This clinical trial tests the impact of a culturally-tailored home-based physical activity program on physical fitness in Hispanic or Latino/Latina adolescent and young adult (AYA) childhood cancer survivors. After treatment for cancer, some AYA survivors experience long-term effects from the cancer and its treatment including weight gain, fatigue and decreased physical fitness. Hispanic or Latino/Latina survivors may have a higher risk of these effects compared to non-Hispanics. Regular physical activity helps maintain healthy weight, energy levels and overall health. Participating in a culturally-tailored home-based physical activity program may help increase physical activity in Hispanic or Latino/Latina AYA childhood cancer survivors.

PRIMARY OBJECTIVES:

I. Use an iterative approach to develop a culturally-tailored multilevel remote-based physical activity (PA) intervention among a total of 20 Latinx adolescent and young adult survivors of childhood cancer (AYA survivors), 8-12 whose preferred language is English and 8-12 whose preferred language is Spanish, using the StepByStep intervention as a starting point. (Stage 1) II. Conduct a randomized controlled trial (RCT) to test the potential efficacy of the culturally-tailored remote-based PA intervention (versus [vs.] Fitbit PA tracker only) with respect to the primary outcome of moderate to vigorous physical activity (MVPA) measured with a validated, wearable Fitbit PA tracker over 12 weeks among a separate group of 170 Latinx AYA survivors whose preferred language is Spanish or English (n=85 per randomization group) and who do not meet PA guidelines at timepoint (T) 1. The control group will receive a Fitbit only. (Stage 2)

SECONDARY OBJECTIVES:

I. Among the patients enrolled to the RCT component of the study, evaluate the potential efficacy of randomization to the intervention group relative to control group with respect to decreasing sedentary time as assessed by a Fitbit PA tracker.

II. Evaluate potential efficacy of randomization to the active intervention group with respect to improvement in reported health-related quality of life.

EXPLORATORY OBJECTIVES:

I. Evaluate potential efficacy of randomization to the active intervention group with respect to physiological measurements predictive of cardiometabolic health.

II. Determine the acceptability of and guidance on improving the intervention phases in preparation for a fully powered, long term RCT by conducting two rounds of post-trial qualitative interviews among participants in the intervention Group n=12-15 for the intensive intervention phase and n=12-15 for the maintenance intervention phase. Preferences and barriers for an additional diet and nutrition component will also be explored.

OUTLINE:

STAGE 1: Patients wear a Fitbit physical activity tracker daily, set physical activity goals, receive text messages, and view private social media peer support group content over 7-10 days once every 3 months. Patients also wear a research grade activity measuring device over 1-3 days and participate in a one-on-one interview once every 3 months for 9 months.

STAGE 2: Patients are randomized to 1 of 2 groups.

GROUP I (INTERVENTION):

INTENSIVE PHASE: Patients wear a Fitbit physical activity tracker daily and receive weekly reminders to wear the Fitbit for 12 weeks. Patients attend weekly goal setting sessions, receive individualized physical activity goals, view and post private social media peer support group content 2-3 times weekly, receive badges, and participate in a monthly Zoom meeting with their peers to discuss physical activity for 12 weeks. Patients may optionally choose a physical activity partner. Partners wear a Fitbit physical activity tracker and receive educational materials about supporting the participant.

MAINTENANCE PHASE: Patients wear a Fitbit physical activity tracker daily and set their own physical activity goals weekly for 4 weeks. Patients also receive access to the social media account and post content for 4 weeks. In addition, patients may continue to have their physical activity partner support them as in the Intensive Phase.

GROUP II (CONTROL): Patients wear a Fitbit physical activity tracker daily for 12 weeks.

Inclusion Criteria:

• Patient must be ≥ 15 years and < 21 years at the time of enrollment
• First diagnosis of malignant neoplasm (International Classification of Diseases for Oncology [ICD-O] behavior code of "3") in first and continuous remission at the time of enrollment
• Curative cancer treatment must have included chemotherapy (including cellular therapy) and/or radiation (including radioactive iodine). Note: Certain stem cell transplant procedures are excluded. Reminder: Children's Oncology Group (COG) therapeutic trial participation is not required
• Completed all chemotherapy and/or radiation therapy in the last 3-36 months. This includes completion of all oral (e.g., tyrosine kinase inhibitors) and/or maintenance chemotherapy
• Self-report of < 420 minutes of moderate-to-vigorous physical activity per week as assessed and documented via the study-specific Physical Activity Worksheet. Note: See the case report forms packet on the COG study web page for the study specific Physical Activity Worksheet
• Ambulatory and no known medical contraindications to increasing physical activity
• No known significant physical or cognitive impairment that would prevent use of the electronic devices used for the protocol intervention (e.g., Fitbit, smartphone, tablet, or computer)
• Able to read and write Spanish or English
• Self-identify as Hispanic, Latino/Latina/Latinx

Exclusion Criteria:

• Patients with previous allogeneic hematopoietic stem cell transplant (HSCT) are excluded. Note: Patients with previous autologous HSCT, chimeric antigen receptor T-cell (CAR T-cell) therapy, and other cellular cancer therapies can participate as long as all other eligibility criteria are satisfied
• Post-menarchal female patients who are pregnant or planning to become pregnant in the next year are excluded. Note: Pregnancy status can be established by clinical history with patient. Post-menarchal female patients are eligible as long as they agree to use an effective contraceptive method (including abstinence) during study participation
• Participants who were enrolled in ALTE2031 (Step by Step) cannot enroll in ALTE2321. Participants who were enrolled in ALTE2321 stage 1 (cultural tailoring) cannot enroll to participate in stage 2 (RCT)
• All patients and/or their parents or legal guardians must sign a written informed consent. Note: Informed consent may be obtained electronically/online if allowed by local site policy and institutional review board (IRB)/research ethics board (REB) of record
• All institutional, Food and Drug Administration (FDA), and National Cancer Institute (NCI) requirements for human studies must be met

Investigators and participating site staff are blinded.