Background: Technology-based interventions are increasingly used to improve physical activity (PA) and diet. Methods: We conducted a systematic review of randomized controlled trials (RCTs) published up to August 2021 that tested mobile health (mHealth) PA and/or dietary interventions among cancer survivors and reported on the feasibility, satisfaction, behavioral change, and/or quality of life (QOL) outcomes. Results: In total, 61 articles were identified on PubMed, and 23 of those met the inclusion criteria. The most common cancers were breast (n = 1000), prostate (n = 713), and colorectal (n = 650). Participants were predominantly White (median: 84%, interquartile range (IQR): 20%) and college-educated (58%). The interventions varied, but the most common combination of components (six studies) was a website/mobile app with an activity tracker and coaching. In terms of duration, 70% (n = 16) of the interventions lasted 12 weeks. The median total tracker wear was 87% of the study days (IQR: 6%) and the median text-message reply rate was 73% (IQR 4%). Most participants (median: 87%; IQR: 16%) were satisfied with at least one intervention component. Eleven out of 18 studies examining behavioral change reported significant between-group differences and six out of 11 studies examining QoL reported significant improvements. Conclusions: mHealth interventions are a promising approach to improving the PA and diets of cancer survivors. Research in racially/ethnically and socioeconomically diverse populations is needed.

Purpose We aimed to estimate the effect of a 12-week web-based dietary intervention with text messages on quality of life (QoL) among colorectal cancer (CRC) survivors. Methods Between 2017 and 2018, 50 CRC survivors were randomized (1:1) to receive a 12-week web-based dietary intervention with daily text messages or wait-list control. Health-related QoL was assessed using the European Organization for the Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire–Core 30 (QLQ-C30) and colorectal quality of life module (QLQ-CR29) at baseline, 12, and 24 weeks. Within- and between-group mean changes in health-related QoL with 95% confidence intervals (CI) were calculated for both arms. Results Compared to the controls, participants receiving the intervention had an improvement in emotional functioning (mean change: 14.3; 95% CI: 3.0, 25.6) at 12 weeks and social functioning (mean change: 13.8; 95% CI: 2.1, 25.5) at 24 weeks. A decrease of fatigue from baseline was also observed in the intervention arm (mean change: − 9.1; 95% CI: − 17.1, − 1.1) at 24 weeks. No other changes in QoL scores were associated with the intervention. Conclusion CRC survivors randomized to receive a web-based dietary intervention with text messages experienced higher emotional and social functioning. Further study with a larger population may be warranted. Trial registration clinicaltrials.gov, NCT02965521. Registered 16 November 2016, https://clinicaltrials.gov/ct2/keydates/NCT02965521

339 Background: A volume-outcome relationship has not yet been comprehensively established for prostate cancer brachytherapy, a treatment modality that is declining in usage, with regard to cancer-specific outcomes. The goal of this study is to describe the relationship between facility brachytherapy case volume and cancer-specific outcomes in patients with localized prostate cancer. Methods: We identified patients in CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) diagnosed with localized prostate cancer between 1999-2007 and treated with brachytherapy. Only community hospital settings had sufficient documented cases for inclusion. The brachytherapy case volume of each facility was based on its total number of brachytherapy-treated prostate cancer patients with facilities above the 75th percentile categorized as high-volume facilities. The primary outcome was biochemical failure based on the Phoenix definition or receipt of salvage treatment after primary brachytherapy. We used logistic regression to compute a propensity score for on high vs low volume facility based on demographic, clinical, and treatment variables. Cumulative incidence of biochemical failure and prostate cancer specific mortality of patients were assessed with lifetable estimates, log-rank test, and Cox proportional hazards regression, adjusted for propensity score and case volume. Secondary outcomes included patient-reported UCLA Prostate Cancer scores for urinary, sexual, and bowel function and bother. Results: We identified 1,282 patients with localized prostate cancer treated with brachytherapy between 1999-2007 across 18 community facilities with median follow-up of 9 years. The median number of brachytherapy cases over the 8 study years was 210. 722 patients (56.3%) received brachytherapy at high-volume (>210 cases) community facilities and 560 patients (43.7%) at low-volume (10-210 cases) facilities. High-volume facilities predominantly used Pd-103 seeds while low-volume facilities predominantly used I-125 seeds. A greater proportion of patients at low-volume facilities had pre-brachytherapy hormone therapy (47% vs 26%; p<0.01). Cumulative incidence of biochemical failure at 10 years was 10.3% for high-volume facilities and 12.5% for low-volume facilities (p=0.27). Cumulative incidence of prostate cancer specific mortality at 10 years was 4.0% for high-volume facilities and 4.5% for low-volume facilities (p=0.62). Patient-reported scores of urinary, sexual, and bowel bother at 6 months following brachytherapy were comparable between the two groups. Conclusions: Patients with localized prostate cancer treated with brachytherapy at high-volume community facilities have similar rates of biochemical failure, prostate cancer specific mortality, and trends in quality of life outcomes compared to those treated at low-volume community facilities.

346 Background: Clinically localized prostate cancer can be treated with prostatectomy, radiation or focal therapy, with known impacts on sexual function. We sought to characterize long term sexual function in a large cohort of men treated with primary EBRT and to differentiate between those who have high vs low sexual function scores at baseline. Methods: Patients enrolled in CaPSURE, a national registry of men diagnosed with prostate cancer, from 1995 - 2017 with clinically localized prostate cancer (cN0M0/X, PSA < = 50) and treated with primary EBRT were included. Sexual function (SF) was self-reported using the UCLA Prostate Cancer Index (PCI). We performed repeated measures mixed models to evaluate SF after EBRT, stratified by baseline SF and adjusted for age, BMI, comorbidities, smoking, clinical risk, receipt of brachytherapy and/or hormonal therapy, and type of clinical site. Results: 1193 patients were included for analysis. Mean age was 70, mean number of comorbidities was 2, and median PSA was 7.5 at diagnosis. Baseline PCI scores were available for 43% of the cohort (data not collected before 1998). The mean PCI score was 38 out of 100 at baseline and after EBRT, declined gradually to 16 by 10 years. When only those men with good SF at baseline were assessed (scores 80 – 100), the initial rate of decline was more severe, but the nadir in this group was higher than those with lower baseline scores. Unadjusted mean PCI scores showed a similar decline amongst both groups, although those with good baseline SF consistently had better scores. 63% of patients were treated for erectile dysfunction (PDE5 inhibitors, intracavernosal injections or both), 13% of whom started therapy before EBRT. In the repeated measures mixed models analysis, we found that SF changed significantly over time and scores differed significantly by age, comorbidities, baseline SF, receipt of brachytherapy boost and concurrent ADT. Conclusions: SF after EBRT declines and persists. The most affected are those who had better PCI scores at baseline, although their overall PCI scores are consistently higher compared to those with baseline scores less than 80. Among both groups however, there was a similar decline that was statistically significant.

393 Background: Radiation therapy is a common form of treatment for men with prostate cancer. Biochemical recurrence (BCR) is most commonly defined using the Phoenix definition of PSA nadir + 2. We sought to characterize long term rates of biochemical recurrence in a large, well-characterized and well-followed cohort of men treated with primary EBRT. Methods: Patients enrolled in CaPSURE, a national registry of men diagnosed with prostate cancer, from 1995 - 2017 with clinically localized prostate cancer (cN0M0/X, PSA<=50) treated with primary EBRT were included. Cancer risk was defined by NCCN criteria. Cox proportional hazards regressions were used to assess associations between patient characteristics and BCR as defined by PSA nadir + 2. Results: 1193 patients were included. Mean age at diagnosis was 70 (SD 6.82), median PSA at diagnosis was 7.6 and mean number of follow up PSA tests was 5. Overall rates of BCR were 17.4% at 5 years and 39.4% at 10 years. Rates of BCR were significantly associated with NCCN risk with high-risk patients having the highest rates of recurrence, followed by intermediate- and low-risk groups (61.5%, 36.4% and 28.5% respectively at 10 years). NCCN high vs low clinical risk was significantly associated with likelihood of BCR (HR 4.8, CI 2.5 – 9.2). Rates of salvage treatment, usually ADT, were 16% at 5 years and 19% at 10 years and these were also significantly associated with NCCN high vs low clinical risk (HR 3.7, CI 2.3 – 6) and concurrent ADT (HR 1.83, CI 1.2 – 2.7). Overall rates of bone metastases were 2.6% at 5 years and 4% at 10 years. Overall prostate cancer specific mortality was 3% at 5 years and 7% at 10 years. Conclusions: In this analysis, rates of BCR were fairly high and consistent with published RTOG studies, but rates of salvage treatment were relatively low in comparison, indicating that not all patients who recur need, are offered or want treatment. The limitations of this analysis include incomplete information on radiation dose and field size. The strengths of this analysis include the size of the cohort and the length of follow-up. Furthermore, as this cohort largely represents treatment in community settings, the results may be broadly applicable.