Comparison of Practice Guidelines, BRCAPRO, and Genetic Counselor Estimates to Identify Germline BRCA1 and BRCA2 Mutations in Pancreatic Cancer

Systematic evidence review and meta-analysis of outcomes associated with cancer genetic counseling

PURPOSE

Genetic counseling (GC) is standard of care in genetic cancer risk assessment (GCRA). A rigorous assessment of the data reported from published studies is crucial to ensure the evidence-based implementation of GC.

METHODS

We conducted a systematic review and meta-analysis of 17 patient-reported and health-services-related outcomes associated with pre- and post-test GC in GCRA in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

Twenty-five of 5393 screened articles met inclusion criteria. No articles reporting post-test GC outcomes met inclusion criteria. For patient-reported outcomes, pre-test GC significantly decreased worry, increased knowledge, and decreased perceived risk but did not significantly affect patient anxiety, depression, decisional conflict, satisfaction, or intent to pursue genetic testing. For health-services outcomes, pre-test GC increased correct genetic test ordering, reduced inappropriate services, increased spousal support for genetic testing, and expedited care delivery but did not consistently improve cancer prevention behaviors nor lead to accurate risk assessment. The GRADE certainty in the evidence was very low or low. No included studies elucidated GC effect on mortality, cascade testing, cost-effectiveness, care coordination, shared decision making, or patient time burden.

CONCLUSION

The true impact of GC on relevant outcomes is not known low quality or absent evidence. Although a meta-analysis found that pre-test GC had beneficial effects on knowledge, worry, and risk perception, the certainty of this evidence was low according to GRADE methodology. Further studies are needed to support the evidence-based application of GC in GCRA.

Genetic counselling referral practices for patients with pancreatic adenocarcinoma: A French retrospective multicentre observational cohort study (CAPANCOGEN)

BACKGROUND/OBJECTIVES

Genetic counselling (GC) is a key step in the identification of inherited germline mutations. However, the oncogenetic practices are poorly described for pancreatic adenocarcinoma (PA) in Europe. The CAPANCOGEN study aimed to describe the GC referral practices in France and assess the implementation of international guidelines in patients with PA.

METHODS

Information about GC referrals with PA was collected in 13 French centres from September 2019 to October 2021. In the 5 largest centres, personal and familial histories of cancers and diseases associated with a higher risk of germline mutations were collected in 460 patients, according to international, American, European and French GC referral guidelines. Univariate and multivariate logistic regression analysis were performed to identify the factors influencing GC referral.

RESULTS

Among 833 patients, a total of 100 patients (12%) had an indication of GC according to local multidisciplinary tumour board meetings (MTBM). Among these patients, 41% did not undergo GC. The median time between MTBM and GC was 55 days (IQR: 14.5-112). Among 460 patients with collected personal and familial history, 31.5% were not referred to a GC despite an existing indication. In multivariate logistic regression analysis, suspected CDKN2A (p = 0.032) or BRCA mutation (p < 0.001), familial pancreatic cancer history (p < 0.001) and controlled disease with first-line platinum-based chemotherapy (p < 0.001) increased the referral rate. Conversely, older age (p = 0.002) and a locally advanced PA (p = 0.045) decreased the risk of GC referral.

CONCLUSIONS

GC referral is inadequate despite valuable information in patients' medical files.

Multidrug resistance genes screening of pancreatic ductal adenocarcinoma based on sensitivity profile to chemotherapeutic drugs

BACKGROUNDS

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types and chemotherapeutic drug resistance is a stumbling block in improving the overall survival of PDAC patients. The nature of specific drug resistant subpopulation within pancreatic ductal adenocarcinoma is believed to be partly attributed to epithelial-mesenchymal transition (EMT) and cell stemness. Various PDAC cell lines show various degrees of resistance to chemotherapeutic agents including gemcitabine (GEM) and 5-fluorouracil (5-FU). In-depth understanding of drug resistance mechanisms and profile heterogeneities could lead to the development of novel and precise therapeutic strategies for addressing the chemo-resistant dilemma in PDAC patients.

METHODS

Cytotoxicity assays were performed by CCK8 in ten common PDAC cell lines including AsPC-1, BxPC-3, CAPAN-1, CFPAC, HPAFII, MIA PaCa-2, PANC-1, Patu-8988, SW1990 and T3M4. RNA-seq data of the ten cell lines were downloaded from Cancer Cell Line Encyclopedia (CCLE) database and subsequently analyzed for differentially expressed genes (DEGs). Based on first-line chemotherapy regimens of PDAC, DEGs between resistant and sensitive cell lines were validated by qRT-PCR. Enriched pathways of differentially expressed genes between the resistant and sensitive cell lines were acquired by Metascape database.

RESULTS

We found that the top two toxic drugs for PDAC cell lines were paclitaxel (PTX) and GEM. Among the ten PDAC cell lines, SW1990 was the most resistant PDAC cell line with the highest IC50 levels for three drugs, while MIA PaCa-2 and BxPC-3 were the most sensitive PDAC cell lines. Differential expression analysis revealed the highest number of DEGs associated with cisplatin (CIS) sensitivity up to 642 genes, of which 181 genes were upregulated and 461 genes were downregulated in CIS-resistant cell lines. The least number of DEGs are associated with GEM sensitivity, of which 37 genes were highly expressed in GEM-resistant PDAC cell lines and 25 genes were lowly expressed. Enrichment analysis of the DEGs revealed that pathways associated with drug resistance were mainly extracellular matrix and cell-cell junction related pathways.

CONCLUSIONS

PDAC cell lines showed diverse sensitivities to commonly used chemotherapeutic agents, which was caused by differential gene expression between the resistant and sensitive cell lines. The heterogeneity and its associated genes were enriched in extracellular matrix and cell-cell junction related pathways. Our study first portrayed the sensitivity profile to chemotherapeutic drugs of PDAC, which would benefit the chemoresistance mechanism study by reemphasizing the vital role of extracellular matrix and cell-cell junction related pathways and helping the selection of suitable PDAC cell lines.

Contribution of germline PALB2 variants to an unselected and prospectively registered pancreatic cancer patient cohort in Pakistan

BACKGROUND

Partner and localizer of BRCA2 (PALB2) is a pancreatic cancer (PC) susceptibility gene reported in Caucasians. However, limited data are available among Asians. We investigated the contribution of PALB2 germline variants to Pakistani PC patients.

METHODS

150 unselected and prospectively enrolled PC patients were comprehensively screened for PALB2 variants, using denaturing high-performance liquid chromatography and DNA sequencing. Novel variants were investigated for their pathogenic effect using in-silico tools. Potentially functional variants were screened in 200 controls.

RESULTS

Twenty-two different PALB2 variants were identified. A missense variant (p.Arg37His) was identified in a 48-years-old male patient with a family history of breast cancer. Another missense variant (p.Trp898Arg) was identified in a 48-years-old male patient with a family history of esophageal cancer. A novel 3' downstream variant (c.∗480A>G) was detected in a 34-years-old female patient with family history of lung cancer. Another novel 3' downstream variant (c.∗417A>C) was identified in a 41-years-old male patient. All these variants were absent in 200 controls. p.Arg37His and p.Trp898Arg were predicted as likely pathogenic. c.∗417A>C and c.∗480A>G were classified as variants of uncertain significance.

CONCLUSION

This is the first study that suggests a minimal contribution of PALB2 variants to PC risk in Pakistani population.

Supplemental Cancer Screening for Women With Dense Breasts: Guidance for Health Care Professionals

Mammography is the standard for breast cancer screening. The sensitivity of mammography in identifying breast cancer, however, is reduced for women with dense breasts. Thirty-eight states have passed laws requiring that all women be notified of breast tissue density results in their mammogram report. The notification includes a statement that differs by state, encouraging women to discuss supplemental screening options with their health care professionals (HCPs). Several supplemental screening tests are available for women with dense breast tissue, but no established guidelines exist to direct HCPs in their recommendation of preferred supplemental screening test. Tailored screening, which takes into consideration the patient's mammographic breast density and lifetime breast cancer risk, can guide breast cancer screening strategies that are more comprehensive. This review describes the benefits and limitations of the various available supplemental screening tests to guide HCPs and patients in choosing the appropriate breast cancer screening.

Current Approaches to Germline Cancer Genetic Testing

The prevalence of genetic predisposition to cancer is greater than initially appreciated, yet most affected individuals remain undiagnosed. Deleterious germline variants in cancer predisposition genes are implicated in 1 in 10 cases of advanced cancer. Next-generation sequencing technologies have made germline and tumor DNA sequencing more accessible and less expensive. Expanded access to clinical genetic testing will improve identification of individuals with genetic predisposition to cancer and provide opportunities to effectively reduce morbidity through precision cancer therapies and surveillance. Cross-disciplinary clinical education in genomic medicine is needed to translate advances in genomic medicine into improved health outcomes.