Predicting chemotherapeutic response and toxicity in colorectal cancer

SUMMARY While treatment for colorectal cancer has evolved significantly over the past 10 years with the introduction of active chemotherapeutic agents and targeted therapies, this has been at the cost of increased toxicity for patients; and significant financial burden for governments and patients. Predicting clinical outcomes, especially given the largely elderly patient population involved, is therefore paramount. This review seeks to summarize existing data regarding the prediction of response and toxicity to chemotherapy agents currently used in the treatment of colorectal cancer.

Systemic inflammation and prediction of chemotherapy outcomes in patients receiving docetaxel for advanced cancer

BACKGROUND

Inflammatory markers are strong prognostic factors for survival in a variety of cancers. This study aimed to investigate the relationships between known inflammatory markers and their ability to predict overall survival (OS) in patients receiving docetaxel therapy.

METHODS

Sixty-eight patients with advanced cancer were enrolled in a clinical trial of single agent docetaxel from 2000 to 2002. Inflammation was measured using baseline cytokine concentrations, acute phase reactant proteins and white blood cell counts. The neutrophil/lymphocyte ratio (NLR) and Glasgow Prognostic Score (GPS) were calculated. Associations between inflammatory markers and their predictive value for OS were tested.

RESULTS

The majority of patients had elevated inflammatory markers (50-70%). Strong inter-relationships were observed between the different inflammatory indices. Only NLR and GPS were independently predictive of OS. A combined NLR and GPS score demonstrated 11 month differences in overall OS between patients with normal and elevated inflammatory status. Normalisation of NLR after three doses of chemotherapy was associated with significant improvement in survival.

CONCLUSION

This study found that NLR predicts the clinical outcomes for patients with advanced cancer treated with docetaxel. The clinical utilisation of NLR should be validated in a larger patient population to confirm its utility.

Clinical trial information as a measure of quality cancer care

Participation in clinical trials enables patients to access new treatment options. Evidence shows improved outcomes in participants compared with nonparticipants in non-small-cell, lung, breast, colorectal, and testicular cancers.

Ministry of Health clinical practice guidelines: schizophrenia

The Ministry of Health (MOH) has updated the clinical practice guidelines on Schizophrenia to provide doctors and patients in Singapore with evidence-based treatment for schizophrenia. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Schizophrenia, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov. sg/mohcorp/publications.aspx?id=26138. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Neutrophil/lymphocyte ratio predicts chemotherapy outcomes in patients with advanced colorectal cancer

BACKGROUND

Advances in the treatment of metastatic colorectal cancer (mCRC) in the last decade have significantly improved survival; however, simple biomarkers to predict response or toxicity have not been identified, which are applicable to all community oncology settings worldwide. The use of inflammatory markers based on differential white-cell counts, such as the neutrophil/lymphocyte ratio (NLR), may be simple and readily available biomarkers.

METHODS

Clinical information and baseline laboratory parameters were available for 349 patients, from two independent cohorts, with unresectable mCRC receiving first-line palliative chemotherapy. Associations between baseline prognostic variables, including inflammatory markers such as the NLR and tumour response, progression and survival were investigated.

RESULTS

In the training cohort, combination-agent chemotherapy (P=0.001) and NLR ≤ 5 (P=0.003) were associated with improved clinical benefit. The ECOG performance status 1 (P=0.002), NLR>5 (P=0.01), hypoalbuminaemia (P=0.03) and single-agent chemotherapy (P<0.0001) were associated with increased risk of progression. The ECOG performance status ≥ 1 (P=0.004) and NLR>5 (P=0.002) predicted worse overall survival (OS). The NLR was confirmed to independently predict OS in the validation cohort (P<0.0001). Normalisation of the NLR after one cycle of chemotherapy in a subset of patients resulted in improved progression-free survival (P=0.012).

CONCLUSION

These results have highlighted NLR as a potentially useful clinical biomarker of systemic inflammatory response in predicting clinically meaningful outcomes in two independent cohorts. Results of this study have also confirmed the importance of a chronic systemic inflammatory response influencing clinical outcomes in patients with mCRC.

Reporting clinical trial information: colorectal cancer trials at Sydney Cancer Centre

BACKGROUND

Clinical trial units are integral to the functioning of a medical oncology department with patient access to clinical trials an important component in patient care. There has been a paucity of potential key performance indicators in medical oncology and clinical trial information may be utilised for this purpose. The aim of this study was to record retrospectively and collate prospectively collected information regarding basic demographics, response rate, progression and survival plus grade 3 or 4 toxicity in patients enrolled in clinical trials for metastatic colorectal cancer at the Sydney Cancer Centre between 1999 and 2007.

METHODS

Baseline patient demographics, clinical response, progression dates, grade 3 or 4 toxicities plus treatment-related fatalities were collected from individual clinical trials. Outcome measures were clinical response, progression-free survival and overall survival.

RESULTS

There was a total of 14 trials undertaken during the defined period for patients with metastatic colorectal cancer. There was available information for 243 patient trials with sufficient information regarding response rates, toxicity, progression and survival. Tumour response rates ranged from 27% to 66% for first line chemotherapy trials and 0% to 20% for non-first line chemotherapy trials. The overall progression-free survival was 6.4 months and overall survival 14.0 months for all trials. There was one treatment-related fatality on clinical trial during this period.

CONCLUSIONS

Results of our clinical database have been used here to illustrate the concept and value of reporting clinical trial information in medical oncology. Public reporting of such information may allow for comparisons between units and for quality improvement.

Clinical, laboratory and molecular factors predicting chemotherapy efficacy and toxicity in colorectal cancer

Colorectal cancer (CRC) treatment has evolved significantly over the last ten years with the use of active chemotherapeutic agents including fluoropyrimidines, oxaliplatin and irinotecan plus targeted monoclonal antibodies bevacizumab, cetuximab and panitumumab. The addition of newer chemotherapeutic agents and targeted therapies has improved patient outcomes at the cost of increased toxicity with not all patients benefiting from these treatments. It is necessary for clinicians to more accurately predict clinical outcomes particularly in the predominantly elderly CRC patient population. This review aims to summarise existing data regarding the use of clinical and laboratory variables plus molecular markers in predicting response, survival and toxicity to chemotherapy agents and targeted monoclonal antibodies currently used in the treatment of CRC.

Is it prime time for personalized medicine in cancer treatment?

Over the last decade, with rapidly advancing biotechnology, the understanding of cancer has changed. The genomic era has resulted in an explosion of targeted therapies and prognostic and predictive biomarkers. This article aims to illustrate the advances made in the practice of oncology as well as the potential and limitations of personalized medicine in cancer.

Predictive biomarkers of clinical response to targeted antibodies in colorectal cancer

Targeted mAbs to VEGFR and EGFR are well-established therapies for the treatment of colorectal cancer. The costs and toxicities associated with these novel treatments are not insignificant, and therefore molecular markers that predict treatment efficacy are needed to individualize the therapy administered to each patient. Recent data in this research field support KRAS mutation testing to guide the selection of EGFR inhibitors for the treatment of colorectal cancer. This review discusses the evidence that KRAS mutation analysis can indicate a beneficial response to EGFR inhibitors, and the potential and limitations of other mutations in the VEGF and EGF signaling pathways as predictive molecular markers in this setting.

Cetuximab-associated pulmonary toxicity

There is increasing evidence for the use of epidermal growth factor receptor (EGFR) inhibitors in head and neck, non-small-cell lung, and colorectal cancers. We report the case of a 78-year-old man with metastatic colorectal cancer (CRC) involving liver and lung who received cetuximab plus irinotecan as third-line treatment. Two months later, he presented with signs and symptoms consistent with bronchiolotis obliterans organizing pneumonia secondary to cetuximab. Reports of cetuximab-associated pulmonary toxicity are rare, although there have been extensive reports of interstitial fibrosis with the use of other EGFR inhibitors such as gefitinib and erlotinib. There are many causes of pulmonary infiltrates in patients treated for advanced CRC, and this case highlights the importance of considering drug toxicity.

Targeted plasma proteome profiling for early prediction of chemotherapy response and toxicity in colorectal cancer (CRC)

e15063

Background: Accurate predictors of chemotherapy response and toxicity in CRC are required to improve the safety, efficacy and costs of treatment. Plasma proteomic profiling using multiple reaction monitoring mass spectrometry (MRM-MS) couples assay multiplexing with high specificity to determine levels of pre-selected biomarker proteins. Our aims were to investigate the utility of plasma proteomic profiling using MRM-MS for predicting: (1) early haematological toxicity, (2) response and (3) survival for patients receiving chemotherapy for CRC. Methods: Patients with locally advanced and metastatic CRC receiving chemotherapy were enrolled. Plasma collection was performed pre-chemotherapy, at day 3 and day 15 of treatment. Toxicity assessments (NCI Criteria v3.0) were prospectively collected for all patients and treatment response (RECIST) assessed for patients with metastatic disease. MRM-MS assays were designed for 39 peptides representing 31 liver derived plasma proteins with reported roles in inflammation and/or cancer. Statistical analysis was performed using the 2-sample t-test to assess statistically significant fold change differences (p<0.05) between sample days for: (1) patients with absence or presence of ≥ Grade 2 neutropenia after two cycles and (2) responders (CR and PR) versus non-responders (SD or PD). Results: Plasma proteomic profiling for 39 peptides was performed for 17 patients. The greatest change in protein levels was observed between Day 3 and 15 with 9% of proteins showing a 1.5 fold or greater change with some proteins showing a ≥ 200-fold change in level. Three proteins (clusterin, paraoxanse and apolipoprotein A1) were significantly different in the group analysed for neutropenia and four proteins (kininogen I, serum paraoxonase/ arylestease 1, apolipoprotein A-1 and complement C4a) were significantly different in the group analysed according to response. Survival analysis was not performed due to the short follow up. Discussion: Our results are encouraging for the use of a robust mass spectrometry technique for early prediction of neutropenia and chemotherapeutic response in CRC.

No significant financial relationships to disclose.

Evaluation of plasma total and cleaved cytokeratin 18 as predictive markers of chemotherapy in colorectal cancer

e15091

Background: Cytokeratin 18 (CK18) is a cytoskeletal protein present in the circulation of cancer patients. Caspase-cleaved CK18 fragments are released from apoptotic cells and may be a simple non-invasive tool for measuring response to chemotherapy. This study aims to assess the associations between levels of CK18 with clinical parameters in patients with metastatic colorectal cancer (mCRC) receiving palliative chemotherapy. Methods: Prospectively collected plasma from 23 mCRC patients were analysed for the presence of total CK18 (M65, Peviva) and cleaved CK18 (M30-Apoptosense, Peviva) using an ELISA assay. 8 patients received 2nd-line chemotherapy (irinotecan) and 15 patients received 1st-line 5FU-based chemotherapy. Levels of both total and cleaved CK18 were determined at day 0 prior to chemotherapy and +24 hours for 2nd-line patients or +72 hours for 1st-line patients post-chemotherapy. Patients were grouped as responders (CR + PR) or non-responders (SD + PD) and results were analysed by non-parametric tests (Mann- Whitney and Wilcoxon Signed Rank Tests). Results: The median age of patients was 62 (range 24–79) with 9 patients (39%) responding to chemotherapy. Pre-chemotherapy, both total and cleaved CK18 levels were significantly lower in patients that responded to chemotherapy compared to non-responders [mean total CK18 responders 447.8U/L (95%CI 286.6–609.0 U/L ) versus mean total CK18 non-responders 999.4U/L (95%CI 602.7–1396.1 U/L), p=0.033; mean cleaved CK18 responders 174.7 U/L (95% CI 26.4–323.0) versus mean cleaved CK18 non-responders 331.4 U/L (95%CI 185.3–477.6), p=0.046]. There was a statistically significant increase in the concentration of total CK18 in the post-chemotherapy samples compared to baseline (p=0.003) however there was no association with response (p=0.12). The mean ratio of cleaved: total CK18 was significantly lower after chemotherapy [baseline 0.33 (95% CI 0.28–0.38) versus post-chemotherapy 0.29 (95%CI 0.24–0.34), p=0.01]. The mean ratio of cleaved: total CK18 at baseline was unable to discriminate between responders and non responders (p=0.83). Conclusions: These data suggest that pre-chemotherapy total and cleaved CK18 plasma levels are potential predictors of chemotherapeutic response for patients with mCRC.

No significant financial relationships to disclose.

Utility of the Health Belief Model in predicting compliance of screening in patients with chronic hepatitis B

BACKGROUND

Regular surveillance is recommended for patients with chronic hepatitis B, to select candidates for anti-viral therapy and detect early complications. However, factors that determine compliance are not well studied.

AIM

To determine the utility of the Health Belief Model in explaining non-compliance, among a group of chronic hepatitis B patients for screening.

METHODS

A total of 192 chronic hepatitis B patients who responded to advertisement for free screening took part in a telephonic interview study. Subjects were asked about the five constructs of the Health Belief Model, and factors associated with recent screening were analysed.

RESULTS

The mean age of the subjects was 42.1 +/- 0.7 years; 77% white male, and 97% Chinese. About 108 patients (56%) had recent screening. At multivariate analysis, only the ability to remember date of follow-up (OR: 4.37; 95% CI: 2.07-9.17) and the perception of having to wait a long time for venepuncture (OR: 0.38; 95% CI: 0.19-0.79) were significantly associated with recent screening.

CONCLUSION

Future public health measures should include improving the logistics of follow-up procedures and providing reminders for screening to improve compliance.

The majority of hepatitis B carriers are not on regular surveillance in Singapore

INTRODUCTION

Carriers of hepatitis B virus (HBV) are at risk of developing long-term complications. Regular surveillance helps detect treatable chronic hepatitis, cirrhosis and liver cancer, and is recommended by practice guidelines in the United States, Europe and Singapore. However, there have been few studies evaluating the follow-up of HBV carriers. This study seeks to determine the proportion of HBV carriers on regular follow-up in Singapore and the impact on hepatitis B disease.

METHODS

An advertisement was taken in local newspapers advertising for free screening to HBV carriers. 387 persons answered the advertisement. The screening comprised history-taking, physical examination, blood tests (liver panel, alphafoetoprotein, hepatitis B surface antigen (Ag) and hepatitis B eAg) and ultrasonography of liver. Further evaluation was conducted if the screening results were abnormal.

RESULTS

Of the 387 HBV carriers, 346 (89 percent) were male and 375 (97 percent) were Chinese. Their mean age was 39 years (range 20-60 years) and 36 percent were positive for HBeAg. 247 (64 percent) were not on regular screening over the past 12 months. 19 (5.4 percent) patients were diagnosed to have complications, namely: 13 had HBeAg-positive chronic hepatitis, two had HBeAg-negative chronic hepatitis, one had early liver cancer who recovered well after a curative resection and three had compensated cirrhosis.

CONCLUSION

Our screening programme diagnosed 5.4 percent of complications among 387 asymptomatic HBV carriers. However, 64 percent of the study subjects were not screened regularly and may pose an important public health threat if they develop long-term complications. Further studies are needed to evaluate and improve patient compliance for screening.

Obstructive sleep apnea. Treatment improves quality of life--and may prevent death

Obstructive sleep apnea syndrome may be just an annoyance to an affected person's bed partner, or it can be a more serious and even dangerous condition for the person involved. One clue to the condition is daytime somnolence, although not all sleepy patients have the syndrome. If obstructive sleep apnea syndrome is confirmed by a polysomnogram, a trial of nasal continuous positive airway pressure (NCPAP) is warranted. If daytime somnolence is unaffected, then it is unlikely that the syndrome is the sole cause of the patient's sleepiness. Alternative diagnoses (eg, narcolepsy, atypical depression) should then be considered. Surgery, orthodontic devices, and pharmacotherapy are generally less effective than NCPAP and are usually reserved for patients who cannot tolerate NCPAP. Surgical techniques may be best suited for patients who have clearly defined craniofacial abnormalities and those who cannot tolerate NCPAP. Weight reduction to near ideal body weight and avoidance of benzodiazepines, opiates, and alcohol should be emphasized in all patients with suspected or confirmed sleep apnea.

Falsely elevated CSF total protein due to carryover in a discrete analyzer (Beckman Astra-8)

Falsely elevated values for CSF total protein, as determined in the Beckman Astra-8 Total Protein Module, were shown to be due to a combined effect of sample cross-contamination and reaction cup contamination by serum samples on the same sample tray. Normal CSF may be misdiagnosed as having an abnormally high protein concentration, due to this interference by normal serum samples. To avoid this carryover phenomenon, it is recommended that 3 saline samples be analysed for total protein before the analysis of the CSF samples; alternatively, all the CSF samples should be analysed separately in one batch.

Programmed electrical stimulation to determine the need for antiarrhythmic therapy in patients with complex ventricular ectopic activity

Patients with complex ventricular ectopy (greater than or equal to Lown grade III) and organic heart disease (OHD) are at increased risk for sudden cardiac death. Despite this fact, many such patients will remain free of symptomatic ventricular arrhythmia and thus are unnecessarily exposed to antiarrhythmic drug toxicity and arrhythmic potentiation. Programmed stimulation (PS) was used to direct therapy in 88 patients with asymptomatic ventricular ectopy complicating OHD. Thirty-three had inducible ventricular tachycardia (VT) and underwent treatment. The 55 patients without inducible VT (less than or equal to 6 repetitive ventricular responses) are the focus of this study. Three patients required treatment for persistent cardiac awareness. The remaining 52 have been followed for 22 months off antiarrhythmic drugs and all have remained free of subsequent major arrhythmic events. Therefore, in patients with complex ventricular ectopy, OHD, and absence of prior symptomatic ventricular arrhythmia, PS identifies patients at low risk for future disabling or life-threatening arrhythmic episodes and patients with absence of inducible VT can usually be managed without antiarrhythmic drugs.