We Honor Our Sister Who Died of Breast Cancer by Saying ‘Yes’ More Often


Sunday, October 13th, 2019.

Over 45,000 runners claimed their space at the starting line of the 42nd Chicago Marathon. It was a crisp fall morning, filled with jitters, excitement, hope, and stories from across the globe. Stories surrounding the topic of “why do you run?”

For one runner in the crowd, her “why” is one of love and loss. Stacey Arenson, a 27-year-old Chicagoan, ran the race with her 30-year-old sister-turned-roommate, Tiffany, cheering her on from the sidelines. Though the challenges that come with preparing to run a marathon are grueling, they pale in comparison to the journey that the Arenson sisters faced over the past three years. 

The two would describe their oldest sister, Leslie, as “the best person ever.” She was kind-hearted. Generous. Spontaneous. Genuine. Adventurous. Lively. Colorful. She connected with people in a way that made them feel incredibly special and she was the big sister that any sibling could dream of. Despite the seven and nine-year age gap between them, the three stayed close through childhood, high school years, and into adulthood. Leslie lead a lifestyle that was career, health, fitness, and family-oriented. 

In October of 2016, their family’s foundation was rocked to its core with the three words that no one wants to hear. “You have cancer.” Specifically, 34-year-old Leslie was diagnosed with triple-negative breast cancer that was treated with chemotherapy, surgery, and radiation. After her first course of treatment and a clean PET scan that represented remission, she underwent a bilateral mastectomy. The family celebrated what the sisters now label as a bittersweet memory of victory. One year after being deemed cancer-free, her disease returned aggressively within her cerebrospinal fluid. Leslie passed in April 2019, and her sisters mourn her loss in ways that most of us could never comprehend. They lean on each other for support and they keep her memory alive through the way they live, the way they treat others, the way they share stories of Leslie, and the way they view bright pink flowers.

This is why Stacey Arenson runs.


Names: Tiffany Arenson, 30 + Stacey Arenson, 27
Careers: Tiffany, pediatric nurse + Stacey, marketing director for a tech startup
Location: Chicago, IL


Tell us a bit about your childhood and what role Leslie played in your family.


Tiffany: Leslie was a combo of a big sister/best friend/mother to us growing up. She showed up for us always and gave us advice whenever we asked. We always wanted everything she had and thought she was the coolest. 

Stacey: Yeah, I totally agree with what Tiff said. She definitely played the big sister, the friend, and the parental guidance role for us. She was nine-and-a-half years older than me — I’m the youngest. We had a normal sibling relationship growing up and were always really close. Our bond definitely grew as we got older. She loved spending time with us and always included us. 

Tiffany: Yeah, she wasn’t a sister who was like, “You’re not invited.” We were always invited to stay with her in the city and go out with her friends. 

Stacey: When she was in college, she would come home for birthdays, school dances, football games to watch me cheer. She valued time with her family more than anyone else I know.

Tiffany: She came to drop me off at college with my dad when I was a freshman. When I got there, I remember telling her, “I have nothing to wear, everyone wears dresses to go out here.” And she went shopping and sent me stuff. 

Stacey: She always was so generous and was so excited about everything that we had going on in our lives. We would call her with updates and she’d be like, “Oh my God! You have to tell me everything.” I miss that a lot.


If there was one thing that you want the world to know about Leslie, what would it be?


Stacey: Just that she was the best person ever. She was the smartest person I knew. She knew everything and she had the best advice. She was honestly just so happy all of the time and so inclusive to everyone around her. In a room, she’d be the one talking to everyone and would find a connection with every single person. She did such a good job keeping up her relationships. We always say that she was the light of our family.

Tiffany: She really was the center of our whole family. Everyone loved her. She was friends with everyone. You know how you lose touch with the people you went to high school with? She never did. She would gain and gain and gain and was so good at keeping in touch with everyone. She really was the best. She was the most positive and optimistic person. She always gave 110 percent in everything she did. 


What is something that you admire most about her?


Tiffany: She was someone who would just get back on the horse every single time. She did not quit or fail, she would just get up and try again.

Stacey: For me, I really admire her positivity and her joy for life. She always wanted to do things. I feel like we stay in sometimes but she would always say, “Come on, let’s go!” And she went. To concerts, to plays, to drinks, out to dinner. 

Tiffany: She was always up to do stuff. She’d find out if an artist was playing nearby and would reach out and say, “Who wants to go, I bought two tickets!” 

Stacey: She was so generous. She bought me the warmest winter coat when I moved to the city because she knew how cold it was to walk everywhere.


Are there any special keepsakes that you have from Leslie or things in your daily life that remind you of her?


Tiffany: So much reminds us of her. Every bright color. Her birthday was last week and my best friends sent me bright pink roses. Her bridesmaids’ dresses were bright pink. She loved color. I’m a neutral person, but she always loved bright. For me, special keepsakes are things she loved and wore all the time. She loved sports and would always wear baseball hats, and now these hats have turned into things I will wear to feel close to her. 

Stacey: I have a couple of bracelets that she wore almost every day and a necklace of hers. It makes me feel close to her.


If you had to pick just one, what is your favorite sister memory that the three of you shared?


Stacey: Leslie and I went to Florida Georgia Line with a couple of her neighbors after her cancer cleared the first time, so it was the first time she drank since she had been diagnosed. We all snuck down to the floor. She was so happy and carefree and we had the best time singing, dancing, and laughing. It was a really good time. And outside of that, I loved when we all would just hang out together.

Tiffany: We would just hang out a lot and we spent so much time together. For me, I miss sitting on her purple couch, watching Love Actually, eating popcorn, and reciting all of the lines in a British accent. Leslie also loved Bub City — so many fun memories there. 

Stacey: We also spent time in Florida together this past winter during New Year’s Eve (also Tiffany’s birthday). We just had the best time boating, sitting by the pool, celebrating. It was one of the moments you don’t want to end.



How has your life and your family changed since the passing of your sister?


Tiffany: Everything has changed without Leslie. There is a palpable absence at all times. Even something as simple as not being able to call her to chat on my commute home from work to listening to country music. She’s constantly on my mind in everything that I do. Grief is a weird thing, because even happy occasions become sad because we wish Leslie was here. We have become a lot closer as a family, we show up to support each other and get together a lot more. 

Stacey: I agree with what you said. It’s hard because we used to talk every single day. I really wanted to call her today. And that happens every day. There’s a huge void. No one else can fill who she was to all of us. Thinking of future things is a lot harder. I want to get married and have kids, but I don’t want to picture her not being there. It just makes me really sad because I know she would love that part of my life.


How did gene testing play a role in your sister’s diagnosis and how does it affect you both today?


Stacey: We did have a family history, but it was all very distant.

Tiffany: Leslie was 33 when she felt a lump in her armpit while she was in the shower. She called me at 5am, and honestly, I thought she was being a hypochondriac. It sounded like it might be a swollen lymph node. She went to an urgent care who also said, “It’s probably nothing, just watch it and follow up if it gets bigger.” She saw a different doctor a few weeks later who referred her to a dermatologist. She sees the dermatologist who refers her to a surgeon. It was finally the surgeon who said, “Let’s get an ultrasound and a mammogram.” To make that appointment, she would have to wait weeks but she was like, “No, f that!” She advocated for herself, called a private practice in the Gold Coast, and got in the next day. The imaging showed a lump and something else very small which they took biopsies of. We found out that it was cancer on my dad’s birthday and they drew blood for the genetic testing the same day. She came back positive for the PALB2 gene

Stacey: Most of our family has since been tested for the gene. In a lot of ways, Leslie has saved so many people in our family so that they can take preventative measures. We also didn’t know the risk of it coming back into the cerebrospinal fluid. We had heard of it coming back in the other breast and she had gotten the surgery at that point, so we thought we were in the clear.

Tiffany: We didn’t know anything about that until it happened. The chance of this diagnosis is so small. But chemotherapy doesn’t cross the blood-brain barrier. So even if it was just one single cancer cell that got through to the CSF, the chemo wouldn’t get there. And that wouldn’t show up on a PET scan. 

Stacey: It was dormant for a couple of months. One day, we went to the suburbs for a bridal lunch that Leslie’s mother-in-law was putting on. We went there to hang out with her when she was getting ready. I noticed she wasn’t wearing heels, which was unlike her. When I asked her about it, she said, “my balance has been off.” We were immediately worried.  

Tiffany: As soon as I saw her, I had a pit in my stomach. I was watching her throughout the day holding a chair for balance. The next day, she went to the ER to get an MRI of her brain and spine. They tried to discharge her with a referral for an MRI, but she was persistent. She stayed until they scanned her. After the scan, the nurses said, “We’re getting your room ready.” Even without official results, they knew it was bad news. In the morning, my dad called me with the news that “they found something on her brain.” I walked out of my bedroom and my roommate was making a smoothie and I literally collapsed. I went to the hospital she was at, the senior resident showed us the imaging. They did a lumbar puncture which confirmed a recurrence and she was discharged home with her husband. Me, my dad, and Stacey went back to my house and we cried for like, three weeks. I was numb. Leslie emailed her breast surgeon and radiation oncologist who helped her to continue care with another team who vowed to do everything that they could. They were great.

Stacey: We knew breast cancer, but we didn’t know anything of what to expect this time around. 

Tiffany: Leptomeningeal carcinomatosis. It was a terrifying new journey. It was weird because she was otherwise feeling fine when she was diagnosed with her recurrence, three weeks before her dream wedding at The Drake. With so many unknowns, Leslie and her fiancé decided to drastically downsize their wedding, only allowing close friends and family. Her medical team was aggressive with the treatment, like they said. Leading up to the wedding, she had a brain shunt placed, was on steroids, and was started on intrathecal chemo. It helped with some symptoms, but it bottomed out her blood counts and she was hospitalized for a few weeks. Her wedding was small and beautiful and happy, but so incredibly hard. Leslie was the most beautiful bride.

Stacey: Nothing else mattered. It really has put so much into perspective for us. I would have given anything for Leslie to have the perfect wedding that she planned. But I’m just thankful that she felt somewhat good and she could have that experience.


Tiffany, you’re a pediatric nurse. Has your experience with your sister changed the way that you view your career path?


Tiffany: The entire experience of watching my sister go through chemotherapy, surgery, radiation, having a recurrence, and ultimately passing has changed me so much. I am so much more emotional in my work. I used to be a hardcore ER nurse. Now, I don’t know how much longer I can do it. Yesterday I had to walk out of the trauma room to cry. I know when it’s coming, so I’m able to take myself out of situations that feel overwhelming. Other times, I’m totally fine. Nine times out of 10 I can go into an oncology patient’s room and I can be compassionate and advocate for them in ways that other people can’t because of my experiences. I know what it’s like to be ‘on the other side of the curtain’ now, and how it feels to get both good and bad news. I’m a lot more open and honest with patients and their family members. Even doing things as simple as making sure that every family member has a chair are little ways that make people feel well cared for.



Stacey, you just ran the Chicago marathon! Can you tell us a bit about that experience and how you honored Leslie through that process?


Stacey: Besides a little bit of knee pain, the marathon was everything I could have hoped for. Training started in June and she passed away at the end of April. Training got me out of bed and gave me something to focus on. Sometimes I just look at myself as a machine. I just keep going and that’s how I did the marathon. I’m like, “one more mile… one more mile.” Leslie would run seven to eight miles in the city every week. I would run with her every once in a while, and I ran a half marathon and the Shamrock Shuffle with her before. When she was diagnosed the second time, I was also going through a breakup. I started running and it helped me. It was the only thing that I did by myself. It also made me feel closer to Leslie because she loved doing that, so I decided to sign up for the marathon. In the back of my mind, I thought, “If I sign up, she’ll have to be here for it.” It was like insurance for me. I wanted her to be there so badly. I thought it would be a happy focus.

The Lynn Sage Foundation funds breast cancer research in Chicago. I reached out to a couple of breast cancer charities and that one spoke to me the most because it’s very research-based. That’s what Leslie needed. She needed more research. 

I reached out to get more involved in the charity and I’m on the board now. I asked if we could fund a clinical trial for Leslie’s type of cancer that metastasized to the cerebrospinal fluid. They were actually in the process of finding something to fund. It was $20,000 to fund and I didn’t think I would raise that much, but I wanted to contribute. After Leslie passed away, so many people donated that I realized that we could fund the entire thing. I ran the marathon for them to help raise money, but I wanted to do it for Leslie. When I told her I was running for that charity she was really happy.

I felt pretty good on the day of the marathon. I had some knee issues and I didn’t know how it would go, but I said “let’s just see what happens.” I got a little emotional on the way there. A song came on in the Uber that made me think about her. During the race, I wasn’t as emotional as I thought I would be. I was so happy. My friends and family were all there. I feel guilty for being so happy because I really wanted Leslie to be there. 

Tiffany: You worked so hard and you deserve to be happy. Leslie wouldn’t have wanted you to be sad. So many people out there supporting Stacey along the whole race. Her friends, my friends, Leslie’s friends, and so much family. 

Stacey: The fact that I did it for Leslie, stuck to it, and saw it through felt really good. There’s so much that goes into it. You push through so much pain and mental toughness. It confirms that I am capable. We went through things that were so much harder and I feel like I can do anything now. It’s been a really insane year and I did it for so many reasons. For my sister, for myself, and for our family. We didn’t really share a lot when Leslie was going through this. After she passed away, it became very public, which brought a weird sense of vulnerability of people knowing something so personal. But it also brought a lot of support. The fact that I stuck to it and saw it through, I know Leslie would have been so proud.


What message would you want readers to take away from your family’s story?


Tiffany: I just feel like Leslie always wanted people to know “if this can happen to me this can happen to anyone.” There was no reason for it to happen to her. She was so healthy. She was like everyone else. Nothing bad ever happened to our family before this. Be persistent. If you think something is off with your body, do something about it. Do self-checks, see a doctor if you feel something, and don’t take no for an answer if you’re suspicious of something. 

I feel another big takeaway is that it’s just not worth it to get caught up and make a big deal of small things that mean nothing. Be thankful for all that you have. 

Stacey: The most important thing is being with and spending time with the people you love most.

Tiffany: Yeah. And getting out there and living life. That was a big takeaway for me. I vowed to start saying “yes” more. You have one life. Live it.

Stacey: And be kind. You never know what other people are going through.


What advice would you give to our readers on the journey of coping with the loss of someone you love?


Tiffany: I feel like you have to let yourself feel. There’s no “normal” way to grieve. Don’t feel ashamed. Don’t feel like there’s a specific way to act. You just have to let it happen. Sometimes you want to cry and you don’t have to push it down. Be kind to yourself. If I want to talk about my sister, I talk about her. I don’t care if it makes people uncomfortable. I say aloud, “Leslie would love that,” or “This is what Leslie would say.” I talked to Leslie every single day, multiple times a day, and that’s my way of keeping her present in my day-to-day life. Also, remind yourself that it’s OK to not be OK. You just went through an awful thing and you’re allowed to be unhappy. And at the same time, it’s OK to go out and laugh and have fun. You’re allowed to be both happy and sad at the same time.

Stacey: It’s helped me to share about it with people if I’m comfortable talking to them. It’s nice to have support. 



Leslie, Tiffany, and Stacey Arenson are The Everygirl…

Funniest Leslie memory: She made dinner for her husband’s kids for the first time a few years ago and made them each a grilled cheese. When she flipped both of the sandwiches they were completely burnt. She then found out that she had used the last of the bread and cheese. She was so upset but went to the store, got new ingredients, and re-made the grilled cheeses. We laughed about it after (but not too soon).

If you caught her singing in her car, what song would she be jamming out to? Garth Brooks! She loved him.

What was her ideal way to spend a Sunday?  Definitely watching sports — she was a huge football fan and has won MANY fantasy football leagues. 

What was her go-to splurge meal? RPM Italian.

Favorite family vacation? Florida beach vacays.

Most valuable piece of advice that she gave you? 

Tiffany: I get my work ethic from Leslie, I watched her work hard and earn everything she accomplished. One thing about Leslie was that she DID things. She was always up for going to concerts, Bears games in a negative windchill, road trips, any adventure — she would just say “yes.” I don’t think I ever heard her say “I don’t feel like it.” So something I do now is I say “yes” more, and “I don’t feel like it” less. 

Stacey: Just to go out there and get after it. Whatever that may be in your life — career, fitness, friends, etc. She was always giving 110 percent and inspired us to do the same.

What’s something that Leslie would kick your butt in 10 times out of 10? Anything sports-related. She was on multiple fantasy football teams and would always win!