Expression Of DNA Mismatch Repair Proteins Research Articles

Two Cases of Mixed Mullerian Adenosarcoma and Endometrioid Adenocarcinoma of the Uterus

Abstract Introduction/Objective Endometrioid adenocarcinoma (EA) arising in close spatial association with Mullerian adenosarcoma (MA) is a recently described entity that should be distinguished from carcinosarcoma. Methods/Case Report We describe two cases of mixed MA and EA of the uterus that presented in our institution in the last 10 years. Both patients were in their 8th decade, showed low grade EA, low stage uterine tumor (pT1bN0), with MA with sarcomatous overgrowth. Clinically, they presented with post-menopausal bleeding and both with history of a first degree relative with colon cancer at the age of 41 and 25, respectively. In case 1, the MA measured 13 cm with rhabdomyosarcoma. Case 2 had a 6 cm polypoid mass protruding from the cervical os. In case 1, the patient had laparoscopic total abdominal hysterectomy with bilateral salpingoophorectomy (TAH-BSO) and bilateral sentinel node biopsies. The patient was disease-free for 6 months, after which she presented with abdominal recurrence by CT scan. She was treated with chemotherapy (Adriamycin and Doxorubicin) but passed away 15 months after surgery. Case 2 presented recently and has been asymptomatic and disease free 2 months after laparoscopic TAH-BSO and bilateral sentinel node biopsies. Both cases showed preservation of DNA mismatch repair protein expression. Results (if a Case Study enter NA) NA Conclusion Twenty two out of 23 cases of this entity were described in the largest series by Hallani et al in the literature. It was suggested that the prognosis of these “mixed” tumors appears to be driven by the sarcomatous component, with only 2 deaths in the series due to MA with rhabdomyosarcoma or sarcomatous overgrowth. When MA with sarcomatous overgrowth was compared with carcinosarcoma by Krivak et al., MA with sarcomatous overgrowth had worse prognosis than carcinosarcoma. More cases of mixed MA and EA are needed for us to determine whether MA with sarcomatous overgrowth in this entity should be treated differently.

IMMU-54. PNEUMOCYSTIS JIROVECII PNEUMONIA INFECTION IN A PATIENT WITH ANAPLASTIC ASTROCYTOMA AND RADIATION NECROSIS IN THE SETTING OF CORTICOSTEROID AND PEMBROLIZUMAB USE

Abstract We present a case with anaplastic astrocytoma and radiation-induced brain necrosis, diagnosed with pneumocystis jirovecii pneumonia(PJP) while receiving corticosteroid and pembrolizumab, an immune checkpoint inhibitor(ICI). ICIs have significantly changed management of many cancer types and are known to be associated with immune related adverse events(irAEs). Recently, concerns have emerged regarding the potential relationship between ICI use and infection risks, and PJP, a rare opportunistic infection, has been reported in patients with ICI treatments with or without corticosteroid use. A 40-year-old man with anaplastic astrocytoma and radiation-induced brain necrosis on corticosteroid and pembrolizumab presented with high fever and tachycardia over three days, and the patient later developed hypoxia and cough. The patient was on dexamethasone for brain radiation necrosis for two months and he received one dose of pembrolizumab two weeks prior to his symptom onset, based on genetic information that showed hypermutated tumor and abnormal DNA mismatch repair protein expression. Chest CT showed abnormal findings from infectious or inflammatory process. Bronchoalveolar lavage sample confirmed positive pneumocystis jiroveci PCR test, confirmed PJP, and he was treated with clindamycin, primaquine, and prednisone. To the best of our knowledge, this is the first reported case of PJP in a patient with primary brain tumor receiving corticosteroid and pembrolizumab. ICIs are being investigated in patients with primary brain tumors and wildly used in patients with malignancies with frequent central nervous system involvements, such as malignant melanomas and non-small cell lung cancers. Awareness of risk for infectious conditions including PJP in patients on ICI treatment, especially with corticosteroid use is crucial for implementing appropriate prophylactic measures and prompt diagnosis and treatment interventions.

Intrathyroid thymic carcinoma: A clinicopathological analysis of 22 cases

ObjectiveIntrathyroid thymic carcinoma (ITTC) is a rare malignancy. The current understanding of ITTC is inadequate, and there is no standard treatment for ITTC. In the present study, we aimed to explore the clinicopathological characteristics of ITTC and identify potential therapeutic targets. MethodsThe clinicopathological characteristics of 22 ITTC patients at our institution were reviewed. The expression of DNA mismatch repair (MMR) proteins and PD-L1 in ITTC were assessed by immunohistochemistry (IHC). ResultsAll patients underwent surgery. There were nine females and 13 males, with a slight male predominance. Their ages ranged from 42 to 79 years (average, 54. 1 years). The diameters of the neck masses ranged from 10 to 100 mm (average, 39 mm). Ipsilateral lymph node (LN) dissection was performed in 18 patients: 12 demonstrated LN metastasis, six showed no LN metastasis, and no lymph nodes were dissected in four. One patient had liver metastasis. CK5/6, P63, CD5, and CD117 were expressed in all cases. All cases were negative for TTF1, PAX8, thyroglobulin, and BRAF V600E. DNA MMR protein expression was retained in all tested tumors, and EBV-encoded small RNA (EBER) in situ hybridization was consistently negative. The Ki67 proliferation index ranged from 10 to 70 %. All patients were followed-up for 14–134 months, four died, six were lost to follow-up, and the remaining patients survived without disease. The PD-L1 combined positive score ranged from 10 to 80 (average: 40). ConclusionOur results confirm that CD5 and CD117 co-expression support a diagnosis of ITTC. All tumors in this cohort were DNA MMR-proficient and were not associated with Epstein-Barr virus (EBV) infection. A high CPS for PD-L1 suggests that immune checkpoint inhibitor therapy may be worthy of further exploration in patients with ITTC.

Clinicopathological and prognostic significance of DNA mismatch-repair protein expression in gastric adenocarcinoma

Although the significance of DNA mismatch repair (MMR) protein expression in colorectal cancer is well-established, it remains contentious in extra-colorectal cancers and mainly in gastric adenocarcinoma. Data from Africa and Arab world remain limited. This study explored the MMR expression in gastric adenocarcinoma and evaluated its clinicopathological and prognostic signification among Tunisian patients. A retrospective study of 72 gastric adenocarcinomas was carried out. Clinicopathological particularities and patient outcomes were recorded. MMR expression was determined by immunohistochemistry on whole sections of archived material. Survival analysis was realized utilizing the Kaplan-Meier estimates and Log-Rank test. Expression of MMR proteins was observed in 84.7% of gastric adenocarcinoma samples. The 11 remaining samples (15.3%) exhibited an altered pattern of MMR protein. A significant association was identified between deficient MMR expression and advanced age (p = 0.03), intestinal type (p = 0.04) and lymph node metastases (p = 0.04). No other significant relationship was observed with the remaining selected tumor features. Patient survival was significantly associated with lymph node invasion (p = 0.002), distant metastases (p = 0.02) and tumor differentiation (p = 0.03), but not with MMR status (p = 0.83). MMR deficiency was related to advanced-age, intestinal type and nodal metastasis, but not to survival of Tunisian patients with gastric adenocarcinoma. Larger multicenter studies with additional molecular investigation are required to more explore these tumors.

The mutational landscape of upper gastrointestinal adenocarcinomas- A study of similarities and differences

PurposeThe gastrointestinal tract is home to a wide variety of neoplasms. Gastrointestinal adenocarcinomas display distinct prognostic patterns. With the advent of next generation sequencing, attempts are being made to delineate distinct molecular characteristics of these adenocarcinomas from adjoining anatomical sites. MethodsThirty-seven cases of upper gastrointestinal adenocarcinomas including those of the esophagus, gastroesophageal junction, stomach, small intestine and gallbladder were retrieved. Next generation sequencing data consisting of base substitutions, copy number variations, indels and rearrangements, in 324 genes, were analyzed for recurrent genetic abnormalities. Statistical analysis was performed using IBM SPSS25 and SAS software. ResultsGenetic alterations were found in 181 genes. APC mutations were found in 50% of the esophageal adenocarcinomas, 5% of the gastric adenocarcinomas and 33.3% of the small intestinal adenocarcinomas (p = 0.04). PIK3 gene family mutations were found in 10% of the gastric adenocarcinomas, 66% of the gall bladder adenocarcinomas and 66% of the small intestinal adenocarcinomas (p = 0.002). The mutations were found exclusively in the PIK3 class 1 family. TP53 mutations were more common in tumors with intact DNA mismatch repair protein expression as assessed by immunohistochemistry (p = 0.042). ConclusionIn this study, APC gene mutations were found to be more frequent in esophageal and small intestinal adenocarcinomas than previously reported. PIK3 class 1 gene family mutations were found to be more frequent in gallbladder and small intestinal adenocarcinomas. An inverse relationship was found between TP53 mutations and loss of DNA mismatch repair protein expression.

Nectin-4 and DNA mismatch repair proteins expression in upper urinary tract urothelial carcinoma (UTUC) as a model for tumor targeting approaches: an ImGO pilot study

BackgroundUpper urinary tract urothelial carcinoma (UTUC) accounts for only about 5–10% of all urothelial cancers and is characterized by an aggressive and frequently rapidly fatal behavior. However, detailed knowledge of its molecular profile is still lacking.Materials and methodsWe identified, by chart analysis, patients who underwent radical nephroureterectomy or diagnostic biopsy for UTUC between January 2015 and August 2020 at the Santa Maria Hospital of Terni, in Italy. Eligible patients were required to have also adequate clinical informations and follow-up details. The primary objective of the study was to evaluate DNA mismatch repair (MMR) proteins and Nectin-4 immunohistochemical expression in UTUC, looking also for an eventual correlation between these molecular features. The secondary objective was to investigate genomic instability in the case of a MMR protein loss. Expression of proteins was assessed by using immunohistochemistry and microsatellite instability (MSI) performed by next generation sequencing. Nectin-4 expression was reported using an intensity scoring system (score, 0–3+), instead the expression of DNA MMR proteins was indicated as present (no loss) or not present (loss).ResultsThirty four cases have been evaluated and 27 considered eligible for the study with their tumor samples analyzed. Nectin-4 was found to be expressed in 44% of cases and 18.5% of patients showed defective-MMR phenotype. We found a significant correlation between Nectin-4 expression and MSH2/MSH6 protein loss. Out of 7 patients with DNA MMR proteins loss or equivocal phenotype, 3 showed MSI.ConclusionsOur pilot study suggest a possible relationship between Nectin-4 and DNA MMR protein expression in UTUC and a clinically significant correlation between defective MMR phenotype and genomic instability. Because of the possible implications of these data for innovative treatment approaches, the need for further studies in this area is warranted.

CD63 and Dna Mismatch Repair Protein Expression in Prostate Cancer

Abstract Protein expression levels in immunohistochemistry and molecular biomarkers have been reported for their ability to predict recurrence, progression, development of metastases, and patient survival. The molecular features in low- and high-grade prostate cancer can differ and influence treatment decision and prognosis. The objective of the current study was to compare the expression of exosomal biomarkers CD63 and mismatch repair proteins (MSH2, MSH6, MLH1, and PMS2) by immunohistochemistry (IHC) in tissue of patients with prostate cancer and benign hyperplasia. Altogether, 62 patients with prostate acinar adenocarcinoma and 20 patients with prostate benign hyperplasia were enrolled in this retrospective study. CD63, MSH2, MSH6, MLH1, and PMS2 expression was analysed by immunohistochemistry. The obtained results showed that CD63 expression was significantly higher in patients with Grade III–V prostate cancer compared to Grade I–II, respectively; 2.23 (1–3) vs 0.92 (0–2) score, p = 0.001. In addition, a significant positive correlation between CD63 expression and grade groups was revealed (Rho = +0.54; p < 0.0001). Furthermore, progression-free survival was significantly higher in patients with low CD63 expression, compared to high CD63 expression (p = 0.0007). MMR expression was absent in 14 patients (four patients with Grade I–II cancer and 10 patients with Grade III–cancer). MMR was present in all cases of benign prostate hyperplasia (mild to moderate staining). The conclusion was that high grade prostate cancer (Grade groups III–V) was characterised by increased CD63 expression, which correlated with progression-free survival.

Clinical outcomes of patients with POLE mutated endometrioid endometrial cancer

ObjectivesAssess outcomes of a clinical cohort of patients with endometrioid endometrial cancer (EEC) harboring somatic POLE exonuclease domain mutations (EDMs). MethodsPatients were consented to a protocol of tumor-normal massively parallel sequencing of 410–468 cancer related genes. EECs subjected to sequencing from 2014 to 2018 were reviewed. Tumors with somatic POLE EDMs were identified. EECs were assessed for microsatellite instability (MSI) using MSIsensor and immunohistochemical analysis for mismatch repair (MMR) proteins. ResultsOf the 451 EECs sequenced, 23 had a POLE EDM (5%): 20 primary and 3 recurrent tumors sequenced. Nineteen cases (83%) were stage I/II and 4 (17%) were stages III/IV. Thirteen EECs (57%) were of FIGO grades 1/2, 10 (43%) grade 3. All patients were treated with surgery and 17 (89%) received adjuvant therapy. Five (22%) demonstrated loss of DNA MMR protein expression, none were due to Lynch syndrome. MSIsensor scores were conclusive for 21 samples: 19 were microsatellite stable and 2 MSI-high. After median follow-up of 30 months, 4/23 (17%) developed recurrences: 3 with initial grade 3 stage I and 1 with grade 1 stage III disease. One patient with grade 2 stage IV EEC had progressive disease after treatment. ConclusionsPatients with POLE EDM EEC have been shown to have a favorable prognosis. In this real-world cohort of patients, de novo metastatic disease and recurrences in initially uterine-confined cases were observed. Further research is warranted before incorporating the presence of POLE EDM into decision-making regarding adjuvant therapy.

Clinicopathologic and genetic characteristics of interval colorectal carcinomas favor origin from missed or incompletely excised precursors

Interval colorectal cancers may arise from missed or incompletely excised precursors or from a unique rapid progression pathway. We compared the clinicopathologic and molecular profiles of interval and matched non-interval colorectal cancer to determine whether interval colorectal cancers harbor any unique genetic characteristics. Fifty one of 982 colorectal cancer (5.2%) were categorized as interval colorectal cancer, defined as colorectal cancer detected in a diagnostic examination prior to the next recommended colonoscopy and at least 1 year after the last colonoscopy. Clinicopathologic characteristics of interval colorectal cancer were compared to non-interval colorectal cancer matched 1:1 on age, gender, and tumor location. Molecular profile of a subset of interval colorectal cancer (n = 20) and matched (1:2) non-interval colorectal cancer (n = 40) were evaluated using next generation sequencing. Interval colorectal cancer were more likely to occur in the right colon (55% vs. 35%; p = 0.02) and in patients > 70 years of age (55% vs. 34%; p = 0.002). Clinicopathologic features and aberrant DNA mismatch repair protein expression were not significantly different between interval and matched non-interval colorectal cancer. The frequency and spectrum of genetic alterations was also similar in interval and matched non-interval colorectal cancer. Similar findings were seen when analysis was restricted to interval colorectal cancer diagnosed <5 years after last colonoscopy (n = 42). Interval and non-interval colorectal cancers share similar clinicopathologic and genetic profiles when matched for tumor location. Interval colorectal cancers and are more likely to develop from missed or incompletely excised precursors rather than a unique rapid progression pathway.

When Should Patients Undergo Genetic Testing for Hereditary Colon Cancer Syndromes?

When Should Patients Undergo Genetic Testing for Hereditary Colon Cancer Syndromes?

Template for Reporting Results of Biomarker Testing of Specimens From Patients With Carcinoma of the Endometrium.

Template for Reporting Results of Biomarker Testing of Specimens From Patients With Carcinoma of the Endometrium.

Clinical Challenges Associated with Universal Screening for Lynch Syndrome-Associated Endometrial Cancer.

Universal testing for Lynch syndrome is now a routine component of the diagnostic work-up of endometrial cancer patients. The purpose of this study was to identify prospectively the barriers to universal screening based on a tissue testing approach [microsatellite instability (MSI) analysis, IHC for DNA mismatch repair proteins, and MLH1 methylation analysis]. Endometrial carcinoma patients (n = 213) prospectively underwent microsatellite instability and IHC testing for expression of DNA mismatch repair (MMR) proteins. Patients with low (MSI-L) or high (MSI-H) levels of tumor MSI or immunohistochemical loss of MLH1 (and absent MLH1 methylation), MSH2, MSH6, or PMS2 were referred to a genetic counselor for consideration of germline testing. Six discordances (3.1% of tested cases) between IHC and MSI were identified. Half of these exhibited heterogeneous immunohistochemical loss of MLH1/PMS2 and were microsatellite stable (MSS). Of the remaining cases, one was MSS with immunohistochemical loss of MSH6, one was MSS with immunohistochemical loss of MLH1/PMS2 and absent MLH1 promoter methylation, and one was MSI-H with intact expression of DNA MMR proteins. Four patients had MSI-L tumors with intact immunohistochemical protein expression; the clinical significance of MSI-L in endometrial cancer is unclear. Eight patients did not have germline mutations despite tissue testing suggesting Lynch syndrome. Including cases with insufficient tissue for testing and patients declining tissue or germline testing, we encountered significant barriers to universal screening in 13.6% of screened patients (29/213) that preclude designation of a tumor as sporadic or hereditary. Cancer Prev Res; 10(2); 108-15. ©2016 AACR.

Defective DNA Mismatch Repair Influences Expression of Endometrial Carcinoma Biomarkers.

Endometrial endometrioid carcinomas are related to estrogen excess and express estrogen and progesterone receptors. However, hormone receptor expression can be variable from tumor to tumor, and this variability is not always explained by differences in tumor grade. Variable expression of other biomarkers that may be used in the diagnostic work-up of endometrial cancer has also been noted. We hypothesized that mismatch repair (MMR) defects may contribute to this variability. A total of 411 unselected endometrial carcinomas were evaluated for immunohistochemical expression of DNA MMR proteins and MLH1 methylation. Loss of immunohistochemical expression of MLH1, MSH2, MSH6, or PMS2 was defined as MMR deficient; positive expression was defined as MMR intact. A case-control cohort of 80 Grade 2 endometrioid carcinomas was selected from this set (40 MMR deficient, 40 MMR intact). Cases were matched for histotype, grade, and age. Estrogen receptor, progesterone receptor, CK7(+), CK20, and Pax-8 immunohistochemistry was evaluated. The median percentage of CK7 tumor cells was significantly lower in the MMR deficient group compared with the MMR intact group. The mean percentage of tumor cells exhibiting estrogen receptor expression was similar in both the MMR-deficient and MMR intact groups. However, there was greater variability in the MMR-deficient group. Our study shows that MMR defects influence the expression of clinically important biomarkers for endometrioid-type endometrial carcinoma as decreased cytokeratin 7 expression is more commonly associated with MMR deficiency.

Evaluation of DNA Mismatch Repair Protein Expression as a Preliminary Screening for Lynch Syndrome in Young Japanese Women with Endometrial Cancer

Background: Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, is an autosomal dominant cancer syndrome. There is an urgent need to identify patients with Lynch syndrome among patients with endometrial cancer. We aimed to evaluate the efficacy of measuring DNA mismatch repair (MMR) expression in young Japanese endometrial cancer patients to differentiate sporadic and Lynch syndrome-associated tumors. Methods: In a retrospective analysis of 50-year-old or younger endometrial cancer patients, 106 tumors were evaluated for MSH2, MSH6, PMS2, and MLH1 expression by immunohistochemistry. Samples lacking MLH1 were further examined by real-time PCR to evaluate hypermethylation of the MLH1 promoter. Clinical characteristics of patients with suspected Lynch syndrome were then evaluated. Results: Among the 106 samples, 25 (23.6%) had reduced MMR protein expression; MLH1, MSH2 and MSH6 staining was negative in 14, 6 and 5 cases, respectively, while no samples were negative for PMS2. Among the 14 cases lacking MLH1 staining, 10 were found to be associated with MLH1 promoter hypermethylation. Therefore, 15 (14.2%) cases of suspected Lynch syndrome-associated endometrial cancer were found. These patients presented with a significantly lower body mass index and had more first-degree relatives diagnosed with a Lynch syndromeassociated cancer. Our cohort included three Lynch syndrome patients with known mutations, and tumor samples from these patients showed an absence of the specific MMR protein that was mutated. Conclusions: Our results demonstrate that immunohistochemical analysis of tumor samples for MMR protein expression can identify patients with Lynch syndrome. With early detection, colorectal cancer outcomes might be drastically improved.

Germline MLH1 Mutations Are Frequently Identified in Lynch Syndrome Patients With Colorectal and Endometrial Carcinoma Demonstrating Isolated Loss of PMS2 Immunohistochemical Expression.

Current guidelines on germline mutation testing for patients suspected of having Lynch syndrome are not entirely clear in patients with tumors demonstrating isolated loss of PMS2 immunohistochemical expression. We analyzed the clinical and pathologic features of patients with tumors demonstrating isolated loss of PMS2 expression in an attempt to (1) determine the frequency of germline MLH1 and PMS2 mutations and (2) correlate mismatch-repair protein immunohistochemistry and tumor histology with germline mutation results. A total of 3213 consecutive colorectal carcinomas and 215 consecutive endometrial carcinomas were prospectively analyzed for DNA mismatch-repair protein expression by immunohistochemistry. In total, 32 tumors from 31 patients demonstrated isolated loss of PMS2 immunohistochemical expression, including 16 colorectal carcinomas and 16 endometrial carcinomas. Microsatellite instability (MSI) polymerase chain reaction was performed in 29 tumors from 28 patients with the following results: 28 tumors demonstrated high-level MSI, and 1 tumor demonstrated low-level MSI. Twenty of 31 (65%) patients in the study group had tumors demonstrating histopathology associated with high-level MSI. Seventeen patients underwent germline mutation analysis with the following results: 24% with MLH1 mutations, 35% with PMS2 mutations, 12% with PMS2 variants of undetermined significance, and 29% with no mutations in either MLH1 or PMS2. Three of the 4 patients with MLH1 germline mutations had a mutation that results in decreased stability and quantity of the MLH1 protein that compromises the MLH1-PMS2 protein complex, helping to explain the presence of immunogenic but functionally inactive MLH1 protein within the tumor. The high frequency of MLH1 germline mutations identified in our study has important implications for testing strategies in patients suspected of having Lynch syndrome and indicates that patients with tumors demonstrating isolated loss of PMS2 expression without a germline PMS2 mutation must have MLH1 mutation analysis performed.

Clinicopathologic analysis with immunohistochemistry for DNA mismatch repair protein expression in synchronous primary endometrial and ovarian cancers.

Synchronous primary endometrial and ovarian cancers have been an important topic in clinical medicine because it is sometimes difficult to distinguish whether there are 2 primary tumors or a single primary tumor and an associated metastasis. In addition, although these tumors are recommended for either immunohistochemistry for DNA mismatch repair (MMR) proteins or a microsatellite instability test in the Bethesda guidelines as Lynch syndrome-associated cancers, few studies have completed these analyses. In this study, we characterized the clinicopathologic features and the expression pattern of MMR proteins in synchronous primary endometrial and ovarian cancers. Clinicopathologic features and the expression pattern of MMR proteins (MLH1, MSH2, and MSH6) were characterized and analyzed in 32 synchronous primary endometrial and ovarian cancers. Most synchronous cancers are endometrioid type (endometrioid/endometrioid) (n = 24, 75%), grade 1 (n = 19, 59.4%), and diagnosed as stage I (n = 15, 46.9%) in both endometrium and ovary. It is worth mentioning that 75% of the patients (n = 24) had endometriosis, which was more common (n = 21, 87.5%) in endometrioid/endometrioid cancers, whereas only 3 cases (37.5%) were of different histology (P = 0.018). Loss of expression of at least 1 MMR protein was observed in 17 (53.1%) of the endometrial tumors and in 10 (31.3%) of ovarian tumors. Only 4 cases (12.5%) that had specific MMR protein loss showed the same type of loss for both endometrial and ovarian tumors, in which 3 of the cases were losses in MLH1. One case showed concordant MSH6 protein loss, although the cases did not meet the Amsterdam criteria II. These results suggest that most synchronous primary endometrial ovarian cancers are not hereditary cancers caused by germ line mutations but rather sporadic cancers.

Adenocarcinoma of the Minor Duodenal Papilla and Its Precursor Lesions

The minor duodenal papilla drains the accessory pancreatic duct of Santorini and lies proximal to the ampulla of Vater. Adenocarcinoma and its precursor lesions arising in the minor papilla are rare. Literature data thus far are limited to a few individual case reports, and the condition is consequently poorly defined. Our study cases were composed of carcinomas fulfilling all of the following criteria: location at 1.5 to 2.5 cm proximal to the major papilla; presence of associated submucosal pancreatobiliary-type ducts with periductal glands or acinar tissue; a predominant submucosal location of the tumor; and lack of an intestinal-type adenoma in the adjacent duodenal mucosa. Tumors were studied morphologically, immunohistochemically, and clinically. Nine cases fulfilling the inclusion criteria were identified. There were 5 men and 4 women with an age range of 50 to 76 years (median, 72 y). The tumor size ranged from 1.2 to 4.4 cm (median, 3 cm). The carcinomas were of colloid type (3 tumors), pancreatobiliary type (4), or nonmucinous intestinal type (2). Five cases were associated with an intraductal papillary mucinous neoplasm (IPMN)-like precursor lesion within the residual structures of the minor papilla in the duodenal submucosa. Immunohistochemically, the intestinal-type and mucinous-type tumors tended to be positive for CK20, CDX2, MUC2, and B72.3, and pancreatobiliary-type tumors tended to be positive for CK7, MUC1, B72.3, and CA125. Loss of DPC4 (Smad4) expression was found in the pancreatobiliary-type carcinomas only. Two tumors showed loss of DNA mismatch-repair protein expression, one losing MLH1 and PMS2 and the other losing MSH6. Both patients were older than 60 years, and neither had germline mutation testing. Follow-up information was available for 6 patients (median follow-up time, 67.5 mo): 3 of the 6 patients died of disease at 60, 75, and 85 months after surgery, respectively, and all 3 patients had an intestinal-type carcinoma (1 colloid and 2 nonmucinous). The patient whose tumor was MSH6 deficient was alive without evidence of disease 51 months after surgery. In conclusion, adenocarcinomas of the minor papilla are rare tumors occurring predominantly in the sixth to seventh decade. Some of them arise from IPMN-like precursors in the residual submucosal minor papilla tissue. Morphologically, immunohistochemically, and clinically they are similar to ampullary or IPMN-associated pancreatic carcinomas and can exhibit either an intestinal, colloid, or pancreaticobiliary phenotype. DNA mismatch-repair deficiency may occur. A careful gross and histologic examination is essential to accurately recognize the site of origin of minor papilla carcinomas.

Reduction of DNA mismatch repair protein expression in airway epithelial cells of premenopausal women chronically exposed to biomass smoke

Biomass burning is a major source of indoor air pollution in rural India. This study examined whether chronic inhalation of biomass smoke causes change in the DNA mismatch repair (MMR) pathway in the airway cells. For this, airway cells exfoliated in sputum were collected from 72 premenopausal nonsmoking rural women (median age 34years) who cooked with biomass (wood, dung, crop residues) and 68 control women who cooked with cleaner fuel liquefied petroleum gas (LPG) for the past 5years or more. The levels of particulate matters with diameters less than 10 and 2.5μm (PM10 and PM2.5) in indoor air were measured by real-time aerosol monitor. Benzene exposure was monitored by measuring trans,trans-muconic acid (t,t-MA) in urine by high-performance liquid chromatography with ultraviolet detector. Generation of reactive oxygen species (ROS) and level of superoxide dismutase (SOD) in airway cells were measured by flow cytometry and spectrophotometry, respectively. Immunocytochemical assay revealed lower percentage of airway epithelial cells expressing MMR proteins mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2) in biomass-using women compared to LPG-using controls. Women who cooked with biomass had 6.7 times higher level of urinary t,t-MA, twofold increase in ROS generation, and 31% depletion of SOD. Indoor air of biomass-using households had three times more particulate matters than that of controls. ROS, urinary t,t-MA, and particulate pollution in biomass-using kitchen had negative correlation, while SOD showed positive correlation with MSH2 and MLH1 expression. It appears that chronic exposure to biomass smoke reduces MMR response in airway epithelial cells, and oxidative stress plays an important role in the process.

Implementation of routine screening for Lynch syndrome in university and safety-net health system settings: successes and challenges

Routine screening for evidence of DNA mismatch repair abnormalities can identify colorectal cancer patients with Lynch syndrome, but impact in usual care settings requires study. After implementing routine screening at our university and safety-net health systems as usual practice, our aims were to determine outcomes, including screening process quality. We conducted a retrospective cohort study from 1 May 2010 to 1 May 2011. Screening included reflexive immunohistochemistry to evaluate DNA mismatch repair protein expression for patients with colorectal cancer aged ≤70 years, with a cancer genetics team following up results. Screening outcomes, as well as challenges to a high-quality screening process were evaluated. We included 129 patients (mean age 56 years, 36% female); 100 had immunohistochemistry screening completed. Twelve patients had abnormal immunohistochemistry: four with definite Lynch syndrome, four with probable Lynch syndrome, and three without Lynch syndrome; one patient had an incomplete work-up. Lynch syndrome was confirmed for 6/13 asymptomatic relatives tested. Screening process quality was optimal for 77.5% of patients. Barriers to optimal quality screening included ensuring reflexive immunohistochemistry completion, complete follow-up of abnormal immunohistochemistry, and timely incorporation of results into clinical decision making. Usual care implementation of routine screening for Lynch syndrome can result in significant rates of detection, even in a largely safety-net setting. To optimize implementation, challenges to high-quality Lynch syndrome screening, such as ensuring reflexive screening completion and clinically indicated genetic testing and follow-up for abnormal screens, must be identified and addressed.

Abstract PR-01: Properties of adenomas in subjects treated with difluoromethylornithine and sulindac for reduction of colorectal adenomas

Abstract Difluoromethyl ornithine (DFMO), an ornithine decarboxylase inhibitor, and sulindac reduced the occurrence of colorectal adenomas by 70% in a phase III randomized placebo controlled clinical trial. The goal of the current study was to compare adenoma location in the colorectum and biomarker expression by immunohistochemistry of formalin fixed paraffin embedded adenomas from treatment and placebo groups in the trial. To take into account the relationship between the locations in the colorectum of multiple adenoma that were removed from individual subjects, the generalized estimation equation (GEE) method was applied for all analyses. The decrease in the reappearance of metachronous adenomas was similar throughout the colorectum in subjects treated with DFMO and sulindac (P = 0.44). For TP53, Ki67, and c-MYC there were no significant differences in the estimated mean percent of cells staining positive between treated and untreated subjects (P&amp;gt;0.5 for all). For BCL-2, LC3B, CEA, sialy1-Tn, cleaved caspase 3 and apoptosis, the proportion of adenoma with expression levels 1+ to 3+ did not differ between subjects treated with DFMO plus sulindac versus those treated with double placebos. For hMSH2, hMSH6, hMLH1 and hPMS2, there was a loss of staining of a greater number of cells on average in adenomas from the control group compared to adenomas from the subjects treated with DFMO and sulindac. For hMSH2, this difference was statistically significant (P = 0.0004). This finding raises the possibility that DFMO and sulindac protect adenomas from loss of DNA mismatch repair protein expression and provides a rationale for further study of the possible role of DFMO and sulindac on DNA mismatch repair protein regulation and chemoprevention in patients at risk for colorectal carcinoma. In conclusion, DFMO decreases the occurrences of adenomas throughout the colorectum, including the right colon, and may have an effect on DNA mismatch repair enzyme expression. These findings provide further rationale for the use of DFMO as a chemopreventative agent for colorectal carcinoma. Citation Information: Cancer Prev Res 2011;4(10 Suppl):PR-01.