Metabolic syndrome and colorectal cancer: is hyperinsulinemia/insulin receptor-mediated angiogenesis a critical process?

OBJECTIVE

Components of metabolic syndrome (MS) have been individually linked to colorectal cancer risk and prognosis; however, an understanding of the dominant mechanisms is lacking.

MATERIALS AND METHODS

Twenty-one patients (10 MS; 11 non-MS) with resectable colorectal cancer were prospectively enrolled. Patients were classified for MS by the World Health Organization criteria and tested for circulating vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), insulin-like growth factor-1 (IGF-1), fasting insulin, and tumor expression of IGF-1 receptor (IGF-1R), insulin-receptor (IR) and receptor for advanced glycation end-products (RAGE). Circulating markers were re-tested 6 months after surgery.

RESULTS

The MS group had significantly higher baseline and post-operative fasting insulin levels (p < 0.001 and 0.003). No differences were observed in circulating IL-6, VEGF, IGF-1 and free IGF-1. By immunohistochemistry (IHC), IGF-1R expression was significantly higher in tumor vs. normal tissues (p < 0.001) while IR expression showed no difference. Interestingly, 64% of tumors demonstrated high IR positivity in the vessels within or surrounding the tumor stroma, but not in the vessels away from the tumor. By reverse transcription polymerase chain reaction (RT-PCR), tumor IGF-1R over-expression (80%) was confirmed, but there was no difference between MS and non-MS patients. Tumor RAGE over-expression was found in 67% of patients and was equally distributed between the two groups.

CONCLUSIONS

Hyperinsulinemia was the only significant factor distinguishing patients with colorectal cancer who have MS. The preferential over-expression of IR in the peri-tumoral microvessels suggests that hyperinsulinemia might contribute to colorectal cancer growth by enhancing angiogenesis.

Predicting the risk of chemotherapy toxicity in older patients: the Chemotherapy Risk Assessment Scale for High-Age Patients (CRASH) score

BACKGROUND

Tools are lacking to assess the individual risk of severe toxicity from chemotherapy. Such tools would be especially useful for older patients, who vary considerably in terms of health status and functional reserve.

METHODS

The authors conducted a prospective, multicentric study of patients aged ≥70 years who were starting chemotherapy. Grade 4 hematologic (H) or grade 3/4 nonhematologic (NH) toxicity according to version 3.0 of the Common Terminology Criteria for Adverse Events was defined as severe. Twenty-four parameters were assessed. Toxicity of the regimen (Chemotox) was adjusted using an index to estimate the average per-patient risk of chemotherapy toxicity (the MAX2 index). In total, 562 patients were accrued, and 518 patients were evaluable and were split randomly (2:1 ratio) into a derivation cohort and a validation cohort.

RESULTS

Severe toxicity was observed in 64% of patients. The Chemotherapy Risk Assessment Scale for High-Age Patients (CRASH) score was constructed along 2 subscores: H toxicity and NH toxicity. Predictors of H toxicity were lymphocytes, aspartate aminotransferase level, Instrumental Activities of Daily Living score, lactate dehydrogenase level, diastolic blood pressure, and Chemotox. The best model included the 4 latter predictors (risk categories: low, 7%; medium-low, 23%; medium-high, 54%; and high, 100%, respectively; P(trend) < .001). Predictors of NH toxicity were hemoglobin, creatinine clearance, albumin, self-rated health, Eastern Cooperative Oncology Group performance, Mini-Mental Status score, Mini-Nutritional Assessment score, and Chemotox. The 4 latter predictors provided the best model (risk categories: 33%, 46%, 67%, and 93%, respectively; P(trend) < .001). The combined risk categories were 50%, 58%, 77%, and 79%, respectively; P(trend) < .001). Bootstrap internal validation and independent sample validation demonstrated stable risk categorization and P(trend) < .001.

CONCLUSIONS

The CRASH score distinguished several risk levels of severe toxicity. The split score discriminated better than the combined score. To the authors' knowledge, this is the first score systematically integrating both chemotherapy and patient risk for older patients and has a potential for future clinical application.

Muscle weakness is a significant problem in older patients receiving chemotherapy

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Background: Accurate prediction of toxicities from chemotherapy in the elderly could lead to improved decision making and supportive care. Methods: A large prospective multicentric cohort study of older cancer patients undergoing chemotherapy is underway to document the occurrence of chemotherapy toxicity and to develop a predictive score: the CRASH score (Chemotherapy Risk Assessment Score for High Age patients). Toxicity, including muscle weakness, is assessed using the Common Toxicity Criteria v.3.0. Results: An analysis of the first 200 patients entered in the study revealed an infrequently highlighted side effect: muscle weakness. Twenty patients were not evaluable for this analysis. Muscle weakness was reported by 22 patients. This represented 12.2% of the patients, of whom 13 (7.2%) had grade 3 muscle weakness. There was no grade 4 muscle weakness. This side effect appears to be independent from fatigue: only 4/22 patients reported concomitant severe (grade 3–4) fatigue, and among the 24 patients with severe fatigue, only 4 reported any muscle weakness. Muscle weakness occurred fairly early during the treatment: median 30 days (range 6–126 days). The muscle weakness was predominantly of two types: a generalized muscle weakness, or a weakness affecting the lower extremities. It was accompanied by falls in two patients. That weakness was present across tumor types, chemotherapy types, individual physicians, and oncology centers. Like the rest of the study population, the majority of these patients had advanced disease. Other frequent severe side effects were: grade 4 neutropenia 31.7%; grade 3–4: hypokalemia 8.8%, hyperglycemia 8.3%, hyponatremia 7.2%, febrile neutropenia 7.2%, diarrhea 7.2%, infection with neutropenia 6.7%. Conclusion: Muscle weakness is a frequent and clinically significant side effect of chemotherapy in the elderly, distinguishable from fatigue. This could be targeted by a preventive physical therapy intervention to prevent muscle deconditioning.

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