Alexis Shapiro's mom Jenny shares the sad update with PEOPLE but says, 'You can't give up hope'
Credit: Courtesy Jenny Shapiro

It’s been a sad week for 13-year-old Alexis Shapiro. The Texas teen – whose family has shared her struggle with hypothalamic obesity over the past few years – learned her brain tumor has grown back.

“After a routine MRI, a tumor regrowth has been found,” Alexis’s mom Jenny tells PEOPLE exclusively. “Although we always knew this was a possibility, we were just beginning to settle down.”

She describes the heartbreak of having to tell Alexis “the beast of a tumor” had returned: “She pulled her shirt up over her mouth, eyes watering, and said, ‘I don’t want to gain weight again.’ The complication of hypothalamic obesity has been her biggest struggle.”

Alexis was first diagnosed with the benign tumor in 2011. An operation to remove it damaged the hypothalamus, the part of the brain that controls when a person feels hungry or full. Within months she developed hypothalamic obesity – a rare, irreversible condition that led to uncontrollable weight gain. She put on 150 lbs. in two and a half years, weighing 203 lbs. by the time she was 12.

Meet Alexis Shapiro, a 12-year-old Suffering from Uncontrollable Weight Gain

“It’s such a danger to be this size,” Jenny told PEOPLE in 2014. “If we don’t do anything about it, she is going to die from all the weight that she has gained and continues to gain.”

After attempts to control her weight through diet and exercise proved futile, Alexis got a sleeve gastrectomy in March 2014. Her health improved immediately – she was taken off diabetes medication and her appetite decreased. Within six months, Shapiro had lost 60 lbs. “I feel more active and more talkative,” she told PEOPLE at the time. “I walk laps every day. I want to do a 5K!”

Alexis Shapiro Is Nearly 60 lbs. Lighter Following Gastric Sleeve Surgery

And she did complete that 5K! In fact, Alexis and her family participated in several road races in 2015. But while her health seemed mostly on the upswing, her weight began to climb again. In August, doctors successfully performed gastric bypass surgery and the Shapiros thought they were finally out of the woods.

Instead, they find themselves preparing for battle once again. “The last few days have been spent at the hospital, with doctor after doctor, test after test,” says Jenny, who adds that the tumor is affecting Alexis’s eyesight this time. “We are meeting with many different specialists to decide the best way to stop it.”

Throughout everything, Jenny remains incredibly proud of her daughter. “Alexis has been so strong,” she says. “But she is scared and does not want surgery to remove the recurrence.”

Jenny and her husband Ian have vowed to stay brave for Alexis and her siblings Kayley, 11 and Ethan, 9. “We have to keep fighting,” says Jenny, who keeps supporters updated through a “Hope and love for Alexis” Facebook page. “I have to show Alexis it’s okay to be scared but you can’t give up – and you definitely can’t give up hope!”