DNA Mismatch Repair-deficient Rectal Cancer Is Frequently Associated With Lynch Syndrome and With Poor Response to Neoadjuvant Therapy.

We evaluated 368 consecutively resected rectal cancers with neoadjuvant therapy for DNA mismatch repair (MMR) protein status, tumor response to neoadjuvant therapy, histopathologic features, and patient survival. Nine (2.4%) rectal cancers were mismatch repair-deficient (MMRD): 8 (89%) Lynch syndrome-associated tumors and 1 (11%) sporadic MLH1-deficient tumor. Of the 9 MMRD rectal cancers, 89% (8/9) had a tumor regression score 3 (poor response) compared with 23% (81/359) of MMR proficient rectal cancers ( P <0.001). Patients with MMRD rectal cancer less often had downstaging after neoadjuvant therapy compared with patients with MMR proficient rectal cancer (11% vs. 57%, P =0.007). In the multivariable logistic regression analysis, MMRD in rectal cancer was associated with a 25.11-fold increased risk of poor response to neoadjuvant therapy (tumor regression score 3) (95% confidence interval [CI]: 3.08-44.63, P =0.003). In the multivariable Cox regression analysis, the only variables significantly associated with disease-free survival were pathologic stage III disease (hazard ratio [HR]=2.46, 95% CI: 1.54-3.93, P <0.001), College of American Pathologists (CAP) tumor regression score 2 to 3 (HR=3.44, 95% CI: 1.76-6.73, P <0.001), and positive margins (HR=2.86, 95% CI: 1.56-5.25, P =0.001). In conclusion, we demonstrated that MMRD in rectal cancer is an independent predictor of poor response to neoadjuvant therapy and infrequently results in pathologic downstaging following neoadjuvant therapy. We also confirmed that MMRD in rectal cancer is strongly associated with a diagnosis of Lynch syndrome. Our results suggest that MMR status may help to provide a more patient-centered approach when selecting neoadjuvant treatment regimens and may help predict tumor response to neoadjuvant therapy.

Combined histopathological risk score using TP53 protein expression, CD8+ T cell density and intratumoral budding is an independent predictor of neoadjuvant therapy response in rectal adenocarcinoma.

AIMS: Neoadjuvant therapy is the recommended treatment for locally advanced rectal adenocarcinoma; however, there remains significant variability in response to therapy. Tumour protein 53 (TP53) has been associated with therapy response and prognosis with conflicting data. Recently, we demonstrated that immune cell density and intratumoral budding (ITB) are predictive factors in rectal cancer. We investigated the predictive value of TP53 immunohistochemistry with CD8+ T cell density and ITB on pretreatment biopsies of rectal adenocarcinoma for response to neoadjuvant therapy. METHODS AND RESULTS: Pretreatment biopsies of rectal adenocarcinoma from 117 patients with neoadjuvant therapy were analysed for TP53 expression by immunohistochemistry, ITB, CD8+ T cell density and mismatch repair protein (MMR) status. Most rectal adenocarcinomas displayed aberrant TP53 expression (86 of 117, 74%). Compared to wild-type TP53, aberrant TP53 expression was associated with proficient MMR status (P = 0.003) and low CD8+ T cell density (P = 0.001). Aberrant TP53 was significantly associated with a partial to poor response to neoadjuvant therapy [odds ratio (OR) = 2.42, 95% confidence interval (CI) = 1.04-5.62, P = 0.04]. A combined histopathological risk score (HRS) was created using CD8+ T cell density, ITB and TP53 expression. Patients were separated into low (none to one factor) and high (two to three factors) HRS categories. In the multivariable model, patients with a high HRS were 3.25-fold more likely to have a partial or poor response to neoadjuvant therapy (95% CI = 1.48-7.11, P = 0.003). CONCLUSIONS: Our study demonstrates that aberrant TP53 expression, high ITB and low CD8+ T cell density in pretreatment biopsies can help predict response to neoadjuvant therapy. These biomarkers may be helpful in identifying patients at risk for therapy resistance.

Intratumoral budding and automated CD8-positive T-cell density in pretreatment biopsies can predict response to neoadjuvant therapy in rectal adenocarcinoma.

Tumor budding and CD8-positive (+) T-cells are recognized as prognostic factors in colorectal adenocarcinoma. We assessed CD8+ T-cell density and intratumoral budding in pretreatment rectal cancer biopsies to determine if they are predictive biomarkers for response to neoadjuvant therapy and survival. Pretreatment biopsies of locally advanced rectal adenocarcinoma from 117 patients were evaluated for CD8+ T-cell density using automated quantitative digital image analysis and for intratumoral budding and correlated with clinicopathological variables on postneoadjuvant surgical resection specimens, response to neoadjuvant therapy, and survival. Patients with high CD8+ T-cell density (≥157 per mm2) on biopsy were significantly more likely to exhibit complete/near complete response to neoadjuvant therapy (66% vs. 33%, p = 0.001) and low tumor stage (0 or I) on resection (62% vs. 30%, p = 0.001) compared with patients with low CD8+ T-cell density. High CD8+ T-cell density was an independent predictor of response to neoadjuvant therapy with a 2.63 higher likelihood of complete response (95% CI 1.04-6.65, p = 0.04) and a 3.66 higher likelihood of complete/near complete response (95% CI 1.60-8.38, p = 0.002). The presence of intratumoral budding on biopsy was significantly associated with a reduced likelihood of achieving complete/near complete response to neoadjuvant therapy (odds ratio 0.36, 95% CI 0.13-0.97, p = 0.048). Patients with intratumoral budding on biopsy had a significantly reduced disease-free survival compared with patients without intratumoral budding (5-year survival 39% vs 87%, p < 0.001). In the multivariable model, the presence of intratumoral budding on biopsy was associated with a 3.35-fold increased risk of tumor recurrence (95% CI 1.25-8.99, p = 0.02). In conclusion, CD8+ T-cell density and intratumoral budding in pretreatment biopsies of rectal adenocarcinoma are independent predictive biomarkers of response to neoadjuvant therapy and intratumoral budding associates with patient survival. These biomarkers may be helpful in selecting patients who will respond to neoadjuvant therapy and identifying patients at risk for recurrence.

Individualized Bayesian Risk Assessment for Cervical Squamous Neoplasia.

BACKGROUND: Cervical screening could potentially be improved by better stratifying individual risk for the development of cervical cancer or precancer, possibly even allowing follow-up of individual patients differently than proposed under current guidelines that focus primarily on recent screening test results. We explore the use of a Bayesian decision science model to quantitatively stratify individual risk for the development of cervical squamous neoplasia. MATERIALS AND METHODS: We previously developed a dynamic multivariate Bayesian network model that uses cervical screening and histopathologic data collected over 13 years in our system to quantitatively estimate the risk of individuals for the development of cervical precancer or invasive cervical cancer. The database includes 1,126,048 liquid-based cytology test results belonging to 389,929 women. From-the-vial, high risk human papilloma virus (HPV) test results and follow-up gynecological surgical procedures were available on 33.6% and 12% of these results (378,896 and 134,727), respectively. RESULTS: Historical data impacted 5-year cumulative risk for both histopathologic cervical intraepithelial neoplasia 3 (CIN3) and squamous cell carcinoma (SCC) diagnoses. The risk was highest in patients with prior high grade squamous intraepithelial lesion cytology results. Persistent abnormal cervical screening test results, either cytologic or HPV results, were associated with variable increasing risk for squamous neoplasia. Risk also increased with prior histopathologic diagnoses of precancer, including CIN2, CIN3, and adenocarcinoma in situ. CONCLUSIONS: Bayesian modeling allows for individualized quantitative risk assessments of system patients for histopathologic diagnoses of significant cervical squamous neoplasia, including very rare outcomes such as SCC.

Multifocal Extraprostatic Extension of Prostate Cancer.

OBJECTIVES: To investigate the prognostic utility of multifocal extraprostatic extension (EPE) on biochemical recurrence after radical prostatectomy. METHODS: We conducted retrospective analysis of biochemical recurrence and prognostic pathologic variables in 673 men with stage pT3a/pT3b prostate cancer from 2000 to 2012. Extent of EPE on radical prostatectomy was divided into three groups: focal EPE (tumor dimension <0.8 mm), established (≥ 0.8 mm), and multifocal (more than one focus of EPE <0.8 mm). RESULTS: Type of EPE had significant effect on recurrence with progressively lower progression-free probability and higher recurrence probability from focal to established to multifocal. Multifocal and established tumors exhibited worse prognostic features and higher hazard ratio than focal. In multivariate analysis, established and multifocal were independent prognostic factors with the greatest adverse prognostic significance associated with multifocal. CONCLUSIONS: Identification of multifocal EPE provides important prognostic information associated with increased likelihood of recurrence compared to focal and established tumors.

Differences in ß-cell function and insulin secretion in Black vs. White obese adolescents: do incretin hormones play a role?

Black youth are at higher risk for type 2 diabetes (T2D) than their White peers. Previously we demonstrated that for the same degree of insulin sensitivity, Black youth have an upregulated ß-cell function and insulin hypersecretion, in response to intravenous (iv) glucose, compared with Whites. To investigate if the same holds true during an oral glucose challenge and because of the important role of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) in augmenting insulin secretion, we examined ß-cell function and incretin hormones in 85 Black and 78 White obese adolescents, with normal glucose tolerance (NGT), during a 2-h oral glucose tolerance test (OGTT) with mathematical modeling of plasma glucose and C-peptide concentrations to assess ß-cell glucose sensitivity (ßCGS), rate sensitivity, potentiation factor, and insulin sensitivity. Incretin, pancreatic polypeptide, and glucagon concentrations were measured during the OGTT. Black obese youth had a heightened early insulin secretion together with significantly greater ßCGS, rate sensitivity, and potentiation factor compared with Whites, with no differences in incretin and glucagon concentrations. Basal and stimulated insulin clearance was lower (p = 0.001) in Black vs. White youth. In conclusion, during an OGTT Black obese youth with NGT demonstrate a pronounced early insulin secretion jointly with heightened ß-cell glucose sensitivity, rate sensitivity, and potentiation factor. These racial disparities in ß-cell function and the pathophysiological components of T2D are unlikely to be attributed to incretin hormones and remain to be investigated further to explain the metabolic basis for the enhanced risk of T2D in back youth.

MLH1-deficient Colorectal Carcinoma With Wild-type BRAF and MLH1 Promoter Hypermethylation Harbor KRAS Mutations and Arise From Conventional Adenomas.

Between 10% and 15% of colorectal carcinomas demonstrate sporadic DNA mismatch-repair protein deficiency as a result of MLH1 promoter methylation and are thought to arise from sessile serrated adenomas, termed the serrated neoplasia pathway. Although the presence of the BRAF V600E mutation is indicative of a sporadic cancer, up to 30% to 50% of colorectal carcinomas with MLH1 promoter hypermethylation will lack a BRAF mutation. We report the clinicopathologic and molecular features of MLH1-deficient colorectal carcinoma with wild-type BRAF and MLH1 promoter hypermethylation (referred to as MLH1-hypermethylated BRAF wild-type colorectal carcinoma, n=36) in comparison with MLH1-deficient BRAF-mutated colorectal carcinoma (n=113) and Lynch syndrome-associated colorectal carcinoma (n=36). KRAS mutations were identified in 31% of MLH1-hypermethylated BRAF wild-type colorectal carcinomas compared with 0% of MLH1-deficient BRAF-mutated colorectal carcinomas and 37% of Lynch syndrome-associated colorectal carcinomas. When a precursor polyp was identified, MLH1-hypermethylated BRAF wild-type colorectal carcinomas arose from precursor polyps resembling conventional tubular/tubulovillous adenomas in contrast to MLH1-deficient BRAF-mutated colorectal carcinomas, which arose from precursor sessile serrated adenomas (P<0.001). Both MLH1-hypermethylated BRAF wild-type colorectal carcinoma and MLH1-deficient BRAF-mutated colorectal carcinoma had a predilection for the right colon compared with Lynch syndrome-associated colorectal carcinoma (86% vs. 92% vs. 49%, P<0.001). There was no significant difference in mucinous differentiation, tumor-infiltrating lymphocytes, Crohn-like reaction, and medullary differentiation between the 3 tumor groups. Using Kaplan-Meier survival functions, there was no significant difference in disease-specific survival between the 3 patient groups (P>0.05). In conclusion, our results indicate that MLH1-hypermethylated BRAF wild-type colorectal carcinomas can harbor KRAS mutations and arise from precursor polyps resembling conventional tubular/tubulovillous adenomas.

ß-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to type 2 diabetes.

Using the hyperglycemic and euglycemic clamp, we demonstrated impaired ß-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled ß-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. ß-Cell function parameters were derived from established mathematical models yielding ß-cell glucose sensitivity (ßCGS), rate sensitivity, and insulin sensitivity in 255 obese adolescents (173 with normal glucose tolerance [NGT], 48 with impaired glucose tolerance [IGT], and 34 with type 2 diabetes [T2D]). The incretin effect was calculated as the ratio of the OGTT-ßCGS to the 2-h hyperglycemic clamp-ßCGS. Incretin and glucagon concentrations were measured during the OGTT. Compared with NGT, ßCGS was 30 and 65% lower in youth with IGT and T2D, respectively; rate sensitivity was 40% lower in T2D. Youth with IGT or T2D had 32 and 38% reduced incretin effect compared with NGT in the face of similar changes in GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) in response to oral glucose. We conclude that glucose sensitivity deteriorates progressively in obese youth across the spectrum of glucose tolerance in association with impairment in incretin effect without reduction in GLP-1 or GIP, similar to that seen in adult dysglycemia.

ß-Cell lipotoxicity in response to free fatty acid elevation in prepubertal youth: African American versus Caucasian contrast.

Prepubertal African American (AA) youth compared with their Caucasian (C) peers have higher insulin secretion, which correlates positively with free fatty acid (FFA) concentration. In our continued efforts to explain the racial disparity in insulinemia, and because FFAs modulate insulin secretion, we hypothesized that AA youth would have a greater response to FFA-induced ß-cell insulin secretion than C youth. We compared the short-term effects of FFA elevation on fasting and glucose-stimulated C-peptide-modeled insulin secretion in prepubertal normal-weight AA versus C peers during a 2-h hyperglycemic clamp (12.5 mmol/L) on two occasions: 1) infusion of normal saline and 2) infusion of 20% intralipid (IL). During IL infusion, insulin sensitivity (IS) declined comparably in AA and C youth. Glucose sensitivity of first- and second-phase insulin secretion showed a significant condition × race interaction being higher in AA youth. Disposition index, ß-cell function relative to IS, declined with IL infusion in AA and C youth, with a significantly greater decrease in Cs compared with AAs. In conclusion, AA and C prepubertal youth both demonstrated a decline in ß-cell function relative to IS during IL infusion, indicative of acute lipotoxicity. The greater decline in C youth compared with AAs may suggest that C youth are more susceptible to ß-cell lipotoxicity than AA youth, or alternatively, that AA youth are hypersensitive to FFA stimulation of ß-cell insulin secretion, consistent with our theory.

HbA(1c) diagnostic categories and ß-cell function relative to insulin sensitivity in overweight/obese adolescents.

OBJECTIVE: The recommended HbA(1c) diagnostic categories remain controversial and their utility in doubt in pediatrics. We hypothesized that alterations in the pathophysiologic mechanisms of type 2 diabetes may be evident in the American Diabetes Association recommended at-risk/prediabetes category (HbA(1c) 5.7 to <6.5%). RESEARCH DESIGN AND METHODS: We compared in vivo hepatic and peripheral insulin sensitivity by [6,6-(2)H(2)] glucose and a 3-h hyperinsulinemic-euglycemic clamp and ß-cell function by a 2-h hyperglycemic clamp (∼225 mg/dL) in overweight/obese (BMI ≥85th percentile) adolescents with prediabetes (HbA(1c) 5.7 to <6.5%) (n = 160) to those with normal HbA(1c) (<5.7%) (n = 44). ß-Cell function was expressed relative to insulin sensitivity (i.e., the disposition index = insulin sensitivity × first-phase insulin). RESULTS: In the prediabetes versus normal HbA(1c) category, fasting glucose, insulin, and oral glucose tolerance test (OGTT) area under the curve for glucose and insulin were significantly higher; hepatic and peripheral insulin sensitivity were lower; and ß-cell function relative to insulin sensitivity was lower (366 ± 48 vs. 524 ± 25 mg/kg/min; P = 0.005). A total of 27% of youth in the normal HbA(1c) category and 41% in the prediabetes HbA(1c) category had dysglycemia (impaired fasting glucose and/or impaired glucose tolerance) by a 2-h OGTT. CONCLUSIONS: Overweight/obese adolescents with HbA(1c) in the at-risk/prediabetes category demonstrate impaired ß-cell function relative to insulin sensitivity, a metabolic marker for heightened risk of type 2 diabetes. Thus, HbA(1c) may be a suitable screening tool in large-scale epidemiological observational and/or interventional studies examining the progression or reversal of type 2 diabetes risk.

Rosette-forming glioneuronal tumor: a pineal region case with IDH1 and IDH2 mutation analyses and literature review of 43 cases.

Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a mixed glio-neuronal neoplasm recently codified by the World Health Organization WHO Classification of Central Nervous System (CNS) Tumors (2007). To date, 43 cases have been described in the literature; most occurring in the fourth ventricle region. We report the fourth case involving the pineal region in a 16-year-old female with signs of increased intracranial pressure (ICP). A stereotactic biopsy of the mass was followed by a debulking procedure. Both specimens revealed classic RGNT histology. The patient had stable scans 7 months post-resection. The clinical, radiological and histopathologic features of the previously described 43 cases are reviewed along with our illustrative case. Mean age of patients was 30 ± 12.8 years with 1.9:1 female to male ratio. The most common presenting signs related to increased ICP and posterior fossa involvement, including: headache (62.8%), ataxia (39.5%) and vomiting and vertigo (both 16.3%). This tumor usually presents with cystic changes (54.5%) with focal enhancement (60.9%) and hydrocephalus (43.2%). Microcalcifications and satellite lesions were common radiographic observations. All reported cases had the classic biphasic pattern. Rosenthal fibers and eosinophilic granular bodies are each present in approximately two thirds of cases. Ki-67 labeling index is consistently low (mean (%): 1.8 ± 0.75 SD). The isocitrate dehydrogenase 1 or 2 mutation found in low grade diffuse gliomas is not identified in this RGNT case. Reported outcome is nearly uniformly excellent after complete or subtotal resection. A solitary report of recurrence after 10 years and the limited experience with this entity suggest that long term follow up is advisable.