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PURPOSE: Our aim was to test whether updated polygenic risk scores (PRS) for susceptibility to cancer affect risk of radiation therapy toxicity. METHODS AND MATERIALS: Analyses included 9,717 patients with breast (n=3,078), prostate (n=5,748) or lung (n=891) cancer from Radiogenomics and REQUITE Consortia cohorts. Patients underwent potentially curative radiation therapy and were assessed prospectively for toxicity. Germline genotyping involved genome-wide single nucleotide polymorphism (SNP) arrays with nontyped SNPs imputed. PRS for each cancer were generated by summing literature-identified cancer susceptibility risk alleles: 352 breast, 136 prostate, and 24 lung. Weighted PRS were generated using log odds ratio (ORs) for cancer susceptibility. Standardized total average toxicity (STAT) scores at 2 and 5 years (breast, prostate) or 6 to 12 months (lung) quantified toxicity. Primary analysis tested late STAT, secondary analyses investigated acute STAT, and individual endpoints and SNPs using multivariable regression. RESULTS: Increasing PRS did not increase risk of late toxicity in patients with breast (OR, 1.000; 95% confidence interval [CI], 0.997-1.002), prostate (OR, 0.99; 95% CI, 0.98-1.00; weighted PRS OR, 0.93; 95% CI, 0.83-1.03), or lung (OR, 0.93; 95% CI, 0.87-1.00; weighted PRS OR, 0.68; 95% CI, 0.45-1.03) cancer. Similar results were seen for acute toxicity. Secondary analyses identified rs138944387 associated with breast pain (OR, 3.05; 95% CI, 1.86-5.01; P = 1.09 × 10-5) and rs17513613 with breast edema (OR, 0.94; 95% CI, 0.92-0.97; P = 1.08 × 10-5). CONCLUSIONS: Patients with increased polygenic predisposition to breast, prostate, or lung cancer can safely undergo radiation therapy with no anticipated excess toxicity risk. Some individual SNPs increase the likelihood of a specific toxicity endpoint, warranting validation in independent cohorts and functional studies to elucidate biologic mechanisms.

Additional file 1: Appendix figure 1. Questionnaire given to patients in the standard group. Appendix figure 2. Questionnaire given to patients in the enhanced group. Appendix figure 3. Summary of the risk of recurrence in very low risk patients. Appendix figure 4. Summary of change in breast appearance in women treated with radiotherapy. Appendix table 1. Summary of script structure. Appendix table 2. Summary of association of age and education level with decisional conflict. Appendix table 3. Summary of decisional conflict subscales results.

BACKGROUND: In an era of low local relapse rates after adjuvant breast radiotherapy, risks of late normal-tissue effects (NTE) need to be balanced against risk of relapse. NTE are assessed using patient-reported outcome measures (PROMs), clinician-reported outcomes (CRO) and photographs. This analysis investigates whether PROMs can be used as primary NTE endpoints in breast radiotherapy trials. METHODS: Analyses were conducted within IMPORT LOW (ISRCTN12852634) at 2 and 5 years. NTE were recorded by CRO, photographs and PROMs. Measures of agreement tested concordance, risk ratios for radiotherapy groups were compared, and influence of baseline characteristics on concordance investigated. RESULTS: In 1095 patients who consented to PROMS and photographs, PROMs were available at 2 and/or 5 years for 976 patients, of whom 909 had CRO and 844 had photographs. Few patients had moderate/marked NTE, irrespective of method used (eg. 19% patients and 9% clinicians reported breast shrinkage at year-5). Patients reported more NTE than assessed from CRO or photographs (p < 0.001 for most NTE). Concordance between assessments was poor on an individual patient level; eg. for year-5 breast shrinkage, % agreement = 48% and weighted kappa = 0.17. Risk ratios comparing radiotherapy schedules were consistent between PROMs and CRO or photographs. CONCLUSIONS: Few patients had moderate/marked NTE irrespective of method used. Patients reported more NTE than CRO and photographs, therefore NTE may be underestimated if PROMs are not used. Despite poor concordance between methods, effect sizes from PROMs were consistent with CRO and photographs, suggesting PROMs can be used as primary NTE endpoints in breast radiotherapy trials.

BACKGROUND: Seroma describes a collection of serous fluid within a cavity, occurring following surgery. Seroma is associated with normal tissue effects (NTE) following breast radiotherapy, as reported by clinicians and on photographs. This study investigates the association between seroma and the NTE breast appearance change collected using patient-reported outcome measures (PROMs) in IMPORT HIGH, as well as investigating the association between breast appearance change and patient/tumour/treatment factors. METHODS: Case-control methodology was used for seroma analysis within IMPORT HIGH. Cases were patients reporting moderate/marked breast appearance change and controls reported none/mild changes at year-3. One control was selected at random for each case. Seromas were graded as not visible/subtle or visible/highly visible on CT radiotherapy planning scans. Logistic regression tested associations, adjusting for patient/tumour/treatment factors. RESULTS: 1078/1149 patients consented to PROMs, of whom 836 (78%) reported whether they had 3-year breast appearance change; 231 cases and 231 controls were identified. 304/462 (66%) patients received chemotherapy. Seroma prevalence was 20% (41/202) in cases and 16% (32/205) in controls, and less frequent in patients receiving adjuvant chemotherapy [10% (24/246) compared with 29% (40/138) without]. Visible seroma was not significantly associated with breast appearance change [OR 1.38 (95%CI 0.83-2.29), p = 0.219]. Larger tumour size, haematoma, current smoking and body image concerns at baseline were independent risk factors. CONCLUSIONS: Seroma was not associated with patient-reported breast appearance change, but haematoma and smoking were significant risk factors. Lack of association may be related to lower prevalence of seroma compared with previous reports, perhaps reflecting patients receiving adjuvant chemotherapy in whom seroma resolves prior to radiotherapy.

PURPOSE: IMPORT LOW demonstrated noninferiority of partial-breast and reduced-dose radiotherapy versus whole-breast radiotherapy for local relapse and similar or reduced toxicity at 5 years. Comprehensive patient-reported outcome measures collected at serial time points are now reported. PATIENTS AND METHODS: IMPORT LOW recruited women with low-risk breast cancer after breast-conserving surgery. Patients were randomly assigned to 40 Gy whole-breast radiotherapy (control), 36 Gy whole-breast and 40 Gy partial-breast radiotherapy (reduced-dose), or 40 Gy partial-breast radiotherapy only (partial-breast) in 15 fractions. European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires Core 30 and Breast Cancer-Specific Module, Body Image Scale, protocol-specific items, and the Hospital Anxiety and Depression Scale were administered at baseline, 6 months, and 1, 2, and 5 years. Patterns of moderate/marked adverse effects (AEs) were assessed using longitudinal regression models, and baseline predictors were investigated. RESULTS: A total of 41 of 71 centers participated in the patient-reported outcome measures substudy; 1,265 (95%) of 1,333 patients consented, and 557 (58%) of 962 reported no moderate/marked AEs at 5 years. Breast appearance change was most prevalent and persisted over time (approximately 20% at each time point). Prevalence of breast hardness, pain, oversensitivity, edema, and skin changes reduced over time ( P < .001 for each), whereas breast shrinkage increased ( P < .001). Analysis by treatment group showed average number of AEs per person was lower in partial-breast (incidence rate ratio, 0.77; 95% CI, 0.71 to 0.84; P < .001) and reduced-dose (incidence rate ratio, 0.83; 95% CI, 0.76 to 0.90; P < .001) versus whole-breast group and decreased over time in all groups. Younger age, larger breast size/surgical deficit, lymph node positivity, and higher levels of anxiety/depression were baseline predictors of subsequent AE reporting. CONCLUSION: Most AEs reduced over time, with fewer AEs in the partial-breast and reduced-dose groups. Baseline predictors for AE reporting were identified. These findings will facilitate informed discussion and shared decision making for future patients receiving moderately hypofractionated breast radiotherapy.

BackgroundTests of tumour treatment time effect in patients prescribed post-operative radiotherapy for early breast cancer have focussed on time to start of radiotherapy rather than overall treatment time. The START randomised trials of radiotherapy fractionation provide an opportunity to directly estimate the effect of treatment acceleration.MethodsBetween 1986 and 2002, a total of 5861 women with early breast cancer were recruited into the UK START pilot (START-P), START-A and START-B randomised trials. START-P and START-A tested 13 fractions of 3.0–3.3Gy against 25 fractions of 2.0Gy with a fixed treatment duration of 5weeks for all schedules; START-B tested 15 fractions of 2.67Gy in 3weeks against 25 fractions of 2.0Gy over 5weeks. Estimates of the effect of length of treatment for local–regional relapse and for a measure of late normal tissue effects (change in photographic breast appearance, for patients following breast conserving surgery) were obtained from Cox proportional hazards regression analyses stratified according to trial.ResultsAt a median follow-up of 10years, 444/5831 (7.6%) patients with data available had a local–regional relapse, and 1135/3185 (35.6%) had mild or marked change in photographic breast appearance by 5years. Adjusting for prognostic factors, the estimate of the overall treatment time effect for local–regional relapse was 0.60Gy/day (95%CI 0.10 to 1.18Gy/day, p=0.02), and 0.14Gy/day (95%CI −0.09 to 0.34Gy/day, p=0.29) for change in photographic breast appearance.ConclusionsCombined analysis of the START trials generates the hypothesis that overall treatment time is a significant determinant of local cancer control after adjuvant whole breast radiotherapy, with approximately 0.6Gy per day ‘wasted’ in compensating for tumour cell proliferation.