Bibliometric analyses are being used more and more to evaluate developments and trends in different fields of research. As for TNBC treatment, immunotherapy—such as pembrolizumab, a monoclonal antibody targeting PD-L1—is currently the hot challenge. Nevertheless, indications of ADC and other targeted therapies are already starting to appear. Bibliometric analysis of clinical trials on TNBC treatment investigations is not accessible, though. Based to available data, since 2010, there have been a significant number of clinical trial studies on TNBC treatment, with a significant upsurge in studies on TNBC immunotherapy after 2015. Research on general therapies for breast cancer was concentrated after 2010, when TNBC treatment was likely to center around chemotherapy, neoadjuvant therapy, and other methods. Furthermore, after 2020, the use of pi3K inhibitors and sacituzumab govitecan medications is starting to become obvious, indicating potential directions for TNBC treatment. However, it is also clear that performing clinical studies costs some time. The majority of pertinent journals have impact factors (IFs) that are relatively large. China comes in second to the United States in terms of research findings about TNBC immunotherapy and treatment in clinical trials. China and the United States are also actively working together on research. Another country with a high rate of research output is Italy, most likely as a result of its highly significant affiliation with the University of Milan.
It is noteworthy that the papers of Goldhirsch A., 2011, in Annals of Oncology and Cortazar, 2014, in The Lancet have received the greatest citations in clinical trials on TNBC therapy possibilities. In 2011, Goldhirsch A concentrated on subtype-specific methods to breast cancer treatment, using subtyping to figure out if the cancer is amenable to immunotherapy with trastuzumab and chemotherapy, endocrine therapy, or chemotherapy. Cortazar, in 2014, in The Lancet, focuses on neoadjuvant therapy for breast cancer. Both articles are closely related to immunotherapy for TNBC. The two most cited investigations on the topic of immunotherapy for TNBC are by Adams S., 2019, in Annals of Oncology, and Schmid P., 2018, in The New England Journal of Medicine. In the former, atezolizumab and naproxenotaxel are combined, and it is shown that this prolongs progression-free survival in patients with metastatic triple-negative breast cancer who have intention-to-treat as well as in the subgroup of patients who have PD-L1 positive. The latter investigated pembrolizumab monotherapy as a follow-up or second-line treatment for patients with mTNBC who had already received treatment. Studies performed in both directions emphasize the role immunotherapy plays in TNBC, with pembrolizumab serving as the main PD-L1 monoclonal antibody medication.
Immunotherapy for TNBC is growing more and more popular, according to two levels of analysis: the topic maps of the literature studies and the keyword co-occurrence analysis in the VOSviewer software. Chemotherapy and neoadjuvant therapy, the typical treatment for breast cancer, were the topic of previous study. But these days, immunotherapies like "pembrolizumab" and "PD-L1 monoclonal antibody"—targeted medicines for various subtypes of breast cancer—have acquired popularity as a means of treating TNBC, and their significance cannot be ignored. Though immunotherapy is now quite popular, alternative targeted medicines, like ADC medications and Pi3K inhibitors, are starting to gain traction and could end up becoming the standard for treating TNBC in the future.
Chemotherapy or neoadjuvant chemotherapy by alone is not the best option for treating TNBC. Chemotherapy is not sufficient to treat TNBC; more sophisticated targeted therapies are required to enhance the prognosis of particular patient subgroups16. Currently, immune checkpoint inhibitors combined with chemotherapy, PARP inhibitors, cancer vaccines, or NK cell treatment are the main targets of immunotherapy research for TNBC17. PD-L1 is an attractive target for therapy because of its high mutation activity and 20% elevation in TNBC patients18. For TNBC patients, a combined study of PD-L1 and tumor-infiltrating lymphocytes can yield predictions19. Further published studies may soon allow for a more thorough bibliometric analysis on the application of PD-L1 in immunotherapy for TNBC.
TNBC can currently be further categorized into subtypes, with different treatment strategies chosen according to the subtype. AR targeted therapy is typically used to treat the LAR subtype; PD-1/PD-L1 inhibitors are usually prescribed to treat the IM subtype; PARP inhibitors are typically used to treat the BL1 subtype; mTOR inhibitors are typically used to treat the BL2 subtype; and PI3K inhibitors are typically used to treat the M/MSL subtype20,21. The percentage of various therapies can be inferred from the frequency with which these terms occur. Nonetheless, TNBC treatment remains challenging particularly because other breast tumors do not express similar therapeutic targets. Another problem with TNBC is its heterogeneity; different subtypes of triple-negative cancers respond variably to the therapies that are now available22.
Although immunotherapy has been a well-liked addition to TNBC's expanding toolkit, only a small percentage of patients have shown any real improvement. Novel immune checkpoint targets, intratumoral injections that directly modify the tumor microenvironment, and small molecule inhibitors are among the latest strategies being researched in an effort to elicit immune responses in refractory cancers. Given the risk for irreversible autoimmune damage and the lack of predictive accuracy of early PD-L1 expression, it is vital to identify patients who will benefit most from treatment as the use of immunotherapy to treat early-stage TNBC increases1. Antibody-drug couplings, or ADCs, have shown potential as a practical and effective class of cancer treatments during recent trials. Trastuzumab deruxtecan was the first ADC medication authorized for the treatment of TNBC, while sacituzumab govitecan came next.The FDA has approved the most recent class of antibody-drug coupling payloads, which is represented by these medications taken together. But with time, the majority of cancers develop treatment resistance, which tends to reduce their efficacy and create a common problem. Therefore, studies on combination therapy are becoming more and more essential23.
Due to its heterogeneity and acquired resistance, single-agent therapy has not produced encouraging outcomes in clinical studies battling invasive TNBC, although demonstrating promising results in cell line and preclinical models. Presently, about eighty percent of clinical studies are looking into novel combination therapy-based therapies for TNBC24. Research suggests that combining proteasome inhibitors with lapatinib (NF-κB inhibitor) or endocrine therapy with Notch-1 inhibitors (like GSI) could be useful methods of therapy for triple negative breast cancer25.