Evaluation of a Method for Grading Late Photographic Change in Breast Appearance after Radiotherapy for Early Breast Cancer

One versus three weeks hypofractionated whole breast radiotherapy for early breast cancer treatment: the FAST-Forward phase III RCT

Background

FAST-Forward aimed to identify a 5-fraction schedule of adjuvant radiotherapy delivered in 1 week that was non-inferior in terms of local cancer control and as safe as the standard 15-fraction regimen after primary surgery for early breast cancer. Published acute toxicity and 5-year results are presented here with other aspects of the trial.

Design

Multicentre phase III non-inferiority trial. Patients with invasive carcinoma of the breast (pT1-3pN0-1M0) after breast conservation surgery or mastectomy randomised (1 : 1 : 1) to 40 Gy in 15 fractions (3 weeks), 27 Gy or 26 Gy in 5 fractions (1 week) whole breast/chest wall (Main Trial). Primary endpoint was ipsilateral breast tumour relapse; assuming 2% 5-year incidence for 40 Gy, non-inferiority pre-defined as < 1.6% excess for 5-fraction schedules (critical hazard ratio = 1.81). Normal tissue effects were assessed independently by clinicians, patients and photographs.

Sub-studies

Two acute skin toxicity sub-studies were undertaken to confirm safety of the test schedules. Primary endpoint was proportion of patients with grade ≥ 3 acute breast skin toxicity at any time from the start of radiotherapy to 4 weeks after completion. Nodal Sub-Study patients had breast/chest wall plus axillary radiotherapy testing the same three schedules, reduced to the 40 and 26 Gy groups on amendment, with the primary endpoint of 5-year patient-reported arm/hand swelling.

Limitations

A sequential hypofractionated or simultaneous integrated boost has not been studied.

Participants

Ninety-seven UK centres recruited 4096 patients (1361:40 Gy, 1367:27 Gy, 1368:26 Gy) into the Main Trial from November 2011 to June 2014. The Nodal Sub-Study recruited an additional 469 patients from 50 UK centres. One hundred and ninety and 162 Main Trial patients were included in the acute toxicity sub-studies.

Results

Acute toxicity sub-studies evaluable patients: (1) acute grade 3 Radiation Therapy Oncology Group toxicity reported in 40 Gy/15 fractions 6/44 (13.6%); 27 Gy/5 fractions 5/51 (9.8%); 26 Gy/5 fractions 3/52 (5.8%). (2) Grade 3 common toxicity criteria for adverse effects toxicity reported for one patient. At 71-month median follow-up in the Main Trial, 79 ipsilateral breast tumour relapse events (40 Gy: 31, 27 Gy: 27, 26 Gy: 21); hazard ratios (95% confidence interval) versus 40 Gy were 27 Gy: 0.86 (0.51 to 1.44), 26 Gy: 0.67 (0.38 to 1.16). With 2.1% (1.4 to 3.1) 5-year incidence ipsilateral breast tumour relapse after 40 Gy, estimated absolute differences versus 40 Gy (non-inferiority test) were -0.3% (-1.0-0.9) for 27 Gy (p = 0.0022) and -0.7% (-1.3-0.3) for 26 Gy (p = 0.00019). Five-year prevalence of any clinician-assessed moderate/marked breast normal tissue effects was 40 Gy: 98/986 (9.9%), 27 Gy: 155/1005 (15.4%), 26 Gy: 121/1020 (11.9%). Across all clinician assessments from 1 to 5 years, odds ratios versus 40 Gy were 1.55 (1.32 to 1.83; p < 0.0001) for 27 Gy and 1.12 (0.94-1.34; p = 0.20) for 26 Gy. Patient and photographic assessments showed higher normal tissue effects risk for 27 Gy versus 40 Gy but not for 26 Gy. Nodal Sub-Study reported no arm/hand swelling in 80% and 77% in 40 Gy and 26 Gy at baseline, and 73% and 76% at 24 months. The prevalence of moderate/marked arm/hand swelling at 24 months was 10% versus 7% for 40 Gy compared with 26 Gy.

Interpretation

Five-year local tumour incidence and normal tissue effects prevalence show 26 Gy in 5 fractions in 1 week is a safe and effective alternative to 40 Gy in 15 fractions for patients prescribed adjuvant local radiotherapy after primary surgery for early-stage breast cancer.

Future work

Ten-year Main Trial follow-up is essential. Inclusion in hypofractionation meta-analysis ongoing. A future hypofractionated boost trial is strongly supported.

Trial registration

FAST-Forward was sponsored by The Institute of Cancer Research and was registered as ISRCTN19906132.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 09/01/47) and is published in full in Health Technology Assessment; Vol. 27, No. 25. See the NIHR Funding and Awards website for further award information.

Dose-escalated simultaneous integrated boost radiotherapy in early breast cancer (IMPORT HIGH): a multicentre, phase 3, non-inferiority, open-label, randomised controlled trial

BACKGROUND

A tumour-bed boost delivered after whole-breast radiotherapy increases local cancer-control rates but requires more patient visits and can increase breast hardness. IMPORT HIGH tested simultaneous integrated boost against sequential boost with the aim of reducing treatment duration while maintaining excellent local control and similar or reduced toxicity.

METHODS

IMPORT HIGH is a phase 3, non-inferiority, open-label, randomised controlled trial that recruited women after breast-conserving surgery for pT1-3pN0-3aM0 invasive carcinoma from radiotherapy and referral centres in the UK. Patients were randomly allocated to receive one of three treatments in a 1:1:1 ratio, with computer-generated random permuted blocks used to stratify patients by centre. The control group received 40 Gy in 15 fractions to the whole breast and 16 Gy in 8 fractions sequential photon tumour-bed boost. Test group 1 received 36 Gy in 15 fractions to the whole breast, 40 Gy in 15 fractions to the partial breast, and 48 Gy in 15 fractions concomitant photon boost to the tumour-bed volume. Test group 2 received 36 Gy in 15 fractions to the whole breast, 40 Gy in 15 fractions to the partial breast, and 53 Gy in 15 fractions concomitant photon boost to the tumour-bed volume. The boost clinical target volume was the clip-defined tumour bed. Patients and clinicians were not masked to treatment allocation. The primary endpoint was ipsilateral breast tumour relapse (IBTR) analysed by intention to treat; assuming 5% 5-year incidence with the control group, non-inferiority was predefined as 3% or less absolute excess in the test groups (upper limit of two-sided 95% CI). Adverse events were assessed by clinicians, patients, and photographs. This trial is registered with the ISRCTN registry, ISRCTN47437448, and is closed to new participants.

FINDINGS

Between March 4, 2009, and Sept 16, 2015, 2617 patients were recruited. 871 individuals were assigned to the control group, 874 to test group 1, and 872 to test group 2. Median boost clinical target volume was 13 cm3 (IQR 7 to 22). At a median follow-up of 74 months there were 76 IBTR events (20 for the control group, 21 for test group 1, and 35 for test group 2). 5-year IBTR incidence was 1·9% (95% CI 1·2 to 3·1) for the control group, 2·0% (1·2 to 3·2) for test group 1, and 3·2% (2·2 to 4·7) for test group 2. The estimated absolute differences versus the control group were 0·1% (-0·8 to 1·7) for test group 1 and 1·4% (0·03 to 3·8) for test group 2. The upper confidence limit for test group 1 versus the control group indicated non-inferiority for 48 Gy. Cumulative 5-year incidence of clinician-reported moderate or marked breast induration was 11·5% for the control group, 10·6% for test group 1 (p=0·40 vs control group), and 15·5% for test group 2 (p=0·015 vs control group).

INTERPRETATION

In all groups 5-year IBTR incidence was lower than the 5% originally expected regardless of boost sequencing. Dose-escalation is not advantageous. 5-year moderate or marked adverse event rates were low using small boost volumes. Simultaneous integrated boost in IMPORT HIGH was safe and reduced patient visits.

FUNDING

Cancer Research UK.

Partial breast irradiation versus whole breast radiotherapy for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane Review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypofractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

On 27 August 2020, we searched the Cochrane Breast Cancer Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and three trial databases. We searched for grey literature: OpenGrey (September 2020), reference lists of articles, conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction, used Cochrane's risk of bias tool and resolved any disagreements through discussion, and assessed the certainty of the evidence for main outcomes using GRADE. Main outcomes were local recurrence-free survival, cosmesis, overall survival, toxicity (subcutaneous fibrosis), cause-specific survival, distant metastasis-free survival and subsequent mastectomy. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included nine RCTs that enrolled 15,187 women who had invasive breast cancer or ductal carcinoma in-situ (6.3%) with T1-2N0-1M0 Grade I or II unifocal tumours (less than 2 cm or 3 cm or less) treated with breast-conserving therapy with negative margins. This is the second update of the review and includes two new studies and 4432 more participants. Local recurrence-free survival is probably slightly reduced (by 3/1000, 95% CI 6 fewer to 0 fewer) with the use of PBI/APBI compared to WBRT (hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.03 to 1.42; 8 studies, 13,168 participants; moderate-certainty evidence). Cosmesis (physician/nurse-reported) is probably worse (by 63/1000, 95% CI 35 more to 92 more) with the use of PBI/APBI (odds ratio (OR) 1.57, 95% CI 1.31 to 1.87; 6 studies, 3652 participants; moderate-certainty evidence). Overall survival is similar (0/1000 fewer, 95% CI 6 fewer to 6 more) with PBI/APBI and WBRT (HR 0.99, 95% CI 0.88 to 1.12; 8 studies, 13,175 participants; high-certainty evidence). Late radiation toxicity (subcutaneous fibrosis) is probably increased (by 14/1000 more, 95% CI 102 more to 188 more) with PBI/APBI (OR 5.07, 95% CI 3.81 to 6.74; 2 studies, 3011 participants; moderate-certainty evidence). The use of PBI/APBI probably makes little difference (1/1000 less, 95% CI 6 fewer to 3 more) to cause-specific survival (HR 1.06, 95% CI 0.83 to 1.36; 7 studies, 9865 participants; moderate-certainty evidence). We found the use of PBI/APBI compared with WBRT probably makes little or no difference (1/1000 fewer (95% CI 4 fewer to 6 more)) to distant metastasis-free survival (HR 0.95, 95% CI 0.80 to 1.13; 7 studies, 11,033 participants; moderate-certainty evidence). We found the use of PBI/APBI in comparison with WBRT makes little or no difference (2/1000 fewer, 95% CI 20 fewer to 20 more) to mastectomy rates (OR 0.98, 95% CI 0.78 to 1.23; 3 studies, 3740 participants, high-certainty evidence).

AUTHORS' CONCLUSIONS

It appeared that local recurrence-free survival is probably worse with PBI/APBI; however, the difference was small and nearly all women remain free of local recurrence. Overall survival is similar with PBI/APBI and WBRT, and we found little to no difference in other oncological outcomes. Some late effects (subcutaneous fibrosis) may be worse with PBI/APBI and its use is probably associated with worse cosmetic outcomes. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver PBI/APBI. We await completion of ongoing trials.

Ten-Year Results of FAST: A Randomized Controlled Trial of 5-Fraction Whole-Breast Radiotherapy for Early Breast Cancer

PURPOSE

Previous studies of hypofractionated adjuvant whole-breast radiotherapy for early breast cancer established a 15- or 16-fraction (fr) regimen as standard. The FAST Trial (CRUKE/04/015) evaluated normal tissue effects (NTE) and disease outcomes after 5-fr regimens. Ten-year results are presented.

METHODS

Women ≥ 50 years of age with low-risk invasive breast carcinoma (pT1-2 pN0) were randomly assigned to 50 Gy/25 fr (5 weeks) or 30 or 28.5 Gy in 5 once-weekly fr of 6.0 or 5.7 Gy. The primary end point was change in photographic breast appearance at 2 and 5 years; secondary end points were physician assessments of NTE and local tumor control. Odds ratios (ORs) from longitudinal analyses compared regimens.

RESULTS

A total of 915 women were recruited from 18 UK centers (2004-2007). Five-year photographs were available for 615/862 (71%) eligible patients. ORs for change in photographic breast appearance were 1.64 (95% CI, 1.08 to 2.49; P = .019) for 30 Gy and 1.10 (95% CI, 0.70 to 1.71; P = .686) for 28.5 Gy versus 50 Gy. α/β estimate for photographic end point was 2.7 Gy (95% CI, 1.5 to 3.9 Gy), giving a 5-fr schedule of 28 Gy (95% CI, 26 to 30 Gy) estimated to be isoeffective with 50 Gy/25 fr. ORs for any moderate/marked physician-assessed breast NTE (shrinkage, induration, telangiectasia, edema) were 2.12 (95% CI, 1.55 to 2.89; P < .001) for 30 Gy and 1.22 (95% CI, 0.87 to 1.72; P = .248) for 28.5 Gy versus 50 Gy. With 9.9 years median follow-up, 11 ipsilateral breast cancer events (50 Gy: 3; 30 Gy: 4; 28.5 Gy: 4) and 96 deaths (50 Gy: 30; 30 Gy: 33; 28.5 Gy: 33) have occurred.

CONCLUSION

At 10 years, there was no significant difference in NTE rates after 28.5 Gy/5 fr compared with 50 Gy/25 fr, but NTE were higher after 30 Gy/5 fr. Results confirm the published 3-year findings that a once-weekly 5-fr schedule of whole-breast radiotherapy can be identified that appears to be radiobiologically comparable for NTE to a conventionally fractionated regimen.

Hypofractionated breast radiotherapy for 1 week versus 3 weeks (FAST-Forward): 5-year efficacy and late normal tissue effects results from a multicentre, non-inferiority, randomised, phase 3 trial

BACKGROUND

We aimed to identify a five-fraction schedule of adjuvant radiotherapy (radiation therapy) delivered in 1 week that is non-inferior in terms of local cancer control and is as safe as an international standard 15-fraction regimen after primary surgery for early breast cancer. Here, we present 5-year results of the FAST-Forward trial.

METHODS

FAST-Forward is a multicentre, phase 3, randomised, non-inferiority trial done at 97 hospitals (47 radiotherapy centres and 50 referring hospitals) in the UK. Patients aged at least 18 years with invasive carcinoma of the breast (pT1-3, pN0-1, M0) after breast conservation surgery or mastectomy were eligible. We randomly allocated patients to either 40 Gy in 15 fractions (over 3 weeks), 27 Gy in five fractions (over 1 week), or 26 Gy in five fractions (over 1 week) to the whole breast or chest wall. Allocation was not masked because of the nature of the intervention. The primary endpoint was ipsilateral breast tumour relapse; assuming a 2% 5-year incidence for 40 Gy, non-inferiority was predefined as ≤1·6% excess for five-fraction schedules (critical hazard ratio [HR] of 1·81). Normal tissue effects were assessed by clinicians, patients, and from photographs. This trial is registered at isrctn.com, ISRCTN19906132.

FINDINGS

Between Nov 24, 2011, and June 19, 2014, we recruited and obtained consent from 4096 patients from 97 UK centres, of whom 1361 were assigned to the 40 Gy schedule, 1367 to the 27 Gy schedule, and 1368 to the 26 Gy schedule. At a median follow-up of 71·5 months (IQR 71·3 to 71·7), the primary endpoint event occurred in 79 patients (31 in the 40 Gy group, 27 in the 27 Gy group, and 21 in the 26 Gy group); HRs versus 40 Gy in 15 fractions were 0·86 (95% CI 0·51 to 1·44) for 27 Gy in five fractions and 0·67 (0·38 to 1·16) for 26 Gy in five fractions. 5-year incidence of ipsilateral breast tumour relapse after 40 Gy was 2·1% (1·4 to 3·1); estimated absolute differences versus 40 Gy in 15 fractions were -0·3% (-1·0 to 0·9) for 27 Gy in five fractions (probability of incorrectly accepting an inferior five-fraction schedule: p=0·0022 vs 40 Gy in 15 fractions) and -0·7% (-1·3 to 0·3) for 26 Gy in five fractions (p=0·00019 vs 40 Gy in 15 fractions). At 5 years, any moderate or marked clinician-assessed normal tissue effects in the breast or chest wall was reported for 98 of 986 (9·9%) 40 Gy patients, 155 (15·4%) of 1005 27 Gy patients, and 121 of 1020 (11·9%) 26 Gy patients. Across all clinician assessments from 1-5 years, odds ratios versus 40 Gy in 15 fractions were 1·55 (95% CI 1·32 to 1·83, p<0·0001) for 27 Gy in five fractions and 1·12 (0·94 to 1·34, p=0·20) for 26 Gy in five fractions. Patient and photographic assessments showed higher normal tissue effect risk for 27 Gy versus 40 Gy but not for 26 Gy versus 40 Gy.

INTERPRETATION

26 Gy in five fractions over 1 week is non-inferior to the standard of 40 Gy in 15 fractions over 3 weeks for local tumour control, and is as safe in terms of normal tissue effects up to 5 years for patients prescribed adjuvant local radiotherapy after primary surgery for early-stage breast cancer.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.

Is breast seroma after tumour resection associated with patient-reported breast appearance change following radiotherapy? Results from the IMPORT HIGH (CRUK/06/003) trial

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.

Can patient-reported outcomes be used instead of clinician-reported outcomes and photographs as primary endpoints of late normal tissue effects in breast radiotherapy trials? Results from the IMPORT LOW trial

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.

Partial-breast radiotherapy after breast conservation surgery for patients with early breast cancer (UK IMPORT LOW trial): 5-year results from a multicentre, randomised, controlled, phase 3, non-inferiority trial

BACKGROUND

Local cancer relapse risk after breast conservation surgery followed by radiotherapy has fallen sharply in many countries, and is influenced by patient age and clinicopathological factors. We hypothesise that partial-breast radiotherapy restricted to the vicinity of the original tumour in women at lower than average risk of local relapse will improve the balance of beneficial versus adverse effects compared with whole-breast radiotherapy.

METHODS

IMPORT LOW is a multicentre, randomised, controlled, phase 3, non-inferiority trial done in 30 radiotherapy centres in the UK. Women aged 50 years or older who had undergone breast-conserving surgery for unifocal invasive ductal adenocarcinoma of grade 1-3, with a tumour size of 3 cm or less (pT1-2), none to three positive axillary nodes (pN0-1), and minimum microscopic margins of non-cancerous tissue of 2 mm or more, were recruited. Patients were randomly assigned (1:1:1) to receive 40 Gy whole-breast radiotherapy (control), 36 Gy whole-breast radiotherapy and 40 Gy to the partial breast (reduced-dose group), or 40 Gy to the partial breast only (partial-breast group) in 15 daily treatment fractions. Computer-generated random permuted blocks (mixed sizes of six and nine) were used to assign patients to groups, stratifying patients by radiotherapy treatment centre. Patients and clinicians were not masked to treatment allocation. Field-in-field intensity-modulated radiotherapy was delivered using standard tangential beams that were simply reduced in length for the partial-breast group. The primary endpoint was ipsilateral local relapse (80% power to exclude a 2·5% increase [non-inferiority margin] at 5 years for each experimental group; non-inferiority was shown if the upper limit of the two-sided 95% CI for the local relapse hazard ratio [HR] was less than 2·03), analysed by intention to treat. Safety analyses were done in all patients for whom data was available (ie, a modified intention-to-treat population). This study is registered in the ISRCTN registry, number ISRCTN12852634.

FINDINGS

Between May 3, 2007, and Oct 5, 2010, 2018 women were recruited. Two women withdrew consent for use of their data in the analysis. 674 patients were analysed in the whole-breast radiotherapy (control) group, 673 in the reduced-dose group, and 669 in the partial-breast group. Median follow-up was 72·2 months (IQR 61·7-83·2), and 5-year estimates of local relapse cumulative incidence were 1·1% (95% CI 0·5-2·3) of patients in the control group, 0·2% (0·02-1·2) in the reduced-dose group, and 0·5% (0·2-1·4) in the partial-breast group. Estimated 5-year absolute differences in local relapse compared with the control group were -0·73% (-0·99 to 0·22) for the reduced-dose and -0·38% (-0·84 to 0·90) for the partial-breast groups. Non-inferiority can be claimed for both reduced-dose and partial-breast radiotherapy, and was confirmed by the test against the critical HR being more than 2·03 (p=0·003 for the reduced-dose group and p=0·016 for the partial-breast group, compared with the whole-breast radiotherapy group). Photographic, patient, and clinical assessments recorded similar adverse effects after reduced-dose or partial-breast radiotherapy, including two patient domains achieving statistically significantly lower adverse effects (change in breast appearance [p=0·007 for partial-breast] and breast harder or firmer [p=0·002 for reduced-dose and p<0·0001 for partial-breast]) compared with whole-breast radiotherapy.

INTERPRETATION

We showed non-inferiority of partial-breast and reduced-dose radiotherapy compared with the standard whole-breast radiotherapy in terms of local relapse in a cohort of patients with early breast cancer, and equivalent or fewer late normal-tissue adverse effects were seen. This simple radiotherapy technique is implementable in radiotherapy centres worldwide.

FUNDING

Cancer Research UK.

Prolongation of overall treatment time as a cause of treatment failure in early breast cancer: An analysis of the UK START (Standardisation of Breast Radiotherapy) trials of radiotherapy fractionation

BACKGROUND

Tests 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.

METHODS

Between 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.

RESULTS

At 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.

CONCLUSIONS

Combined 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.

Do Patient-reported Outcome Measures Agree with Clinical and Photographic Assessments of Normal Tissue Effects after Breast Radiotherapy? The Experience of the Standardisation of Breast Radiotherapy (START) Trials in Early Breast Cancer

AIMS

In radiotherapy trials, normal tissue effects (NTE) are important end points and it is pertinent to ask whether patient-reported outcome measures (PROMs) could replace clinical and/or photographic assessments. Data from the Standardisation of Breast Radiotherapy (START) trials are examined.

MATERIALS AND METHODS

NTEs in the treated breast were recorded by (i) annual clinical assessments, (ii) photographs at 2 and 5 years, (iii) PROMs at 6 months, 1, 2 and 5 years after radiotherapy. Hazard ratios for the radiotherapy schedules were compared. Measures of agreement of assessments at 2 and 5 years tested concordance.

RESULTS

PROMs were available at 2 and/or 5 years for 1939 women, of whom 1870 had clinical and 1444 had photographic assessments. All methods were sensitive to the dose difference between schedules. Patients reported a higher prevalence for all NTE end points than clinicians or photographs (P < 0.001 for most NTEs). Concordance was generally poor; weighted kappa at 2 years ranged from 0.05 (telangiectasia) to 0.21 (shrinkage and oedema). The percentage agreement was lowest between PROMs and photographic assessments of change in breast appearance (38%).

CONCLUSIONS

All three methods produced similar conclusions for the comparison of trial schedules, despite low concordance between the methods on an individual patient basis. Careful consideration should be given to the different contributions of the measures of NTE in future radiotherapy trials.

Correlation between DNA damage responses of skin to a test dose of radiation and late adverse effects of earlier breast radiotherapy

AIM

To correlate residual double strand breaks (DSB) 24h after 4Gy test doses to skin in vivo and to lymphocytes in vitro with adverse effects of earlier breast radiotherapy (RT).

PATIENTS AND METHODS

Patients given whole breast RT ⩾5years earlier were identified on the basis of moderate/marked or minimal/no adverse effects despite the absence ('RT-Sensitive', RT-S) or presence ('RT-Resistant', RT-R) of variables predisposing to late adverse effects. Residual DSB were quantified in skin 24h after a 4Gy test dose in 20 RT-S and 15 RT-R patients. Residual DSB were quantified in lymphocytes irradiated with 4Gy in vitro in 30/35 patients.

RESULTS

Mean foci per dermal fibroblast were 3.29 (RT-S) vs 2.80 (RT-R) (p=0.137); 3.28 (RT-S) vs 2.60 (RT-R) in endothelium (p=0.158); 2.50 (RT-S) vs 2.41 (RT-R) in suprabasal keratinocytes (p=0.633); 2.70 (RT-S) vs 2.35 (RT-R) in basal epidermis (p=0.419); 12.1 (RT-S) vs 10.3 (RT-R) in lymphocytes (p=0.0052).

CONCLUSIONS

Residual DSB in skin following a 4Gy dose were not significantly associated with risk of late adverse effects of breast radiotherapy, although exploratory analyses suggested an association in severely affected individuals. By contrast, a significant association was detected based on the in vitro response of lymphocytes.

Does breast composition influence late adverse effects in breast radiotherapy?

BACKGROUND

Large breast size is associated with increased risk of late adverse effects after surgery and radiotherapy for early breast cancer. It is hypothesised that effects of radiotherapy on adipose tissue are responsible for some of the effects seen. In this study, the association of breast composition with late effects was investigated along with other breast features such as fibroglandular tissue distribution, seroma and scar.

METHODS

The patient dataset comprised of 18 cases with changes in breast appearance at 2 years follow-up post-radiotherapy and 36 controls with no changes, from patients entered into the FAST-Pilot and UK FAST trials at The Royal Marsden. Breast composition, fibroglandular tissue distribution, seroma and scar were assessed on planning CT scan images and compared using univariate analysis. The association of all features with late-adverse effect was tested using logistic regression (adjusting for confounding factors) and matched analysis was performed using conditional logistic regression.

RESULTS

In univariate analyses, no statistically significant differences were found between cases and controls in terms of breast features studied. A statistically significant association (p < 0.05) between amount of seroma and change in photographic breast appearance was found in unmatched and matched logistic regression analyses with odds ratio (95% CI) of 3.44 (1.28-9.21) and 2.57 (1.05-6.25), respectively.

CONCLUSIONS

A significant association was found between seroma and late-adverse effects after radiotherapy although no significant associations were noted with breast composition in this study. Therefore, the cause for large breast size as a risk factor for late effects after surgery and optimally planned radiotherapy remains unresolved.

The Cambridge Breast Intensity-modulated Radiotherapy Trial: Comparison of Clinician- versus Patient-reported Outcomes

AIMS

Breast radiotherapy-associated toxicity is often reported using clinical and photographic assessments. The addition of patient-reported outcome measures (PROMs) is becoming more common. This study investigated the concordance between clinician- and patient-reported outcomes.

MATERIALS AND METHODS

The Cambridge Breast Intensity-modulated Radiotherapy (IMRT) trial prospectively collected data on clinician assessment and PROMs at 2 and 5 years after breast radiotherapy. Clinician assessment included physical examination and photographic assessment. PROMs included European Organization for Research and Treatment of Cancer (EORTC) BR23 questionnaire and four breast radiotherapy-specific questions. The correlation between patient and clinician scores were analysed on an independent patient basis using percentage agreement, Cohen's kappa coefficient (k) and Bowker's test of symmetry. The analysis was repeated after stratifying patients based on age, baseline Hospital Anxiety and Depression Score (HADS) and baseline body image score.

RESULTS

At 2 and 5 years, a weak level of concordance was seen between the clinician-based assessment and PROMS for all the five toxicity end points (k = 0.05-0.21), with individual patient-based agreement of 32.9-78.3% and a highly discordant Bowker's test of symmetry (P < 0.001). The most frequently reported moderate-severe toxicity by patients was change in breast appearance (14% at both 2 and 5 years), whereas it was breast induration (36% and 25% at 2 and 5 years, respectively) by the clinicians. The lack of concordance was not affected by patient's age, baseline HADS and baseline body image score.

CONCLUSIONS

This study found that moderate-severe toxicity reported by patients is low and the overall concordance between clinicians and patients is low. This could be due to methodological limitations or alternatively reflects the subjective nature of PROMs. Incorporation of a patient's perception on treatment-related toxicity will have important implications for treatment decisions and follow-up care.

Cytokine levels as biomarkers of radiation fibrosis in patients treated with breast radiotherapy

BACKGROUND

Radiation fibrosis is not easily measurable although clinical scores have been developed for this purpose. Biomarkers present an alternative more objective approach to quantification, and estimation in blood provides accessible samples. We investigated if blood cytokines could be used to measure established fibrosis in patients who have undergone radiotherapy for breast cancer.

METHODS

We studied two cohorts treated by breast-conserving surgery and radiotherapy in the UK START Trial A, one with breast fibrosis (cases) and one with no or minimal fibrosis (controls). Two candidate cytokines, plasma connective tissue growth factor (CTGF) and serum interleukin-6 (IL6) were estimated by ELISA. Comparisons between cases and controls used the t-test or Mann-Whitney test and associations between blood concentration and clinical factors were assessed using the Spearman rank correlation coefficient.

RESULTS

Seventy patients were included (26 cases, 44 controls). Mean time since radiotherapy was 9.9 years (range 8.3-12.0). No statistically significant differences between cases and controls in serum IL6 (median (IQR) 0.84 pg/ml (0.57-1.14), 0.75 pg/ml (0.41-1.43) respectively) or plasma CTGF (331.4 pg/ml (234.8-602.9), 334.5 pg/ml (270.0-452.8) were identified. There were no significant associations between blood cytokine concentration and age, fibrosis severity, breast size or time since radiotherapy.

CONCLUSIONS

No significant difference in IL6 or CTGF concentrations was detected between patients with breast fibrosis and controls with minimal or no fibrosis.

Patient reported outcome measures (PROMs) following forward planned field-in field IMRT: results from the Cambridge Breast IMRT trial

BACKGROUND

The use of intensity-modulated radiotherapy (IMRT) in breast cancer reduces clinician-assessed breast tissue toxicity including fibrosis, telangectasia and sub-optimal cosmesis. Patient reported outcome measures (PROMs) are also important as they provide the patient's perspective. This longitudinal study reports on (a) the effect of forward planned field-in-field IMRT (∼simple IMRT) on PROMs compared to standard RT at 5 years after RT, (b) factors affecting PROMs at 5years after RT and (c) the trend of PROMs over 5 years of follow up.

METHODS

PROMs were assessed at baseline (pre-RT), 6, 24 and 60 months after completion of RT using global health (EORTC QLQ C30) and 4 breast symptom questions (BR23). Also, 4 breast RT-specific questions were included at 6, 24 and 60 months: change in skin appearance, firmness to touch, reduction in breast size and overall change in breast appearance since RT. The benefits of simple IMRT over standard RT at 5 years after RT were assessed using standard t-test for global health and logistic regression analysis for breast symptom questions and breast RT-specific questions. Clinical factors affecting PROMs at 5 years were investigated using a multivariate analysis. A repeated mixed model was applied to explore the trend over time for each of PROMs.

RESULTS

(89%) 727/815, 84%, 81% and 61% patients completed questionnaires at baseline, 6, 24 and 60 months respectively. Patients reported worse toxicity for all four BR23 breast symptoms at 6 months, which then improved over time (p<0.0001). They also reported improvement in skin appearance and breast hardness over time (p<0.0001), with no significant change for breast shrinkage (p=0.47) and overall breast appearance (p=0.13). At 5years, PROMs assessments did not demonstrate a benefit for simple IMRT over standard radiotherapy. Large breast volume, young age, baseline surgical cosmesis and post-operative infection were the most important variables to affect PROMs.

CONCLUSIONS

This study was unable to demonstrate the benefits of IMRT on PROMs at 5years. PROMs are influenced by non-radiotherapy factors and surgical factors should be optimised to improve patients' outcome. Only a small proportion of patients report moderate-severe breast changes post radiotherapy, with most PROMs improving over time. The difference in clinician assessment and PROMs outcome requires further investigation.

Randomized controlled trial of intensity-modulated radiotherapy for early breast cancer: 5-year results confirm superior overall cosmesis

PURPOSE

There are few randomized controlled trial data to confirm that improved homogeneity with simple intensity-modulated radiotherapy (IMRT) decreases late breast tissue toxicity. The Cambridge Breast IMRT trial investigated this hypothesis, and the 5-year results are reported.

PATIENTS AND METHODS

Standard tangential plans of 1,145 trial patients were analyzed; 815 patients had inhomogeneous plans (≥ 2 cm(3) receiving 107% of prescribed dose: 40 Gy in 15 fractions over 3 weeks) and were randomly assigned to standard radiotherapy (RT) or replanned with simple IMRT; 330 patients with satisfactory dose homogeneity were treated with standard RT and underwent the same follow-up as the randomly assigned patients. Breast tissue toxicities were assessed at 5 years using validated methods: photographic assessment (overall cosmesis and breast shrinkage compared with baseline pre-RT photographs) and clinical assessment (telangiectasia, induration, edema, and pigmentation). Comparisons between different groups were analyzed using polychotomous logistic regression.

RESULTS

On univariate analysis, compared with standard RT, fewer patients in the simple IMRT group developed suboptimal overall cosmesis (odds ratio [OR], 0.68; 95% CI, 0.48 to 0.96; P = .027) and skin telangiectasia (OR, 0.58; 95% CI, 0.36 to 0.92; P = .021). No evidence of difference was seen for breast shrinkage, breast edema, tumor bed induration, or pigmentation. The benefit of IMRT was maintained on multivariate analysis for both overall cosmesis (P = .038) and skin telangiectasia (P = .031).

CONCLUSION

Improved dose homogeneity with simple IMRT translates into superior overall cosmesis and reduces the risk of skin telangiectasia. These results are practice changing and should encourage centers still using two-dimensional RT to implement simple breast IMRT.

The impact of dose heterogeneity on late normal tissue complication risk after hypofractionated whole breast radiotherapy

BACKGROUND AND PURPOSE

Linear quadratic models predict that hypofractionation increases the biological effect of physical dose inhomogeneity. The clinical significance of this effect was tested retrospectively in a trial of adjuvant breast hypofractionation.

METHODS

The UK FAST trial randomised 915 women after breast conservation surgery between standard fractionation and two dose levels of a 5-fraction regimen delivering 5.7 or 6.0 Gy fractions in 5 weeks, using 3D dosimetry. Logistic regression tested for association between the absolute volumes receiving different isodose level >100% of prescribed dose (hotspots) and the risk of change in 2-year photographic breast appearance. The strength of this association was compared between control and hypofractionated groups.

RESULTS

Three hundred and ninety datasets from 11 participating centres were available for analysis. At 2 years post-randomisation, 81 (20.8%) had mild change and 24 (6.2%) had marked change in photographic breast appearance. After adjusting for breast size and surgical deficit, there was no statistically significant association between the risk of 2-year change in breast appearance and dose inhomogeneity in either the control or hypofractionated schedules, according to the various definitions of hotspots analysed. The magnitude of the effect of dosimetry on 2-year change in breast appearance did not vary significantly between control and hypofractionated schedules for any of the dosimetry parameters (p>0.05 for all heterogeneity tests).

CONCLUSION

Dose inhomogeneity had no greater impact on the risk of 2-year change in photographic breast appearance after hypofractionated breast radiotherapy than after standard fractionation.

Association of breast tumour bed seroma with post-operative complications and late normal tissue toxicity: results from the Cambridge Breast IMRT trial

AIMS

There are two main surgical techniques for managing the tumour bed after breast cancer excision. Firstly, closing the defect by suturing the cavity walls together and secondly leaving the tumour bed open thus allowing seroma fluid to collect. There is debate regarding which technique is preferable, as it has been reported that a post-operative seroma increase post-operative infection rates and late normal tissue side effects.

METHODS

Data from 648 patients who participated in the Cambridge Breast IMRT trial were used. Seromas were identified on axial CT images at the time of radiotherapy planning and graded as not visible/subtle or easily visible. An association was sought between the presence of seroma and the development of post-operative infection, post-operative haematoma and 2 and 5 years normal tissue toxicity (assessed using serial photographs, clinical assessment and self assessment questionnaire).

RESULTS

The presence of easily visible seroma was associated with increased risk of post-operative infection (OR = 1.80; p = 0.004) and post-operative haematoma (OR = 2.1; p = 0.02). Breast seroma was an independent risk factor for whole breast induration and tumour bed induration at 2 and 5 years. The presence of breast seroma was also associated with inferior overall cosmesis at 5 years. There was no significant association between the presence of seroma and the development of either breast shrinkage or breast pain.

CONCLUSION

The presence of seroma at the time of radiotherapy planning is associated with increased rates of post-operative infection and haematoma. It is also an independent risk factor for late normal tissue toxicity. This study suggests that full thickness surgical closure may be desirable for patients undergoing breast conservation and radiotherapy.

Quality assurance analysis of participating centres' protocol compliance to a UK multicentre hypofractionated breast (FAST) trial

OBJECTIVES

The FAST (FASTer radiotherapy for breast radiotherapy) trial is a UK Phase 2 multicentre randomised clinical trial evaluating a five-fraction schedule of whole-breast radiotherapy following local excision of early breast cancer. The purpose of this quality assurance study was to analyse the radiotherapy planning data in order to confirm compliance with the trial protocol.

METHODS

915 patients were recruited between 2004 and 2007 from 18 centres. The protocol required that all centres should use three-dimensional dose compensations to optimise radiotherapy plans. Planning techniques, maximum dose (D(max)) and dose-volume histograms from treatment plans were evaluated and compared between centres. The homogeneity of plans was tested by creating a cut-off value of 5% for the percentage of breast volume receiving >105% of the prescribed dose.

RESULTS

672 data sets from 15 centres were available. 93% (624/672) of plans were treated using forward-planned multileaf collimator (MLC) segments, 6% with breast compensators and 1% with inverse-planned MLC segments. 94% (635/672) of patients had a D(max)≤107% of the prescribed dose. 11% (74/672) of plans delivered >105% of the prescribed dose to >5% of the breast volume.

CONCLUSION

Reviewing the data in this study, 95% of plans submitted by centres complied with the protocol. With the improved breast radiotherapy standards shown in FAST centres, the following recommendations were suggested for future UK breast radiotherapy trials: (i) the minimum, mean and maximum dose to the whole-breast planning target volume (PTV) should be recorded and assessed; (ii) apart from having a D(max)≤107% of the prescribed dose, ≤5% of PTV should a receive dose >105% of the prescription dose.

First results of the randomised UK FAST Trial of radiotherapy hypofractionation for treatment of early breast cancer (CRUKE/04/015)

BACKGROUND AND PURPOSE

Randomised trials testing 15- or 16-fraction regimens of adjuvant radiotherapy in women with early breast cancer have reported favourable outcomes compared with standard fractionation. To evaluate hypofractionation further, two 5-fraction schedules delivering 1 fraction per week have been tested against a 25-fraction regimen.

MATERIALS AND METHODS

Women aged ⩾50years with node negative early breast cancer were randomly assigned after microscopic complete tumour resection to 50Gy in 25 fractions versus 28.5 or 30Gy in 5 once-weekly fractions of 5.7 or 6.0Gy, respectively, to the whole breast. The primary endpoint was 2-year change in photographic breast appearance.

RESULTS

Nine hundred and fifteen women were recruited from 2004 to 2007. Seven hundred and twenty-nine patients had 2-year photographic assessments. Risk ratios for mild/marked change were 1.70 (95% CI 1.26-2.29, p<0.001) for 30Gy and 1.15 (0.82-1.60, p=0.489) for 28.5Gy versus 50Gy. Three-year rates of physician-assessed moderate/marked adverse effects in the breast were 17.3% (13.3-22.3%, p<0.001) for 30Gy and 11.1% (7.9-15.6%, p=0.18) for 28.5Gy compared with 9.5% (6.5-13.7%) after 50Gy. With a median follow-up in survivors of 37.3months, 2 local tumour relapses and 23 deaths have occurred.

CONCLUSIONS

At 3years median follow-up, 28.5Gy in 5 fractions is comparable to 50Gy in 25 fractions, and significantly milder than 30Gy in 5 fractions, in terms of adverse effects in the breast.

The Cambridge Breast Intensity-modulated Radiotherapy Trial: patient- and treatment-related factors that influence late toxicity

AIMS

The effect of patient- and treatment-related factors in the development of late normal tissue toxicity after radiotherapy is not yet fully established. The aim of this study was to elucidate the relative importance of such factors in the development of late toxicity after breast-conserving surgery and adjuvant breast radiotherapy.

MATERIALS AND METHODS

Patient- and treatment-related factors were analysed in 1014 patients who had received adjuvant radiotherapy to the breast in the Cambridge Breast Intensity-modulated Radiotherapy (IMRT) Trial. Late toxicity data were collected using photographic and clinical assessments and patient-reported questionnaires at 2 years after radiotherapy.

RESULTS

On multivariate analysis, a larger breast volume was statistically significantly associated with the development of breast shrinkage assessed by serial photographs (odds ratio per litre increase in breast volume = 1.98, 95% confidence interval 1.41, 2.78; P < 0.0005), telangiectasia (odds ratio = 3.94, 95% confidence interval 2.49, 6.24; P < 0.0005), breast oedema (odds ratio = 3.65, 95% confidence interval 2.54, 5.24; P < 0.0005) and pigmentation (odds ratio = 1.75, 95% confidence interval 1.21, 2.51; P = 0.003). Current smokers had an increased risk of developing pigmentation (odds ratio = 2.09, 95% confidence interval 1.23, 3.54; P = 0.006). Patients with a moderate or poor post-surgical cosmesis had a greatly increased risk of moderate or poor overall cosmesis (odds ratio = 38.19; 95% confidence interval 21.9, 66.7; P < 0.0005). Postoperative infection requiring antibiotics was associated with increased risk of telangiectasia (odds ratio = 3.39, 95% confidence interval 1.94, 5.91; P < 0.0005) and breast oversensitivity (odds ratio = 1.78, 95% confidence interval 1.27, 2.49; P = 0.001).

CONCLUSIONS

In this study, the greatest risk factors for the development of late toxicity 2 years after breast-conserving surgery and adjuvant radiotherapy were larger breast volume, baseline pre-radiotherapy surgical cosmesis, postoperative infection and possibly smoking. These factors seem to be more important than relatively small differences in dose inhomogeneity and the addition of boost radiotherapy at 2 years after the completion of radiotherapy. The modification of potentially preventable risk factors, such as postoperative infection and smoking, may limit the development of late toxicity after breast radiotherapy.

Randomized controlled trial of forward-planned intensity modulated radiotherapy for early breast cancer: interim results at 2 years

PURPOSE

This single-center randomized trial was designed to investigate whether intensity-modulated radiotherapy (IMRT) reduces late toxicity in patients with early-stage breast cancer.

METHODS AND MATERIALS

The standard tangential plans of 1,145 nonselected patients were analyzed. The patients with inhomogeneous plans were randomized to a simple method of forward-planned IMRT or standard radiotherapy (RT). The primary endpoint was serial photographic assessment of breast shrinkage.

RESULTS

At 2 years, no significant difference was found in the development of any photographically assessed breast shrinkage between the patients randomized to the interventional or control group (odds ratio, 1.51; 95% confidence interval, 0.83-1.58; p = .41). The patients in the control group were more likely to develop telangiectasia than those in the IMRT group (odds ratio, 1.68; 95% confidence interval 1.13-2.40; p = .009). Poor baseline surgical cosmesis resulted in poor overall cosmesis at 2 years after RT. In patients who had good surgical cosmesis, those randomized to IMRT were less likely to deteriorate to a moderate or poor overall cosmesis than those in the control group (odds ratio, 0.63; 95% confidence interval, 0.39-1.03, p = .061).

CONCLUSIONS

IMRT can lead to a significant reduction in telangiectasia at comparatively early follow-up of only 2 years after RT completion. An important component of breast induration and shrinkage will actually result from the surgery and not from the RT. Surgical cosmesis is an important determinant of overall cosmesis and could partially mask the longer term benefits of IMRT at this early stage.

Radiotherapy breast boost with reduced whole-breast dose is associated with improved cosmesis: the results of a comprehensive assessment from the St. George and Wollongong randomized breast boost trial

PURPOSE

To evaluate comprehensively the effect of a radiotherapy boost on breast cosmetic outcomes after 5 years in patients treated with breast-conserving surgery.

METHODS

The St. George and Wollongong trial (NCT00138814) randomized 688 patients with histologically proven Tis-2, N 0-1, M0 carcinoma to the control arm of 50 Gy in 25 fractions (342 patients) and the boost arm of 45 Gy in 25 fractions to the whole breast followed by a 16 Gy in 8 fraction electron boost (346 patients). Five-year cosmetic outcomes were assessed by a panel subjectively in 385 patients and objectively using pBRA (relative breast retraction assessment). A subset of patients also had absolute BRA measurements. Clinician assessment and patient self-assessment of overall cosmetic and specific items as well as computer BCCT.core analysis were also performed.

RESULTS

The boost arm had improved cosmetic overall outcomes as scored by the panel and BCCT.core software with 79% (p = 0.016) and 81% (p = 0.004) excellent/good cosmesis respectively compared with 68% in no-boost arm. The boost arm also had lower pBRA and BRA values with a mean difference of 0.60 and 1.82 mm, respectively, but was not statistically significant. There was a very high proportion of overall excellent/good cosmetic outcome in 95% and 93% in the boost and no-boost arms using patient self-assessment. However, no difference in overall and specific items scored by clinician assessment and patient self-assessment was found.

CONCLUSION

The results show the negative cosmetic effect of a 16-Gy boost is offset by a lower whole-breast dose of 45 Gy.

No association between SNPs regulating TGF-β1 secretion and late radiotherapy toxicity to the breast: results from the RAPPER study

BACKGROUND AND PURPOSE

Several small studies have reported associations between TGFB1 single nucleotide polymorphisms (SNPs), considered to increase secretion of TGF-β1, and greater than 3-fold increases in incidence of fibrosis - an indicator of late toxicity after radiotherapy in breast cancer patients.

MATERIALS AND METHODS

Two SNPs in TGFB1, C-509T (rs1800469) and L10P (rs1800470), were genotyped in 778 breast cancer patients who had received radiotherapy to the breast. Late radiotherapy toxicity was assessed two years after radiotherapy using a validated photographic technique, clinical assessment and patient questionnaires.

RESULTS

On photographic assessment, 210 (27%) patients showed some degree of breast shrinkage, whilst 45 (6%) patients showed marked breast shrinkage. There was no significant association of genotype at either of the TGFB1 SNPs with any measure of late radiation toxicity.

CONCLUSION

This adequately powered trial failed to confirm previously reported increases in fibrosis with TGFB1 genotype - any increase greater than 1.36 can be excluded with 95% confidence. Similar frequent failures to replicate associations with candidate genes have been resolved using genome-wide association scans: this methodology detects common, low risk alleles but requires even larger patient numbers for adequate statistical power.