Germline genetic variants implicated in increasing lifetime risk of pancreatic cancer (PDAC) have been identified in ∼4% to 10% of cases. Clinical features such as family history have poor ...sensitivity in identifying carriers of these risk variants. Genetic testing for these germline variants has potential to guide risk assessment and surveillance recommendations in high-risk individuals to promote prevention and early detection measures. Furthermore, identification of novel germline variants can offer important insights into pathogenesis that may inform precision medicine approaches. This article reviews current understanding of germline mutations associated with PDAC risk and implications of genetic testing.
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Background: The prevalence of Lynch syndrome in Iceland is the highest described so far or 1:226 with three founder mutations, one in MSH6 and two in PMS2, and was first reported in 2017. Lynch ...syndrome predisposes carriers to colorectal cancer and metachronous primaries. Most data on metachronous colorectal cancer reflects on MLH1 and MSH2 carriers and is not well described in MSH6 and PMS2 carriers. The purpose of this study was to examine the cumulative incidence of metachronous colorectal cancer in Icelandic Lynch syndrome carriers diagnosed with colorectal cancer from 1955-2017. Methods: This retrospective study included all individuals with pathogenic variants in mismatch repair genes identified in a nationwide genotype database and a colorectal cancer diagnosis in the Icelandic Cancer Registry from 1955-2017. DeCODE genetics has collected extensive genotypic information on the Icelandic population sequencing the whole genomes of 49,708 Icelanders and imputing genotypes into 116,573 Icelanders whose DNA had been genotyped with SNP chips. Cancer information was obtained from patient charts and cause of death obtained from the Cause of Death Register. All polyp pathology was accessed in the pathology registry and reassessed by two pathologists. Results: A total of 65 individuals developed colorectal cancer during the study period with 34 (52.3%) PMS2 carriers and 25 (38.5%) MSH6 carriers. The cumulative incidence of metachronous colorectal cancer was low or one case (1.5%) in an MSH2 carrier with a median follow-up time of 58 months (Q1 8.0, Q3 167.0, range 0-365 months) in the cohort. Only two (3.1%) individuals, one with MSH2 and one with MSH6 pathogenic variants, underwent a total colectomy. Median age at first colorectal cancer diagnosis was 63 years (Q1 54.0, Q3 72.5, range 28-94). Thirty-one (47.7%) individuals had polyps resected during the study period with adenomas (67.1%) being the most common. Significantly more MSH6 carriers had a history of advanced adenomas as compared to PMS2 carriers (36.0 % vs 11.8%, p = 0.026). Five-year colorectal cancer survival was 81.4% for PMS2 carriers and 71.5% for MSH6 carriers. Conclusions: The incidence of metachronous colorectal cancer was zero in Lynch syndrome carriers with MSH6 or PMS2 pathogenic variants from 1955-2017 despite these individuals not undergoing rigorous Lynch syndrome screening. This would support performing segmental colectomies and following European screening guidelines for MSH6 and PMS2 carriers in Iceland.
Promising New Agents for Colorectal Cancer Das, Satya; Ciombor, Kristen K.; Haraldsdottir, Sigurdis ...
Current treatment options in oncology,
06/2018, Volume:
19, Issue:
6
Journal Article
Peer reviewed
Open access
Opinion statement
Choosing the optimal treatment approach for patients with metastatic colorectal cancer (mCRC) demands that oncologists assess both clinical and genomic variables and individualize ...care based upon the findings. Clinically, choices depend on assessing the side of the colon in which the primary tumor originates, the sites and burden of metastatic disease, the patient’s performance status, and their individual comorbidities. Genomic assessment of the tumor to discern the mutational status of genes such as RAS/RAF, HER2, and TRK, as well as assessing whether tumors have defective mismatch repair (dMMR) or high microsatellite instability (MSI-H), all factor in to potential treatment options and can determine clinical trial eligibility. Metastasectomy may be an option for patients with a low burden of disease and accessible liver- or lung-limited metastases. In some unresectable cases, systemic therapy with a FOLFOX- or FOLFIRI-based regimen with or without a biologic agent can lead to sufficient disease reduction to make a patient eligible for resection of metastatic disease. Tumor sidedness and
RAS
mutational status guide which biologic we add to the initial chemotherapy backbone, with patients with left-sided,
RAS
wild-type (WT) tumors receiving anti-epidermal growth factor receptor (EGFR)-directed therapy and patients with right-sided tumors or those with
RAS
mutations receiving bevacizumab. In patients with tumors that manifest microsatellite instability or deficient mismatch repair, we typically administer checkpoint inhibitors such as pembrolizumab or nivolumab after progression on irinotecan- or oxaliplatin-based therapies. In patients with progressive disease, we routinely send tumor tissue for next generation sequencing (NGS) to assess for the presence of actionable genomic alterations such as
HER2
,
BRAF
, and
TRK
fusions and offer them the option of enrollment on clinical trials with agents targeting those or other identified alterations.
Pancreatobiliary malignancies are relatively uncommon and the overall prognosis is poor. Treatment options for advanced disease are limited to systemic therapy for metastatic disease and a ...combination of systemic therapy and radiation therapy for locally advanced but unresectable tumors. There have been significant advances in the treatment of pancreatobiliary cancers in recent years but the prognosis for patient survival remains disappointingly poor. We review the current treatment options for locally advanced pancreatobiliary malignancies and highlight recent advances in systemic therapy, including novel approaches using targeted treatments.
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