Infectious complications in head and neck cancer patients treated with cetuximab: propensity score and instrumental variable analysis

Bloodstream infection in patients with head and neck cancer: a major challenge in the cetuximab era

PURPOSE

To assess the impact of bloodstream infection (BSI) in patients with head and neck cancer (HNC) in the cetuximab era.

METHODS

We prospectively analysed the epidemiology, microbiology and outcomes of 51 BSI episodes occurring in 48 patients with HNC (2006-2017). We performed a retrospective matched-cohort study (1:2) to determine the risk factors for BSI. Finally, we compared patients who died with those who survived to identify risk factors for mortality.

RESULTS

The most frequent HNC localization was the oropharynx (43%), and pneumonia was the most frequent source (25%). Gram-positive BSI occurred in 55% cases, mainly due to Streptococcus pneumoniae (21%), and among Gram-negatives, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae were the most frequent. Hypoalbuminemia (OR 8.4; 95% CI, 3.5-19.9), previous chemotherapy (OR, 3.2; 95% CI, 1.3-7.4) and cetuximab therapy (OR, 2.8; 95% CI, 1.6-6.7) were significant risk factors for BSI. Patients with BSI had a higher overall case-fatality rate than patients without BSI (OR, 4.4; 95% CI, 1.7-11.8). Hypoalbuminemia was an independent risk factor for the early (7 day) and overall (30 day) case-fatalities, with ORs of 0.8 (95% CI, 0.6-0.9) and 0.8 (95% CI, 0.7-0.97), respectively. The presence of comorbidities (OR, 7; 95% CI, 1.4-34) was also an independent risk factor for overall case-fatality.

CONCLUSIONS

BSI causes high mortality in patients with HNC and is most often secondary to pneumonia. It occurs mainly among patients with hypoalbuminemia who receive treatment with cetuximab or chemotherapy. The development of BSI in patients with HNC impairs their outcome, especially in the presence of hypoalbuminemia and comorbidities.

Irradiation enhanced risks of hospitalised pneumonopathy in lung cancer patients: a population-based surgical cohort study

OBJECTIVE

Pulmonary radiotherapy has been reported to increase a risk of pneumonopathy, including pneumonitis and secondary pneumonia, however evidence from population-based studies is lacking. The present study intended to explore whether postoperative irradiation increases occurrence of severe pneumonopathy in lung cancer patients.

DESIGN, SETTING AND PARTICIPANTS

The nationwide population-based study analysed the Taiwan National Health Insurance Research Database (covered >99% of Taiwanese) in a real-world setting. From 2000 to 2010, 4335 newly diagnosed lung cancer patients were allocated into two groups: surgery-RT (n=867) and surgery-alone (n=3468). With a ratio of 1:4, propensity score was used to match 11 baseline factors to balance groups.

INTERVENTIONS/EXPOSURES

Irradiation was delivered to bronchial stump and mediastinum according to peer-audited guidelines.

OUTCOMES/MEASURES

Hospitalised pneumonia/pneumonitis-free survival was the primary end point. Risk factors and hazard effects were secondary measures.

RESULTS

Multivariable analysis identified five independent risk factors for hospitalised pneumonopathy: elderly (>65 years), male, irradiation, chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD). Compared with surgery-alone, a higher risk of hospitalised pneumonopathy was found in surgery-RT patients (HR, 2.20; 95% CI, 1.93-2.51; 2-year hospitalised pneumonia/pneumonitis-free survival, 85.2% vs 69.0%; both p<0.0001), especially in elderly males with COPD and CKD (HR, 13.74; 95% CI, 6.61-28.53; p<0.0001). Unexpectedly, we observed a higher risk of hospitalised pneumonopathy in younger irradiated-CKD patients (HR, 13.07; 95% CI, 5.71-29.94; p<0.0001) than that of elderly irradiated-CKD patients (HR, 4.82; 95% CI, 2.88-8.08; p<0.0001).

CONCLUSIONS

A high risk of hospitalised pneumonopathy is observed in irradiated patients, especially in elderly males with COPD and CKD. For these patients, close clinical surveillance and aggressive pneumonia/pneumonitis prevention should be considered. Further investigations are required to define underlying biological mechanisms, especially for younger CKD patients.

Subgroup Analysis According to Human Papillomavirus Status and Tumor Site of a Randomized Phase II Trial Comparing Cetuximab and Cisplatin Combined With Radiation Therapy for Locally Advanced Head and Neck Cancer

PURPOSE

We report a subgroup analysis primarily focused on human papillomavirus (HPV)-related oropharyngeal cancer (OPC) from the Cetuximab Plus Radiotherapy Versus Cisplatin Plus Radiotherapy in Locally Advanced Head and Neck Cancer (CTXMAB+RT; ClinicalTrials.gov identifier NCT01216020) trial comparing radiation therapy with concomitant cisplatin (CDDP) versus concomitant cetuximab (CTX) as first-line treatment of locally advanced head and neck cancer.

METHODS AND MATERIALS

The data from all the patients in the CTXMAB+RT trial were reviewed and separately analyzed in 3 groups: p16-positive OPC, p16-negative OPC, and all other cancer sites. The endpoints of interest were locoregional control (LC), metastasis-free survival, cancer-specific survival (CSS), and overall survival (OS). Severe and fatal infectious complications were also reanalyzed to more thoroughly investigate the association between CTX treatment and potentially life-threatening reactions.

RESULTS

A total of 33 patients had OPC. The HPV status was available for 30 of the 33 patients. Thus, 3 patients treated with CDDP but with unknown HPV status were excluded from the survival analysis. The small number of patients in each group did not allow for significance to be reached for any of the outcomes analyzed. A trend favored the CDDP arm in the p16-positive group for the 2-year LC and OS/CSS rates (100% vs 72.9% and 100% vs 77.8% for CDDP vs CTX). In this group of patients, the hazard ratio for the treatment arm (CTX vs CDDP) was 4.7 (95% confidence interval [CI] 0.5-40.3) for LC, 3.4 (95% CI 0.4-30.5) for OS, and 2.4 for CSS (95% CI 0.2-23.2). A survival benefit favoring the CDDP arm was not evident in the p16-negative OPC group or for patients with cancer located in other sites. Serious or fatal infectious complications occurred only in the CTX arm.

CONCLUSIONS

In patients with p16-positive OPC in the CTXMAB+RT trial, CTX had lower efficacy than CDDP, with possible implications for treatment selection in this clinical setting.

Performing both propensity score and instrumental variable analyses in observational studies often leads to discrepant results: a systematic review

OBJECTIVES

Propensity score (PS) and instrumental variable (IV) are analytical techniques used to adjust for confounding in observational research. More and more, they seem to be used simultaneously in studies evaluating health interventions. The present review aimed to analyze the agreement between PS and IV results in medical research published to date.

STUDY DESIGN AND SETTING

Review of all published observational studies that evaluated a clinical intervention using simultaneously PS and IV analyses, as identified in MEDLINE and Web of Science.

RESULTS

Thirty-seven studies, most of them published during the previous 5 years, reported 55 comparisons between results from PS and IV analyses. There was a slight/fair agreement between the methods [Cohen's kappa coefficient = 0.21 (95% confidence interval: 0.00, 0.41)]. In 23 cases (42%), results were nonsignificant for one method and significant for the other, and IV analysis results were nonsignificant in most situations (87%).

CONCLUSION

Discrepancies are frequent between PS and IV analyses and can be interpreted in various ways. This suggests that researchers should carefully consider their analytical choices, and readers should be cautious when interpreting results, until further studies clarify the respective roles of the two methods in observational comparative effectiveness research.

Sepsis in head and neck cancer patients treated with chemotherapy and radiation: Literature review and consensus

The reporting of infection/sepsis in chemo/radiation-treated head and neck cancer patients is sparse and the problem is underestimated. A multidisciplinary group of head and neck cancer specialists from Italy met with the aim of reaching a consensus on a clinical definition and management of infections and sepsis. The Delphi appropriateness method was used for this consensus. External expert reviewers then evaluated the conclusions carefully according to their area of expertise. The paper contains seven clusters of statements about the clinical definition and management of infections and sepsis in head and neck cancer patients, which had a consensus. Furthermore, it offers a review of recent literature in these topics.

Incidence and risk of severe infections associated with anti-epidermal growth factor receptor monoclonal antibodies in cancer patients: a systematic review and meta-analysis

BACKGROUND

Anti-epidermal growth factor receptor (EGFR)-monoclonal antibodies (MoAbs) have been widely used in a variety of malignancies. Severe infections (≥grade 3) are potentially life-threatening adverse events with these drugs. However, the contribution of anti-EGFR MoAbs to infections is still unknown. We performed this meta-analysis to determine the overall incidence and risk of severe infections in cancer patients treated with these drugs.

METHODS

The databases of PubMed and abstracts presented at oncology conferences and published in the proceedings were searched for relevant studies from January 2000 to May 2014. Summary incidences, relative risks (RRs) and 95% confidence intervals (CIs) were calculated by using either random effects or fixed effect models according to the heterogeneity of included studies.

RESULTS

A total of 14,066 patients from 26 randomized controlled trials (RCTs) were included. The use of anti-EGFR-MoAbs significantly increased the risk of developing severe infections (RR 1.34, 95%CI: 1.10 to 1.62, P=0.003) in cancer patients, but not for fatal infections (RR 1.62, 95%CI: 0.81 to 3.26, P=0.18). Meta-regression indicated the infections might possibly occur early in the treatment with anti-EGFR MoAbs. On sub-group analysis, the risk of severe infections significantly varied with tumor type (P=0.001). When stratified by specific anti-EGFR MoAbs, a significantly increased risk of infections with cetuximab was observed (P<0.001), but not for panitumumab (P=0.98). Additionally, the use of anti-EGFR MoAbs significantly increased the risk of severe infections when used in conjunction with cisplatin (RR 1.48, 95%CI 1.22 to 1.79, P<0.001) or irinotecan (RR 1.53, 95%CI 1.12 to 2.10, P=0.008). When stratified by specific infectious events, anti-EGFR-MoAbs significantly increased the risk of developing severe sepsis (RR 4.30, 95%CI: 1.80 to 10.27; P=0.001).

CONCLUSIONS

Anti-EGFR MoAbs treatment significantly increases the risk of developing severe infectious events in cancer patients. The risk may vary with tumor types. Clinicians should be aware of the risks of severe infections with the administration of these drugs in cancer patients.

Infectious complications in cancer patients treated with anti-EGFR monoclonal antibodies cetuximab and panitumumab: a systematic review and meta-analysis

BACKGROUND

Clinical trials have reported a substantial variation in the risk of infection related to anti-EGFR monoclonal antibodies (mAbs) cetuximab and panitumumab. We performed a systematic review and meta-analysis to assess the infection risk in cancer patients treated with anti-EGFR mAbs.

PATIENTS AND METHODS

We searched PubMed and the ASCO online database of meeting abstracts up to January 2014 for relevant clinical trials. Eligible studies included randomized controlled trials (RCTs) of cetuximab and panitumumab that reported adequate safety data for grade 3-4 infection or febrile neutropenia (FN). The summary incidence, relative risk (RR) and 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 14,957 patients from 28 trials were included. Treatment with anti-EGFR mAbs was associated with an increased risk of high-grade infection (RR, 1.49; 95% CI, 1.33-1.66; P<0.001) and FN (RR, 1.27; 95% CI, 1.09-1.48; P=0.002). The incidence of high-grade infection and FN due to anti-EGFR mAbs was 9.3% (95% CI, 7.2-12.0%) and 5.3% (95% CI, 3.3-8.3%), respectively. A significantly increased risk of high-grade infection was observed in all subgroups analyses (type of anti-EGFR mAb, therapy of control arm and duration of treatment) except for tumor type (only colorectal cancer and non-small cell lung cancer (NSCLC) groups had the increased risk). Subgroup analyses revealed a significantly increased risk of FN in the following subgroups: cetuximab, NSCLC and treatment duration longer than the median of all trials (3.1months).

CONCLUSIONS

The use of anti-EGFR mAbs is associated with a significantly higher risk of high-grade infection and febrile neutropenia.

Association between phosphorylated AMP-activated protein kinase and acetyl-CoA carboxylase expression and outcome in patients with squamous cell carcinoma of the head and neck

Background

Epidemiological studies have indicated that impaired glucose metabolism may increase the risk of squamous cell carcinoma of the head and neck (SCCHN). AMP-activated protein kinase (AMPK) regulates glucose and lipid metabolism via the phosphorylation and subsequent inactivation of its downstream target acetyl-CoA carboxylase (ACC).Thus, we analyzed the expression of pAMPK and its downstream target phosphorylated acetyl-CoA carboxylase (pACC), as well as their impact on the survival of patients with resected SCCHN.

Methods

One hundred eighteen patients with surgically resected SCCHN were enrolled. Immunohistochemical (IHC) staining for pAMPK and pACC was performed using tissue microarrays of operative specimens of SCCHN. The expression was divided into two or three groups according to the IHC score [pAMPK: negative (0), positive (1–3); pACC: negative (0), low expression (1, 2), and high expression (3)]. Statistical analysis was performed to determine the association of pAMPK expression with clinicopathological features and pACC and pErk expression.

Results

The positive rates of pAMPK and pACC expression were 64.4% (76/118) and 68.6% (81/118), respectively. pAMPK was significantly higher in patients aged younger than 60 years (P = 0.024; χ²test) and those with early-stage (T1/T2; P = 0.02; χ² test) and oral cavity (P = 0.026; Fisher’s exact test) tumors. In multivariate analysis, pAMPK expression was not significantly correlated with overall survival (OS) (adjusted hazard ratio [HR]: 0.66; 95% confidence interval [CI]: 0.35–1.23), whereas high pACC expression was independently associated with worse OS in node-positive patients (adjusted HR: 17.58; 95% CI: 3.50–88.18).

Conclusions

Strong expression of pACC was found to be an independent prognostic marker for patients with node-positive SCCHN. Our results suggest that pACC may play a role in tumor progression of SCCHN and may help to identify patient subgroups at high risk for poor disease outcome.

High incidence of ischemic stroke occurrence in irradiated lung cancer patients: a population-based surgical cohort study

Background and Purpose

A high risk of stroke occurrence has been reported in several types of irradiated cancer patients. However, clinical data are lacking in irradiated lung cancer patients. The present study intended to explore a risk level of ischemic stroke occurrence in irradiated lung cancer patients.

Methods

A nationwide population-based database obtained from the Taiwan National Health Insurance was analyzed. Between 2003 and 2006, we recruited 560 resected lung cancer patients into two study groups: surgery-plus-irradiation (n = 112) and surgery-alone (n = 448). Patients treated with chemotherapy were excluded. Propensity score match was used for pairing cases with a ratio of 1∶4. Two-year ischemic-stroke-free survival was defined as the primary endpoint.

Results

Three observations supported a high risk of ischemic stroke occurrence in patients with postoperative irradiation when compared with those patients with surgery alone: first, a high incidence per 1,000 person-year (22.3 versus 11.2, 1.99 folds); second, a low two-year ischemic-stroke-free survival rate (92.2% versus 98.1%, P = 0.019); and third, a high adjusted hazard ratio (HR, 4.19; 95% CI, 1.44–12.22; P = 0.009). More notably, the highest risk of ischemic stroke occurrence was found in irradiated patients who had diabetes mellitus (HR, 34.74; 95% CI, 6.35->100; P<0.0001).

Conclusions

A high incidence of ischemic stroke was observed in irradiated lung cancer patients, especially in those with diabetes mellitus. For these patients, close clinical surveillance and strict diabetes control should be considered. Further studies to define detail biological mechanisms are encouraged.