Immunohistochemical Study and Clinicopathologic Correlation of Cox-2 and Her-2 Expression in Colorectal Carcinoma: A 5-Year Retrospective Study.

BACKGROUND: Colorectal cancer (CRC) is the fourth most common cancer in Nigeria, and it affects mostly persons in their middle age. In a bid to gain some insight into the molecular characteristics of CRC in our environment, we set out to investigate the expression of COX-2 and HER-2 among Nigerian subjects. OBJECTIVES: To evaluate the expression of COX-2 and HER-2 and determine their correlation with clinicopathologic parameters in surgically resected histologically diagnosed cases of colorectal cancer. METHODS: Fifty-three paraffin-embedded tissue blocks of colorectal resections and corresponding patient information were retrieved from the archives of the Anatomic and Molecular Pathology Department of Lagos University Teaching Hospital. A 4-micron slide section was obtained from each specimen and immunohistochemistry for COX-2 and HER-2 expression was performed. RESULTS: Mean age of cases was 53.9years with an almost equal M:F ratio of 1.12:1. Half of the cases were moderately differentiated adenocarcinoma and 17% were high grade tumors. Eighty three percent of the tumours showed positive cytoplasmic COX-2 expression and extremely low membranous HER-2 positivity was observed in 2%. There was no significant correlation between COX-2 expression and age, gender, tumour location, tumour size, depth of invasion or lymph node status. However, COX-2 expression revealed a significant correlation with tumour grade (p= 0.013). CONCLUSION: This study detects a high COX-2 and low HER- 2 expression in colorectal cancer using immunohistochemistry, suggesting a possible role for COX-2 in CRC pathogenesis. This report should trigger further investigations of both markers vis-à-vis the management of CRC in our environment.

CONTEXTE: Le cancer colorectal (CCR) est le quatrième cancer le plus fréquent au Nigeria et il touche surtout les personnes d'âge moyen. Dans le but de mieux comprendre les caractéristiques moléculaires du CCR dans notre environnement, nous avons entrepris d'étudier l'expression de COX-2 et de HER-2 chez les sujets nigérians. OBJECTIFS: Évaluer l'expression de COX-2 et HER-2 et déterminer leur corrélation avec les paramètres clinicopathologiques dans les cas de cancer colorectal diagnostiqués histologiquement et réséqués chirurgicalement. MÉTHODES: Cinquante-trois blocs de tissus inclus en paraffine provenant de résections colorectales et les informations correspondantes sur les patients ont été récupérés dans les archives du département de pathologie anatomique et moléculaire du Lagos University Teaching Hospital. Une section de lame de 4 microns a été obtenue de chaque spécimen et une immunohistochimie pour l'expression de COX-2 et HER-2 a été réalisée. RÉSULTATS: L'âge moyen des cas était de 53,9 ans avec un rapport M:F presque égal de 1,12:1. La moitié des cas étaient des adénocarcinomes modérément différenciés et 17% des tumeurs de haut grade. Quatre-vingt-trois pour cent des tumeurs présentaient une expression cytoplasmique positive de la COX-2 et une positivité HER-2 membranaire extrêmement faible a été observée dans 2 % des cas. Il n'y avait pas de corrélation significative entre l'expression de la COX-2 et l'âge, le sexe, la localisation de la tumeur, la taille de la tumeur, la profondeur de l'invasion ou le statut des ganglions lymphatiques. Cependant, l'expression du COX-2 a révélé une corrélation significative avec le grade de la tumeur (p= 0,013). CONCLUSION: Cette étude détecte une forte expression de COX- 2 et une faible expression de HER-2 dans le cancer colorectal en utilisant l'immunohistochimie, suggérant un rôle possible de COX-2 dans la pathogenèse du CCR. Ce rapport devrait déclencher des investigations plus poussées des deux marqueurs vis-à-vis de la gestion du CRC dans notre environnement.

Pharmacogenomics-Based Point-of-Care Clinical Decision Support Significantly Alters Drug Prescribing.

Changes in behavior are necessary to apply genomic discoveries to practice. We prospectively studied medication changes made by providers representing eight different medicine specialty clinics whose patients had submitted to preemptive pharmacogenomic genotyping. An institutional clinical decision support (CDS) system provided pharmacogenomic results using traffic light alerts: green = genomically favorable, yellow = genomic caution, red = high risk. The influence of pharmacogenomic alerts on prescribing behaviors was the primary endpoint. In all, 2,279 outpatient encounters were analyzed. Independent of other potential prescribing mediators, medications with high pharmacogenomic risk were changed significantly more often than prescription drugs lacking pharmacogenomic information (odds ratio (OR) = 26.2 (9.0-75.3), P < 0.0001). Medications with cautionary pharmacogenomic information were also changed more frequently (OR = 2.4 (1.7-3.5), P < 0.0001). No pharmacogenomically high-risk medications were prescribed during the entire study when physicians consulted the CDS tool. Pharmacogenomic information improved prescribing in patterns aimed at reducing patient risk, demonstrating that enhanced prescription decision-making is achievable through clinical integration of genomic medicine.

SNP discovery, expression and cis-regulatory variation in the UGT2B genes.

UGT2B enzymes metabolize multiple endogenous and exogenous molecules, including steroid hormones and clinical drugs. However, little is known about the inter-individual variation in gene expression and its determinants. We re-sequenced candidate regulatory regions and the partial coding regions (41.1 kb) of UGT2B genes and identified 332 genetic variants. We measured gene expression in normal breast and liver samples and observed different patterns. The expression levels varied greatly across individuals in both tissues and were significantly correlated with each other in liver. Genotyping of tagging single-nucleotide polymorphisms (SNPs) in the same samples and association tests between genotype and transcript levels identified 62 variants that were associated with at least one UGT2B mRNA levels in either tissue. Most of these cis-regulatory SNPs were not shared between tissues, suggesting that this gene family is regulated in a tissue-specific manner. Our results provide insight into studying the role of UGT2B variation in hormone-dependent cancers and drug response.

Atopy is associated with asthma in adults living in rural and urban southwestern Nigeria.

RATIONALE: Factors affecting the course of asthma are not clearly understood in rural and urban communities within low-resource countries. Furthermore, the interactions between atopy, environmental exposure, and helminthic infections in modulating asthma have not been well investigated. OBJECTIVES: To conduct a feasibility study to examine the relationship between atopy and asthma in adults at two rural Health Centers and urban university college hospital in southwestern Nigeria. METHODS: A convenient sample of 55 consecutive patients with stable physician-diagnosed asthma and 55 age-matched nonasthmatic controls seen at the outpatient clinics in two rural Health Centers and an urban university hospital were enrolled. All subjects underwent blood test, allergy skin test, and stool examination for ova and parasites. Wilcoxon sign-rank tests were used to compare serum eosinophilia and allergy skin test between the two groups. RESULTS: Asthmatics in both urban and rural settings had significantly more positive skin reactions to house dust mite, cockroach, mold, and mouse epithelium than nonasthmatic controls (p < .05). Mean total serum IgE was also significantly higher in asthmatics than in nonasthmatic controls (360 vs. 90 IU/L, p <.001). Stool parasitemia was infrequent in both groups and not statistically significant. CONCLUSION: Atopy is associated with adult asthma in southwest Nigeria. Larger studies to confirm the nature of this association and to examine the role of helminthic infection and other environmental factors on the expression of asthma are needed.

Predictors of contralateral breast cancer in BRCA1 and BRCA2 mutation carriers.

PURPOSE: The objective of this study was to estimate the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers; and measure the extent to which host, family history, and cancer treatment-related factors modify the risk. PATIENTS AND METHODS: Patients were 810 women, with stage I or II breast cancer, for whom a BRCA1 or BRCA2 mutation had been identified in the family. Patients were followed from the initial diagnosis of cancer until contralateral mastectomy, contralateral breast cancer, death, or last follow-up. RESULTS: Overall, 149 subjects (18.4%) developed a contralateral breast cancer. The 15-year actuarial risk of contralateral breast cancer was 36.1% for women with a BRCA1 mutation and was 28.5% for women with a BRCA2 mutation. Women younger than 50 years of age at the time of breast cancer diagnosis were significantly more likely to develop a contralateral breast cancer at 15 years, compared with those older than 50 years (37.6 vs 16.8%; P=0.003). Women aged <50 years with two or more first-degree relatives with early-onset breast cancer were at high risk of contralateral breast cancer, compared with women with fewer, or no first-degree relatives with breast cancer (50 vs 36%; P=0.005). The risk of contralateral breast cancer was reduced with oophorectomy (RR 0.47; 95% CI 0.30-0.76; P=0.002). CONCLUSION: The risk of contralateral breast cancer risk in BRCA mutation carriers declines with the age of diagnosis and increases with the number of first-degree relatives affected with breast cancer. Oophorectomy reduces the risk of contralateral breast cancer in young women with a BRCA mutation.

Germline mutations in CDH1 are infrequent in women with early-onset or familial lobular breast cancers.

BACKGROUND: Germline mutations in CDH1 are associated with hereditary diffuse gastric cancer; lobular breast cancer also occurs excessively in families with such condition. METHOD: To determine if CDH1 is a susceptibility gene for lobular breast cancer in women without a family history of diffuse gastric cancer, germline DNA was analysed for the presence of CDH1 mutations in 318 women with lobular breast cancer who were diagnosed before the age of 45 years or had a family history of breast cancer and were not known, or known not, to be carriers of germline mutations in BRCA1 or BRCA2. Cases were ascertained through breast cancer registries and high-risk cancer genetic clinics (Breast Cancer Family Registry, the kConFab and a consortium of breast cancer genetics clinics in the United States and Spain). Additionally, Multiplex Ligation-dependent Probe Amplification was performed for 134 cases to detect large deletions. RESULTS: No truncating mutations and no large deletions were detected. Six non-synonymous variants were found in seven families. Four (4/318 or 1.3%) are considered to be potentially pathogenic through in vitro and in silico analysis. CONCLUSION: Potentially pathogenic germline CDH1 mutations in women with early-onset or familial lobular breast cancer are at most infrequent.

Characterizing early contrast uptake of ductal carcinoma in situ with high temporal resolution dynamic contrast-enhanced MRI of the breast: a pilot study.

Improvements in the reliable diagnosis of preinvasive ductal carcinoma in situ (DCIS) by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are needed. In this study, we present a new characterization of early contrast kinetics of DCIS using high temporal resolution (HiT) DCE-MRI and compare it with other breast lesions and normal parenchyma. Forty patients with mammographic calcifications suspicious for DCIS were selected for HiT imaging using T(1)-weighted DCE-MRI with ∼7 s temporal resolution for 90 s post-contrast injection. Pixel-based and whole-lesion kinetic curves were fit to an empirical mathematical model (EMM) and several secondary kinetic parameters derived. Using the EMM parameterized and fitted concentration time curve for subsequent analysis allowed for calculation of kinetic parameters that were less susceptible to fluctuations due to noise. The parameters' initial area under the curve (iAUC) and contrast concentration at 1 min (C(1 min)) provided the highest diagnostic accuracy in the task of distinguishing pathologically proven DCIS from normal tissue. There was a trend for DCIS lesions with solid architectural pattern to exhibit a negative slope at 1 min (i.e. increased washout rate) compared to those with a cribriform pattern (p < 0.04). This pilot study demonstrates the feasibility of quantitative analysis of early contrast kinetics at high temporal resolution and points to the potential for such an analysis to improve the characterization of DCIS.

Parity and breastfeeding are protective against breast cancer in Nigerian women.

As the relation between reproductive factors and breast cancer risk has not been systematically studied in indigenous women of sub-Saharan Africa, we examined this in a case-control study in Nigeria. In-person interviews were conducted using structured questionnaires to collect detailed reproductive history in 819 breast cancer cases and 569 community controls between 1998 and 2006. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI). Compared with women with menarcheal age<17 years, the adjusted OR for women with menarcheal age>or=17 years was 0.72 (95% CI: 0.54-0.95, P=0.02). Parity was negatively associated with risk (P-trend=0.02) but age at first live birth was not significant (P=0.16). Importantly, breast cancer risk decreased by 7% for every 12 months of breastfeeding (P-trend=0.005). It is worth noting that the distribution of reproductive risk factors changed significantly from early to late birth cohorts in the direction of increasing breast cancer incidence. Our findings also highlight the heterogeneity of breast cancer aetiology across populations, and indicate the need for further studies among indigenous sub-Saharan women.

An exploratory analysis of HER-2 amplification and overexpression in advanced endometrial carcinoma: a Gynecologic Oncology Group study.

OBJECTIVES: To investigate the frequency and potential prognostic or predictive value of HER-2 amplification or overexpression in advanced and recurrent endometrial cancers. METHODS: Immunohistochemical staining (IHC; DAKO Herceptest) and fluorescence in situ hybridization (FISH; Vysis Inc. PathVysion DNA Probe Kit) were performed on specimens collected on a randomized Gynecologic Oncology Group (GOG) protocol testing the addition of paclitaxel to doxorubicin/cisplatin. RESULTS: HER-2 overexpression (either 2+ (moderate) or 3+ (strong) immunostaining) and HER-2 gene amplification (a ratio of HER-2 copies to chromosome 17 (CEP17) copies > or = 2) were detected in 44% (104 of 234; 58 were 2+ and 46 were 3+) and 12% (21 of 182) of specimens, respectively. There was a significant increased frequency of overexpression in serous tumors vs. all others (23 of 38, 61% vs. 81 of 196, 41%, respectively, P=0.03). HER-2 amplification also appeared to be more common in serous tumors, but results were not significant (6 of 28, 21% vs. 15 of 141, 11%, P=0.12). There was a significant association between grade and HER-2 amplification among nonserous tumors, with grades 1, 2, and 3 cancers demonstrating 3%, 2%, and 21% amplification, respectively (P=0.003). Neither overexpression nor amplification predicted overall survival (OS) after adjusting for treatment and performance status. CONCLUSIONS: HER-2 amplification was more common in high grade tumors with a trend to being more common in serous tumors. There was no clear evidence for a survival difference or a difference in benefit from the addition of paclitaxel for women with HER-2 amplified or overexpressed tumors; however, power to detect clinically meaningful differences was low.

Phenotypic heterogeneity in multiple myeloma families.

PURPOSE: To describe a series of families with familial multiple myeloma (MM). Observations were used to generate hypotheses about the role of genetic factors, the mode of inheritance of these factors, and the association of other cancers with familial MM. PATIENTS AND METHODS: This observational study consisted of 39 families with multiple cases of MM or related disorders from four collaborating research centers. Each center followed its usual family study method. Probands were interviewed, and, when possible, cancers were verified by medical records and pathology review. A working pedigree was compiled on each family. RESULTS: Seventeen families had affected members in two or more generations, and eight families had two or more affected members in a single generation. Four families had two or more members with plasma cell dyscrasias, with or without a single case of MM. In the remaining 10 families, a single MM case occurred with a family history of other cancers. Other cancers observed in family members included hematologic malignancies and solid tumors. In families with MM in multiple generations, there was a decrease in the age at MM diagnosis in successive generations. CONCLUSION: The study of familial MM may provide insights into the pathogenesis and, ultimately, the control and prevention of MM and related disorders. Population-based epidemiologic studies are crucial, but because of the rarity of familial MM, a concerted case-finding approach may also be fruitful. Therefore, we propose an international consortium to study familial MM, and we invite all interested colleagues to participate.

Progesterone receptor variant increases ovarian cancer risk in BRCA1 and BRCA2 mutation carriers who were never exposed to oral contraceptives.

Oral contraceptives have been shown to be protective against hereditary ovarian cancer. The variant progesterone receptor allele named PROGINS is characterized by an Alu insertion into intron G and two additional mutations in exons 4 and 5. The PROGINS allele codes for a progesterone receptor with increased stability and increased hormone-induced transcriptional activity. We studied the role of the PROGINS allele as a modifying gene in hereditary breast and ovarian cancer. The study included 195 BRCA1 and BRCA2 carriers with a prior diagnosis of ovarian cancer, 392 carriers with a diagnosis of breast cancer and 249 carriers with neither cancer. Fifty-eight women had both forms of cancer. Five hundred and ninety-five women had a BRCA1 mutation and 183 women had a BRCA2 mutation. Overall, there was no association between disease status and the presence of the PROGINS allele. Information on oral contraception use was available for 663 of the 778 carriers of BRCA1 or BRCA2 mutations. Among the 449 subjects with a history of oral contraceptive use (74 cases and 365 controls), no modifying effect of PROGINS was observed [odds ratio (OR) 0.8; 95% confidence interval (CI) 0.5-1.3]. Among the 214 carriers with no past exposure to oral contraceptives, the presence of one or more PROGINS alleles was associated with an OR of 2.4 for ovarian cancer, compared to women without ovarian cancer and with no PROGINS allele (P = 0.004; 95% CI 1.4-4.3). The association was present after adjustment for ethnic group and for year of birth.

Identification of a 1.2 Kb cDNA fragment from a region on 9p21 commonly deleted in multiple tumor types.

Chromosome band 9p21 is a frequent target of homozygous deletion in many tumor types. Putative tumor suppressor genes, CDKN2A (p16), p14(ARF) and CDKN2B (p15), were localized to 9p21. However, there have been reports that suggest that there may be other genes targeted for inactivation in the region. We have developed a method to search for transcribed sequences within large genomic regions. We tested our approach in a 100-kilobase region on 9p21, which is 40 kilobases telomeric to CDKN2A. The method, termed expressed sequence selection (ESS), resulted in the isolation of genomic fragments known to be from 9q21 that are homologous to transcribed sequences. One fragment was used to obtain a 1.2 kilobase cDNA. The sequence of the 5' half of the cDNA was almost identical to exons 3-5 of the MTAP gene, which maps to chromosome band 9p21. The 3' portion of the cDNA had sequence homology to the ALA gene, which maps to chromosome arm 9q. Using Northern blot analysis, the 1.2 Kb cDNA identified several widely expressed transcripts ranging from 1 Kb to 8.5 Kb and displayed a complex pattern of alternative splicing in which certain exons of the 1.2 Kb cDNA are excluded from some of the splice products. Using cancer tissue Northern blots, we could show that all of the transcripts are absent from a leukemia cell line and a lung cancer cell line (K562, A549) with homozygous, genomic deletions within chromosome band 9p21. In addition, the 7 Kb transcript is also absent from two additional tumor cell lines (Molt4, a leukemia derived cell line, and in G361, a melanoma derived cell line) with homozygous deletions. Further investigation will determine whether the difference in the expression pattern between the 7 Kb transcript compared with the other sized transcripts could be due to specific targeting for alteration in certain tumor types.

Cancer genetics in oncology practice.

Cancer is a genetic disease caused by the progressive accumulation of mutations in critical genes that control cell growth and differentiation. Completion of the Human Genome Project promises to revolutionize the practice of Medicine, especially Oncology care. The tremendous gains in the knowledge of the structure and function of human genes will surely impact the diagnosis, prognosis and treatment of cancer. Moreover, it will lead to more effective cancer control through the use of genetics to quantify individual cancer risks. This article reviews the current status of genetic testing and counseling for cancer risk assessment and will suggest a framework for integrating such counseling into oncology practice.

Alterations of the 9p21 and 9q33 chromosomal bands in clinical bladder cancer specimens by fluorescence in situ hybridization.

PURPOSE: To better define cytogenetic mechanisms of CDKN2 loss at 9p21 and of DBCCR1 loss at 9q33 in bladder cancer, and to determine correlation with p53 and pRb. EXPERIMENTAL DESIGN: Two-color fluorescence in situ hybridization (FISH) using a chromosome 9 centromeric probe and locus-specific probes was performed. p53 and pRb were assessed by immunohistochemistry. RESULTS: Thirty-seven of fifty-five (67%) samples exhibited 9p21 loss, and 32 of 44 (73%) exhibited 9q33 loss. Twelve of 43 informative samples exhibited only 9p21 loss (5 cases) or only 9q33 loss (7 cases). Homozygous deletions were noted at 9p21 and 9q33 in 31 and 14% of cases, respectively, but 9q33 homozygous deletions were generally observed in only a minor clone. There was no correlation of any chromosome 9 loss with stage, but stage did correlate with chromosome 9 ploidy status; aneusomy 9 was observed in 33% of T(a) lesions and 71% of more advanced cases (P = 0.01). Aneusomy 9 was loosely correlated with p53 abnormalities (P = 0.07), but no correlation between any chromosome 9 and pRb abnormalities was discerned. CONCLUSIONS: This study strengthens the proposition that chromosome 9 losses occur early in bladder oncogenesis and before p53 alterations or development of aneusomy. The correlation of aneusomy 9 with p53 abnormalities is consistent with the presumed role of p53 in maintaining cytogenetic stability. Although the observed homozygous deletions strengthen the hypotheses that CDKN2 and DBCCR1 are important tumor suppressor genes, there is no evidence that either is a more critical or an earlier target for oncogenesis.

A case of pulmonary toxicity associated with G-CSF and doxorubicin administration.

The cytokine growth factor, G-CSF (granulocyte colony-stimulating factor), is commonly used in oncologic practice and is generally believed to be a safe agent to administer. We describe here a case of pulmonary toxicity associated with the concurrent administration of G-CSF and doxorubicin. We contend that G-CSF contributed to the life-threatening lung injury in our patient, and discuss additional reports in the literature of pulmonary toxicity associated with the use of this agent.

Male breast cancer in Cowden syndrome patients with germline PTEN mutations.

Cowden syndrome (CS) (OMIM 158350) is a multiple hamartoma syndrome associated with germline mutations in the PTEN tumour suppressor gene. While CS is characterised most commonly by non-cancerous lesions (mucocutaneous trichilemmomas, acral and palmoplantar keratoses, and papillomatous papules), it is also associated with an increased susceptibility to breast cancer (in females) and thyroid cancer, as well as non-cancerous conditions of the breast and thyroid. Here we report two cases of male breast cancer occurring in patients with classical CS phenotypes and germline PTEN mutations. The first subject was diagnosed with CS indicated primarily by mucocutaneous papillomatosis, facial trichilemmomas, and macrocephaly with frontal bossing at the age of 31 years. He developed breast cancer at 41 years and subsequently died of the disease. A PTEN mutation, c.802delG, was identified in this subject, yet none of his family members showed evidence of a CS phenotype, suggesting that this PTEN mutation may be a de novo occurrence. The second subject had a CS phenotype including multiple trichilemmomas and thyroid adenoma, developed male breast cancer at 43 years, and died of the disease at 57 years. He was a carrier of a PTEN mutation c.347-351delACAAT that cosegregated with the CS phenotype in affected family members. These two cases of male breast cancer associated with germline PTEN mutations and the CS phenotype suggest that CS may be associated with an increased risk of early onset male as well as female breast cancer.

Effect of radiotherapy after breast-conserving treatment in women with breast cancer and germline BRCA1/2 mutations.

PURPOSE: Recent laboratory data suggest a role for BRCA1/2 in the cellular response to DNA damage. There is a paucity of clinical data, however, examining the effect of radiotherapy (RT), which causes double-strand breaks, on breast tissue from BRCA1/2 mutation carriers. Thus the goals of this study were to compare rates of radiation-associated complications, in-breast tumor recurrence, and distant relapse in women with BRCA1/2 mutations treated with breast-conserving therapy (BCT) using RT with rates observed in sporadic disease. PATIENTS AND METHODS: Seventy-one women with a BRCA1/2 mutation and stage I or II breast cancer treated with BCT were matched 1:3 with 213 women with sporadic breast cancer. Conditional logistic regression models were used to compare matched cohorts for rates of complications and recurrence. RESULTS: Tumors from women in the genetic cohort were associated with high histologic (P =.0004) and nuclear (P =.009) grade and negative estrogen (P=.0001) and progesterone (P=.002) receptors compared with tumors from the sporadic cohort. Using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity scoring, there were no significant differences in acute or chronic morbidity in skin, subcutaneous tissue, lung, or bone. The 5-year actuarial overall survival, relapse-free survival, and rates of tumor control in the treated breast for the patients in the genetic cohort were 86%, 78%, and 98%, respectively, compared with 91%, 80%, and 96%, respectively, for the sporadic cohort (P = not significant). CONCLUSION: There was no evidence of increased radiation sensitivity or sequelae in breast tissue heterozygous for a BRCA1/2 germline mutation compared with controls, and rates of tumor control in the breast and survival were comparable between BRCA1/2 carriers and controls at 5 years. Although additional follow-up is needed, these data may help in discussing treatment options in the management of early-stage hereditary breast cancer and should provide reassurance regarding the safety of administering RT to carriers of a germline BRCA1/2 mutation.