristics were obtained from the Netherlands Cancer Registry. Diagnostic CT scans were retrieved to assess cross-sectional areas of skeletal muscle and adipose tissue at the third lumbar vertebrae. Information on dose-limiting toxicity [DLT] and relative administered dose (as % of BSA-based-planned-dose) were retrieved from medical charts. Associations between body composition, muscle quality and chemotherapy-induced toxicities were determined using Cox-regression and linear-regression analyses.Results: We found that DLT incidence was 90% in our cohort: 50% had their dose reduced, 30% their next cycle postponed, 4% a full treatment stop and 6% was hospitalized at their first DLT. Most common were reductions in oxaliplatin dose whilst keeping the capecitabine dose constant. Cox regression analysis indicated no association between body composition or muscle quality and DLT during the first treatment cycle or time to the first DLT. Multiple linear regression showed that higher IMAT-index and IMAT muscle percentage were associated with a lower relative administered dose of oxaliplatin.Conclusions: In conclusion; only IMAT, not skeletal or fat area was associated with dose-limiting toxicities among these CRC patients who received CAPOX treatment.