A competing risk analysis of colorectal cancer recurrence after curative surgery.

BACKGROUND: This study examines the effect of prognostic patient and disease characteristics on colorectal cancer (CRC) recurrence after curative resection. We used competing risk analysis with death as a competing risk. This method provides the clinician a perspective into a patient's actual risk of experiencing a recurrence. METHODS: A retrospective cohort study of patients diagnosed with CRC who underwent curative resection for CRC from 2003-2007 at the Royal University Hospital in Saskatoon was completed. The outcome of interest was the first CRC recurrence, either local or distant metastasis. Demographic data, tumor characteristics, adjuvant treatment and follow-up data, date of local recurrence or metastasis were recorded from the medical record. Univariate analysis was completed to look at the relationship between each of the prognostic indicators and recurrence. Multivariable modelling (subdistribution regression modelling) was done to identify the main risk factors in determining recurrence. RESULTS: Of 148 patients, 38 (25.7%) experienced a recurrence, 16 (10.8%) died without evidence of recurrence, and 94 (63.5%) experienced neither outcome. The median follow-up was 30.5 months (interquartile range 10.6-50). In univariable subdistribution regression, T-stage, N-stage, vascular invasion and positive margins were all predictive of cancer recurrence, with p ≤ 0.001, with subdistribution hazard ratios for T4 stage at 11.93, T3 stage at 2.46, N2 stage at 10.58, and presence of vascular invasion at 4.27. N-stage remained as the sole predictor in multivariable regression. Cumulative incidence function (CIF) of recurrence at 48 months after surgery was 15%, 27% and 90% for N1/2, N3 and N4 respectively. CONCLUSION: The highest CIF of recurrence was associated with T4 stage, N2 stage, and vascular invasion. Patient's age, tumour location, type, or histological grade were not found to have a significant effect on the success of CRC surgery in precluding a recurrence.

Patient opinions on contralateral prophylactic mastectomy: A patient-driven discussion in need of tuning?

BACKGROUND: Rates of contralateral prophylactic mastectomy (CPM) are increasing among women with unilateral breast cancer despite low rates of contralateral recurrence and lack of survival benefit. We aimed to investigate the decisional needs and supports required to ensure adequate and quality decision-making by patients with breast cancer facing the decision regarding CPM. METHODS: In this qualitative study, we used semistructured interviews developed with the use of the Ottawa Decision Support Framework to investigate the decisional needs and supports of women (aged > 18 yr) with nonhereditary breast cancer who had previously discussed CPM with their care provider. Patients were recruited from 2 academic cancer centres in Toronto, Ontario. Interviews were conducted between June 2016 and October 2017. We analyzed responses to the open-ended questions iteratively and inductively to establish major themes within the results. RESULTS: Ten patients were recruited. Eight patients reported having initiated the discussion about CPM. Although most patients reported feeling supported, 6 mentioned some degree of decisional conflict. Cancer risk reduction was the most commonly reported perceived benefit of CPM (9 patients), followed by improved psychologic well-being (7). Most patients (8) did not mention the lack of survival benefit of CPM as a disadvantage of the procedure. Patients indicated that information resources (in 8 cases) and improved counselling from their health care team (in 7) would assist in decision-making. CONCLUSION: Our findings illustrate the disconnect between true and perceived risks (i.e., surgical risk) and benefits (potential recurrence and survival benefit) of CPM, which is not being managed adequately despite support from the health care team. A decision aid may address unmet patient need by providing a reliable resource regarding the benefits and risks of this procedure, while helping patients understand their values and realign their expectations.

Abnormal screens among nonmutation carriers in the High Risk Ontario Breast Screening Program.

BACKGROUND: The Ontario Breast Screening Program was expanded in 2011 to offer annual MRI and mammography to women with high-risk genetic mutations (e.g., BRCA1/2) and women with strong family histories and ≥25% estimated lifetime risk of breast cancer. Data to support high-risk screening is less clear in the nonmutation carrier group, as MRI has lower specificity among this population. The potential unintended consequences may be considerable and need to be explored. We aimed to describe the frequency of abnormal screens and biopsies. METHODS: Demographic surveys and chart review consent were sent to a sample of 441 individuals enrolled in a high-risk screening program at two tertiary care hospitals in Toronto, Ontario. Retrospective cross-sectional chart review was undertaken for clinicopathologic data. The frequencies of abnormal screens and biopsies were calculated. RESULTS: One hundred sixty-nine nonmutation carriers were included. The majority were white, employed, and highly educated. The median International Breast Cancer Intervention Study lifetime risk of breast cancer was 28.0% (range 24.5%-89.0%). 108 individuals (64%) experienced at least 1 abnormal screen and 13 (8%) had 3 or more over a median 3 years of screening (range 1-6 years). Of 55 biopsies, 3 (5.5%) were malignant. The cancer detection rate was 8.4/1000 screens (95% CI 3.2-22.4). CONCLUSIONS: An MRI-based screening program for nonmutation carriers was effective at diagnosing breast cancer. However, this population experienced a high rate of abnormal screens and intervention. Further research is needed to improve the performance of MRI-based screening in these women.

Practitioner Opinion on Contralateral Prophylactic Mastectomy: How Do We Steer a Patient-Driven Discussion?

BACKGROUND: Contralateral prophylactic mastectomy (CPM) is increasing despite a recent statement from The American Society of Breast Surgeons discouraging average-risk women with unilateral breast cancer (BC) from undergoing CPM. The objective of our study was to conduct a needs assessment of BC health practitioners to gather information about their opinions, attitudes, and experiences surrounding CPM. METHODS: The Ottawa Decision Support Framework was the theoretical framework for the development of the interview guide. Semistructured interviews were conducted until data saturation with a convenience sample of 16 BC practitioners (Ontario, Canada), including oncologic and reconstructive surgeons, medical oncologists, and nurse navigators. RESULTS: Nearly all practitioners identified the discussion regarding CPM as patient-initiated. The majority of practitioners (13/16) described their role as supporting the patient in the decision-making process. Practitioners described educating patients on the lack of survival benefit and in general discouraging CPM. Practitioners agreed that most patients demonstrate decisional conflict (11/16) as a barrier to decision-making, and it is a challenge to realign patients' understanding and expectations. Almost all practitioners (15/16) identified a need for information materials to help educate patients on the risks and benefits of CPM and to help realign expectations. CONCLUSIONS: Practitioners have identified CPM in average-risk women with unilateral BC as a patient-driven phenomenon that is on the rise, despite highlighting the increased risk of complications and lack of survival benefit. Our practitioner needs assessment identifies the need for a dynamic decision aid to help guide the shared decision-making process for practitioners and patients.

Metastatic ductal carcinoma of the breast to colonic mucosa.

Breast cancer is the most common malignancy among women, while invasive ductal carcinoma is the most common type of invasive breast cancer. Metastatic spread to the colon and rectum in breast cancer is rare. This report describes a case of a 69-year-old woman with metastatic ductal breast cancer to the rectosigmoid, presenting as an incidental finding on screening colonoscopy. The breast carcinoma was first diagnosed 2 years prior. Colonic biopsies from colonoscopy confirmed metastatic adenocarcinoma consistent with a breast primary. Ultimately her clinical condition worsened as she developed malignant ascites, a small bowel obstruction, and new bone metastases, and the patient succumbed to her illness. Cases of metastatic breast cancer to the gastrointestinal tract have predominantly been lobular breast carcinoma. Increased awareness of colonic metastasis may lead to more accurate diagnosis and earlier systemic treatment.

Damage to the optic chiasm in myelin oligodendrocyte glycoprotein-experimental autoimmune encephalomyelitis mice.

Optic chiasm lesions in myelin oligodendrocyte glycoprotein (MOG)-experimental autoimmune encephalomyelitis (EAE) mice were characterized using magnetic resonance imaging (MRI) and validated using electron microscopy (EM). MR images were collected from 3 days after induction to remission, approximately 20 days after induction. Hematoxylin and eosin, solochrome cyanin-stained sections, and EM images were obtained from the optic chiasms of some mice approximately 4 days after disease onset when their scores were thought to be the highest. T2-weighted imaging and apparent diffusion coefficient map hyperintensities corresponded to abnormalities in the optic chiasms of EAE mice. Mixed inflammation was concentrated at the lateral surface. Degeneration of oligodendrocytes, myelin, and early axonal damage were also apparent. A marked increase in chiasm thickness was observed. T2-weighted and diffusion-weighted MRI can detect abnormalities in the optic chiasms of MOG-EAE mice. MRI is an important method in the study of this model toward understanding optic neuritis.

Blood-brain barrier disruption in CCL2 transgenic mice during pertussis toxin-induced brain inflammation.

BACKGROUND: The chemokine CCL2 has an important role in the recruitment of inflammatory cells into the central nervous system (CNS). A transgenic mouse model that overexpresses CCL2 in the CNS shows an accumulation of leukocytes within the perivascular space surrounding vessels, and which infiltrate into the brain parenchyma following the administration of pertussis toxin (PTx). METHODS: This study used contrast-enhanced magnetic resonance imaging (MRI) to quantify the extent of blood-brain barrier (BBB) disruption in this model pre- and post-PTx administration compared to wild-type mice. Contrast-enhanced MR images were obtained before and 1, 3, and 5 days after PTx injection in each animal. After the final imaging session fluorescent dextran tracers were administered intravenously to each mouse and brains were examined histologically for cellular infiltrates, BBB leakage and tight junction protein. RESULTS: BBB breakdown, defined as a disruption of both the endothelium and glia limitans, was found only in CCL2 transgenic mice following PTx administration and seen on MR images as focal areas of contrast enhancement and histologically as dextrans leaking from blood vessels. No evidence of disruption in endothelial tight junctions was observed. CONCLUSION: Genetic and environmental stimuli were needed to disrupt the integrity of the BBB in this model of neuroinflammation.

Magnetic resonance imaging indicators of blood-brain barrier and brain water changes in young rats with kaolin-induced hydrocephalus.

BACKGROUND: Hydrocephalus is associated with enlargement of cerebral ventricles. We hypothesized that magnetic resonance (MR) imaging parameters known to be influenced by tissue water content would change in parallel with ventricle size in young rats and that changes in blood-brain barrier (BBB) permeability would be detected. METHODS: Hydrocephalus was induced by injection of kaolin into the cisterna magna of 4-week-old rats, which were studied 1 or 3 weeks later. MR was used to measure longitudinal and transverse relaxation times (T1 and T2) and apparent diffusion coefficients in several regions. Brain tissue water content was measured by the wet-dry weight method, and tissue density was measured in Percoll gradient columns. BBB permeability was measured by quantitative imaging of changes on T1-weighted images following injection of gadolinium diethylenetriamine penta-acetate (Gd-DTPA) tracer and microscopically by detection of fluorescent dextran conjugates. RESULTS: In nonhydrocephalic rats, water content decreased progressively from age 3 to 7 weeks. T1 and T2 and apparent diffusion coefficients did not exhibit parallel changes and there was no evidence of BBB permeability to tracers. The cerebral ventricles enlarged progressively in the weeks following kaolin injection. In hydrocephalic rats, the dorsal cortex was more dense and the white matter less so, indicating that the increased water content was largely confined to white matter. Hydrocephalus was associated with transient elevation of T1 in gray and white matter and persistent elevation of T2 in white matter. Changes in the apparent diffusion coefficients were significant only in white matter. Ventricle size correlated significantly with dorsal water content, T1, T2, and apparent diffusion coefficients. MR imaging showed evidence of Gd-DTPA leakage in periventricular tissue foci but not diffusely. These correlated with microscopic leak of larger dextran tracers. CONCLUSIONS: MR characteristics cannot be used as direct surrogates for water content in the immature rat model of hydrocephalus, probably because they are also influenced by other changes in tissue composition that occur during brain maturation. There is no evidence for widespread persistent opening of BBB as a consequence of hydrocephalus in young rats. However, increase in focal BBB permeability suggests that periventricular blood vessels may be disrupted.

Histochemical visualization and diffusion MRI at 7 Tesla in the TgCRND8 transgenic model of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that has been characterized by gross cortical atrophy, cellular neurodegeneration, reactive gliosis, and the presence of microscopic extracellular amyloid plaques and intracellular neurofibrillary tangles. Earlier diagnoses of AD would be in the best interest of managing the patient and would allow for earlier therapeutic intervention. By measuring the apparent diffusion coefficient (ADC) using diffusion-weighted imaging (DWI), a type of magnetic resonance imaging (MRI), one can quantify alterations in water diffusivity resulting from microscopic structural changes in the cell at early stages that are associated with pathophysiological processes of brain injury and/or disease progression. Whether or not this methodology is useful for AD is a question under examination. For example, DWI in suspected AD patients has shown increases in mean ADC values in the hippocampus and diminished diffusion anisotropy in the posterior white matter. However, in some cases, hippocampal ADC values appear not to change in AD patients. Moreover, to our knowledge, all DWI studies in suspected AD patients to date are technically incomplete in experimental design, because corresponding histological sections demonstrating actual plaque deposition are lacking and so it is not clear that ADC changes actually correspond to plaque deposition. In our study, we used DWI in the TgCRND8 transgenic model of Alzheimer's disease in conjunction with histological techniques and found robust plaque deposition in the transgenic strain in older animals (12-16 months old). However, we did not find statistically significant changes (p > 0.05) in ADC values (although ADC values in TgCRND8 mice did decrease in all regions examined) in mice 12-16 months old. Collectively, recent results from human studies and in rodent AD transgenic models support our findings and suggest that amyloid beta plaque load is not likely the major or primary component contributing to diffusional changes, if they occur.

Magnetic resonance imaging of blood-spinal cord barrier disruption in mice with experimental autoimmune encephalomyelitis.

Inflammation, demyelination, and blood-spinal cord barrier (BSB) breakdown occur in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. The purpose of this study was to evaluate the utility of MRI for detecting lesions and BSB disruption in vivo during EAE in the mouse lumbar spinal cord, to determine how MR features of BSB disruption change during the course of disease, and to relate such changes to clinical signs and histological features of disease. Following induction of EAE in C57BL/6 mice, contrast-enhanced (CE) T(1)-weighted MR images were acquired to detect BSB disruption in the lumbar spinal cord at the early stage of disease, at peak disease, and at remission, and T(2)-weighted images were obtained to monitor spinal cord morphology. Following imaging the spinal cords were assessed in situ for general features of inflammation, BSB leakage, activated macrophages/microglia, and demyelination. No focal lesions were evident on T(2)-weighted MR images. BSB disruption was greatest at the onset of signs of disease, and decreased progressively thereafter. Inflammation and demyelination were pronounced at the initial stage of disease and at peak disease, and were decreased at remission. Nonuniform contrast enhancement indicated that breakdown of the BSB occurred predominantly within the white matter (WM) of the spinal cord.