Development and validation of the PREMMplus clinical prediction model for multigene hereditary cancer risk assessment

1579

Background: Current clinical prediction models provide syndrome-specific numeric estimates of an individual's likelihood of having a specific hereditary cancer syndrome (e.g., PREMM5 for Lynch syndrome; BRCAPRO for BRCA1/2). With the emergence of multigene panel testing (MGPT), there is a need to evaluate individuals' risk of carrying a pathogenic variant in a diverse array of cancer susceptibility genes in parallel. This study’s aim was to develop and validate the PREMMplus clinical prediction model for multigene cancer risk assessment. Methods: PREMMplus was developed in a cohort of 7296 individuals who had undergone germline MGPT at a single center. Logistic regression models were used to examine candidate predictive variables – including age, sex, ethnicity, and personal/family history of cancer – to provide a numeric estimate of an individual’s likelihood of carrying a pathogenic/likely pathogenic germline variant in one of 18 cancer susceptibility genes (11 high- [ APC, BRCA1/2, CDH1, EPCAM, MLH1, MSH2, MSH6, biallelic MUTYH, PMS2, and TP53] and 7 moderate-penetrance [ ATM, CDKN2A, CHEK2, PALB2, PTEN, RAD51C, and RAD51D]). Model performance was validated in an independent dataset of 14845 individuals who had undergone MGPT at a commercial laboratory. Results: Using clinical characteristics, including personal/family history of 18 cancers plus colorectal adenoma burden, PREMMplus demonstrated an excellent ability to predict pathogenic variants in high penetrance genes at 90% sensitivity. PREMMplus had acceptable performance with the addition of 7 moderate penetrance genes. PREMMplus was well-calibrated and demonstrated comparable performance in the external validation dataset. Conclusions: PREMMplus is the first validated risk assessment model to quantify an individual’s likelihood of carrying pathogenic variants in a wide diversity of cancer risk genes, and can be used to select individuals who should undergo MGPT. As expected, PREMMplus’s discriminatory capacity was reduced with the inclusion of moderate penetrance cancer risk genes. [Table: see text]

Clinical Factors Associated With Gastric Cancer in Individuals With Lynch Syndrome

BACKGROUND & AIMS

Lynch syndrome is the most common inherited cause of gastrointestinal cancer and increases risk for a variety of malignancies, including gastric cancer. We aimed to identify clinical factors associated with gastric cancer in carriers of germline variants causing Lynch syndrome.

METHODS

We collected data from 52,758 consecutive individuals tested for genetic variants associated with Lynch syndrome from June 2006 through July 2013 at a commercial laboratory. We obtained clinical and demographic data, as well as information on personal and family histories of cancer (first- and second-degree relatives) from forms completed by ordering providers. We performed multivariate logistic regression to identify clinical factors associated with gastric cancer in carriers of mutations that cause Lynch syndrome (pathogenic mutations).

RESULTS

After we excluded individuals with missing clinical data (n = 1664) or with multiple pathogenic mutations (n = 8), we analyzed data from 51,086 individuals. Of these, 3828 persons carried pathogenic mutations (1346 with mutations in MLH1, 1639 with mutations in MSH2, 670 with mutations in MSH6, 145 with mutations in PMS2, and 28 with mutations in EPCAM). Of the 3828 carriers of pathogenic mutations, 41 (1.1%) had a previous gastric cancer and 350 (9.1%) had 1 or more first- or second-degree relatives with gastric cancer. In multivariate analysis, male sex (odds ratio [OR], 2.82; 95% CI, 1.48-5.38), older age (OR, 2.07 per 10 years; 95% CI, 1.64-2.61), mutations in MLH1 (OR, 6.53; 95% CI, 1.50-28.42) or MSH2 (OR, 5.23 compared to mutations in MSH6, PMS2, or EPCAM; 95% CI, 1.21-22.71), and number of first-degree relatives with gastric cancer (OR, 2.52; 95% CI, 1.42-4.45), but not second-degree relatives (OR, 1.12; 95% CI, 0.40-3.18) were independently associated with gastric cancer among carriers of pathogenic mutations.

CONCLUSIONS

In an analysis of data from almost 4000 carriers of Lynch syndrome-associated mutations, we found history of gastric cancer to be independently associated with male sex, older age, mutations in MLH1 or MSH2, and number of first-degree relatives with gastric cancer. These findings suggest that personalized, risk-stratified approaches to gastric cancer surveillance may be appropriate for individuals with Lynch syndrome-associated mutations.

NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 1.2020

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic provide recommendations for genetic testing and counseling for hereditary cancer syndromes, and risk management recommendations for patients who are diagnosed with syndromes associated with an increased risk of these cancers. The NCCN panel meets at least annually to review comments, examine relevant new data, and reevaluate and update recommendations. These NCCN Guidelines Insights summarize the panel's discussion and most recent recommendations regarding criteria for high-penetrance genes associated with breast and ovarian cancer beyond BRCA1/2, pancreas screening and genes associated with pancreatic cancer, genetic testing for the purpose of systemic therapy decision-making, and testing for people with Ashkenazi Jewish ancestry.

A Multi-Institutional Cohort of Therapy-Associated Polyposis in Childhood and Young Adulthood Cancer Survivors

Prior small reports have postulated a link between gastrointestinal polyposis and childhood and young adulthood cancer (CYAC) treatment (therapy-associated polyposis; TAP), but this remains a poorly understood phenomenon. The aim of this study was to describe the phenotypic spectrum of TAP in a multi-institutional cohort. TAP cases were identified from eight high-risk cancer centers. Cases were defined as patients with ≥10 gastrointestinal polyps without known causative germline alteration or hereditary colorectal cancer predisposition syndrome who had a history of prior treatment with chemotherapy and/or radiotherapy for CYAC. A total of 34 TAP cases were included (original CYAC: 27 Hodgkin lymphoma, three neuroblastoma, one acute myeloid leukemia, one medulloblastoma, one nephroblastoma, and one non-Hodgkin lymphoma). Gastrointestinal polyposis was first detected at a median of 27 years (interquartile range, 20-33) after CYAC treatment. A total of 12 of 34 (35%) TAP cases had ≥50 colorectal polyps. A total of 32 of 34 (94%) had >1 histologic polyp type. A total of 25 of 34 (74%) had clinical features suggestive of ≥1 colorectal cancer predisposition syndrome [e.g., attenuated familial adenomatous polyposis (FAP), serrated polyposis syndrome, extracolonic manifestations of FAP, mismatch repair-deficient colorectal cancer, or hamartomatous polyposis] including 8 of 34 (24%) with features of multiple such syndromes. TAP is an apparently acquired phenomenon that should be considered in patients who develop significant polyposis without known causative germline alteration but who have had prior treatment for a CYAC. Patients with TAP have features that may mimic various hereditary colorectal cancer syndromes, suggesting multiple concurrent biologic mechanisms, and recognition of this diagnosis may have implications for cancer risk and screening.

Improving cascade genetic testing for families with inherited pancreatic cancer (PDAC) risk: The GENetic Education, Risk Assessment and TEsting (GENERATE) study

TPS779

Background: 4-10% of PDAC patients harbor pathogenic germline variants in cancer susceptibility genes, including APC, ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, and TP53. For families with such pathogenic variants, the greatest potential impact of germline testing is to identify relatives with the same variant (cascade testing), thereby providing the opportunity for early detection and interception of PDAC and other associated cancers. Numerous factors limit cascade testing in real-world practice, including family dynamics, widespread geographic distribution of relatives, access to genetic services, and misconceptions about the importance of germline testing, such that the preventive benefits of cascade testing are often not fully realized. The primary aim of this study is to analyze two alternative strategies for cascade testing in families with inherited PDAC risk. Methods: 1000 individuals with a confirmed pathogenic germline variant in any of the above genes in a 1st/2nd degree relative and a 1st/2nd degree relative with PDAC will be remotely enrolled through the study website (www.GENERATEstudy.org) and randomized between two methods of cascade testing (individuals with prior genetic testing will be ineligible): Arm 1 will undergo pre-test genetic education with a pre-recorded video and live interactive session with a genetic counselor via a web-based telemedicine platform (Doxy.me), followed by germline testing through Color Genomics; Arm 2 will undergo germline testing through Color Genomics without dedicated pre-test genetic education. Color Genomics will disclose results to study personnel and directly to participants in both arms. All participants will have the option of pursuing additional telephone-based genetic counseling through Color Genomics. The primary outcome will be uptake of cascade testing. Secondary outcomes will include self-reported genetic knowledge, cancer worry, distress, decisional preparedness, familial communication, and screening uptake, which will be measured via longitudinal surveys. Enrollment is underway nationwide as of May, 2019. Clinical trial information: NCT03762590.

Implementation of systematic genetic counseling (GC) and multigene germline testing (MGT) for pancreatic cancer (PC) patients (pts)

678

Background: MGT identifies cancer susceptibility gene variants in 4-10% of unselected PC pts. Such data have prompted national guidelines to recommend GC and MGT of all PC pts, but the benefits and barriers to implementing systematic testing are unknown. This study’s aim was to study the implementation of universal GC for all PC pts seen in an academic oncology practice. Methods: In 12/2016, all Dana-Farber Cancer Institute (DFCI) gastrointestinal oncologists were recommended to refer all PC pts for GC and MGT. In 10/2018, workflows were changed such that PC patients were automatically scheduled for GC consultation on the same day as their initial oncologic evaluation (unless patients opted out), rather than relying on provider referral. Clinical and germline data were collected on a consecutive cohort of PC pts undergoing GC and MGT from 3/1/2017-3/31/2019. Two additional months (4/1/2019-5/31/2019) were collected for clinical quality assessment purposes. Results: 1305 (48.3/month) PC pts were seen for oncologic new patient visits, 318 (25.1%; 12.1/month) of whom underwent GC. Rates of GC/MGT increased significantly after the 10/2018 workflow change (8.2 PC pts/month [17.2% of all new PC pts seen] versus 20.3 PC pts/month, [40.9% of all new PC pts seen]; p<0.01). Of the 318 PC pts who underwent GC, 29 (9.1%; 95% CI 6.4-11.9%; 2.2% of all PC pts seen) were found to carry germline PC susceptibility gene mutations on MGT. Rates of mutation carrier identification increased after the clinical workflow change from 0.79 mutation carriers/month (1.6% of all new PC pts seen) to 1.75 mutation carriers/month (3.5% of all new PC pts seen). The majority of identified mutation carriers have either received therapy targeted towards their germline mutation or are undergoing first-line palliative systemic therapy with potential for future targeted therapy. Conclusions: Clinical implementation of routine GC/MGT in PC pts is feasible and results in the detection of mutations that are actionable for PC pts and at-risk family members. Systematized workflows for GC evaluation not reliant on active referral result in markedly higher uptake of MGT and mutation carrier identification. Clinical trial information: NCT03060720.

Phase Ib study of gemcitabine, nab-paclitaxel, and ficlatuzumab in patients with advanced pancreatic cancer

693

Background: Paired-related homeodomain transcription factor 1 (Prrx1) isoforms are involved in pancreatic development, pancreatitis, and carcinogenesis. Hepatocyte growth factor (HGF) is a transcriptional target of Prrx1b. Ficlatuzumab is a recombinant humanized HGF antibody, that neutralizes HGF/c-Met binding and HGF-induced c-Met phosphorylation. In preclinical pancreatic ductal adenocarcinoma (PDAC) models, inhibition of Prrx1b-HGF signaling using ficlatuzumab and gemcitabine reduced primary tumor volume and eliminated metastatic disease. Methods: Patients (pts) with previously-untreated metastatic PDAC enrolled in a phase Ib dose escalation study with 3+3 design and two dose cohorts of ficlatuzumab (10mg/kg and 20mg/kg) administered intravenously every other week with gemcitabine (G; 1000mg/m2) and nab-paclitaxel (A; 125mg/m2) given 3 weeks on and 1 week off. This was followed by an expansion phase at the maximally tolerated dose (MTD) of the combination. Results: 24 pts (sex, 12M:12F; median age, 69 years [range, 51-82 years]) were enrolled. No dose-limiting toxicities were identified in the phase 1b (N = 6 pts) and ficlatuzumab at 20mg/kg with GA was advanced to the expansion phase (N = 18 pts). By RECISTv1.1 in the full study population, 7 (29%) pts had partial response, 15 (63%) had stable disease, and 2 (8%) could not be evaluated. Median progression-free survival was 8 months (range, 3-16 months), 4 pts are still on study treatment. The primary toxicities attributed to ficlatuzumab included hypoalbuminemia (grade 3, 21%; any grade, 91%) and edema (grade 3, 8%; any grade, 91%). Nine (38%) of the 24 pts discontinued study treatment due to these toxicities prior to disease progression. Conclusions: The combination of ficlatuzumab with gemcitabine and nab-paclitaxel is associated with durable treatment responses but also significant hypoalbuminemia and edema that may impair treatment tolerability. Serial blood samples were collected for circulating HGF measurements, and mandatory pretreatment biopsies were collected for tumor c-MET pathway activation and 3D organoid culture drug sensitivity testing. Clinical trial information: NCT03316599.

Irinotecan, cetuximab, and bevacizumab (CBI) versus irinotecan, cetuximab, and placebo (CI) in irinotecan-refractory metastatic colorectal cancer (mCRC): Results from an ACCRU network randomized phase II trial

102

Background: Combination irinotecan and cetuximab is approved for irinotecan-refractory mCRC; it is unknown if the addition of bevacizumab would improve outcomes. We studied the efficacy and safety of CBI compared with CI in patients (pts) with RAS wildtype, irinotecan-refractory mCRC. Methods: In this multicenter, randomized, double-blind, placebo-controlled phase II trial, pts with RAS wildtype mCRC and no prior anti-epidermal growth factor receptor therapy who failed at least 1 irinotecan-based chemotherapy regimen and received bevacizumab in at least 1 prior line of therapy were randomized 1:1 to irinotecan 180 mg/m2 (or previously tolerated dose), cetuximab 500 mg/m2, and bevacizumab 5 mg/kg vs CI every 2 wks until disease progression, intolerable toxicity, or withdrawal of consent. The primary endpoint was progression free survival (PFS). Multivariable Cox proportional hazard models stratified by number of prior lines of therapy and bevacizumab receipt in immediate prior line were performed. Secondary endpoints included overall survival (OS), objective response rate (ORR), and adverse events (AEs). The study was closed early in January 2018 for reasons related to accrual and funding after enrollment of 36 out of a planned 60 pts. Results: Between July 2015 and December 2017, 36 pts were randomized (19 to CBI, 17 to CI). 34 pts (94%) were treated with 2 or more prior chemotherapy regimens. Baseline characteristics were similar between arms. Median PFS was 9.7 vs 5.5 mo for CBI and CI arms, respectively (log-rank P =0.76; multivariable HR = 0.64; 95% CI, 0.25-1.66). Median OS was 19.7 vs 10.2 mo for CBI and CI (log-rank P= 0.04; multivariable HR = 0.41; 95% CI, 0.15-1.09). ORR was 37% for CBI vs 12% for CI ( P =0.13). Grade 3 or higher AEs occurred in 47% of pts receiving CBI vs 35% for CI ( P =0.46). Conclusions: In this prematurely discontinued trial, there were non-significant increases in PFS and ORR and a statistically significant 9.5 mo increase in median OS in favor of CBI compared to CI. Further investigation of CBI for treatment of irinotecan-refractory mCRC is warranted. Clinical trial information: NCT02292758.

Feasibility of pharmacist co-management for patients prescribed oral anticancer therapy for gastrointestinal cancers

77

Background: There is an increased use of oral anti-cancer therapies (OACTs) for treatment of gastrointestinal (GI) cancers. While OACTs provide convenience compared to IV agents, they carry similar risks for drug-drug interactions (DDI), toxicities, and unique challenges like adherence and drug access. Patients on OACTs have fewer touch-points with clinicians, requiring more patient ownership of treatment. Pharmacist co-management of pts has been shown to be successful in teaching and monitoring of IV therapy. We sought to assess feasibility of pharmacist co-management for pts prescribed OACTs for treatment of GI cancers. Methods: In 2019, the Dana-Farber GI Cancer Center (GCC) had an embedded pharmacist 8 hrs/week to help with co-management of pts on OACTs. The pharmacist provided (1) in-person and telephone teaching; (2) comprehensive medication reconciliation; (3) DDI review; and (4) supportive care recommendations. Patients were identified by reviewing provider schedules and through provider referrals. The initial teach visit was one-on-one with each patient before initiation, with joint visits with providers thereafter for monitoring and adherence checks. Data were collected to quantify the types of support/recommendation provided by pharmacist and the impact on clinical workflow. Results: After 4 months in the GCC clinic, the pharmacist has co-managed 26 new pts, 61% seen in-person. In initial visits, the pharmacist identified 3 DDI, updated 15 medication lists, and assisted 11 pts/or providers with drug access and drug information. The pharmacist saw 10 of 26 pts for follow up, totaling 21 encounters. The pharmacist assisted in 17 of the 21 encounters with drug access and drug information. Pharmacist spent 20 min/pt on teaching. For follow-up visits, the pharmacist did not additional incur clinic resources as patients were seen with providers. Conclusions: Pharmacist co-management of patients on OACTs is feasible and offers an added safety resource to pts and providers from initial teaching to monitoring. Future research will focus on the impacts of co-management on clinical outcomes, such as the use of emergency/hospital visits, the duration of therapy, and adherence.

Clinical Factors Associated with Urinary Tract Cancer in Individuals with Lynch Syndrome

BACKGROUND

Lynch syndrome confers markedly increased risks of various malignancies, including urinary tract cancers (UTC; renal pelvis, ureter, bladder, and possibly kidney cancers). It is unknown how to determine which Lynch syndrome carriers are at highest UTC risk. Our aim was to identify clinical factors associated with UTC among Lynch syndrome carriers.

METHODS

The study population was a cohort of 52,758 consecutively ascertained individuals undergoing Lynch syndrome testing at a commercial laboratory. Clinical data were obtained from test request forms completed by the ordering provider. Univariate analysis and multivariate logistic regression were performed to identify factors associated with UTC among Lynch syndrome carriers.

RESULTS

Compared with noncarriers, Lynch syndrome carriers were significantly more likely to have had UTC (4.1% vs. 1.2%; P < 0.0001). Lynch syndrome-associated UTC was independently associated with male sex [OR 1.95; 95% confidence interval (CI), 1.38-2.76], increased age (OR 2.44 per 10 years; 95% CI, 2.11-2.82), familial burden of UTC (OR 2.69 per first-/second-degree relative with UTC; 95% CI, 1.99-3.63), and pathogenic EPCAM/MSH2 variants (OR 4.01; 95% CI, 2.39-6.72) but not MLH1 variants (OR 1.17; 95% CI, 0.63-2.17), race, or history of other Lynch syndrome-associated malignancy. A total of 143 of 158 (90.5%) Lynch syndrome carriers with UTC had ≥1 of the following characteristics: male sex, EPCAM/MSH2 variants, or family history of UTC; 1,236 of 1,251 (98.8%) Lynch syndrome carriers lacking all of these characteristics had no history of UTC.

CONCLUSIONS

Specific clinical factors can reliably identify Lynch syndrome carriers most likely to be at risk for UTC.

IMPACT

A predictable subset of Lynch syndrome carriers may be most likely to benefit from UTC surveillance/prevention.

Health behaviours and beliefs in individuals with familial pancreatic cancer

Individuals at high risk for pancreatic cancer are recommended surveillance and healthy lifestyle behaviours and patient experience with recommendations are understudied. To describe engagement and experience with surveillance, tobacco and alcohol use, health beliefs and motivation (Champion Health Belief Measure) and the relationship with personal, psychosocial (Impact of Event Scale), and familial characteristics. Interest in integrative therapies (complementary therapies) are described. A multi-site cross-sectional survey including individuals at high risk for pancreatic cancer with no diagnosis of pancreatic cancer who have been evaluated at a comprehensive cancer center. Descriptive statistics and Wilcoxon rank sum test and Fisher's exact test were used to assess univariate associations. Of the 132 respondents (72% response rate), 92 (70%) reported undergoing surveillance which was associated with older age (p = 0.001). Of which, 36% and 51% report that magnetic resonance imaging (MRI) or endoscopic ultrasound (EUS), respectively, were uncomfortable; 22% and 30% dread the next MRI or EUS, respectively. Of those who reported alcohol consumption (n = 88); 15% consumed 1 or more drinks daily and no alcohol consumption was associated with higher Impact of Event scale scores (p = 0.024). A total of six participants were currently smoking every day or some days. Participants reported high motivation to engage in heathy behaviours and 92% were interested in integrative therapies. In these select participants, most were engaging in pancreatic cancer surveillance, alcohol intake was moderate, and tobacco intake was minimal. Modifiable factors, such as experience and comfort with surveillance could be addressed. The sample is motivated to engage in behavioural health intervention.

FOLFOX plus ziv-aflibercept or placebo in first-line metastatic esophagogastric adenocarcinoma: A double-blind, randomized, multicenter phase 2 trial

BACKGROUND

Antiangiogenic therapy is a proven therapeutic modality for refractory gastric and gastroesophageal junction adenocarcinoma. This trial assessed whether the addition of a high affinity angiogenesis inhibitor, ziv-aflibercept, could improve the efficacy of first-line mFOLFOX6 (oxaliplatin, leucovorin, and bolus plus infusional 5- fluorouracil) in metastatic esophagogastric adenocarcinoma.

METHODS

Patients with treatment-naive metastatic esophagogastric adenocarcinoma were randomly assigned (in a 2:1 ratio) in a multicenter, placebo-controlled, double-blind trial to receive first-line mFOLFOX6 with or without ziv-aflibercept (4 mg/kg) every 2 weeks. The primary endpoint was 6-month progression-free survival (PFS).

RESULTS

Sixty-four patients were randomized to receive mFOLFOX6 and ziv-aflibercept (43 patients) or mFOLFOX6 and a placebo (21 patients). There was no difference in the PFS, overall survival, or response rate. Patients treated with mFOLFOX6/ziv-aflibercept tended to be more likely to discontinue study treatment for reasons other than progressive disease (P = .06). The relative dose intensity of oxaliplatin and 5-fluorouracil was lower in the mFOLFOX6/ziv-aflibercept arm during the first 12 and 24 weeks of the trial. There were 2 treatment-related deaths due to cerebral hemorrhage and bowel perforation in the mFOLFOX6/ziv-aflibercept cohort.

CONCLUSIONS

Ziv-aflibercept did not increase the anti-tumor activity of first-line mFOLFOX6 in metastatic esophagogastric cancer, potentially because of decreased dose intensity of FOLFOX. Further evaluation of ziv-aflibercept in unselected, chemotherapy-naive patients with metastatic esophagogastric adenocarcinoma is not warranted.

Improving cascade genetic testing for families with inherited pancreatic cancer (PDAC) risk: The genetic education, risk assessment and testing (GENERATE) study

TPS4162

Background: 4-10% of PDAC patients harbor pathogenic germline variants in cancer susceptibility genes, including APC, ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, and TP53. For families with such pathogenic variants, the greatest potential impact of germline testing is to identify relatives with the same pathogenic variant (cascade testing), thereby providing the opportunity for early detection and cancer interception of PDAC and other associated malignancies. Numerous factors limit cascade testing in real-world practice, including family dynamics, widespread geographic distribution of relatives, access to genetic services, and misconceptions about the importance of germline testing, such that the preventive benefits of cascade testing are often not fully realized. The primary aim of this study is to analyze two alternative strategies for cascade testing in families with inherited PDAC susceptibility. Methods: 1000 individuals (from approximately 200 families) with a confirmed pathogenic germline variant in any of the above genes in a 1st/2nd degree relative and a 1st/2nd degree relative with PDAC will be remotely enrolled through the study website (www.generatestudy.org) and randomized between two different methods of cascade testing (individuals with prior genetic testing will be ineligible): Arm 1 will undergo pre-test genetic education with a pre-recorded video and live interactive session with a genetic counselor via a web-based telemedicine platform (Doxy.me), followed by germline testing through Color Genomics; Arm 2 will undergo germline testing through Color Genomics without dedicated pre-test genetic education. Color Genomics will disclose results to study personnel and directly to participants in both arms. Participants in both arms will have the option of pursuing additional telephone-based genetic counseling through Color Genomics. The primary outcome will be uptake of cascade testing. Secondary outcomes will include participant self-reported genetic knowledge, cancer worry, distress, decisional preparedness, familial communication, and screening uptake, which will be measured via longitudinal surveys. Enrollment will begin February, 2019. Clinical trial information: NCT03762590.

Genetics of Familial and Sporadic Pancreatic Cancer

In the previous decade, comprehensive genomic analyses have yielded important insights about the genetic alterations that underlie pancreatic tumorigenesis. Whole-exome and whole-genome sequencing of pancreatic ductal adenocarcinomas have confirmed the critical driver genes altered in the majority of pancreatic cancers, as well as identified numerous less frequently altered driver genes, and have delineated cancer subgroups with unique biological and clinical features. It is now appreciated that pancreatic susceptibility gene alterations are often identified in patients with pancreatic cancer without family histories suggestive of a familial cancer syndrome, prompting recent efforts to expand gene testing to all patients with pancreatic cancer. Studies of pancreatic cancer precursor lesions have begun to elucidate the evolutionary history of pancreatic tumorigenesis and to help us understand the utility of biomarkers for early detection and targets to develop new therapeutic strategies. In this review, we discuss the results of comprehensive genomic characterization of pancreatic ductal adenocarcinoma and its precursor lesions, and we highlight translational applications in early detection and therapy.

Effect of High-Dose vs Standard-Dose Vitamin D3 Supplementation on Progression-Free Survival Among Patients With Advanced or Metastatic Colorectal Cancer: The SUNSHINE Randomized Clinical Trial

IMPORTANCE

In observational studies, higher plasma 25-hydroxyvitamin D (25[OH]D) levels have been associated with improved survival in metastatic colorectal cancer (CRC).

OBJECTIVE

To determine if high-dose vitamin D3 added to standard chemotherapy improves outcomes in patients with metastatic CRC.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind phase 2 randomized clinical trial of 139 patients with advanced or metastatic CRC conducted at 11 US academic and community cancer centers from March 2012 through November 2016 (database lock: September 2018).

INTERVENTIONS

mFOLFOX6 plus bevacizumab chemotherapy every 2 weeks and either high-dose vitamin D3 (n = 69) or standard-dose vitamin D3 (n = 70) daily until disease progression, intolerable toxicity, or withdrawal of consent.

MAIN OUTCOMES AND MEASURES

The primary end point was progression-free survival (PFS) assessed by the log-rank test and a supportive Cox proportional hazards model. Testing was 1-sided. Secondary end points included tumor objective response rate (ORR), overall survival (OS), and change in plasma 25(OH)D level.

RESULTS

Among 139 patients (mean age, 56 years; 60 [43%] women) who completed or discontinued chemotherapy and vitamin D3 (median follow-up, 22.9 months), the median PFS for high-dose vitamin D3 was 13.0 months (95% CI, 10.1 to 14.7; 49 PFS events) vs 11.0 months (95% CI, 9.5 to 14.0; 62 PFS events) for standard-dose vitamin D3 (log-rank P = .07); multivariable hazard ratio for PFS or death was 0.64 (1-sided 95% CI, 0 to 0.90; P = .02). There were no significant differences between high-dose and standard-dose vitamin D3 for tumor ORR (58% vs 63%, respectively; difference, -5% [95% CI, -20% to 100%], P = .27) or OS (median, 24.3 months vs 24.3 months; log-rank P = .43). The median 25(OH)D level at baseline for high-dose vitamin D3 was 16.1 ng/mL vs 18.7 ng/mL for standard-dose vitamin D3 (difference, -2.6 ng/mL [95% CI, -6.6 to 1.4], P = .30); at first restaging, 32.0 ng/mL vs 18.7 ng/mL (difference, 12.8 ng/mL [95% CI, 9.0 to 16.6], P < .001); at second restaging, 35.2 ng/mL vs 18.5 ng/mL (difference, 16.7 ng/mL [95% CI, 10.9 to 22.5], P < .001); and at treatment discontinuation, 34.8 ng/mL vs 18.7 ng/mL (difference, 16.2 ng/mL [95% CI, 9.9 to 22.4], P < .001). The most common grade 3 and higher adverse events for chemotherapy plus high-dose vs standard-dose vitamin D3 were neutropenia (n = 24 [35%] vs n = 21 [31%], respectively) and hypertension (n = 9 [13%] vs n = 11 [16%]).

CONCLUSIONS AND RELEVANCE

Among patients with metastatic CRC, addition of high-dose vitamin D3, vs standard-dose vitamin D3, to standard chemotherapy resulted in a difference in median PFS that was not statistically significant, but with a significantly improved supportive hazard ratio. These findings warrant further evaluation in a larger multicenter randomized clinical trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01516216.

Recent advances in Lynch syndrome

Lynch syndrome is one of the most common hereditary cancer predisposition syndromes and is associated with increased risks of colorectal and endometrial cancer, as well as multiple other cancer types. While the mechanism of mismatch repair deficiency and microsatellite instability and its role in Lynch-associated carcinogenesis has been known for some time, there have been significant advances recently in diagnostic testing and the understanding of the molecular pathogenesis of Lynch tumors. There is also an increased awareness that the clinical phenotype and cancer risk varies by specific mismatch repair mutation, which in turn has implications on surveillance strategies for patients. Even the treatment of Lynch-associated cancers has changed with the addition of immunotherapy for advanced disease. This progress report aims to review some of the many advances in epidemiology, molecular pathogenesis, diagnosis, clinical phenotype, cancer surveillance, treatment, and chemo- and immune-prevention strategies in the Lynch syndrome field over the past 5 years.

Family history of cancer, Ashkenazi Jewish ancestry, and pancreatic cancer risk

Background

Individuals with a family history of cancer may be at increased risk of pancreatic cancer. Ashkenazi Jewish (AJ) individuals carry increased risk for pancreatic cancer and other cancer types.

Methods

We examined the association between family history of cancer, AJ heritage, and incident pancreatic cancer in 49 410 male participants of the prospective Health Professionals Follow-up Study. Hazard ratios (HRs) were estimated using multivariable-adjusted Cox proportional hazards models.

Results

During 1.1 million person-years (1986–2016), 452 participants developed pancreatic cancer. Increased risk of pancreatic cancer was observed in individuals with a family history of pancreatic (HR, 2.79; 95% confidence interval [CI], 1.28–6.07) or breast cancer (HR, 1.40; 95% CI, 1.01–1.94). There was a trend towards higher risk of pancreatic cancer in relation to a family history of colorectal cancer (HR, 1.21; 95% CI, 0.95–1.55) or AJ heritage (HR, 1.29; 95% CI, 0.94–1.77). The risk was highly elevated among AJ men with a family history of breast or colorectal cancer (HR, 2.61 [95% CI, 1.41–4.82] and 1.92 [95% CI, 1.05–3.49], respectively).

Conclusion

Family history of pancreatic cancer was associated with increased risk of this malignancy. Family history of breast or colorectal cancer was associated with the increased risk among AJ men.

Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer

PURPOSE

Germline variants in double-strand DNA damage repair (dsDDR) genes (e.g., BRCA1/2) predispose to pancreatic adenocarcinoma (PDAC) and may predict sensitivity to platinum-based chemotherapy and poly(ADP) ribose polymerase (PARP) inhibitors. We sought to determine the prevalence and significance of germline cancer susceptibility gene variants in PDAC with paired somatic and survival analyses.

METHODS

Using a customized next-generation sequencing panel, germline/somatic DNA was analyzed from 289 patients with resected PDAC ascertained without preselection for high-risk features (e.g., young age, personal/family history). All identified variants were assessed for pathogenicity. Outcomes were analyzed using multivariable-adjusted Cox proportional hazards regression.

RESULTS

We found that 28/289 (9.7%; 95% confidence interval [CI] 6.5-13.7%) patients carried pathogenic/likely pathogenic germline variants, including 21 (7.3%) dsDDR gene variants (3 BRCA1, 4 BRCA2, 14 other dsDDR genes [ATM, BRIP1, CHEK2, NBN, PALB2, RAD50, RAD51C]), 3 Lynch syndrome, and 4 other genes (APC p.I1307K, CDKN2A, TP53). Somatic sequencing and immunohistochemistry identified second hits in the tumor in 12/27 (44.4%) patients with germline variants (1 failed sequencing). Compared with noncarriers, patients with germline dsDDR gene variants had superior overall survival (hazard ratio [HR] 0.54; 95% CI 0.30-0.99; P = 0.05).

CONCLUSION

Nearly 10% of PDAC patients harbor germline variants, although the majority lack somatic second hits, the therapeutic significance of which warrants further study.

Validation of a targeted next-generation sequencing approach to detect mismatch repair deficiency in colorectal adenocarcinoma

Mismatch repair protein deficiency is a hallmark of cancers associated with Lynch syndrome and is a biomarker for response to immunotherapy. With the increasing adoption of cancer next-generation sequencing, there has been a movement to develop screening approaches that take advantage of the unique mutational signatures of mismatch repair-deficient tumors. Here, we develop a sequencing-based metric that distinguishes mismatch repair-deficient from mismatch repair-proficient colorectal adenocarcinomas with comparison to immunohistochemical staining. We find that a single criterion of three or more single base pair insertion or deletion mutations per megabase sequenced, occurring in mononucleotide repeat regions of four or more nucleotides, is sufficient to detect mismatch repair deficiency with 96% sensitivity and 100% specificity in a training set of 241 cancers and 96% sensitivity and 99% specificity in a validation set of 436 additional cancers. Using data from the same cohort, we also find that sequencing information from only three genes-ARID1A, KMT2D, and SOX9-is sufficient to detect mismatch repair-deficient colorectal adenocarcinomas with 76% sensitivity and 98% specificity in the validation set. These findings support the notion that targeted next-generation sequencing already being performed for clinical or research purposes can also be used to accurately detect mismatch repair deficiency in colorectal adenocarcinomas.

Recent Advances in Lynch Syndrome: Diagnosis, Treatment, and Cancer Prevention

Identification of individuals with inherited predispositions to cancer, including Lynch syndrome, can help prevent cancer and cancer-related death by allowing for the uptake of specific cancer prevention and screening as well as the use of therapies directed toward the underlying neoplastic process for individuals with advanced cancer. In the 25 years since the discovery of microsatellite instability (MSI) and the first recognition of germline mismatch repair (MMR) gene variants as the etiologic basis of Lynch syndrome, there has been tremendous progress in the understanding of the spectrum of cancer risk associated with Lynch syndrome as well as in cancer prevention and risk-reduction strategies. The past few years, in particular, have brought transformative changes in the treatment of Lynch syndrome-associated cancers with immune checkpoint inhibitors. In parallel, advances in next-generation sequencing (NGS) technologies now allow rapid and scalable somatic and germline sequencing that promises to help identify Lynch syndrome in individuals who otherwise lack classic phenotypes. Last, real progress is being made to understand more sophisticated methods of precision cancer prevention, including chemotherapeutic prevention agents (e.g., aspirin) and strategies that leverage the immune system to facilitate primary cancer prevention in otherwise-healthy Lynch syndrome carriers.

A Phase II and Biomarker Study of Sorafenib Combined with Modified FOLFOX in Patients with Advanced Hepatocellular Carcinoma

PURPOSE

Sorafenib is a standard first-line treatment for advanced hepatocellular carcinoma (HCC). The phase III SHARP trial showed a median time-to-progression (mTTP) of 5.5 months, overall response rate (ORR) of 2%, and median overall survival (mOS) of 10.7 months with sorafenib. FOLFOX4 has shown modest activity in advanced HCC. We evaluated the combination of sorafenib and modified (m)FOLFOX in a single-arm, multicenter phase II study.

PATIENTS AND METHODS

The study included Child-Pugh A patients with advanced HCC and no prior systemic therapies. Patients received sorafenib 400 mg twice a day for 2 weeks, followed by concurrent mFOLFOX [5-fluorouracil (5-FU) 1,200 mg/m²/day for 46 hours, leucovorin 200 mg/m², and oxaliplatin 85 mg/m² biweekly]. The primary endpoint was mTTP with an alternative hypothesis of 7 months, and secondary endpoints included ORR, mOS, and circulating biomarkers.

RESULTS

The study enrolled 40 patients: HCV/EtOH/HBV, 43%/28%/13%; Child-Pugh A5, 70%. Notable grade 3/4 adverse events (AE) included AST/ALT elevation (28%/15%), diarrhea (13%), hyperbilirubinemia (10%), hand-foot syndrome (8%), and bleeding (8%). mTTP was 7.7 months [95% confidence interval (CI): 4.4-8.9], ORR 18%, and mOS 15.1 months (7.9-16.9). Sorafenib + mFOLFOX increased plasma PlGF, VEGF-D, sVEGFR1, IL12p70, and CAIX and CD4⁺ and CD8⁺ effector T lymphocytes and decreased plasma sVEGFR2 and s-c-KIT and regulatory T cells (Tregs). Shorter TTP was associated with high baseline sVEGFR1. Shorter TTP and OS were associated with increases in Tregs and CD56^Dim natural killer (NK) cells after sorafenib alone and plasma sMET after combination treatment (all P < 0.05).

CONCLUSIONS

Sorafenib + mFOLFOX met the prespecified endpoint with encouraging efficacy but moderate hepatotoxicity. Thus, this regimen may be effective in select patients with adequate liver reserve. Biomarker evaluations suggested a correlation between time-to-progression (TTP) and angiogenic biomarkers and circulating Tregs.

Precision Prevention and Early Detection of Cancer: Fundamental Principles

Prevention and early detection is critical for reducing the population cancer burden. Two approaches have been used: Population approaches change social norms (e.g., smoking bans) or impose incentives (e.g., cigarette taxes); high-risk strategies intervene upon individuals with elevated cancer risk (e.g., smoking cessation). Knowledge about carcinogenesis mechanisms, extreme exposures, and inherited susceptibility provides opportunities to develop precision prevention and early-detection (PPED) strategies. PPED aims to understand the basis of risk, identify groups that optimally benefit from interventions, characterize heterogeneity in intervention responses, optimize intervention timing, and minimize toxicities. We propose a framework around which PPED strategies can be developed. Currently available cancer prevention and early-detection approaches have the potential to reduce a large proportion of the cancer burden in the population. However, even if fully implemented, existing methods cannot fully eliminate the cancer burden. New PPED approaches that exploit the growing knowledge of molecular and biological cancer mechanisms should be developed and implemented. Cancer Discov; 8(7); 803-11. ©2018 AACR.