Can You Improve Your Response to Certain Immunotherapy Drugs?

Cancer treatments that use a strategy called immune checkpoint blockade (ICB) have entered clinical practice in a big way, with six drugs now approved by the U.S. Food and Drug Administration (FDA) for a variety of cancers. These drugs release “brakes” on the immune system, boosting its ability to kill cancer cells. Specifically, they target the proteins PD-1 or CTLA-4, which are found on the immune system’s T cells, or the protein PD-L1 on tumor and other cells. Patients’ response rates, however, have been lower than hoped for in most cancers.

Much research and discussion has focused on analysis of particular features in tumors themselves that predict how they might respond to ICB. However, because ICB drugs act on immune system proteins, it is clear that each patient’s immune system is a major player in shaping response to treatment, and that certain tumor-independent features are at play. Here’s what we know about seven factors besides tumors themselves that may predict a patient’s response to ICB: Continue reading…

New HERizons: HER2-Positive Breast Cancer and the Legacy of Herceptin

Twenty years ago, no targeted treatments existed for breast cancers with high levels of a protein called HER2 (HER2-positive, or HER2+). The significance of HER2 in breast cancer had only been recognized in 1987, when excessive levels of the protein were identified in about 20% of breast cancers. Oncologists realized that high levels of HER2 mark a type of cancer with a poor prognosis, as compared to the predominant type of breast cancer: estrogen receptor-positive, HER2 negative (HER2-).

The possibility of targeting HER2 to treat cancer was fulfilled in 1998, when the U.S. Food and Drug Administration (FDA) approved Herceptin (generic name trastuzumab), for treatment of metastatic HER2+ breast cancer. Made by Genentech, Herceptin is a type of drug known as a humanized antibody, meaning that it mimics an immune system attack on tumor cells, specifically those with high levels of HER2. Now, 20 years later, it is easier to appreciate the significance of this drug, which literally changed the lives of many HER2+ breast cancer patients, and continues to do so today. Continue reading…

Predicting If an Immune Checkpoint Drug Will Work

Drugs that activate the immune system to attack cancer in a process known as immune checkpoint blockade (ICB) are a focus of intense investigation. A number of them are already approved by the U.S. Food and Drug Administration (FDA) for various cancers; namely, the anti-CTLA4 antibody ipilimumab (Yervoy), two anti-PD-1 antibodies: pembrolizumab (Keytruda) and nivolumab (Opdivo), and three anti-PD-L1 drugs: atezolizumab (Tecentriq), avelumab (Bavencio) and durvalumab (Imfinzi). These ICB drugs have the potential to induce durable cancer regressions, but the majority of cancer patients just do not respond to them at all.

Biomarkers, signature molecules in the blood or other tissue, can sometimes be used to predict a patient’s response to a given treatment. But no reliable biomarkers exist for ICB, and this is a serious concern. Patients who may really benefit from ICB could be overlooked, and patients who are not likely to respond may receive useless (and very expensive) ICB treatment.

Most potential response predictors that have already been identified are not yet useful for one or all of the following reasons: they are not extensively validated, their significance is still uncertain and may differ from one cancer (or even one patient) to another, or they are technically challenging for routine use. These markers are addressed below. Continue reading…

FAQs After Diagnosis: Early Stage Hormone-Positive Breast Cancer

This post is written by ASK Cancer Commons Scientist and Product Team Member Amanda Nottke, PhD. Dr. Nottke regularly provides guidance to patients through our ASK Cancer Commons service.

After a diagnosis of early stage, hormone-positive breast cancer, you may find yourself facing several daunting decisions, such as choosing between the extensive surgery of mastectomy versus a more minor lumpectomy procedure paired with radiation (with all its challenging side effects). And once surgery is complete, what next? Hormone therapy is clearly indicated for many women, but which drug, and how long to take it? And what about chemo—how to know if the tough side effects are worth the possible reduction in risk of recurrence?

Fortunately, there are a wealth of quality datasets available to inform these decisions. Below are some of the questions we get most frequently from patients using our ASK Cancer Commons service, answered according to the latest thinking from scientific literature and our expert physician network. If you are facing your own cancer treatment decisions and would like free one-one-one expert support, please submit your case here.

1. If my doctor has said either mastectomy or lumpectomy plus radiation are appropriate for me, how do I choose?

Many studies have looked at this, and overall the outcomes for mastectomy versus lumpectomy plus radiation are extremely similar (both are effective treatments, so you can instead weigh the side effects of radiation versus the more intensive surgery of the mastectomy). This webpage provides a helpful summary of the pros and cons of mastectomy compared to lumpectomy. Continue reading…

A Gut Feeling: Bacteria in Your Gut May Affect Cancer Treatment

The human gut contains hundreds of species bacteria, which are known to contribute to various bodily functions (such as digestion, of course!) but they also shape our immune system. Now, recent research has revealed how our microbiomes (the abundant bacteria living in our bodies) may affect the efficacy of immune checkpoint blockade (ICB) in cancer treatment.

How it started: about two years ago, an American group of scientists led by Thomas Gajewski of the University of Chicago noticed that melanoma (and some other cancers’) growth in mice was influenced heavily by the type of bacteria found in the mouse gut. They worked with mice purchased from two different vendors, and realized that mice from one vendor had consistently slower-growing tumors. Bifidobacterium bacteria present in the mouse gut were pinpointed to be the culprit, because transfer of Bifidobacterium to mice that did not have it was able to slow down melanoma growth. Treatment with an immune anti-PD-L1 drug was effective in mice that had the bacteria, but not in mice lacking it. Continue reading…

New Trends in Pre-Surgery Treatments for Breast Cancer

Non-metastatic breast cancers are most often treated with surgery, but if the tumors are fairly large, or involve nearby lymph nodes, neoadjuvant (pre-operative) treatments with chemotherapy (NAC) are done first. NAC often reduces the tumor size and kills cancer cells in lymph nodes, if present, prior to surgery, improving the outcome. The best possible result of neoadjuvant treatment is pCR (pathologic compete response), when the tumor is no longer visible in imaging studies. Here, I review the new directions in which neoadjuvant treatments are evolving.

Today, treatments for metastatic breast cancers are tailored for specific subtypes. Starting with the introduction of the drug trastuzumab (Herceptin) for HER2-positive cancers, new, more specific treatment options were eventually developed and approved for other types as well. Estrogen deprivation endocrine therapies, lately prescribed in combination with CDK4/6 inhibitors, are used in estrogen receptor (ER)-positive cancers. Triple negative cancers (TNBC) are still treated mostly with chemotherapy, but immune checkpoint drugs and PARP inhibitors are explored in clinical trials, with some successes reported.

However, neoadjuvant treatments (except for HER2+ cancers) remain largely limited to chemotherapy regimens. This is starting to change now, with new approaches tailored to the cancer type being investigated in clinical trials.

In this regard, it is important to mention the I-SPY2 trial, NCT01042379, which started in 2010 and is for women with stage II-III breast cancer. It offers about a dozen drugs that are chosen based on particular features of the newly diagnosed cancers. This trial has a unique design and has produced some important results. Additional treatments and trials for various types of breast cancer are discussed below. Continue reading…

ASCO 2017: Breast Cancer Treatment News

Last month, the annual American Society of Clinical Oncology (ASCO) meeting took place in Chicago. Thousands of oncologists, patients, and journalists gathered to learn about the most recent developments in cancer research and treatment. Here are some breast cancer highlights from the meeting:

Triple negative breast cancer (TNBC) is considered more responsive to treatment with immune checkpoint drugs than any other type of breast cancer. So far, these drugs have primarily been explored in metastatic TNBC, in combination with chemotherapy. The combination of “anti-PD-L1” and “anti-PD-1” immune checkpoint drugs with chemotherapy has now been examined in early-stage TNBC, in which a breast tumor can be surgically removed after neoadjuvant chemotherapy. Continue reading…

Testing for Tumor Mutations: Liquid Biopsy Versus Traditional Biopsy

Liquid biopsies, virtually unknown even a year or two ago, are becoming common tools in precision diagnostics for cancer. Here, I will try to explain some of the more important differences between liquid and “traditional” tumor biopsies.

Biopsies of solid tumors (e.g., lung, breast, or brain tumors) involve surgically removing a small part of a tumor and sending it to pathology lab. In the last few years, doctors have also started to send some tumor samples to special service labs that analyze tumor DNA for the presence of cancer-related mutations.

By definition, regular biopsies can be intrusive and are sometimes associated with side effects, such as bleeding or infection. However, they provide some really essential information; i.e., the histology and grade of the tumor and other tumor characteristics necessary to determine the best choice of treatment. For lung cancer, for example, a biopsy determines the type of tumor—adenocarcinoma, squamous cancer, small-cell lung cancer, or another, less common type. For breast cancer, a routine test will determine if the tumor expresses estrogen, progesterone receptors, and a protein called HER2. These tests are critically important in guiding treatment choices. If mutational analysis of cancer-related genes is also performed (which doesn’t always happen, unfortunately), it may guide treatment with targeted drugs. Continue reading…