Apparent diffusion coefficient as a non-invasive predictor of treatment response and recurrence in locally advanced rectal cancer

AIM

To evaluate the role of pretreatment apparent diffusion coefficient (ADC) as a predictor of treatment response and local recurrence in patients with locally advanced rectal cancer who underwent neoadjuvant therapy.

MATERIALS AND METHODS

Forty-nine patients who underwent preoperative diffusion-weighted magnetic resonance imaging (MRI) followed by neoadjuvant chemoradiation and surgery were enrolled in the study. The mean tumour ADC was measured independently from multiple, non-overlapping regions of interest (ROIs) to cover the entire tumour area on a single section by two radiologists and patients were followed postoperatively for a median of 16.4 months. Diagnostic accuracy of ADC for predicting treatment response and recurrence was evaluated using the area under the receiver-operating characteristic (ROC) curve, sensitivity, specificity, and predictive values. Univariate and multivariate analyses including clinical tumour (cT) staging, carcinoembryonic antigen (CEA) level, lymph-node involvement, tumour grade, surgical margin, vascular involvement, and ADC were performed with respect to recurrence. Interobserver agreement of ADC values was assessed.

RESULTS

Twenty patients showed response to neoadjuvant therapy and recurrence was noted in 17 patients. Low pretreatment ADC, MRI findings of cT4 staging, and node involvement were significantly related to poor treatment response. Sensitivity and specificity of ADC = 0.833 × 10(-3) mm(2)/s for prediction of treatment response was 75 and 48% for reader 1 and 65 and 52% for reader 2, respectively. Univariate and multivariate analyses identified pretreatment tumour ADC as the only predictive factor for recurrence. Sensitivity and specificity of ADC = 0.833 × 10(-3) mm(2)/s for prediction of recurrence was 86 and 77% for reader 1 and 80 and 69% for reader 2, respectively. Interobserver agreement for measuring ADC was good with a kappa value of 0.70.

CONCLUSION

Pretreatment rectal tumour ADC values may be an early biomarker for predicting treatment response and local recurrence in patients who underwent neoadjuvant chemoradiation.

Intestinal alkaline phosphatase prevents metabolic syndrome in mice

Metabolic syndrome comprises a cluster of related disorders that includes obesity, glucose intolerance, insulin resistance, dyslipidemia, and fatty liver. Recently, gut-derived chronic endotoxemia has been identified as a primary mediator for triggering the low-grade inflammation responsible for the development of metabolic syndrome. In the present study we examined the role of the small intestinal brush-border enzyme, intestinal alkaline phosphatase (IAP), in preventing a high-fat-diet-induced metabolic syndrome in mice. We found that both endogenous and orally supplemented IAP inhibits absorption of endotoxin (lipopolysaccharides) that occurs with dietary fat, and oral IAP supplementation prevents as well as reverses metabolic syndrome. Furthermore, IAP supplementation improves the lipid profile in mice fed a standard, low-fat chow diet. These results point to a potentially unique therapy against metabolic syndrome in at-risk humans.

Infectious pathogens and hematologic malignancy

Infectious pathogens have been linked to the genesis of malignancy in a variety of different settings. Initial studies in virology led to the important discovery of key genetic alterations underlying common malignancies, and further, lent support to the notion that malignancy can be promoted by the process of viral infection and cellular transformation. In this review, we summarize a series of hematologic malignancies with derivations from and associations with infectious organisms. Among these are a variety of lymphomas, including Hodgkin's lymphoma (Hodgkin's disease), Burkitt lymphoma, and a host of other non-Hodgkin's lymphomas. Through innovative and ground-breaking studies, some of these malignancies have been directly linked to viral infection, such as the Epstein-Barr virus (EBV), while others have been merely associated with infection through epidemiologic studies and case-reports. Some malignancies have been demonstrated to be caused by viral infection, such as adult T-cell leukemia and lymphoma (ATLL), which is caused by the human T cell lymphotropic virus type I (HTLV-I), in certain endemic area. In the future, additional malignant states may be found to be associated with infectious etiology, which could allow for novel approaches to prevention and treatment.