The respiratory illness commonly referred to as “coronavirus” and officially called COVID-19 has changed life as we know it.
For people with serious health conditions, such as breast cancer, and their loved ones, the uncertainty of this situation, the need for physical distancing, job losses and financial concerns, and possible changes in cancer treatments has been especially distressing.
The Centers for Disease Control and Prevention (CDC) says that the risk of becoming seriously ill from COVID-19 is low for most people. However, it’s very important to know that people who are currently diagnosed with cancer, including breast cancer, have a higher risk of severe illness if they get COVID-19. At this time, it's not known if having a history of cancer increases your risk of serious complications from COVID-19.
Some breast cancer treatments — including chemotherapy, targeted therapies, and immunotherapy — can weaken the immune system and possibly cause lung problems. People who have weakened immune systems or lung problems have a much higher risk of serious complications if they become infected with this virus. For most people, the immune system recovers within a couple of months after completing these treatments. But your immune system's recovery time can vary and depends on several factors. If you've received these treatments in the past, it's not clear if you're at higher risk of serious complications from COVID-19.
People with breast cancer that has metastasized (spread) to the lungs also can have lung problems that may get worse if they develop COVID-19.
The virus has now spread to most countries in the world and across all 50 states here in the United States. But the number of cases varies in different regions, so your immediate risk of coming into contact with the virus depends on where you live. The risk of infection will continue to change over time as cases increase and decrease in different areas.
To protect yourself and help reduce the spread of the virus, it’s important to listen to health experts who recommend staying at home, limiting contact with others, wearing a mask when you are around people you don't live with, following other precautions, and getting vaccinated when and if you can.
If you or a loved one are receiving treatment for breast cancer during the COVID-19 pandemic, here’s what you need to know:
- What is coronavirus?
- Can people with breast cancer get a COVID-19 vaccine?
- How does COVID-19 spread between people?
- What are the symptoms of COVID-19?
- What should I do if I develop COVID-19 symptoms?
- Who is at risk of getting COVID-19?
- How can I protect myself and others?
- Should I wear a face mask?
- Is it safe for breast cancer screening or treatment to be delayed or changed?
- How can I manage anxiety and loneliness while isolating?
- Listen to the latest COVID-19 podcast episodes
What is coronavirus?
Coronaviruses are a large group of viruses that can cause respiratory illness in humans and animals. The coronavirus you’ve heard about in the news is called SARS-CoV-2, and the illness it causes is called coronavirus disease 2019, which is why it’s abbreviated as COVID-19.
The first case was diagnosed in China in December 2019, and it has since spread to almost all countries throughout the world. Some coronaviruses spread from animals to people, and that appears to be the case with SARS-CoV-2, which is thought to have originated in bats and first infected people at a live animal market.
Can people with breast cancer get a COVID-19 vaccine?
Yes, the COVID-19 vaccines currently authorized for emergency use are considered safe and effective for people with cancer and a history of cancer in most cases. The CDC, the National Comprehensive Cancer Network (NCCN), and other expert medical groups have recommended that people with cancer should be prioritized for vaccination. Still, everyone’s situation is different, and you should talk with your doctor about getting vaccinated.
In December 2020, the U.S. Food and Drug Administration (FDA) authorized the first COVID-19 vaccines for emergency use: the Pfizer-BioNTech COVID-19 vaccine and the Moderna COVID-19 vaccine. The Johnson & Johnson (J&J) COVID-19 vaccine (also called the Janssen vaccine) was authorized in February 2021. Other COVID-19 vaccines are being used in other countries, and more are being developed and may eventually be approved, as well.
On April 13, 2021, the FDA and CDC called for a pause in the use of the J&J vaccine “out of an abundance of caution” to give healthcare providers time to better understand and treat a rare health condition involving blood clots that occurred in six people who received the J&J vaccine.
Because the vaccines do not contain live viruses, they can be used in people with weakened immune systems, including people being treated for cancer. The FDA has found that these vaccines are safe and highly effective for preventing COVID-19, especially serious illness and death from the disease. It is still unclear how long the protection lasts and whether you can give someone else COVID-19 if you are exposed to the virus after being vaccinated. So it’s recommended that mask wearing and physical distancing in public continue for some time.
Experts have recommended that most people with cancer or a history of cancer should get a COVID-19 vaccine. Still, you should talk to your doctor about whether getting vaccinated is the right decision for your individual situation.
Learn more about COVID-19 Vaccine Facts for People With Breast Cancer.
How does COVID-19 spread between people?
This virus mostly spreads through close contact with other people (within 6 feet) through droplets of respiratory fluids produced when a person coughs or sneezes. These respiratory droplets can travel through the air and either be inhaled or otherwise get into the noses, mouths, or eyes of people nearby.
The virus is very contagious — about 3 times as contagious as the flu, CDC director Robert Redfield, M.D., said in an interview. People become contagious up to 2 days before developing symptoms, but it’s important to know that many people who become infected don't develop noticeable symptoms, and you can still catch the virus from them.
The main way the virus spreads is through close contact with others. As doctors have learned more about the virus, the risk of getting infected by touching a contaminated surface and then touching your face seems lower than previously thought. Still, it’s smart to continue frequently washing your hands and not touching your face in public.
What are the symptoms of COVID-19?
According to the CDC, a wide range of symptoms have been reported for COVID-19, ranging from mild to severe. Symptoms may appear from 2 to 14 days after you’re exposed to the virus.
People with these common symptoms may have COVID-19:
- shortness of breath or difficulty breathing
- aches and pains
- sore throat
- loss of taste or sense of smell
- nausea or vomiting
- runny nose or congestion
This list doesn’t include all the symptoms that have been linked to COVID-19. Call your doctor if you have other severe symptoms or if you are concerned about symptoms you’re experiencing.
“Often, [COVID-19] can start out with symptoms similar to a common cold,” Halle Moore, M.D., director of breast oncology at the Cleveland Clinic, told Breastcancer.org. “Patients may experience fatigue, a sore throat, and a cough, but they will usually get a fever, as well. The illness can also progress to shortness of breath and respiratory difficulties.”
Most people who get COVID-19 have mild respiratory symptoms and can recover at home in about 2 weeks. However, symptoms can become severe in certain people.
Severe symptoms that require immediate medical attention include:
- difficulty breathing or shortness of breath
- persistent chest pain or pressure
- confusion or inability to awaken
- blueish color in the lips or face
If you or a loved one experiences any of these emergency warning signs, call 911 immediately. People who are older than 60 and people who have existing serious health conditions such as cancer, chronic kidney disease, COPD (chronic obstructive pulmonary disease), heart disease, obesity, sickle cell disease, a weakened immune system, or diabetes, and people who smoke appear to have a higher risk of developing severe illness and complications from COVID-19. This includes people who are receiving cancer treatments that can weaken the immune system or cause lung problems and people who have cancer that has spread (metastasized) to the lungs.
Possible complications of COVID-19 include:
- organ failure
What should I do if I develop symptoms?
If you experience fever, cough, or shortness of breath, you should call your doctor. If you or a loved one experiences severe symptoms that can signal an emergency, such as difficulty breathing, persistent chest pain or pressure, confusion or inability to awaken, or blueish color in the lips or face, immediate medical attention is needed and you should call 911. Make sure to tell the 911 operator that you suspect COVID-19 so the responders can take the necessary precautions to protect themselves.
People who experience mild symptoms can usually stay home while the illness runs its course and recover in about 2 weeks. But if you are receiving treatment for breast cancer, you should definitely let your doctor know.
“Anybody who’s on any treatment that can suppress the immune system should always call their doctor if they notice a fever or if they have severe cold or flu-like symptoms,” says Dr. Moore. “For someone who’s receiving chemotherapy for breast cancer, a fever is a medical emergency anyway, so that’s something that they need to contact their medical team for.” If you do need to seek medical care for symptoms of COVID-19, Dr. Moore says it’s very important to let your healthcare provider know about your symptoms ahead of time.
“It’s important to call ahead and not just show up to a doctor’s office with symptoms,” she says. “That way the medical team can get a better sense of the severity of the symptoms, determine whether this is something that can be managed at home, something that can be seen in the clinic, or something that needs to be treated in the emergency department. In addition, calling ahead will help the healthcare team take precautions to help prevent exposure to others.”
If you do become sick, you can take the following steps to protect others:
- stay home, unless you need medical care
- separate yourself from others in your home
- cover your mouth and nose when you cough or sneeze, properly dispose of tissues, and wash your hands
- monitor your symptoms and temperature
- wear a face mask when around others; you should also wear a face mask if you are caring for someone who is sick
You should follow these steps until all the points below are true:
- 10 days have passed since you first noticed symptoms
- your fever goes away for 1 full day without fever-reducing medicine
- your symptoms have improved, though loss of taste and smell may last for weeks or months after you recover and don't need to delay the end of your isolation
Not everyone needs to be tested for COVID-19. If you develop symptoms, ask your doctor if a test is available and recommended for you.
Who is at risk of getting COVID-19?
The CDC says that most people have a low risk of becoming seriously ill from COVID-19. However, it's important to understand the difference between your risk of becoming seriously ill if you do become infected vs. your risk of being infected in the first place.
While we know that people with a current diagnosis of cancer are at a higher risk of severe illness from COVID-19, research suggests that people diagnosed with cancer may be at higher risk for COVID-19 infection if they are exposed to the virus. This makes it extra important to limit your contact with other people and follow other safety practices like wearing a mask in public if you have been diagnosed with cancer.
The virus has now spread to most countries in the world and in communities across all 50 U.S. states, and your individual risk of being exposed to the virus — whether or not it makes you seriously ill — depends on where you live and what precautions you're taking. The risk of being exposed to the virus will continue to change as the number of COVID-19 cases go up and down in different areas of the country and as more people are vaccinated.
People who currently have a higher risk of becoming infected include:
- those who have not been vaccinated against COVID-19
- those who live in communities where the virus is spreading
- healthcare workers who may be exposed to sick people
- people who require frequent hospital visits for medical care
- those who have had close contact with people who have been infected
- people who have recently traveled to places where the virus is known to have spread
- people who are unable to limit their contact with others
How can I protect myself and others?
The best way to avoid becoming sick from COVID-19 is to get vaccinated if you can and avoid being exposed to the virus.
In December 2020, the FDA authorized the first COVID-19 vaccines for emergency use: the Pfizer-BioNTech COVID-19 vaccine and the Moderna COVID-19 vaccine. The Johnson & Johnson (J&J) COVID-19 vaccine (also called the Janssen vaccine) was authorized in February 2021. On April 13, 2021, the FDA and the CDC called for a pause in the use of the J&J vaccine while they study a potential safety issue after six women developed a rare health condition involving blood clots.
Other COVID-19 vaccines are being used in other countries, and more are being developed and may eventually be authorized, as well. It is still unclear how long the protection from a COVID-19 vaccine lasts. It is also still unclear whether you can give someone else COVID-19 if you are exposed to the virus after being vaccinated. So it's recommended that mask wearing and social/physical distancing in public continue for some time.
Learn more about COVID-19 Vaccine Facts for People with Breast Cancer.
In addition to getting vaccinated when and if you can, it’s important to take other safety precautions to lower your risk of getting sick, especially if you have a serious health problem such as breast cancer. Wearing a mask in public and avoiding close contact with people you don't live with are strongly recommended to protect yourself and reduce the spread of COVID-19.
Staying at home and not seeing your loved ones can be difficult, but it’s important to do right now for your own safety and for the greater good.
Recommended social distancing practices include the following, when possible:
- stay at home
- avoid public spaces
- avoid public transportation and unnecessary travel
- avoid social gatherings
- work from home
- stay at least 6 feet away from people when out in public
- avoid physical contact such as handshakes, hugs, and kisses in social situations
- avoid contact with people who are or may be sick
In addition to limiting contact with other people, here are some steps you can take to help protect yourself and others against this virus or any harmful germs:
- Wash your hands frequently using soap and water for at least 20 seconds, especially after being out in public, coughing, sneezing, or blowing your nose.
- Use alcohol-based hand sanitizer with at least 60% alcohol when soap and water aren’t available.
- Don't touch your face when your hands aren’t clean, and make it a habit to not touch your face when you're outside your home.
- Wear a face mask when in public places (but make sure you do this safely; learn more below).
- Practice healthy habits: eat well, exercise, avoid or limit alcohol, don't smoke or vape, and get enough sleep.
- Switch to glasses if you wear contact lenses to avoid touching your eyes more than necessary, or follow proper contact lens hygiene.
If you are receiving treatment for breast cancer, or if you are living with breast cancer that has metastasized (spread) to the lungs, the following extra precautions may help you protect yourself:
- be extra vigilant about hand hygiene and not touching your face
- avoid close contact with friends and family and take precautions if you depend on them for medical care
- make a plan with your doctor to monitor for symptoms
- make a plan with your caregiver or other loved ones in case you or they get sick
- make a plan with your employer to work from home if you’re not already doing so
- stock up on medications
- ask a friend or family member to shop for groceries or pick up medications for you
If you need to visit a healthcare facility for your medical care, all staff members and patients should be wearing masks and practicing social distancing. It’s also OK to ask healthcare providers and caregivers to wash their hands before touching you. And it’s a good idea to talk to your oncologist about any other protective measures that may be recommended for your unique situation.
Because this is a continually changing situation, it’s wise to pay attention to the CDC’s updates to continue assessing the risks in your area.
“Since this is such a changing landscape, it’s important for people to visit CDC.gov or their state health department website for updated information,” says Dr. Moore. “Some hospitals and state health departments are also setting up hotlines to help keep people informed or answer questions.”
Should I wear a face mask?
On Friday, April 3, 2020, the CDC recommended that everyone wear a face mask when out in public places. Many states made wearing a face mask in public a requirement.
Research has shown that many people who are infected with COVID-19 don't know it because they have no symptoms. Wearing a face mask in public can help protect you from infection, and can help prevent people with no symptoms from spreading the virus.
Research also has shown that the coronavirus that causes COVID-19 travels in droplets that range in size from larger blobs (think of a drop that you can see when someone sneezes) to very tiny aerosol microdroplets. Masks can help keep the larger droplets from getting into your mouth from your surroundings and also help keep any large droplets from leaving your mouth and getting into the air.
If you have been fully vaccinated for COVID-19, the CDC still recommends that you wear a mask if you’re:
- indoors with people who have a high risk of severe complications from COVID-19
- in public
- gathering with unvaccinated people from more than one other household
People are considered fully vaccinated:
- 2 weeks after their second dose of the Pfizer or Moderna vaccine
- 2 weeks after the single dose of the Johnson & Johnson vaccine
Read more about COVID-19 Vaccine Facts for People With Breast Cancer.
The CDC recommends reusable cloth masks with two or more layers of fabric that is washable and does not make it hard to breathe. Fabric that is tightly woven with a thread count of 180 or higher is a good option. To check on how tightly woven the fabric you plan to use for your mask is, hold the material up to the light. If you see a lot of light coming through or even see the fibers of the fabric, it’s a good idea to choose a different material.
The CDC also recommends non-medical disposable face masks with two or more layers of non-woven material. For extra protection, the CDC says you can wear two masks — many people wear a disposable mask underneath and a cloth mask on top.
The CDC does not currently recommend using masks that are intended for healthcare workers (such as N95 masks), masks with exhalation valves, masks that are made with non-breathable fabric (such as vinyl), or face shields alone.
It’s very important to make sure that you put on, wear, and take off your mask properly:
- The mask should be tightly fitted to your face. Any open space on the sides allow droplets to get through. Many news reports have shown people wearing masks that don’t cover their noses or are flopping on their faces. These masks are not doing much to protect the wearer or the people around them. Masks that have a nose wire can provide a better fit on the bridge of your nose.
- When you’re taking off the mask, never allow the outside of the mask to touch your face and never touch the outside of the mask with your hands. Take the mask off by the ear loops or ties and very carefully move it away from your face. When you’re out in public, don’t pull the mask down below your mouth to talk and then put it back on again. Keep your mask tightly fitted to your face the entire time you’re out. It’s a good idea to wash your mask with warm water and soap as soon as you’re done wearing it and then let it dry thoroughly before you use it again. A mask is not as effective when it’s wet.
Wearing a face mask is not a substitute for social distancing practices. Just because you and your friends are wearing masks doesn’t mean that you can be close to each other. You still need to avoid contact with others, stay 6 feet away from people when out in public, and stay home if you are sick.
Is it safe for breast cancer screening or treatment to be delayed or changed?
At the beginning of the pandemic, many hospitals and other healthcare facilities delayed or canceled elective procedures, meaning screenings, surgeries, and other treatments that were not considered urgent, emergencies, or otherwise indicated for life-threatening conditions. This was distressing if it happened to you or a loved one — if you were scheduled to have a cancer screening, surgery, or other treatment, you probably felt that it was urgent. But these tough decisions were made to help protect people from the risk of getting COVID-19 in a healthcare facility and to make sure healthcare providers had the resources they needed to treat people with severe cases of COVID-19.
Cancer treatment cancellations and delays were often being made on a case-by-case basis, and the policies are different and rapidly changing among healthcare facilities. If this has happened to you, know that you are not alone — many people diagnosed with cancer had their treatments changed or delayed.
Most radiology and imaging centers are now offering routine mammograms again. So, if your annual mammogram was delayed, you should reschedule as soon as possible. Routine screenings are different than tests performed on people with cancer symptoms — if you have symptoms, you should tell your doctor and follow their recommendations for next steps.
Doctors are looking at each person’s unique situation and diagnosis when deciding how to best move forward with breast cancer treatment during the pandemic. For example, they are looking at whether a person has a higher risk of becoming seriously ill from a COVID-19 infection due to a weakened immune system from treatments such as chemotherapy or targeted therapy, or because of their age or other health problems.
Healthcare facilities have adopted stricter safety practices to reduce the risk of exposing people to COVID-19. At the same time, many cancer treatment plans have been changed so people don’t have to spend as much time at these facilities. Medical appointments are being spread out to avoid close contact between people, more appointments are being done over the phone or online, and hospital stays after surgery have been shortened. In some cases, fewer in-person visits are required to complete chemotherapy or radiation therapy.
Still, all of the usual treatment options may not always be available to people with breast cancer during the pandemic. In the spring of 2020, for example, people may have had to wait weeks or months for certain breast cancer surgeries unless they were diagnosed with an aggressive type of breast cancer. Also, breast imaging was only available for urgent cases, access to new treatments through clinical trials was limited, and fertility-preserving procedures were not available in some places.
Talk to your doctor about the best way to proceed to make sure you can get the best care possible in this challenging situation. You may be able to see healthcare providers virtually for certain appointments through telemedicine (by phone or internet video).
Read more about how the pandemic affected breast cancer treatment in our Special Report: COVID-19's Impact on Breast Cancer Care.
How can I manage anxiety and loneliness while isolating?
Limiting your contact with others is critically important for protecting yourself and lowering your risk of getting COVID-19. But long-term social distancing is not easy and can lead to feelings of anxiety, depression, and loneliness. If you’re experiencing these feelings while isolating at home, you are not alone — so many of us are going through it with you.
Fortunately, there are plenty of things we can do to manage these feelings and stay connected with our loved ones. Here are some tips from licensed clinical social worker Kelly Grosklags on how to manage the loneliness or anxiety you might be feeling during this time of social distancing because of COVID-19:
- Use social media and electronic tools such as FaceTime, Zoom, Google Hangouts, messaging apps, and texts to stay in touch with loved ones.
- Start a virtual book club with your friends.
- If you don’t have internet access or have limited access, phone calls are also a great way to keep in touch.
- Consider writing letters to people with dementia who are in care facilities and may not be able to work a phone.
- Take up a new hobby: knitting, jigsaw puzzles, crossword puzzles. Learning something new can take your mind off the COVID-19 situation for a little while.
- Many museums, aquariums, and zoos are giving people online access to their resources. Soothe yourself with some beautiful artwork or some waddling penguins.
- Above all, remember to breathe and live in the now. Living in the past can make you depressed. Living in the future can make you fearful. Live in the now and practice gratitude for the good things in your life.
Listen to the latest COVID-19 podcast episodes
Hear from experts about issues related to COVID-19 that are important to people with breast cancer:
American Rescue Plan: Benefits for the Breast Cancer Community, with Joanna Fawzy Morales, Esq.
Update on COVID-19 Vaccines, with Halle Moore, M.D.
Understanding the COVID-19 Vaccines, with Hana El Sahly, M.D.
Weslinne's Story: Diagnosed With Breast Cancer During COVID-19, with Weslinne Cespedes
Flu Vaccines and Holiday Safety During the COVID-19 Pandemic, with Elizabeth Robilotti, M.D.
COVID-19 Testing Confusion, with Megan Kruse, M.D.
COVID-19 and Breast Cancer Care: Follow-Up Questions, with Brian Wojciechowski, M.D.
Quarantine Fatigue: How to Stay Vigilant About Your Safety During the COVID-19 Pandemic, with Jackie Gollan, M.D.
COVID-19 and Metastatic Breast Cancer, with Shirley Mertz, chair, Metastatic Breast Cancer Alliance
Update: Breast Surgery and Reconstruction During COVID-19, with Julie Sprunt, M.D., FACS, and Elisabeth Potter, M.D.
COVID-19 Insurance and Financial Issues for People With Breast Cancer, with Joanna Morales, Esq, CEO, Triage Cancer
Staying Active During Quarantine: Tips for People With Breast Cancer, with Sami Mansfield, cancer exercise specialist
Breast Surgery and Reconstruction During COVID-19, with Julie Sprunt, M.D., FACS, and Elisabeth Potter, M.D.
COVID-19 and Breast Cancer Treatment, with Brian Wojciechowski, M.D.
Managing Loneliness and Anxiety During This Time of Social Distancing, with Kelly Grosklags, LICSW, BCD, FAAGC
COVID-19: What We Know Now, with Angela Rasmussen, Ph.D.
We’re all in this together
While the developing news about COVID-19 can be distressing, Breastcancer.org Founder and Chief Medical Officer Marisa Weiss, M.D., would like to remind you that we’re all in this together and that there are common sense precautions we can all take to protect ourselves and our families.
“The COVID-19 pandemic reminds us that it’s a small world out there,” she says. “We are all interconnected in good and sometimes dangerous ways. For now, it’s wise to lay low and stay home whenever possible, especially if you’re at high risk of having complications from getting this virus.”
Please practice social distancing as recommended by the CDC, WHO, and your local and state governments:
- stay home
- avoid close contact with others
- wash your hands thoroughly and often
- wear a mask
- get vaccinated when and if you can
If we all do our part, we can protect ourselves, our families, and our communities from this pandemic.
We want to know how the COVID-19 pandemic is affecting your life and your treatment. Join the conversation in the Breastcancer.org Community Discussion Boards, and tell us how you’re managing this situation throughout your treatment or survivorship.
Adam Leitenberger, editorial director
Jamie DePolo, senior editor
This content was developed with contributions from the following experts:
Halle Moore, M.D., director of breast oncology, Cleveland Clinic
Marisa Weiss, M.D., chief medical officer
Brian S. Wojciechowski, M.D., medical adviser
World Health Organization COVID-19 pages: https://www.who.int/emergencies/diseases/novel-coronavirus-2019
U.S. Centers for Disease Control and Prevention COVID-19 pages: https://www.cdc.gov/coronavirus/2019-ncov/index.html
American Society of Clinical Oncology COVID-19 Patient Care Information: https://www.asco.org/asco-coronavirus-information/care-individuals-cancer-during-covid-19
MIT COVID-19 Relative Risk Factors Comparison Map: https://www.covidalliance.com/interactive-data-tools
Johns Hopkins Coronavirus Resources Center: https://coronavirus.jhu.edu/map.html
Harvard Health Publishing Coronavirus Resource Center: https://www.health.harvard.edu/diseases-and-conditions/coronavirus-resource-center
Science Magazine Coronavirus Research, Commentary and News: https://www.sciencemag.org/coronavirus-research-commentary-and-news
New England Journal of Medicine COVID-19 page: https://www.nejm.org/coronavirus
National Comprehensive Cancer Center Network COVID-19 Resources: https://www.nccn.org/covid-19/
American Society for Radiation Oncology Recommendations and Information: https://www.astro.org/Daily-Practice/COVID-19-Recommendations-and-Information
Annals of Internal Medicine. “A War on Two Fronts: Cancer Care in the Time of COVID-19”: https://annals.org/aim/fullarticle/2764022/war-two-fronts-cancer-care-time-covid-19
American Society of Breast Surgeons Recommendations on Treatment During COVID-19 Pandemic: https://www.breastsurgeons.org/docs/news/The_COVID-19_Pandemic_Breast_Cancer_Consortium_Recommendations_EXECUTIVE_SUMMARY.pdf?01
American Society of Plastic Surgeons Statement on Breast Reconstruction During COVID-19 Pandemic: https://www.plasticsurgery.org/documents/medical-professionals/COVID19-Breast-Reconstruction-Statement.pdf
This special content made possible in part through generous support from AstraZeneca; Daiichi Sankyo; Eisai; Genentech; Lilly Oncology; Pfizer; Seattle Genetics; an independent educational grant from Merck & Co., Inc.; and individuals like you.