Treatment selection bias for chemotherapy persists in colorectal cancer patient cohort studies even in comprehensive propensity score analyses

Prediction of moderate and severe toxicities of chemotherapy in older patients with cancer: a propensity weighted analysis of ELCAPA cohort

BACKGROUND

Currently available predictive models for chemotherapy-related toxicity are not sufficiently discriminative in older patients with cancer and do not consider moderate toxicities. The purpose of this study was to identify factors associated with moderate and severe chemotherapy toxicities in older patients with cancer.

MATERIALS AND METHODS

Patients aged 70+ recruited in the prospective ELCAPA cohort were analyzed. A total of 837 patients with data on toxicities had received chemotherapy without other systemic treatment and were included between 2015 and 2022. To adjust for any imbalances in the distribution of covariates between patients receiving single-agent chemotherapy vs combination chemotherapy, we applied overlap weighting (a propensity-score-based technique). We used multinomial logistic regression.

RESULTS

Median (interquartile range) age was 81 (77-84). Forty-one percent experienced moderate toxicity, and 33% experienced severe toxicity. Hematologic toxicities accounted for 53% of severe toxicities and 66% of moderate toxicities. Age <80 years, cancer type, metastatic status, Eastern Cooperative Oncology Group performance status (ECOG-PS) >1, no cognitive impairment were associated with combination chemotherapy decision. In a univariate analysis with overlap weighting, no factors were associated with moderate toxicity. Hemoglobin < 0 g/dL and a CIRS-G score >12 were associated with severe toxicity. In a multivariate analysis, only hemoglobin < 10 g/dL was independently associated with severe toxicity, adjusted OR 2.96 (95% CI, 1.20-7.29).

CONCLUSION

By addressing indication bias for combination chemotherapy decision, only anemia and not cancer type, combination chemotherapy was predicting for severe chemotherapy-related toxicity in older patients with cancer. We did not find any predictors of moderate chemotherapy-related toxicity.

A signature based on 11 autophagy genes for prognosis prediction of colorectal cancer

Aim

To develop an autophagy-gene-based signature that could help to anticipate the therapeutic effects of Colorectal Cancer (CRC).

Methods

We downloaded the gene expression profiles of CRC samples from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) datasets. Genes with significant prognostic value in CRC were screened through univariate Cox regression analysis, while the LASSO Cox regression method was applied to screen optimal genes to construct the autophagy‐related prognostic signature.

Results

11 autophagy genes were identified and selected for the establishment of prognosis prediction model for CRC patients. The CRC patients were classified into the low- and high-risk groups according to the optimal cutoff value. The time-dependent ROC curves indicated the good performance of this model in prognosis prediction, with AUC values of 0.66, 0.66, and 0.67 at 1, 3 and 5 years for TCGA samples, as well as AUC values of 0.63, 0.65 and 0.64 for GEO samples, respectively. The multivariate Cox regression analysis results confirmed risk score as the independent marker for prognosis prediction in CRC. Besides, the constructed nomogram also had high predictive value. The results analysis on the tumor infiltrating immune cells (TIICs) relative ratios and mRNA levels of key immune checkpoint receptors indicated the signature was closely related to immune microenvironment of CRC in the context of TIICs and immune checkpoint receptors’ mRNA level. The proportion of MSI-L + MSI-H in the high-risk group was higher than that in the low-risk group. Moreover, the tumor purity was evaluated by estimate function package suggested that lower tumor purity in CRC might lead to a poorer prognosis.

Conclusion

The autophagy-related features obtained in this study were able to divide the CRC patients into low- and high-risk groups, which should be contribute to the decision-making of CRC treatment.

Inpatient rehabilitation therapy among colorectal cancer patients - utilization and association with prognosis: a cohort study

BACKGROUND

Inpatient rehabilitation therapy (IRT) is commonly offered to cancer patients during or after cancer treatment in Germany. However, little is known about utilization and long-term effects of this offer in colorectal cancer (CRC) patients. We aimed to assess IRT utilization, determinants of utilization and the association between IRT and survival in CRC patients.

MATERIALS AND METHODS

CRC patients diagnosed in 2005-2014 recruited in the population-based DACHS study in South West Germany were included. Determinants of IRT utilization were assessed by multivariable logistic regression. Hazard ratios (HRs) of the association of IRT with overall and disease-specific survival were estimated by adjusted Cox proportional hazards models. Modified landmark approach was applied to avoid immortal time biased results.

RESULTS

Among the included CRC patients (n = 3704), 43.6% underwent IRT. Patients who did not live in a relationship with a partner, worked as employee and who reported higher levels of physical activity were more likely to undergo IRT. Patients were less likely to undergo IRT if they had private health insurance, were diagnosed with cancer stage IV, received no or laparoscopic cancer surgery or were treated in a hospital with medium vs. high surgical volume. The median follow-up time was 4.4 years (post-landmark). Utilization of IRT was associated with better overall (HR 0.81, 95% confidence interval 0.72-0.92) and disease-specific survival (HR 0.72, 95% confidence interval 0.61-0.85).

CONCLUSION

Almost every other CRC patient underwent IRT. Next to clinical characteristics, identified social and lifestyle characteristics seemed to play an essential role in the decision-making. Use of IRT was associated with better overall and disease-specific survival.

Early discontinuation and dose reduction of adjuvant chemotherapy in stage III colon cancer patients

BACKGROUND

The benefit of chemotherapy in colon cancer patients is well documented but depends largely on whether patients complete the planned treatment regimen. We evaluated predictors of early discontinuation (EDChemo) and dose reduction of chemotherapy, especially the role of adverse treatment effects, in stage III patients who received adjuvant chemotherapy.

METHODS

Stage III colon cancer patients who were diagnosed in 2003-2014 and recruited into a population-based study in Germany and received FOLFOX [5-fluorouracil (5-FU), leucovorin (LV), and oxaliplatin], capecitabine monotherapy (CapMono), or 5-FU/LV were included. We assessed determinants of EDChemo and dose reduction using multivariable logistic regression. Also, we estimated proportions of EDChemo and dose reduction that are attributable to adverse effects using attributable fractions.

RESULTS

EDChemo and dose reduction rates were 52% and 17% for FOLFOX, 28% and 9% for CapMono, and 45% and 6% for 5-FU/LV, respectively. Predictors of EDChemo were low-grade tumor and treatment in a medium-volume hospital (for FOLFOX), obesity (for CapMono), and increasing age, T4 stage, and treatment in a medium-volume hospital (for 5-FU/LV). Adverse effects were particularly strongly associated with EDChemo and contributed to about 63%, 51%, and 32% of EDChemo of FOLFOX, CapMono, and 5-FU/LV, respectively. Of the various adverse effects, gastrointestinal events showed the strongest associations with EDChemo and accounted for about 7%, 26%, and 20% of EDChemo of FOLFOX, CapMono, and 5-FU/LV, respectively. Adverse effects were, moreover, a strong determinant of dose reduction and accounted for about 82% of all cases.

CONCLUSIONS

EDChemo is common in stage III colon cancer patients receiving chemotherapy and more than half of the cases of EDChemo and dose reduction are due to adverse treatment effects. Further research should address the potential for reducing EDChemo and dose reduction rates by close monitoring of patients for early signs and enhanced management of adverse effects, especially gastrointestinal events.

Impact of Age and Comorbidity on Multimodal Management and Survival from Colorectal Cancer: A Population-Based Study

This retrospective population-based study examined the impact of age and comorbidity burden on multimodal management and survival from colorectal cancer (CRC). From 2000 to 2015, 1479 consecutive patients, who underwent surgical resection for CRC, were reviewed for age-adjusted Charlson comorbidity index (ACCI) including 19 well-defined weighted comorbidities. The impact of ACCI on multimodal management and survival was compared between low (score 0–2), intermediate (score 3) and high ACCI (score ≥ 4) groups. Changes in treatment from 2000 to 2015 were seen next to a major increase of laparoscopic surgery, increased use of adjuvant chemotherapy and an intensified treatment of metastatic disease. Patients with a high ACCI score were, by definition, older and had higher comorbidity. Major elective and emergency resections for colon carcinoma were evenly performed between the ACCI groups, as were laparoscopic and open resections. (Chemo)radiotherapy for rectal carcinoma was less frequently used, and a higher rate of local excisions, and consequently lower rate of major elective resections, was performed in the high ACCI group. Adjuvant chemotherapy and metastasectomy were less frequently used in the ACCI high group. Overall and cancer-specific survival from stage I-III CRC remained stable over time, but survival from stage IV improved. However, the 5-year overall survival from stage I–IV colon and rectal carcinoma was worse in the high ACCI group compared to the low ACCI group. Five-year cancer-specific and disease-free survival rates did not differ significantly by the ACCI. Cox proportional hazard analysis showed that high ACCI was an independent predictor of poor overall survival (p < 0.001). Our results show that despite improvements in multimodal management over time, old age and high comorbidity burden affect the use of adjuvant chemotherapy, preoperative (chemo)radiotherapy and management of metastatic disease, and worsen overall survival from CRC.

The association of comorbidities with administration of adjuvant chemotherapy in stage III colon cancer patients: a systematic review and meta-analysis

Background:

Chemotherapy is an established treatment for stage III colon cancer cases. Older age is known to be associated with less chemotherapy use in these patients, but there might be other relevant factors besides age that influence treatment administration. We summarized evidence on associations between comorbidity and adjuvant chemotherapy administration in stage III colon cancer patients in a systematic review and meta-analysis.

Methods:

We searched the PubMed and Web of Science databases up to 2 June 2020 for studies on comorbidities and chemotherapy use in patients with stage III colon cancer. Summary odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using random-effects models. Subgroup analyses according to year of colon cancer diagnosis, timing of comorbidity assessment, and geographical region were also conducted.

Results:

Thirty-three studies were included in this review, including 219,406 stage III colon cancer patients overall. Chemotherapy administration was 60.9% (95% CI: 56.9% to 64.9%), increasing from 57.1% before 2001 to 66.3% after 2010. There were inverse associations between comorbidities and chemotherapy administration. Compared with patients with Charlson comorbidity score 0, those with scores 1 (OR = 0.79, 95% CI = 0.72–0.87) and 2+ (OR = 0.49, 95% CI = 0.42–0.56) received chemotherapy less often. Among comorbidities, the strongest predictors of chemotherapy non-use were dementia (OR = 0.37, 95% CI = 0.33–0.54), followed by heart failure (OR = 0.44, 95% CI = 0.28–0.70) and stroke (OR = 0.56, 95% CI = 0.38–0.81).

Conclusions:

Merely 60% of stage III colon cancer patients receive chemotherapy. Comorbidities are strong predictors of chemotherapy non-use, but the association differs by comorbid condition and is strongest with dementia. Given the survival disadvantage of colon cancer patients with comorbidities, further evidence on the risk–benefit ratio of chemotherapy according to the type and severity of comorbidity and on the extent to which the survival disadvantage of comorbidity is explained by less use or lower tolerability of chemotherapy is needed to foster personalized medical care in these patients.

Adjuvant chemotherapy in rectal cancer: state of the art and future perspectives

PURPOSE OF REVIEW

The value of adjuvant chemotherapy in rectal cancer is controversial with opinions varying from 'not be used' since randomized trials have not shown significant gains to 'be used as in colon cancer' as the need is the same and colon and rectal cancers are quite similar. This review will look upon data critically and with open eyes.

RECENT FINDINGS

With the exception of one randomized phase II trial (ADORE) revealing a significant gain in disease-free survival using one more effective regimen (mFOLFOX) than bolus 5-fluorouracil leucovorin, no new data have been presented. However, bringing up aspects in previous trials, either considered irrelevant for the present situation or overall negative, of what adjuvant treatment can achieve, a small reduction (hazard ratio about 0.8) in the risk of recurrence is present. This reduction is not fundamentally different from that in colon cancer considering that adjuvant treatment for rectal cancer cannot be initiated as rapidly as it can after a colon cancer diagnosis.

SUMMARY

Adjuvant chemotherapy after rectal cancer surgery reduces recurrence risks but the benefit is limited and for most patients not clinically relevant. Neoadjuvant therapy can be more effective but results from randomized trials are not yet available.

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.

Obesity and Cancer Treatment Outcomes: Interpreting the Complex Evidence

A wealth of epidemiological evidence, combined with plausible biological mechanisms, present a convincing argument for a causal relationship between excess adiposity, commonly approximated as body mass index (BMI, kg/m²), and incident cancer risk. Beyond this relationship, there are a number of challenges posed in the context of interpreting whether being overweight (BMI 25.0-29.9 kg/m²) or obese (BMI ≥ 30.0 kg/m²) adversely influences disease progression, cancer mortality and survival. Elevated BMI (≥ 25.0 kg/m²) may influence treatment selection of, for example, the approach to surgery; the choice of chemotherapy dosing; the inclusion of patients into randomised clinical trials. Furthermore, the technical challenges posed by an elevated BMI may adversely affect surgical outcomes, for example, morbidity (increasing the risk of surgical site infections), reduced lymph node harvest (and subsequent risk of under-staging and under-treatment) and increased risk of margin positivity. Suboptimal chemotherapy dosing, associated with capping chemotherapy in obese patients as an attempt to avoid excess toxicity, might be a driver of poor prognostic outcomes. By contrast, the efficacy of immune checkpoint inhibition may be enhanced in patients who are obese, although in turn, this observation might be due to reverse causality. So, a central research question is whether being overweight or obese adversely affects outcomes either directly through effects of cancer biology or whether adverse outcomes are mediated through indirect pathways. A further dimension to this complex relationship is the obesity paradox, a phenomenon where being overweight or obese is associated with improved survival where the reverse is expected. In this overview, we describe a framework for evaluating methodological problems such as selection bias, confounding and reverse causality, which may contribute to spurious interpretations. Future studies will need to focus on prospective studies with well-considered methodology in order to improve the interpretation of causality.

Blood markers of oxidative stress are strongly associated with poorer prognosis in colorectal cancer patients

Oxidative stress has been implicated in the initiation of several cancers, including colorectal cancer (CRC). Whether it also plays a role in CRC prognosis is unclear. We assessed the associations of two oxidative stress biomarkers (Diacron's reactive oxygen metabolites [d-ROMs] and total thiol level [TTL]) with CRC prognosis. CRC patients who were diagnosed in 2003 to 2012 and recruited into a population-based study in Germany (n = 3361) were followed for up to 6 years. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the associations of d-ROMs and TTL (measured from blood samples collected shortly after CRC diagnosis) with overall survival (OS) and disease-specific survival (DSS) were estimated using multivariable Cox regression. Particularly pronounced associations of higher d-ROMs with lower survival were observed in stage IV patients, with patients in the highest (vs lowest) tertile having much lower OS (HR = 1.52, 95% CI = 1.14-2.04) and DSS (HR = 1.61, 95% CI = 1.20-2.17). For TTL, strong inverse associations of TTL with mortality were observed within all stages. In patients of all stages, those in the highest (vs lowest) quintile had substantially higher OS (HR = 0.48, 95% CI = 0.38-0.62) and DSS (HR = 0.52, 95% CI = 0.39-0.69). The addition of these biomarkers to models that included age, sex, tumor stage and subsite significantly improved the prediction of CRC prognosis. The observed strong associations of higher d-ROMs and lower TTL levels with poorer prognosis even in stage IV patients suggest that oxidative stress contributes significantly to premature mortality in CRC patients and demonstrate a large potential of these biomarkers in enhancing the prediction of CRC prognosis beyond tumor stage.