Greetings from a chilly San Antonio as the San Antonio Breast Cancer Symposium (SABCS) continues. Starting Thursday morning and continuing for the remaining two days, the symposium will start with poster sessions featuring presentations from research teams from around the world covering all facets of breast cancer, from biology to epidemiology, to treatment and clinical trials. BCRF is highly represented with more than 25 poster presentations and numerous podium talks from BCRF investigators throughout the day.
A highlight of Thursday morning’s poster session was a poster presented by BCRF’s Scientific Program Manager, Dr. Maneesh Kumar, reporting on a project he supervised on behalf of the Metastatic Breast Cancer Alliance (Alliance) with two talented BCRF summer interns from City University NY, Abdul Rashid Abdulai and Keshan Kissoon. Since one of the goals of the Alliance is to increase access to clinical trials for metastatic breast cancer (MBC) patients, Dr. Kumar and his team devised a visual online tool that patients with MBC can use to search active clinical trials. This visualization tool is an interactive way MBC patients can find clinical trials that may be of interest to them. You can read more about the project in this Alliance blog.
Commenting on the impact of the project, Dr. Kumar noted: “This is not just a great tool for MBC patients; the project itself brought together two very talented college students in very different fields who have become great friends with a shared passion for breast cancer. It was very rewarding for me to have been a part of the collaboration.”
Liquid Biopsy: Promise and Challenges
The concept that doctors will someday be able to detect or monitor disease or predict disease risk in a sample of blood has gained traction in recent years with the rapid development of a technology called microfluidics, which is the foundation of liquid (i.e. blood) biopsy. Most of us are used to the idea of a biopsy as a piece of tissue that is surgically removed to be examined for the presence of disease, such as cancer. The tissue is typically stained to detect certain characteristics or proteins that help doctors make a diagnosis and prognosis. During and after treatment, a patient may be further screened by MRIs or ultrasounds to monitor response to treatment or detect new disease, which may in some cases require additional biopsies.
Biopsies are also very important in clinical trials; they play a crucial role in mapping the course of disease and identifying biomarkers of response, drug resistance or other information that can be used to guide future clinical trials that will improve the standard of care. Ideally, researchers need to collect tissue (biopsy) at particular time points determined by their research design, but often these time points include before, during and after treatment.
So, what if a biopsy was as easy as collecting a tube of blood?
In Thursday’s plenary session, BCRF investigator Dr. Ben Park gave a compelling and thought-provoking talk on the evolution of liquid biopsy technology, and its promise and challenges in clinical application. In a previous conversation with BCRF, Dr. Park described his work to measure plasma tumor DNA (ptDNA) in patients with early stage and metastatic breast cancer. In that conversation and again in his plenary talk, Dr. Park spoke with excitement about the potential of ptDNA and other tumor markers detected in blood to change clinical care, reduce overtreatment, advance precision medicine, and improve quality of life for breast cancer patients. He cautioned, however, that while the technology is highly advanced, the assays must be clinically validated. Quoting Dr. Daniel Hayes, current American Society of Clinical Oncology (ASCO) president and fellow BCRF investigator, “A bad test can be just as bad as a bad drug,” emphasizing the need to be meticulous in both analytical and clinical validation in order to move any liquid biopsy assay from the research bench to clinical practice. Towards this effort, Dr. Park described a new clinical trial he is conducting through the Translational Breast Cancer Research Consortium (TBCRC040) designed to validate his earlier work. The multi-institution trial will be conducted in higher risk patients receiving neoadjuvant chemotherapy. Dr. Park’s team will analyze blood after chemotherapy to determine whether surgery can be avoided. Commenting on the study, Dr. Park said, “If there is no tumor left in the breasts and the blood is found negative for disease, in the future, these women may not need surgery to treat their breast cancer. This could change the way we treat breast cancer.”
Harnessing the Immune System in Breast Cancer Therapies
The re-emergence of immunotherapy for cancer has been driven by the discovery that tumors can put the brakes on the immune response, essentially hiding themselves from the immune cells designed to kill them. Blocking this immunosuppressive device with targeted immunotherapies, called check point inhibitors such as PD1/PDL-1 inhibitors and anti-CTLA-4 drugs, can restore immune response. These therapies have resulted in durable responses for some patients with lung, melanoma and renal cancers.
Breast cancer has long been considered a less immunogenic cancer—meaning the tumor cells don’t produce proteins that trigger the immune system. But in recent years, we are beginning to see that certain breast cancers, triple negative and some HER2-positive cancers, do in fact contain an immune component called tumor infiltrating lymphocytes (TILs). Clinical trials in triple negative and HER-positive breast cancers suggest that the amount of TILs in a tumor can predict for a better response to standard breast cancer therapy.
BCRF investigator Dr. Leisha Emens discussed how to move forward and build on the clinical success of immunotherapy to achieve better outcomes of this strategy in breast cancer. Dr. Emens stressed that the clinical challenge will be in improving the efficacy of immunotherapy in more patients—in essence converting non-responders to responders. Combination therapies that boost the immune system in conjunction with an immune-targeting agent will likely increase the number of patients who respond and the duration of response. Vaccine therapies have been less successful but there have been efforts to improve this strategy. Several clinical trials are ongoing to test a variety of new vaccine approaches across a broad spectrum of cancers, including metastatic, triple negative and HER2-positive breast cancers. Read more about immunotherapy and BCRF’s support of this research in our earlier blog.
In other news, here are some highlights from the SABCS press room: