Factors influencing parental consent for participation in clinical research involving their children in Egypt

Factors affecting parents' decision to involve their children in clinical research have not been studied in all cultural backgrounds. We aimed to explore the attitudes and beliefs influencing parents' decision to involve their children in clinical research in Mansoura, Egypt. Of 523 families approached, 357 filled the questionnaire. Only 98 (27.5%) parents consented to involve their child in clinical research. The children of consenters were significantly older than refusers: 8.6 (SD 7.2) versus 2.6 (SD 1.2) years. Factors favouring consent were: research of benefit to child (84.7%), enough explanation about the benefits (40.8%) and to learn more about child's condition (29.6%). Factors favouring refusal were: use of new drugs or vaccines (89.6%) and invasive procedures (84.2%). Parents' rate of consent was positively correlated with the research being non-invasive and the belief that research was of benefit to their child and negatively correlated with belief that refusal may negatively affect the care provided to their child.

Association between pretreatment haemoglobin levels and morphometric characteristics of the tumour, response to neoadjuvant treatment and long-term outcomes in patients with locally advanced rectal cancers

AIM

The study was carried out to investigate whether pretreatment haemoglobin (Hb) levels act as a biomarker in the management of patients with locally advanced rectal cancer.

METHOD

We prospectively collected data on all patients within our cancer network with localized low rectal cancer treated with preoperative radiotherapy/chemoradiotherapy at Mount Vernon Centre for Cancer Treatment between March 1994 and July 2008. Pretreatment Hb level was assessed as an independent variable for the whole study sample and dichotomised at a value of 12 g/dl. A multivariate analysis of covariance (MANCOVA) was conducted on parameters that had significant association on univariate analysis of covariance (ANCOVA) and correlational (Kendall tau/Pearson) analyses. Kaplan-Meier survival analysis and Cox proportional hazard models were used to determine significant prognostic markers. Statistical significance was set at 0.05.

RESULTS

463 patients (male/female 2:1; median age = 66 years, interquartile range = 56.5-73.0) were included in the analysis. There was significant tumour response of T stage (P < 0.001) and N stage (P < 0.001), with 17.6% of patients achieving a pathological complete response. Pretreatment Hb value was inversely related to the craniocaudal vertical tumour length (P = 0.02) and pretreatment T stage of the tumour (P = 0.01). Patients with Hb levels of < 12 g/dl and moderately differentiated adenocarcinoma were less responsive. Local recurrence was more common in patients with a pretreatment Hb of < 12 g/dl (hazard ratio = 1.78) over a median follow up of 24 months, but this was not statistically significant (P = 0.08).

CONCLUSION

The pretreatment Hb level might be used as a biomarker of rectal tumour morphology, response to neoadjuvant chemoradiation and risk of local recurrence.

Abstract P4-01-14: Can MRI predict the response to neoadjuvant chemotherapy in breast cancer accurately?

Introduction: Magnetic resonance imaging (MRI) has been increasingly used to assess response to neoadjuvant chemotherapy (NAC). The aim of this retrospective study was to investigate the accuracy of MRI in predicting pathological complete response (pCR) and residual disease in patients treated with NAC.

Methods: 152 patients with invasive breast cancer were treated with NAC (2005–2009). In our institute the response to neoadjuvant anthracycline (AC) based chemotherapy is monitored with MRI scanning before NAC and after 2 and 4 cycles. Taxane based chemotherapy was substituted for AC chemotherapy if MRI response was deemed inadequate.

Response to NAC was measured using the modified response evaluation criteria in solid tumours (RECIST). Tumour extent and response on final MRI were correlated with the pathological findings on post-surgical specimens. pCR was defined as absence of invasive cancer. Sensitivity and specificity of MRI reporting was determined against response on histopathology. Potential predictive factors for response on MRI were assessed for significance.

Results: In total, patients had 2(14.5%), 3(60.5%) or 4(25%) MRI scans. pCR was seen in 37(24.3%) patients. After 2 cycles of NAC, positive response (partial or complete) was seen on MRI in 76(50%) patients. Response was more likely in focal tumours versus multifocal tumours (chi square (χ2) 3.83, p = 0.05). In the non-responding group (n = 76), 74 had their treatment switched and a later response was detected in 50(67.6%) cases on MRI.

In the 133 patients with 3 or more MRI scans, final MRI size was compared to tumour size on pathology. Median tumour extent on final MRI was 25.5mm (range 0–120) and median whole tumour size on pathology was 22.5mm (range 0–120). MRI response was apparent in 115 (75.7%) cases (sensitivity = 92.3%, specificity = 56.3% and PPV = 93.9%). In a 2-tailed analysis MRI response showed strong correlation with actual pathological response (spearman's = 0.501, p &lt; 0.0001). MRI correctly diagnosed pCR in 15 of 37(40.5%) patients with pCR. Linear regression shows that overall tumour extent on MRI was highly predictive of whole tumour size on pathology (coefficient = 0.459, p &lt; 0.0001). However, MRI overestimated residual disease in 24(18%) cases (median size difference of 39mm, range 12–120mm) and underestimated minimal residual disease in 12(9%) cases.

In univariate analysis, time of response to NAC was a predictor of pCR (p = 0.013), with greater number of early responders having pCR than late responders. Complete response on MRI was a significant predictor of pCR (p &lt; 0.0001), with a greater proportion of patients having pCR compared to those not showing complete response on MRI. Both complete response on final MRI (p = 0.276) and pCR (p = 0.069) show favourable disease-free survival (DFS), however neither reaches statistical significance on Kaplan-Meier curve (Median follow up of 43 months, range 13–78).

Conclusions: Early responders and tumours achieving complete response on MRI are significant predictors of histopathological response. Serial MRI is predictive of response to NAC and possibly also a predictor of DFS. In this series MRI overestimated residual disease in nearly 1 in 5 patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-01-14.

Absence status epilepticus with computed tomographic brain changes following metrizamide myelography

Absence status epilepticus following metrizamide myelography was associated with computed tomographic scan evidence of a high concentration of the dye in brain gray matter. We suggest that absence status epilepticus is due to the direct effect of metrizamide on the cortex and that this clinically treatable condition may have escaped diagnosis in previous reports.