Reporting of tobacco use and tobacco-related analyses in cancer cooperative group clinical trials: a systematic scoping review

BACKGROUND

Continued smoking after a diagnosis of cancer negatively impacts cancer outcomes, but the impact of tobacco on newer treatments options is not well established. Collecting and evaluating tobacco use in clinical trials may advance understanding of the consequences of tobacco use on treatment modalities, but little is known about the frequency of reporting and analysis of tobacco use in cancer cooperative clinical trial groups.

PATIENTS AND METHODS

A comprehensive literature search was conducted to identify cancer cooperative group clinical trials published from January 2017-October 2019. Eligible studies evaluated either systemic and/or radiation therapies, included ≥100 adult patients, and reported on at least one of: overall survival, disease/progression-free survival, response rates, toxicities/adverse events, or quality-of-life.

RESULTS

A total of 91 studies representing 90 trials met inclusion criteria with trial start dates ranging from 1995 to 2015 with 14% involving lung and 5% head and neck cancer patients. A total of 19 studies reported baseline tobacco use; 2 reported collecting follow-up tobacco use. Seven studies reported analysis of the impact of baseline tobacco use on clinical outcomes. There was significant heterogeneity in the reporting of baseline tobacco use: 7 reported never/ever status, 10 reported never/ex-smoker/current smoker status, and 4 reported measuring smoking intensity. None reported verifying smoking status or second-hand smoke exposure. Trials of lung and head and neck cancers were more likely to report baseline tobacco use than other disease sites (83% versus 6%, P < 0.001).

CONCLUSIONS

Few cancer cooperative group clinical trials report and analyze trial participants' tobacco use. Significant heterogeneity exists in reporting tobacco use. Routine standardized collection and reporting of tobacco use at baseline and follow-up in clinical trials should be implemented to enable investigators to evaluate the impact of tobacco use on new cancer therapies.

Abstract P5-04-27: Investigating the incidence of ESR1 gene amplification in breast cancers resistant to multiple endocrine agents

Background: Around 70% of all breast cancers (BCs) are estrogen receptor positive (ER+), but some do not respond to endocrine therapy (ET) and many eventually develop resistance. ESR amplification (ESRA) linked to an increase in ESR1 gene expression is known to occur in some cancers that are endocrine resistant. However, the incidence of ESRA has been the object of debate and its clinical significance remains unclear. This study aimed to investigate the incidence of ESRA in BCs resistant to multiple sequential ETs and optimise a fluorescence in-situ hybridisation (FISH) methodology to robustly detect ESRA.

Methods: Two unique cohorts have been studied:

(A) 20 post-menopausal women with ER+ BC with acquired resistance to letrozole, subsequently treated with up to 4 different lines of ET. Serial RNA and DNA from 3-5 cancer samples per patient (58 samples from 20 patients) were analysed by Ribo0-RNAseq and DNA exome sequencing;

(B) 18 post-menopausal women who developed ER+ BC recurrences on 1st line adjuvant letrozole, then on 2nd line tamoxifen and subsequently on 3rd line exemestane. Tissues were collected at the time of each surgery.

We have optimised a FISH method to assess ESRA in these tissues.

Results: In cohort A, 6/20 patients developed ESR1 gene amplification (ESRA) at some point during treatment. In 5 of these cases, ESRA was only found while on 2nd or 3rd line exemestane but was not present on acquired resistance to previous letrozole or tamoxifen. 1 patient had ESRA at the time of first recurrence on letrozole.

The FISH method showed concordance with the genomic analysis. This suggests that ESRA may be associated with BCs that are treated with and then become resistant to exemestane.

ESRA is also evident in samples from Cohort B, which includes 18 exemestane resistant cases. The complete analysis is ongoing.

Conclusions:

· ESRA can be seen in ER+ recurrent BCs.

· ESRA may be associated with BCs treated with 2nd or 3rd line exemestane.

· The frequency of ESRA in endocrine and exemestane resistance can now be ascertained using an optimised FISH-based method, which is more cost-effective than alternative genomic and biochemical methods.

Citation Format: Turnbull AK, Martinez-Perez C, Mok S, Tanioka M, Fernando A, Renshaw L, Keys J, Wheless A, Garrett A, Parker J, He X, Sims AH, Carey LA, Perou CM, Dixon JM. Investigating the incidence of ESR1 gene amplification in breast cancers resistant to multiple endocrine agents [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-27.

Abstract P5-11-03: Measurement of on-treatment proliferation biomarkers in nodal metastasis improves prediction of endocrine therapy response using the EA2CliN test

Background: The majority of patients with early-stage estrogen receptor positive (ER+) breast cancer (BC) are treated with adjuvant endocrine therapy (ET) after surgery to reduce the risk of recurrence. Recently, we have developed and validated an immunohistochemistry (IHC) based assay (EndoAdjuvant2 Clinical; EA2Clin) that measures pre-treatment IL6ST level together with clinical variables and on-treatment MCM4 to assess proliferation. We have previously shown that it can accurately identify responders and non-responders to ET and predicts recurrence-free survival (RFS) and BC-specific overall survival (BCSS). We postulated that measuring on-treatment proliferation in lymph node metastases (LN+) rather in the primary cancer might further improve the accuracy of the test for these patients. The aim was to test and validate this in cohorts of pre- and post-menopausal women (preMW & PMW) treated with preoperative ET (tamoxifen (T), fulvestrant (F), letrozole (L) or anastrozole (A)) and subsequent adjuvant ET.

Methods: Cohorts: (1) 137 PMW with ER+ BC, 59 were LN+, treated with neoadjuvant L (median duration 4.8 months, range 1-33), then surgery followed by adjuvant L (n=109) or other ET (n=28); (2) 148 PMW with ER+ BC, 55 were LN+, treated with 2 weeks of preoperative L (n=76) or A (n=72), then surgery followed by adjuvant L (n=69) or T (n=79); (3) 52 preMW with ER+ BC, 24 were LN+, treated with 2 weeks of preoperative T (n=26) or 1x750mg dose of F (n=26), then surgery followed by adjuvant T. All LN+ patients had sentinel node biopsies or clearance. The median follow-up was 6.5 years (cohort 1), 6.3 years (cohort 2) and 10.2 years (cohort 3).

EA2Clin: Patients are classified as:

· Low risk: ER+ and LN-negative and &lt;2cm or pre-treatment IL6ST 2+/3+ (IHC) and post-treatment MCM4 in the primary has &lt;20% positive nuclear staining.

· High risk: ER+ LN+ grade 3 BCs &gt;2cm or pre-treatment IL6ST is 0 or 1+, or IL6ST is 2+ or 3+ and MCM4 in the primary has &gt;10% positive nuclear staining.

EA2CliN uses the post-treatment level of MCM4 in the nodes, rather than the primary cancer.

Results: In cohort 1, EA2Clin (using primary tumour MCM4) was significantly associated with both RFS (P=0.0003, HR=13.17, 95%CI=5.48-13.61) and BCSS (P=0.005, HR=11.91, 95%CI=8.73-31.42). The 5 and 10 year actuarial recurrence rates were 5%/5% and 48%/64% for the low and high-risk groups respectively.

In the same cohort, using the MCM4 level in the node (EA2CliN) there was an even more significant association with both RFS (P&lt;0.00009, HR=18.16, 95%CI=12.59-19.46) and BCSS (P=0.002, HR=12.93, 95%CI=5.43-25.62). The 5 and 10 year actuarial recurrence rates were 0%/0% and 48%/72% for the low and high-risk groups respectively. Further validation of EA2CliN in cohorts 2 and 3 is underway.

Discussion:

· Direct measurement of on-treatment proliferation biomarkers in LN metastases improves prediction of outcomes to ET in women with BC.

· This tests identifies a group of low risk women that are node negative and node positive with a 100% RFS and BCSS.

· This is the most impressive predictive test for patients with ER+ breast cancer yet developed.

Citation Format: Turnbull AK, Mok S, Martinez-Perez C, Fernando A, Renshaw L, Keys J, Sims AH, Dixon JM. Measurement of on-treatment proliferation biomarkers in nodal metastasis improves prediction of endocrine therapy response using the EA2CliN test [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-11-03.

Rough endoplasmic reticulum trafficking errors by different classes of mutant dentin sialophosphoprotein (DSPP) cause dominant negative effects in both dentinogenesis imperfecta and dentin dysplasia by entrapping normal DSPP

Families with nonsyndromic dentinogenesis imperfecta (DGI) and the milder, dentin dysplasia (DD), have mutations in one allele of the dentin sialophosphoprotein (DSPP) gene. Because loss of a single Dspp allele in mice (and likely, humans) causes no dental phenotype, the mechanism(s) underling the dominant negative effects were investigated. DSPP mutations occur in three classes. (The first class, the mid-leader missense mutation, Y6D, was not investigated in this report.) All other 5′ mutations of DSPP result in changes/loss in the first three amino acids (isoleucine-proline-valine [IPV]) of mature DSPP or, for the A15V missense mutation, some retention of the hydrophobic leader sequence. All of this second class of mutations caused mutant DSPP to be retained in the rough endoplasmic reticulum (rER) of transfected HEK293 cells. Trafficking out of the rER by coexpressed normal DSPP was reduced in a dose-responsive manner, probably due to formation of Ca2+-dependent complexes with the retained mutant DSPP. IPV-like sequences begin many secreted Ca2+-binding proteins, and changing the third amino acid to the charged aspartate (D) in three other acidic proteins also caused increased rER accumulation. Both the leader-retaining A15V and the long string of hydrophobic amino acids resulting from all known frameshift mutations within the 3′-encoded Ca2+-binding repeat domain (third class of mutations) caused retention by association of the mutant proteins with rER membranes. More 5′ frameshift mutations result in longer mutant hydrophobic domains, but the milder phenotype, DD, probably due to lower effectiveness of the remaining, shorter Ca2+-binding domain in capturing normal DSPP protein within the rER. This study presents evidence of a shared underlying mechanism of capturing of normal DSPP by two different classes of DSPP mutations and offers an explanation for the mild (DD-II) versus severe (DGI-II and III) nonsyndromic dentin phenotypes. Evidence is also presented that many acidic, Ca2+-binding proteins may use the same IPV-like receptor/pathway for exiting the rER.

Targeting the progression of Parkinson's disease

By the time a patient first presents with symptoms of Parkinson's disease at the clinic, a significant proportion (50-70%) of the cells in the substantia nigra (SN) has already been destroyed. This degeneration progresses until, within a few years, most of the cells have died. Except for rare cases of familial PD, the initial trigger for cell loss is unknown. However, we do have some clues as to why the damage, once initiated, progresses unabated. It would represent a major advance in therapy to arrest cell loss at the stage when the patient first presents at the clinic. Current therapies for Parkinson's disease focus on relieving the motor symptoms of the disease, these unfortunately lose their effectiveness as the neurodegeneration and symptoms progress. Many experimental approaches are currently being investigated attempting to alter the progression of the disease. These range from replacement of the lost neurons to neuroprotective therapies; each of these will be briefly discussed in this review. The main thrust of this review is to explore the interactions between dopamine, alpha synuclein and redox-active metals. There is abundant evidence suggesting that destruction of SN cells occurs as a result of a self-propagating series of reactions involving dopamine, alpha synuclein and redox-active metals. A potent reducing agent, the neurotransmitter dopamine has a central role in this scheme, acting through redox metallo-chemistry to catalyze the formation of toxic oligomers of alpha-synuclein and neurotoxic metabolites including 6-hydroxydopamine. It has been hypothesized that these feed the cycle of neurodegeneration by generating further oxidative stress. The goal of dissecting and understanding the observed pathological changes is to identify therapeutic targets to mitigate the progression of this debilitating disease.

Gene expression signature predicts chemoresponse of microdissected papillary serous ovarian tumors

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Background: The purpose of this study was to identify a predictive gene signature for chemoresponse in patients with advanced stage papillary serous ovarian cancer. Methods: Expression profiling was performed on 50 chemonaive, microdissected advanced stage papillary serous ovarian cancers using Affymetrix Human Genome U133 Plus 2.0 microarrays. Chemoresistance was defined as disease progression while the patients remained on primary chemotherapy. Nine normal human ovarian surface epithelial (HOSE) brushings were also assessed to quantify normal gene expression levels. Validation was performed by quantitative real time PCR using the HOSE isolates and microdissected ovarian tumor samples. Results: A supervised learning algorithm applied to genes differentially expressed between chemosensitive/resistance tumors (p < 0.001) using leave-one-out cross-validation (LOOCV), identified over 2000 genes associated with tumor chemosensitivity. The chemoresponsive gene list was further refined to 576 genes by including only genes used for all LOOCV iterations. An independent gene list was generated comparing expression profiles of chemoresistant tumors to HOSE. The two lists were compared to identify common genes, generating final classifier list of 75 genes that included genes involved in apoptosis, RNA processing, protein ubiquitination, transcription regulation, and other novel genes. We hypothesized genes identified in both data sets would be predictive and biologically relevant. Of these 75 genes, 20 were validated by real-time PCR. Validated genes were ranked by a univariate t-stat value to further resolve the predictor. 4 multivariate predictor algorithms demonstrated the 10 top ranked validated genes maximixed prediction accuracy (compound covariate, 91%; diagonal linear discriminant analysis, 91%; 3-nearest neighbor, 86%; nearest centroid, 95%). The predictive value of these genes will be evaluated on an independent sample set. Conclusions: Gene expression profiling can distinguish between chemosensitive and chemoresistant ovarian cancers. This signature can predict response to therapy and has identified novel biologically and clinically relevant targets.

No significant financial relationships to disclose.

Overexpression of alpha(v)beta6 integrin in serous epithelial ovarian cancer regulates extracellular matrix degradation via the plasminogen activation cascade

Recent evidence suggests that integrins are involved in the multi-step process of tumour metastasis. The biological relevance of alpha(v) integrins and associated beta-subunits in ovarian cancer metastasis was examined by analysing the expression of these cell surface receptors in nine ovarian cancer cell lines and also in the primary human ovarian surface epithelial cell line (HOSE). beta1, beta3 and beta5 subunits were present in all ten ovarian cell lines. beta6 subunit was present at varying levels in eight out of nine cancer cell lines but was absent in the HOSE cell line. Immunohistochemical staining showed that beta6 was present in both non-invasive (borderline) and high-grade ovarian cancer tissues but was absent in benign and normal ovarian tissue. High alpha(v)beta6 integrin expressing ovarian cancer cell lines had high cell surface expression of uPA and uPAR. Ovarian cancer cell lines expressing high to moderate level of alpha(v)beta6 integrin demonstrated ligand-independent enhanced levels of high molecular weight (HMW)-uPA and pro-matrix metalloproteinase 2 and 9 (pro-MMP-2 and pro-MMP-9) expression in the tumour-conditioned medium. High and moderate expression of alpha(v)beta6 integrin correlated with increased plasminogen-dependent degradation of extracellular matrix which could be inhibited by inhibitors of plasmin, uPA and MMPs or by monoclonal antibody against uPA, MMP-9 or alpha(v)beta6 integrin. These results suggest that endogenous de novo expression of alpha(v)beta6 integrin in ovarian cancer cells may contribute to their invasive potential, and that alpha(v)beta6 expression may play a role in ovarian cancer progression and metastasis.

Frequency of the BRCA1 185delAG mutation among Jewish women with ovarian cancer and matched population controls

Among women of Ashkenazi Jewish origin, a frameshift mutation of the BRCA1 gene, designated 185delAG, occurs with a carrier frequency of approximately 1% and is estimated to account for about 39% of ovarian cancer cases occurring prior to age 50 years. To determine the actual frequency of this mutation among Jewish women with ovarian cancer, we tested DNA collected as part of an ongoing population-based case-control study of genetic and environmental factors for epithelial ovarian cancer in eastern Massachusetts. Using single-stranded conformational polymorphism analysis followed by direct sequencing, we found that 6 (19.4%) of 31 Jewish patients were carriers for a 185delAG mutation compared to 0 of 23 Jewish controls (P=0.03) Using empiric logic [correction of logits], the estimated relative risk for ovarian cancer associated with a 185delAG mutation is 12.0. The average age of the 6 patients with mutations was 48.3 years, significantly younger than the average of 57.4 years observed for the 25 patients without the mutation (P-0.05). For ovarian cancer diagnosed prior to age 50 years, three (37.5%) of eight patients carried the mutation. None of the six patients with the mutation had a history consistent with hereditary breast ovarian cancer syndrome, although two had a personal history of prior cancer. Our results provide empiric conformation of the estimated prevalence of 185delAG mutations among Jewish women with ovarian cancer.

Transcriptional analyses of the gene region that encodes human histidyl-tRNA synthetase: identification of a novel bidirectional regulatory element

A recombinant phage clone containing the 5' end of the gene HRS encoding human histidyl-tRNA synthetase (HRS) has been isolated. Primer extension analyses indicated that there are two types of HRS transcripts. The longer transcripts were initiated from a single transcription start point (tsp) located approximately 455 bp upstream and the shorter transcripts were initiated from multiple tsp located approximately 38 to 82 bp upstream from the HRS ATG start codon. Functionally, we have identified two regions (+1 to -122; -185 to -502), each of which when placed 5' of a promoterless cat construct can initiate transcription in both orientations after transfection into HeLa cells. A pair of imperfect inverted repeats (IIR) was located within the region +1 to -122. Using mobility shift assays, we have identified a nuclear factor that binds specifically to each half of the IIR. However, this pair of IIR (-73 to -110) was not sufficient for bidirectional transcription activity. At least one copy of a 27-bp oligodeoxyribonucleotide (oligo), which spans -94 to -120, was required in order to facilitate bidirectional transcription activity. From mobility shift assays using HeLa cell nuclear extracts and this 27-bp oligo, we have identified two DNA-protein complexes, both of which are presumably required to initiate bidirectional transcription.

Molecular characterization and mapping of murine genes encoding three members of the stefin family of cysteine proteinase inhibitors

Stefins or Type 1 cystatins belong to a large, evolutionarily conserved protein superfamily, the members of which inhibit the papain-like cysteine proteinases. We report here on the molecular cloning and chromosomal localization of three newly identified members of the murine stefin gene family. These genes, designated herein as mouse stefins 1, 2, and 3, were isolated on the basis of their relatively increased expression in moth-eaten viable compared to normal congenic mouse bone marrow cells. The open reading frames of the stefin cDNAs encode proteins of approximately 11.5 kDa that show between 50 and 92% identity to sequences of stefins isolated from various other species. Data from Southern analysis suggest that the murine stefin gene family encompasses at least 6 and possibly 10-20 members, all of which appear to be clustered in the genome. Analysis of interspecific backcross mice indicates that the genes encoding the three mouse stefins all map to mouse chromosome 16, a localization that is consistent with the recent assignment of the human stefin A gene to a region of conserved homology between human chromosome 3q and the proximal region of mouse chromosome 16.