Immunotherapy in triple-negative breast cancer: A literature review and new advances

The current situation regarding the availability and accessibility of anticancer drugs for breast cancer in the Peruvian public health systems Guillermo Vale

Background: Breast cancer incidence in the United States is lower in Hispanic/Latina (H/L) compared with African American/Black or Non-Hispanic White women. An Indigenous American breast cancer–protective germline variant (rs140068132) has been reported near the estrogen receptor 1 gene. This study tests the association of rs140068132 and other polymorphisms in the 6q25 region with subtype-specific breast cancer risk in H/Ls of high Indigenous American ancestry. Methods: Genotypes were obtained for 5,094 Peruvian women with (1,755) and without (3,337) breast cancer. Associations between genotype and overall and subtype-specific risk for the protective variant were tested using logistic regression models and conditional analyses, including other risk-associated polymorphisms in the region. Results: We replicated the reported association between rs140068132 and breast cancer risk overall [odds ratio (OR), 0.53; 95% confidence interval (CI), 0.47–0.59], as well as the lower odds of developing hormone receptor negative (HR−) versus HR+ disease (OR, 0.77; 95% CI, 0.61–0.97). Models, including HER2, showed further heterogeneity with reduced odds for HR+HER2+ (OR, 0.68; 95% CI, 0.51–0.92), HR−HER2+ (OR, 0.63; 95% CI, 0.44–0.90) and HR−HER2− (OR, 0.77; 95% CI, 0.56–1.05) compared with HR+HER2−. Inclusion of other risk-associated variants did not change these observations. Conclusions: The rs140068132 polymorphism is associated with decreased risk of breast cancer in Peruvians and is more protective against HR− and HER2+ diseases independently of other breast cancer-associated variants in the 6q25 region. Impact: These results could inform functional analyses to understand the mechanism by which rs140068132-G reduces risk of breast cancer development in a subtype-specific manner. They also illustrate the importance of including diverse individuals in genetic studies.

Background: A substantial portion of the genetic predisposition for breast cancer is explained by multiple common genetic variants of relatively small effect. A subset of these variants, which have been identified mostly in individuals of European (EUR) and Asian ancestries, have been combined to construct a polygenic risk score (PRS) to predict breast cancer risk, but the prediction accuracy of existing PRSs in Hispanic/Latinx individuals (H/L) remain relatively low. We assessed the performance of several existing PRS panels with and without addition of H/L-specific variants among self-reported H/L women. Methods: PRS performance was evaluated using multivariable logistic regression and the area under the ROC curve. Results: Both EUR and Asian PRSs performed worse in H/L samples compared with original reports. The best EUR PRS performed better than the best Asian PRS in pooled H/L samples. EUR PRSs had decreased performance with increasing Indigenous American (IA) ancestry, while Asian PRSs had increased performance with increasing IA ancestry. The addition of two H/L SNPs increased performance for all PRSs, most notably in the samples with high IA ancestry, and did not impact the performance of PRSs in individuals with lower IA ancestry. Conclusions: A single PRS that incorporates risk variants relevant to the multiple ancestral components of individuals from Latin America, instead of a set of ancestry-specific panels, could be used in clinical practice. Impact: The results highlight the importance of population-specific discovery and suggest a straightforward approach to integrate ancestry-specific variants into PRSs for clinical application.

BACKGROUND The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (a novel coronavirus), which was first identified amid an outbreak of respiratory illness cases in Wuhan, China and declared a global health emergency, is currently considered an additional challenge in the management of patients with breast cancer (BC). Cancer patients are more vulnerable to becoming infected with severe acute respiratory syndrome coronavirus 2 and are more likely to suffer additional complications that can increase mortality. Identifying those BC patients who require more urgent therapy than others in the current situation is essential. These recommendations are based on and have been adapted from those similarly published by international scientific societies for BC management. They are divided mainly by clinical stage (early, advanced), subtype [luminal, human epidermal growth factor receptor 2 (HER2), triple-negative], or type of medical treatment and setting (neoadjuvant, adjuvant, metastatic). Recommendations for HER2 and triple-negative subtypes are similar, whereas in luminal subtype there are various options of management. The objective is to adapt guidelines to local context through relevant decision-makers, avoiding duplication of efforts and optimizing use or resources. We hope that these recommendations will help medical oncologists provide the best quality care to BC patients during the COVID-19 pandemic with information tailored to our healthcare system. AIM To establish and adapt recommendations from those published by international scientific societies for BC management. METHODS The Peruvian Society of Medical Oncology developed a consensus and propose here a manuscript with recommendations for oncological medical treatment of BC during the COVID-19 pandemic. The Peruvian Society of Medical Oncology invited a panel of experts and opinion leaders on BC working in major health care systems around Peru. Panel experts selected three international clinical practice guidelines (National Comprehensive Cancer Network, European Society for Medical Oncology, Spanish Foundation Research Group in Breast Cancer), considering that these are more representative in COVID-19 management. Also, the panel agreed to include at least one European and American clinical practice guideline. RESULTS Recommendations about BC management during the COVID-19 pandemic were divided mainly by clinical stage (early, advanced), subtype (luminal, HER2, triple-negative), or type of medical treatment and setting (neoadjuvant, adjuvant, metastatic). Recommendations for HER2 and triple-negative subtypes were similar between clinical practice guidelines, whereas in luminal subtype there were various options of management. One hundred twelve recommendations were reviewed, adapted, and voted. A consensus was made in order to provide best decisions of management, avoid duplication of efforts, and optimize medical resources, considering health care system reality. These recommendations are not intended to replace clinical judgment. CONCLUSION Most of recommendations are similar, mainly in high-risk subtypes (HER2, triple-negative). Certain societies adapt them to deal with different situations involving the best decision in the management of BC patients.

Advanced breast cancer is an incurable disease, with a median overall survival of 3 years, including in countries without access problems. Although chemotherapy is reserved in some cases, it is still used in many countries as a first-line therapy. The aim of our study is to evaluate the first-line treatment choices and the factors that influence therapeutic decisions. A retrospective analysis was conducted of hormone receptor (+)/HER2 (−) advanced breast cancer patients classified into three groups according to the first-line and second-line treatment received: endocrine therapy–chemotherapy, endocrine therapy–endocrine therapy and chemotherapy–endocrine therapy. Additionally, we explored the overall survival of sequencing therapy groups. First-line chemotherapy was chosen in 34% of patients. Also, around 60% of our patients met the “aggressive disease” criteria from the RIGHT Choice trial, justifying the use of chemotherapy in a population with poor prognosis. Furthermore, de novo and progressive disease were prognostic factors that influenced the use of chemotherapy as a first-line treatment. Regarding overall survival, the sequencing treatment groups in this trial saw an increase in survival compared with patients of the MONALEESA trials (endocrine therapy alone arms). No significant differences in progression-free survival or overall survival were found in the treatment sequencing groups. There was a higher use of chemotherapy as a first-line therapy, with de novo and “aggressive disease” criteria being the main factors to influence the decision.