Invasive penile carcinoma: Are p16, p53 and HPV ISH prognostically significant?

394

Background: Penile carcinoma accounts for 0.4% to 0.6% of all malignancies in men. Due to its low incidence the prognostic role of clinicopathological characteristics, p16, p53 and HPV infection remains unclear. We report our experience with p16, p53 and HPV ISH (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 66) in determining the aggressive nature of this carcinoma. Methods: A tissue microarray (TMA) of 57 cases of invasive penile squamous cell carcinomas was immunohistochemically stained with immunohistochemical stains p16 and p53. HPV ISH was performed as well. The TMA slides were scored semi quantitatively by a specialized genitourinary surgical pathologist. The H score was calculated for p53 using a combination of staining intensity and extent according to the following formula: H score = 1 x % of tumor cells with weak staining + 2 x % of tumor cells with moderate staining + 3 x % of tumor cells with strong staining, resulting in a total score of 0 – 300. Calculations for p53 were done considering values above 0 as positive. For p16 and HPV ISH, the results were recorded as negative or positive. The overall survival curves for up to 60 months were estimated by Kaplan-Meier (KM) method. Results: HPV ISH was positive in 23 cases and p16 was positive in 23 cases as well. However, there were 9 discordant cases between the two (p16+/HPV ISH- = 5; p16-/HPV ISH+ = 4). p53 was positive in 39 cases. Tumors positive for HPV ISH had a better survival as compared to HPV ISH negative tumors (p = 0.0040; Hazard ratio 4.991). Whereas p16 (p = 0.206; Hazard ratio 1.838) and p53 (p = 0.1582; Hazard ratio 0.5198) were not significantly associated with survival at 60 months. Conclusions: Overall HPV positive penile carcinomas appear to have a distinct biology with better prognosis. There is no significant difference in survival for tumors with different p16 and p53 expression.

S1406: Randomized phase II study of irinotecan and cetuximab with or without vemurafenib in BRAF-mutant metastatic colorectal cancer (mCRC)

TPS790

Background: BRAFV600 mutations are associated with inferior survival and objective responses to the mutated BRAF inhibitor vemurafenib in patients with mCRC. Blockade of BRAFV600 by vemurafenib causes feedback upregulation of EGFR, whose signaling activities can be impeded by cetuximab. In murine models of BRAFV600 mCRC, the addition of irinotecan to vemurafenib and cetuximab leads to greater anti-tumor activity. Recent phase I studies with the combination of BRAF and EGFR inhibition resulted in response rates substantially higher than either agent alone, with objective responses in 4 of 8 BRAFV600 mCRC patients treated with vemurafenib, cetuximab, and irinotecan. Methods: The SWOG 1406 trial (NCT 02164916) is a randomized phase II study of irinotecan (180 mg/m2 IV every 14 days) and cetuximab (500 mg/m2 IV every 14 days) with or without vemurafenib (960 mg PO twice daily). Eligible adult patients have histologically confirmed colorectal adenocarcinoma with metastatic disease. Tumors must have a BRAFV600 mutation and be wild-type for KRAS and NRAS. BRAF testing may be conducted using any CLIA-compliant lab. Alternatively, screening can be provided through a central lab. Patients must have received one or two prior systemic regimens for unresectable locally advanced or metastatic disease and must not have received anti-EGFR agents. Prior treatment with irinotecan is allowed. Patients randomized to the control arm may crossover to the experimental arm at progression. Target enrollment is 78 patients. The primary endpoint is PFS. Optional participation in a co-clinical trial will be offered in selected sites whereby patients’ biopsies will be used to establish patient-derived xenografts to study correlations between patient and PDX with respect to treatment responses and mechanisms of treatment resistance. This trial has support from all adult cooperative groups and utilizes the Central IRB to facilitate study initiation. Conclusions: mCRC patients harboring BRAFV600E mutations may benefit from EGFR and BRAF blockade. We encourage screening for the BRAF mutation early in the course of metastatic disease therapy and for second line therapy on this trial. Clinical trial information: NCT 02164916.

Human epidermal growth factor receptor 2 testing in primary breast cancer in the era of standardized testing: a Canadian prospective study

PURPOSE

Therapies that target overexpression of human epidermal growth factor receptor 2 (HER2) rely on accurate and timely assessment of all patients with new diagnoses. This study examines HER2 testing of primary breast cancer tissue when performed with immunohistochemistry (IHC) and additional in situ hybridization (ISH) for negative cases (IHC 0/1+). The analysis focuses on the rate of false-negative HER2 tests, defined as IHC 0/1+ with an ISH ratio ≥ 2.0, in eight pathology centers across Canada.

PATIENTS AND METHODS

Whole sections of surgical resections or tissue microarrays (TMAs) from invasive breast carcinoma tissue were tested by both IHC and ISH using standardized local methods. Samples were scored by the local breast pathologist, and consecutive HER2-negative IHC results (IHC 0/1+) were compared with the corresponding fluorescence or silver ISH result.

RESULTS

Overall, 711 surgical excisions of primary breast cancer were analyzed by IHC and ISH; HER2 and chromosome 17 centromere (CEP17) counts were available in all cases. The overall rate of false-negative samples was 0.84% (six of 711 samples). Interpretable IHC and ISH scores were available in 1,212 cases from TMAs, and the overall rate of false-negative cases was 1.6% (16 of 978 cases).

CONCLUSION

Our observation confirms that IHC is an adequate test to predict negative HER2 status in primary breast cancer in surgical excision specimens, even when different antibodies and IHC platforms are used. The study supports the American Society of Clinical Oncology/College of American Pathologists and Canadian testing algorithms of using IHC followed by ISH for equivocal cases.

Evaluation of E-cadherin, β-catenin and vimentin protein expression using quantitative immunohistochemistry in nasopharyngeal carcinoma patients

PURPOSE

Aberrant expression of proteins involved in epithelial-to-mesenchymal transition have been described in various cancers. In this retrospective study, we sought to evaluate E-cadherin, β-catenin and vimentin protein expression in non-metastatic nasopharyngeal (NPC) patients treated with curative intent, examine their relationship with each other, and with clinical outcome measures.

METHODS

Pre-treatment formalin-fixed paraffin-embedded biopsies of 140 patients treated between January 2000 and December 2007 were assembled into a tissue microarray (TMA). Automated quantitative immunohistochemistry (AQUA®) was performed on sequential TMA sections stained with fluorescent-labeled antibodies against E-cadherin, β-catenin and vimentin. Cox proportional hazards regression was used to estimate the effect of cytoplasmic vimentin, cytoplasmic E-cadherin, β-catenin nuclear/cytoplasmic ratio expression on overall survival and disease-free survival.

RESULTS

The average age of the patients was 51.7 years (SD=12.1; range 18-85), 66% were male, 71% had a KPS ≥ 90% at the start of treatment and 65% had stage III/IV disease. After adjusting for performance status, WHO and stage, high E-cadherin levels over the 75th percentile were found to produce a significantly increased risk for both a worse overall survival (HR = 2.53, 95% CI 1.21, 5.27) and disease free survival (DFS; HR = 2.14, 95%CI 1.28, 3.59). Vimentin levels over the first quartile produced an increased risk for a worse DFS (HR = 2.21, 95% CI 1.11, 4.38). No association was seen between β-catenin and survival.

CONCLUSION

In this cohort of NPC patients, higher levels of E-cadherin and higher levels of vimentin were associated with worse outcomes. Further work is needed to understand the role of these epithelial mesenchymal transition proteins in NPC.

Abstract 2167: Infertility and risk of incident endometrial carcinoma: a pooled analysis from the Epidemiology of Endometrial Cancer Consortium

Background: Nulliparity is an established endometrial cancer risk factor, but whether this association is related to infertility is unclear. Although there are many underlying causes of infertility, few studies have assessed risk relationships according to specific causes. Despite concerns that most treatments induce ovulation and that the endometrium is highly hormonally-responsive, previous studies have provided conflicting results on treatment associations.

Methods: To address these issues, we conducted a pooled analysis of 8,151 cases and12,471 controls from 2 cohort and 12 case-control studies conducted in 1982 to 2009 (N. America, Europe, Australia, Asia). All studies provided self-reported infertility, causes and treatments, except for 1 study that relied on data from national registries. Study-specific exposures and covariate data were harmonized across studies. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusted for study, age, interview year, race, parity, oral contraceptive and menopausal hormone use, and body mass index. If data were not reported for a particular variable, that study was excluded from the variable-specific analysis.

Results: Nulliparous women had an elevated endometrial cancer risk compared with parous women (adjusted OR=1.73; 95% CI: 1.58-1.90).Women with self-reported infertility also had an increased risk (adjusted OR=1.22; 95% CI: 1.13-1.32) compared with those without infertility issues, even after adjusting for parity; the strongest associations was seen among studies that defined infertility as unsuccessfully trying to conceive for 2+ years (adjusted OR=1.31; 95% CI: 1.07-1.60). Infertility was associated with similar risks among nulliparous (1.22; 1.10-1.48) and parous (1.22; 1.12-1.34) women, although there was no increased risk associated with infertility among those who had given birth to 3+ children. Two infertility causes associated with risk elevation were endometriosis (adjusted OR=2.08; 95% CI: 1.46-2.95 compared with women no infertility problems) and anovulation (adjusted OR=1.40; 95% CI: 1.16-1.70). Based on relatively small numbers, none of the individual treatments (in vitro fertilization, selective estrogen response modulators, gonatropins, progestins, estrogens) were substantially related to risk.

Conclusion: Based on mainly self-reported infertility data, we found that parity and infertility independently contribute to endometrial cancer risk, with parity seemingly being the predominant risk predictor. Understanding residual endometrial cancer relationships related to causes of infertility and infertility treatment may benefit from documented medical information on causes of infertility and treatment parameters.

Citation Format: Hannah P. Yang, Linda S. Cook, Elisabete Weiderpass, Hans-Olov Adami, Kristin E. Anderson, Hui Cai, James R. Cerhan, Tess Clendenen, Ashley S. Felix, Christine Friedenreich, Montserrat Garcia-Closas, Marc T. Goodman, Xiaolin Liang, Jolanta Lissowska, Lingeng Lu, Anthony M. Magliocco, Susan E. McCann, Kristen B. Moysich, Sara H. Olson, Malcolm C. Pike, Silvia Polidoro, Fulvio Ricceri, Harvey Risch, Carlotta Sacerdote, V. Wendy Setiawan, Xiao Ou Shu, Amanda B. Spurdle, Britton Trabert, Penelope M. Webb, Nicolas Wentzensen, Yong-Bing Xiang, Youming Xu, Herbert Yu, Anne Zeleniuch-Jacquotte, Louise A. Brinton. Infertility and risk of incident endometrial carcinoma: a pooled analysis from the Epidemiology of Endometrial Cancer Consortium. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2167. doi:10.1158/1538-7445.AM2014-2167

The prognostic value of HPV status and p16 expression in patients with carcinoma of the anal canal

Background

In anal cancer studies, the detection frequency of high-risk HPV (human papillomavirus) is variable, depending on the method used. There are limited data reporting results of different HPV detection techniques in the same clinical series, and very few correlating results with clinical outcome.

Objectives

To evaluate tumor expression of p16/HPV16 using three different methods, and to determine their association with clinical outcome in patients with anal canal squamous cell carcinomas (SCC).

Design

This retrospective study included patients with anal canal SCC treated with definitive radiotherapy or chemoradiotherapy at a single institution between 1992 and 2005. Formalin-fixed paraffin–embedded tumor samples from 53 of the 89 (60%) patient pre-treatment biopsies were adequate for tissue microarray construction. HPV status was determined using: p16 expression by conventional immunohistochemistry (IHC) and quantitative IHC (AQUA), HPV genotype analysis by chromogenic in situ hybridization (CISH) and HPV linear array sub-typing. Expression status was correlated with clinical outcome.

Results

80% (28/35) of patient tumors had high p16 expression using conventional IHC. HPV16 CISH was positive in 81% (34/42) of tumors, and 78% (28/36) of tumors were HPV subtype 16. HPV16 CISH correlated with p16 evaluated by conventional IHC (correlation coefficient 0.46; p = 0.01) and by p16 AQUA score (correlation coefficient 0.49; p = 0.001). A subset of cases (15%) had very high p16 quantitative IHC scores (>244) and were associated with a higher incidence of local or distant recurrence (p = 0.04).

Conclusions

The vast majority (80%) of anal canal SCC in our series were positive for HPV16/p16, regardless of the testing method used. The exploratory analysis of automated quantitative IHC scoring was the only technique to define a subset of patients with a worse prognosis by p16 expression status on univariate analysis. Further exploration of the molecular mechanisms of treatment resistance in association with very high p16 expression is warranted.

Genome-wide association study of subtype-specific epithelial ovarian cancer risk alleles using pooled DNA

Epithelial ovarian cancer (EOC) is a heterogeneous cancer with both genetic and environmental risk factors. Variants influencing the risk of developing the less-common EOC subtypes have not been fully investigated. We performed a genome-wide association study (GWAS) of EOC according to subtype by pooling genomic DNA from 545 cases and 398 controls of European descent, and testing for allelic associations. We evaluated for replication 188 variants from the GWAS [56 variants for mucinous, 55 for endometrioid and clear cell, 53 for low-malignant potential (LMP) serous, and 24 for invasive serous EOC], selected using pre-defined criteria. Genotypes from 13,188 cases and 23,164 controls of European descent were used to perform unconditional logistic regression under the log-additive genetic model; odds ratios (OR) and 95 % confidence intervals are reported. Nine variants tagging six loci were associated with subtype-specific EOC risk at P < 0.05, and had an OR that agreed in direction of effect with the GWAS results. Several of these variants are in or near genes with a biological rationale for conferring EOC risk, including ZFP36L1 and RAD51B for mucinous EOC (rs17106154, OR = 1.17, P = 0.029, n = 1,483 cases), GRB10 for endometrioid and clear cell EOC (rs2190503, P = 0.014, n = 2,903 cases), and C22orf26/BPIL2 for LMP serous EOC (rs9609538, OR = 0.86, P = 0.0043, n = 892 cases). In analyses that included the 75 GWAS samples, the association between rs9609538 (OR = 0.84, P = 0.0007) and LMP serous EOC risk remained statistically significant at P < 0.0012 adjusted for multiple testing. Replication in additional samples will be important to verify these results for the less-common EOC subtypes.

Genome-wide association study of endometrial cancer in E2C2

Endometrial cancer (EC), a neoplasm of the uterine epithelial lining, is the most common gynecological malignancy in developed countries and the fourth most common cancer among US women. Women with a family history of EC have an increased risk for the disease, suggesting that inherited genetic factors play a role. We conducted a two-stage genome-wide association study of Type I EC. Stage 1 included 5,472 women (2,695 cases and 2,777 controls) of European ancestry from seven studies. We selected independent single-nucleotide polymorphisms (SNPs) that displayed the most significant associations with EC in Stage 1 for replication among 17,948 women (4,382 cases and 13,566 controls) in a multiethnic population (African America, Asian, Latina, Hawaiian and European ancestry), from nine studies. Although no novel variants reached genome-wide significance, we replicated previously identified associations with genetic markers near the HNF1B locus. Our findings suggest that larger studies with specific tumor classification are necessary to identify novel genetic polymorphisms associated with EC susceptibility.

Case-control study of lifetime alcohol consumption and endometrial cancer risk

Purpose

Alcohol consumption is hypothesized to increase the risk of endometrial cancer by increasing circulating estrogen levels. This study sought to investigate the association between lifetime alcohol consumption and endometrial cancer risk.

Methods

We recruited 514 incident endometrial cancer cases and 962 frequency age-matched controls in this population-based case–control study in Alberta, Canada, from 2002 to 2006. Participants completed in-person interviews querying lifetime alcohol consumption and other relevant health and lifestyle factors. Participants reported the usual number of drinks of beer, wine, and liquor consumed; this information was compiled for each drinking pattern reported over the lifetime to estimate average lifetime exposure to alcohol.

Results

Lifetime average alcohol consumption was relatively low (median intake: 3.9 g/day for cases, 4.9 g/day for controls). Compared with lifetime abstainers, women consuming >2.68 and ≤8.04 g/day alcohol and >8.04 g/day alcohol on average over the lifetime showed 38 and 35 % lower risks of endometrial cancer, respectively (p trend = 0.023). In addition, average lifetime consumption of all types of alcohol was associated with decreased risks. There was no evidence for effect modification by body mass index, physical activity, menopausal status, and hormone replacement therapy use combined and effects did not differ by type of endometrial cancer (type I or II).

Conclusion

This study provides epidemiologic evidence for an inverse association between relatively modest lifetime average alcohol consumption (approximately 1/4 to 1/2 drink/day) and endometrial cancer risk. The direction of this relation is consistent with previous studies that examined similar levels of alcohol intake.

Endometrial cancer and a family history of cancer

OBJECTIVE

Lynch Syndrome (LS), an inherited genetic syndrome, predisposes to cancers such as colorectal and endometrial. However, the risk for endometrial cancer (EC) in women not affected by LS, but with a family history of cancer, is currently unknown. We examined the association between a family history of cancer and the risk for EC in non-LS patients.

METHODS

This population-based case-control study included 519 EC cases and 1015 age-matched controls and took place in Alberta, Canada between 2002 and 2006. Information about risk factors, including family history of cancer in first and second degree relatives, was ascertained via in-person interviews. Microsatellite instability (MSI) status of tumor tissue was assessed to determine involvement of DNA mismatch repair (MMR) genes.

RESULTS

A first or second degree family history of uterine cancer was modestly associated with the risk for overall EC [odds ratio (OR), 1.3; 95% confidence interval (CI), 0.9, 1.9], and the risks were similar for MSI+cancer (OR=1.5, 95%CI=0.7, 3.3) and MSI- cancer (OR=1.3, 95%CI=0.8, 2.4). Although consistent, these associations were modest and not significant. In contrast, the risk for MSI+cancer was elevated with a reported family history of colorectal cancer (OR=1.4, 95%CI=1.0, 2.2), but not for MSI- cancer.

CONCLUSIONS

A family history of uterine cancer may be modestly associated with EC risk in non-LS patients regardless of MSI status, suggesting that risk was not related to inherited defects in the MMR gene pathway. These results provide preliminary support for an EC-specific genetic syndrome.

Anthropometric measures and the risk of endometrial cancer, overall and by tumor microsatellite status and histological subtype

Obesity is an established risk factor for endometrial cancer, but this association is not well understood for subtypes of endometrial cancer. We evaluated the association of recent and adult-life obesity with subtypes of endometrial cancer based on microsatellite status (microsatellite-stable (MSS) vs. microsatellite-instable (MSI)) and histology (type I vs. type II). Analyses were based on a population-based case-control study (524 cases and 1,032 controls) conducted in Alberta, Canada (2002-2006) and included the following groupings of subtypes: MSS = 337 and MSI = 130; type I = 458 and type II = 66. Logistic and polytomous logistic regression were used to estimate odds ratios and 95% confidence intervals for overall endometrial cancer and subtypes of endometrial cancer, respectively. The risks of all subtypes of endometrial cancer, except type II, increased with an increase in all of the anthropometric characteristics examined. The risks for MSI tumors were suggestively stronger than those for MSS tumors; the risk with high (≥30) body mass index (weight (kg)/height (m)(2)) was significantly stronger for MSI tumors (odds ratio = 4.96, 95% confidence interval: 2.76, 8.91) than for MSS tumors (odds ratio = 2.33, 95% confidence interval: 1.66, 3.28) (P-heterogeneity = 0.02). Obesity is associated with most subtypes of endometrial cancer, and further studies are warranted to elucidate the biological mechanisms underlying the stronger risk for the MSI subtype with a high body mass index.

Type I and II endometrial cancers: have they different risk factors?

PURPOSE

Endometrial cancers have long been divided into estrogen-dependent type I and the less common clinically aggressive estrogen-independent type II. Little is known about risk factors for type II tumors because most studies lack sufficient cases to study these much less common tumors separately. We examined whether so-called classical endometrial cancer risk factors also influence the risk of type II tumors.

PATIENTS AND METHODS

Individual-level data from 10 cohort and 14 case-control studies from the Epidemiology of Endometrial Cancer Consortium were pooled. A total of 14,069 endometrial cancer cases and 35,312 controls were included. We classified endometrioid (n = 7,246), adenocarcinoma not otherwise specified (n = 4,830), and adenocarcinoma with squamous differentiation (n = 777) as type I tumors and serous (n = 508) and mixed cell (n = 346) as type II tumors.

RESULTS

Parity, oral contraceptive use, cigarette smoking, age at menarche, and diabetes were associated with type I and type II tumors to similar extents. Body mass index, however, had a greater effect on type I tumors than on type II tumors: odds ratio (OR) per 2 kg/m(2) increase was 1.20 (95% CI, 1.19 to 1.21) for type I and 1.12 (95% CI, 1.09 to 1.14) for type II tumors (P heterogeneity < .0001). Risk factor patterns for high-grade endometrioid tumors and type II tumors were similar.

CONCLUSION

The results of this pooled analysis suggest that the two endometrial cancer types share many common etiologic factors. The etiology of type II tumors may, therefore, not be completely estrogen independent, as previously believed.

Bladder preservation therapy for muscle-invading bladder cancers on Radiation Therapy Oncology Group trials 8802, 8903, 9506, and 9706: vascular endothelial growth factor B overexpression predicts for increased distant metastasis and shorter survival

BACKGROUND

From 1988 to 1999, the Radiation Therapy Oncology Group (RTOG) conducted four prospective studies (8802, 8903, 9506, 9706) of patients with clinical stage T2-4a muscle-invasive bladder cancer. Treatment was selective bladder preservation using transurethral surgery (TURBT) plus cisplatin-based induction and consolidation chemoradiation regimens, reserving radical cystectomy for invasive tumor recurrence. We investigated vascular endothelial growth factor (VEGF) pathway biomarkers in this unique clinical dataset (median follow-up of 3.1 years).

METHODS

A total of 43 patients with tissue available from the entry TURBT were included in this analysis. Expression of VEGF ligands and receptors were quantified and scored by the AQUA platform (HistoRX, now Genoptix, Carlsbad, CA) and analyzed after median split.

RESULTS

VEGF expression levels were not associated with increased rates of complete response to induction chemoradiation. Higher levels of cytoplasmic VEGF-B, VEGF-C, and VEGF-R2 were associated with decreased overall survival rates. The 3-year overall survival estimates for high and low expressers were 43.7% and 75% for VEGF-B cytoplasm (p = .01), 40.2% and 86.7% for VEGF-C cytoplasm (p = .01), and 49.7% and 66.7% for VEGF-R2 cytoplasm (p = .02). Higher expression levels of cytoplasm VEGF-B were associated with higher rates of distant failure (p = .01).

CONCLUSIONS

Although VEGF ligands and receptors do not appear to be associated with complete response to induction chemoradiation for muscle-invasive bladder cancer, we report significant associations with overall survival and distant failure for certain VEGF family members.

Hormonal and reproductive risk factors for sporadic microsatellite stable and unstable endometrial tumors

Hormonal and reproductive factors modulate bioavailable estrogen to influence endometrial cancer risk. Estrogen affects the microsatellite status of tumors, but the relation between these estrogen-related factors and microsatellite instability (MSI) status of endometrial tumors is not known. We evaluated associations between hormonal and reproductive factors and risks of microsatellite stable (MSS) and MSI endometrial cancer among postmenopausal women (MSS cases = 258, MSI cases = 103, and controls = 742) in a population-based case-control study in Alberta, Canada (2002-2006). Polytomous logistic regression was used to estimate ORs and 95% confidence intervals (95% CI). We observed a significant trend in risk reduction for MSI (Ptrend = 0.005) but not MSS (Ptrend = 0.23) cancer with oral contraceptive use; with 5-year use or more, the risk reduction was stronger for MSI (OR = 0.42; 95% CI, 0.23-0.77) than for MSS cancer (OR = 0.80; 95% CI, 0.54-1.17; Pheterogeneity = 0.05). For more recent use (<30 years), the risk reduction was stronger for MSI (OR = 0.36; 95% CI, 0.19-0.69) than for MSS cancer (OR = 0.77; 95% CI, 0.51-1.15; Pheterogeneity = 0.032). No differential risk associations were observed for menopausal hormone use, parity and age at menarche, menopause or first pregnancy. We found limited evidence for statistical heterogeneity of associations of endometrial cancer risk with hormonal and reproductive factors by MSI status, except with oral contraceptive use. This finding suggests a potential role for the MMR system in the reduction of endometrial cancer risk associated with oral contraceptive use, although the exact mechanism is unclear. This study shows for the first time that oral contraceptive use is associated with a reduced risk for MSI but not for MSS endometrial cancer.

Abstract 2494: Liquid chromatography-multiple reaction monitoring mass spectrometry biomarker quantification for breast cancer patient assessment

Introduction: A quantitative mass spectrometry platform has been developed for measuring biomarkers of protein expression and phosphorylation in breast cancer. The quantification of numerous biomarkers from a single tissue specimen has the potential to impact patient care. Specifically, the focus of initial development was on the expression and phosphorylation of estrogen receptor alpha (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2). However, immunohistochemical assessments of Ki-67 and vimentin are also widely used for monitoring proliferation in breast cancer. The integration of tissue quality control measurements, quantification of proliferation biomarkers, and ER/PR/HER2 evaluation could improve patient assessment and open novel avenues for patient classification, prognosis, and selection of therapy in breast cancer.

Experimental Procedures: Breast cancer cell lines MCF7, BT474, and T47D were used to develop peptide-based quantitative assays, including stable isotope-labeled standard peptides, (n = 31) for protein expression and phosphorylation biomarkers using liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM) of digested whole cell lysates or SDS-PAGE fractionated proteins followed by immunoprecipitation to examine expression and phosphorylation of ER/PR/HER2 (IP-LC-MRM). Using 2 mg of total protein, the sample is divided into three parts. Tissue QC biomarkers and expression levels of Ki67, vimentin, and HER2 are measured in digests of whole cell lysate or tissue homogenate (1% of sample). Then, parallel IP strategies are used for HER2 (10% of sample) and ER/PR (90%) before LC-MRM analysis of expression and phosphorylation. Multiplex IP of the three proteins was not successful, because the amplification of HER2 could not be accommodated. The sensitivity of each assay was tested using serial dilutions of cell lysate to evaluate requirements for analysis of clinical specimens.

Data Summary: LC-MRM assays for both unmodified and phosphorylated peptides have been developed and characterized for each protein using cell line models. Assays have been implemented in cell lines to study Estradiol/EGF stimulation as well as lapatinib inhibition of HER2. Data has been generated for pre-treatment frozen tissue specimens from breast cancer patients that are either HER2+ or ER+ (n = 12 per group). The analysis of a larger group of patients and in clinical scenarios (e.g. comparison of naïve and drug resistant tissues from the same patient) will establish the clinical utility of these assays.

Conclusions: The ability to examine protein expression as well as phosphorylation status in these biomarkers with quantitative mass spectrometry has the potential to improve the selection of targeted therapeutics.

Citation Format: Yi Chen, David J. Britton, Elizabeth R. Wood, Anthony M. Magliocco, Ian Pike, John M. Koomen. Liquid chromatography-multiple reaction monitoring mass spectrometry biomarker quantification for breast cancer patient assessment. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2494. doi:10.1158/1538-7445.AM2013-2494

Abstract 3545: ATM, TS and RRM1 protein expression in nasopharyngeal carcinomas (NPC) treated with curative intent

Background: Although NPC is a radiation and chemotherapy sensitive tumour, some patients still relapse with distant metastatic disease. Biomarkers are needed to help identify which patients are at higher risk of relapse and/or who will respond to therapy. Ataxia telangiectasia mutated (ATM) is a putative marker for radiation sensitivity while, thymidylate synthetase (TS), and ribonucleotide reductase subunit M1 (RRM1) levels have been associated with response to 5FU and gemcitabine, two chemotherapy agents often used in NPC. We characterized the protein expression of ATM, TS, and RRM1 in tumours from 146 patients with non-metastatic NPC treated at two Canadian institutions between Jan 2000-Dec 2007 and explored the relationship of each marker with clinical outcomes. Methods: Pre-treatment, formalin-fixed, paraffin-embedded NPC tumour specimens were assembled in a tissue microarray. ATM, TS and RRM1 protein expression were evaluated by quantitative fluorescence immunohistochemistry and with automated quantitative digital image analysis (AQUA) using the Y170, TS106 and 60073-2-Ig monoclonal antibodies respectively. Protein expression levels were assessed in tumour, tumour cytoplasm, tumour nuclear, and non-malignant tumour stroma compartments. The effect of protein expression levels on overall survival (OS) and disease-free survival (DFS) was examined using Cox regression. For all biomarkers, AQUA scores were analyzed in quartiles. Results: Patient characteristics were: mean age=52 years (SD=12.2; range 18 to 85), 67% male, 73% KPS ≥ 90%, WHO type 1/2/3=11%/28%/61%, stage III/IV=65%. Fifty-eight (40%) patients received platinum-based CRT; the remainder was treated with RT alone. With a median follow-up of 50 months (range 3 to 120), the 5 year survival rates were 71% (95% CI=62%-78%) for OS and 48% (95% CI=39%-57%) for DFS. After adjusting for KPS, stage, and WHO type, OS was worse for the group with tumour:stromal (T/S) ATM ratios in the top quartile versus those in the lowest quartile (p=0.049). OS was also worse for tumours with TS levels in the lowest quartile versus the top quartile (p=0.033). RRM1 was not associated with outcomes (p=0.748). There was no significant effect of any of the biomarkers on disease-free survival (ATM T/S p=0.708; TS p=0.978; RRM1 p=0.918). Conclusions: In our cohort of non-metastatic NPC patients, relative overexpression of ATM and low TS protein levels were associated with worse outcomes suggesting further investigation of these potential biomarkers is warranted.

Citation Format: Alexander C. Klimowicz, Amanda Jagdis, Tien Phan, Janessa J. Laskin, Harold Y. Lau, Jodi E. Siever, Stephanie K. Petrillo, Thomas A. Thomson, M. Sarah Rose, Anthony M. Magliocco, Desirée Hao. ATM, TS and RRM1 protein expression in nasopharyngeal carcinomas (NPC) treated with curative intent. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3545. doi:10.1158/1538-7445.AM2013-3545

Abstract A10: Stromal CAIX expression in oral squamous cell carcinoma and corresponding lymph node metastases

Background: Hypoxia is an almost ubiquitous feature of human solid tumours. However, the direct measurement of oxygen concentration in head and neck squamous cell carcinoma (HNSCC) has been conducted almost exclusively in the metastatic lymph nodes, not the primary tumor. Hypoxia is associated with resistance to both radiotherapy (RT) and chemotherapy in squamous cell cancers (SCCs). However, endogenous markers of hypoxia (EMH) have not reproducibly predicted clinical outcome. However, historically, the method used to assign hypoxic status according to directly measured oxygen concentration (polarographic electrode) and EMH (typically immunohistochemistry) have fundamentally differed.

Methods: Demographic data and clinical outcomes of 61 patients with oral squamous cell carcinoma (OSCC) treated with primary surgery +/- adjuvant radiation were collected. Tissue microarray's with representative samples of patients' tumors were constructed from paraffin-embedded blocks. Automated quantitative immunohistochemistry (AQUA) was performed to measure expression and distribution of carbonic anhydrase IX (CAIX). Kaplan-Meier survival analysis and the log-rank test was used to assess the impact of vimentin-defined stromal CAIX (in both primary tumor and nodal metastases) on survival.

Results: High stromal CAIX expression in the primary tumor was associated with significantly worse 5-year disease-specific survival. There was a statistically significant but relatively weak correlation between stromal CAIX expression in the primary tumor and the corresponding lymph nodes (r2:0.359; p=0.013). Stromal CAIX expression in the lymph node metastases was not significantly associated with 5-year disease-specific survival.

Conclusions: Previous literature presenting the prognostic impact of directly measured hypoxia, using a polarographic electrode, was based predominantly on measurements from lymph nodes, not the primary tumor. Furthermore, comparisons with EMH were based solely on percentage of tumor cells that were positively stained, not the intensity of staining. We present the results of a tumor comparment-specific, quantitative fluorescent IHC method and the survival associated with EMH in the tumor microenvironment in the primary tumor and lymph node metastases.

Citation Format: Shamir Chandarana, Pinaki Bose, Alexander C. Klimowicz, Stephanie K. Petrillo, Mie Konno, Luke Rudmik, Steven C. Nakoneshny, Wayne T. Matthews, Anthony M. Magliocco, Joseph C. Dort, Nigel T. Brockton. Stromal CAIX expression in oral squamous cell carcinoma and corresponding lymph node metastases. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr A10.

PIK3CA mutational status and overall survival in patients with cervical cancer treated with radical chemoradiotherapy

OBJECTIVE

Mutational activation of PIK3CA is associated with poor prognosis in patients with solid tumors, and may predict favorable response to PI3K/AKT/mTOR pathway inhibitors. However, PIK3CA mutational status has not previously been evaluated in patients with cervical carcinoma treated with radical chemoradiotherapy (CRT). The aims of this study were (1) to evaluate the frequency of PIK3CA mutations in patients with cervical cancer treated with radical CRT and (2) to examine the effect of tumor PIK3CA mutational status in pre-treatment biopsies on overall survival (OS) and progression-free survival (PFS).

METHODS

Patients with cervical cancer, treated at a single institution with radical CRT, from 1999 to 2008, were eligible for this retrospective study. Pre-treatment tumor biopsies (n=157) were retrieved. Genomic DNA was extracted from tumor blocks, and exons 9 and 20 of the PIK3CA gene were sequenced for mutations.

RESULTS

Eighty-two tumors were sequenced for both exon 9 and exon 20. 19/82 (23%) tumors were PIK3CA mutation positive; of these 84% were squamous cell carcinomas. 79% of mutations were in exon 9. PIK3CA mutation status was strongly associated with overall survival (OS) in FIGO stage IB/II patients, unadjusted HR 6.0 (95% CI 2.1-17.5), p=0.0002, but not stage III/IVA patients, unadjusted HR 1.0 (95% CI 0.32-3.1), p=0.98.

CONCLUSIONS

In cervical cancer patients treated with CRT, tumor PIK3CA mutation status was associated with overall survival in FIGO stage IB/II cervix cancers. Further evaluation with a larger dataset will be required to validate these findings to inform potential clinical trials designs involving PI3K/AKT/mTOR pathway inhibitors.

Abstract P1-07-10: Comparison of three commercial ER/PR assays on a single clinical outcome series

Introduction: Adjuvant tamoxifen is the standard therapy for early stage hormone receptor+ breast cancers (BC). Estrogen receptor (ER) and progesterone receptor (PR) analysis is routinely performed by immunohistochemical (IHC) testing on BC specimens to assist in determining hormone receptor status and patient treatment. ER/PR IHC methodologies and guidelines have recently come under review. Many clinical laboratories have opted to use platform specific, ready-to-use (RTU) ER/PR assays provided by three companies: Dako, Leica and Ventana. While each of these companies are using antibodies that were validated on BC clinical outcome series, these platform specific RTU assays have never been directly compared using the same clinical outcome series. We present a systematic comparison of the three platform specific RTU ER/PR assays, using a retrospective BC cohort, to evaluate the concordance and reproducibility of the RTU ER/PR assays, and to assess the ability of the RTU ER assays to predict tamoxifen response.

Methods: The Calgary Tamoxifen Cohort is a retrospective database containing demographic, clinical and pathological data for 820 BC patients diagnosed between 1985–2000 at the Tom Baker Cancer Centre (Calgary, Canada). Formalin-fixed paraffin-embedded tissue blocks were available for 511 patients, and replicate 0.6mm cores were taken and built into tissue microarrays (TMAs). The TMAs were stained using the platform specific assays on the DakoLink Plus, Ventana BenchMark Ultra, or Bond-III Leica autostainers. Slides were manually scored by the Allred method.

Results: Ventana and Dako had the best concordance for ER (κ=0.90). Substantial agreement was seen for ER staining between Leica and Ventana (κ=0.79), and Dako and Leica (κ=0.66). Agreement was more consistent between the three platforms for PR staining (κ=0.78–0.82). Inter-observer reproducibility was evaluated for all three platforms between three observers: Dako ER (κ=0.80–0.92) and PR (κ=0.69–0.90); Leica ER (κ=0.67–0.83) and PR (κ=0.70–0.89); Ventana ER (κ=0.88–1.00) and PR (κ=0.78–0.94). TMAs were rescored and intra-observer agreement was calculated: Dako ER (κ=1.00) and PR (κ=0.98); Leica ER (κ=0.91) and PR (κ=0.94); Ventana ER (κ=1.00) and PR (κ=0.94). ER Allred scores were dichotomized using current standards and univariate analysis for 5-year disease free survival was performed. All platforms achieved significance with the logrank test and hazard ratio (HR) estimates (p &lt; 0.0001). Cox models were also run to adjust for lymph node status, grade, size and HER2 status. ER status determined by Dako [HR=0.37(0.19–0.74), p = 0.005] and Ventana [HR=0.40(0.18–0.87), p = 0.021] maintained significance, while ER status determined by Leica [HR=0.61(0.31–1.20), p = 0.154] did not.

Conclusions: Concordance between RTU assays demonstrated more variation for ER than PR. All assays showed substantial agreement for inter- and intra- observer reproducibility. Although ER RTU assays from all vendors performed as expected in univariate analysis, multivariate models demonstrated differences. Dako and Ventana appeared equivalent in the multivariate analysis, each providing prognostic information, whereas Leica did not achieve independence in this analysis.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-10.

Case-control study of markers of insulin resistance and endometrial cancer risk

Markers of insulin resistance such as the adiponectin:leptin ratio (A:L) and the homeostasis model assessment ratio (HOMA-IR) are associated with obesity and hyperinsulinemia, both established risk factors for endometrial cancer, and may therefore be informative regarding endometrial cancer risk. This study investigated the association between endometrial cancer risk and markers of insulin resistance, namely adiponectin, leptin, the A:L ratio, insulin, fasting glucose, and the HOMA-IR. We analyzed data from 541 incident endometrial cancer cases and 961 frequency age-matched controls in a population-based case-control study in Alberta, Canada from 2002 to 2006. Participants completed interview-administered questionnaires were assessed for anthropometric measures, and provided 8-h fasting blood samples either pre- or postoperatively. Blood was analyzed for concentrations of leptin, adiponectin, and insulin by immunoassay, and fasting plasma glucose levels were determined by fluorimetric quantitative determination. Compared with the lowest quartile, the highest quartile of insulin and HOMA-IR was associated with 64% (95% confidence intervals (CI): 1.12-2.40) and 72% (95% CI: 1.17-2.53) increased risks of endometrial cancer, respectively, and the highest quartile of adiponectin was associated with a 45% (95% CI: 0.37-0.80) decreased risk after multivariable adjustments. Null associations were observed between fasting glucose, leptin and A:L, and endometrial cancer risk. This population-based study provides evidence for a role of insulin resistance in endometrial cancer etiology and may provide one possible pathway whereby obesity increases the risk of this common cancer. Interventions aimed at decreasing both obesity and insulin resistance may decrease endometrial cancer risk.