Merajver, Sofía D.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, and Prostate are intended to serve as a resource for health care providers to identify individuals who may benefit from cancer risk assessment and genetic counseling and testing; help guide decisions related to genetic testing; and facilitate a multidisciplinary approach in the comprehensive care of individuals at increased risk for hereditary breast, ovarian, pancreatic, and prostate cancer. The current guidelines focus primarily on assessment of pathogenic and likely pathogenic (P/LP) variants associated with increased risk of breast, ovarian, pancreatic, and prostate cancer and recommended approaches to genetic counseling/testing and care strategies in individuals with these P/LP variants associated with increased risk of these cancers. These NCCN Guidelines Insights summarize the panel’s most recent recommendations regarding screening for prostate cancer and pancreas cancer, as well as testing criteria for nonepithelial ovarian cancer.

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic/likely pathogenic (P/LP) variants associated with increased risk of breast, ovarian, pancreatic, and prostate cancer, including BRCA1 , BRCA2 , CDH1 , PALB2 , PTEN , and TP53 , and recommended approaches to genetic counseling/testing and care strategies in individuals with these P/LP variants. These NCCN Guidelines Insights summarize important updates regarding: (1) a new section for transgender, nonbinary and gender diverse people who have a hereditary predisposition to cancer focused on risk reduction strategies for ovarian cancer, uterine cancer, prostate cancer, and breast cancer; and (2) testing criteria and management associated with TP53 P/LP variants and Li-Fraumeni syndrome.

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic or likely pathogenic variants associated with increased risk of breast, ovarian, and pancreatic cancer and recommended approaches to genetic testing/counseling and management strategies in individuals with these pathogenic or likely pathogenic variants. This manuscript focuses on cancer risk and risk management for BRCA-related breast/ovarian cancer syndrome and Li-Fraumeni syndrome. Carriers of a BRCA1/2 pathogenic or likely pathogenic variant have an excessive risk for both breast and ovarian cancer that warrants consideration of more intensive screening and preventive strategies. There is also evidence that risks of prostate cancer and pancreatic cancer are elevated in these carriers. Li-Fraumeni syndrome is a highly penetrant cancer syndrome associated with a high lifetime risk for cancer, including soft tissue sarcomas, osteosarcomas, premenopausal breast cancer, colon cancer, gastric cancer, adrenocortical carcinoma, and brain tumors.

Abstract Purpose: Low-dose tamoxifen reduces breast cancer risk, but remains untested in chest-irradiated cancer survivors—a population with breast cancer risk comparable with BRCA mutation carriers. We hypothesized that low-dose tamoxifen would be safe and efficacious in reducing radiation-related breast cancer risk. Patients and Methods: We conducted an investigator-initiated, randomized, phase IIb, double-blinded, placebo-controlled trial (FDA IND107367) between 2010 and 2016 at 15 U.S. sites. Eligibility included ≥12 Gy of chest radiation by age 40 years and age at enrollment ≥25 years. Patients were randomized 1:1 to low-dose tamoxifen (5 mg/day) or identical placebo tablets for 2 years. The primary endpoint was mammographic dense area at baseline, 1 and 2 years. IGF-1 plays a role in breast carcinogenesis; circulating IGF-1 and IGF-BP3 levels at baseline, 1 and 2 years served as secondary endpoints. Results: Seventy-two participants (low-dose tamoxifen: n = 34, placebo: n = 38) enrolled at a median age of 43.8 years (35–49) were evaluable. They had received chest radiation at a median dose of 30.3 Gy. Compared with the placebo arm, the low-dose tamoxifen arm participants had significantly lower mammographic dense area (P = 0.02) and IGF1 levels (P < 0.0001), and higher IGFBP-3 levels (P = 0.02). There was no difference in toxicity biomarkers (serum bone-specific alkaline phosphatase, lipids, and antithrombin III; urine N-telopeptide cross-links) between the treatment arms. We did not identify any grade 3–4 adverse events related to low-dose tamoxifen. Conclusions: In this randomized trial in chest-irradiated cancer survivors, we find that low-dose tamoxifen is effective in reducing established biomarkers of breast cancer risk and could serve as a risk-reduction strategy.

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.

Background: Lymphoma patients exposed to chest RT during adolescence/young adulthood are at increased risk for BC; the cumulative incidence exceeds 20% by age 45 and the BC risk is comparable to that in women with BRCA1 mutations. These findings present an urgent yet unmet need to reduce the risk of BC in RT-exposed lymphoma survivors. The risk of BC is 50% lower in chest RT-exposed survivors who also receive ovarian radiation, suggesting a critical role of endogenous estrogens in RT-related breast carcinogenesis, making tamoxifen (a selective estrogen receptor modulator) an attractive risk-reducing option. Tamoxifen administered at 20 mg/d is effective in BC prevention in other high risk populations, but severe adverse events (SAE: venous thromboembolism, endometrial cancer) have limited its broad use. Previous biomarker trials in the general population have shown that LDTam (5mg/d) is not inferior to tamoxifen at 20 mg/d in reducing BC risk, and is associated with a safer AE profile. Mammographic breast density (MBD) is an established biomarker of BC risk; high MBD is associated with a 4-fold higher risk of BC. We hypothesized that LDTam would be effective in reducing BC risk (using MBD as a primary endpoint) in chest RT-exposed lymphoma survivors. We used an investigator-initiated, multi-institutional, randomized phase IIb, double blind, placebo controlled trial (FDA IND 107367) to test this hypothesis. Methods: Female patients from 13 sites were ≥25y at enrollment, with a history of exposure to chest RT at ≥12 Gy by age 40 for their primary cancer, and were off therapy for ≥6 mo. Subjects with a prior history of BC/DCIS, B/L mastectomy, or baseline MBD <25% in both breasts were excluded. Tamoxifen 5mg or identical placebo tablets were provided by Sharp Clinical Services (Allentown, PA) under good manufacturing practice. Subjects were randomized 1:1 in a double-blinded fashion by a Web-based system to receive LDTam or placebo daily for 2y. MBD (in both breasts) was measured centrally on digital scans independently by 3 radiologists at baseline, 1y and 2y. Using an intention-to-treat analysis, the efficacy of LDTam in reducing MBD was compared between the LDTam and placebo arms by applying a linear mixed effects model for bivariate normally distributed data with random intercept and time*treatment arm effects. Correlations between the left and right breasts and within radiologists were accounted for in the model. Treating clinicians and all research staff were blinded to the treatment arm. Results: A total of 72 patients (LDTam: n=34; placebo: n=38) participated in the trial; primary diagnosis: Hodgkin lymphoma (86%); non-Hodgkin lymphoma (10%); other (3%); median age at diagnosis of primary cancer: 21.5y (IQR, 16-28), and at trial enrollment: 43.8y (35-49); median time from diagnosis of primary cancer to study: 17.0y (12-26). Median chest RT dose: 30.3 Gy (21-37.3); 11% had received pelvic radiation; 39% were post-menopausal at study. Participant characteristics were comparable between the two treatment arms, as was the mean baseline MBD (LDTam: 52.6% vs. placebo: 50.4%, p=0.6). The time*treatment arm effect was statistically significant (LDTam vs. placebo: estimate = -1.7, SE = 0.5, p = 0.001), indicating a significantly lower mean fitted MBD for LDTam (43.9%) vs. placebo (47.3%) at 2y (Figure). This represented a 16.5% relative reduction in MBD on the LDTam arm, corresponding to an estimated 33% lower risk of BC (assuming that reductions in MBD have the same benefit in lymphoma survivors as they do in the general population). There were no grade 3 or 4 AEs related to LDTam. Grade 2 AEs did not differ between treatment arms (LDTam: 44.1% vs. placebo: 36.8%, p=0.6). There was no difference in the prevalence of moderate-to-severe patient-reported outcomes between the treatment arms (Table). Conclusion: Low-dose tamoxifen was associated with a significantly steeper decline in MBD in chest RT-exposed lymphoma survivors, when compared with placebo, and was safe and well-tolerated. This is the first trial demonstrating efficacy of a pharmacologic intervention in reducing a biomarker strongly associated with breast cancer risk in lymphoma survivors with a past history of chest radiation. Disclosures Palomares: Covance: Other: Medical monitoring. Henderson:Seattle Genetics: Research Funding. OffLabel Disclosure: The drug is a low-dose tamoxifen, a selective estrogen receptor modulator. Tamoxifen in standard doses is used to reduce the risk of breast cancer in high risk populations. Tamoxifen in standard or low doses have not been tested before for chest-irradiated cancer survivors to reduce the risk of radiation-related breast cancer.