Oncology · Medical Literature
[Comment] Chest wall radiotherapy in SUPREMO: a quality-of-life perspective
Abstract
The recently reported SUPREMO trial evaluated chest wall radiotherapy after mastectomy in patients with intermediate-risk breast cancer. Although chest wall radiotherapy did not improve overall survival, local recurrence was reduced (hazard ratio [HR] 0·45 [95%CI 0·20 to 0·99]), with an absolute benefit of just under 2%.1 With improving outcomes in modern breast cancer therapy, such incremental gains must be weighed against the burden of treatment-related toxicity. In this regard, Galina Velikova and colleagues2 are to be commended for their successful effort to include patient-reported quality of life (QOL) as a key component of the SUPREMO trial.
Clinical relevance
In patients with intermediate-risk breast cancer after mastectomy, does chest wall radiotherapy — which reduces local recurrence but not overall survival — impose a meaningful quality-of-life burden that should inform shared decision-making? __SNAPSHOT__ {"studyDesign":"Published editorial comment (commentary) in The Lancet Oncology, contextualizing the 5-year quality-of-life results from the SUPREMO phase 3 randomized controlled trial (Velikova et al., Lancet Oncology 2026 Aug;27(8):959–972)","setting":"International, multicenter; QOL substudy restricted to UK patients enrolled across >100 hospitals","sampleSize":"Main SUPREMO trial: n=1,688 (radiotherapy: n=853, no radiotherapy: n=835); QOL substudy: UK cohort only (exact n for 5-year QOL report not specified in abstract of this commentary)","population":"Women aged ≥18 years with intermediate-risk breast cancer defined as pT1–2N1, pT3N0, or pT2N0 with histological grade 3 and/or lymphovascular invasion, who had undergone mastectomy and axillary surgery","intervention":"Adjuvant chest wall radiotherapy (40–50 Gy in 15–25 fractions)","comparator":"No radiotherapy (observation with standard follow-up)","primaryOutcome":"10-year overall survival (main trial); patient-reported quality of life across multiple validated domains (QOL substudy secondary endpoint reported here at 5 years)","followUp":"5-year QOL data reported in the referenced Velikova et al. paper; full QOL assessments planned at 1, 2, 5, and 10 years","fundingSource":"UK Medical Research Council; National Institute for Health and Care Research; European Organisation for Research and Treatment of Cancer; Dutch Cancer Society; and other non-profit sources. No industry funding reported."}
Key findings
The commentary references the main SUPREMO trial result that chest wall radiotherapy did not improve 10-year overall survival. Local recurrence was reduced (HR 0.45, 95% CI 0.20–0.99), with an absolute risk reduction of just under 2% — a statistically significant but numerically small benefit. NNT to prevent one local recurrence event is approximately 50 (calculated from ~2% absolute benefit), indicating a high treatment burden relative to the locoregional benefit. The 5-year QOL substudy (Velikova et al.) demonstrated persistent worse chest wall symptoms in the radiotherapy group, particularly in patients who underwent sentinel lymph node biopsy followed by axillary lymph node clearance (difference: −5.29, 95% CI −8.53 to −2.05; p=0.0015). At 2-year follow-up (the previously published QOL data), no significant between-group differences were observed in arm/shoulder symptoms, body image, fatigue, overall QOL, physical function, or anxiety/depression. The 5-year results reportedly showed worse chest wall toxicity but no effect on other QOL domains, with subgroup analyses suggesting potential negative QOL effects of chemotherapy and combined axillary surgery. No survival benefit was established. The commentary's primary contribution is to frame the ~2% absolute local recurrence reduction against demonstrable patient-reported chest wall toxicity, arguing that this trade-off warrants individualized clinical deliberation.
Practice implications
This is an editorial commentary, not a primary data report; the underlying primary evidence derives from the SUPREMO trial and the accompanying Velikova et al. 5-year QOL publication (Lancet Oncology, August 2026). The commentary establishes that chest wall radiotherapy after mastectomy in intermediate-risk breast cancer reduces local recurrence by roughly 2% (absolute) but does not improve overall survival, and does so at a cost of worsened patient-reported chest wall symptoms extending to at least 5 years — with greater toxicity in patients requiring combined axillary procedures. The findings apply most directly to women meeting SUPREMO's eligibility criteria (pT1–2N1, pT3N0, or pT2N0 with grade 3/LVI), though generalizability to contemporary practice is limited by the trial's exclusive use of chest-wall-only irradiation (without regional nodal irradiation), reliance on complete axillary dissection rather than sentinel node biopsy, and enrolment of a patient population with relatively low baseline recurrence risk (~3% chest wall recurrence in the no-radiotherapy arm). Patients treated with modern comprehensive regional nodal irradiation, sentinel node staging, or biologically favorable tumors (e.g., low Oncotype DX recurrence score) were not adequately represented. The commentary does not establish that QOL data alone should change practice, but rather reinforces the importance of integrating patient-reported outcomes alongside efficacy endpoints in post-mastectomy radiotherapy decision-making. Only abstract-level and secondary-source data were available for this summary; the full 5-year QOL manuscript (Velikova et al.) should be consulted for complete statistical outputs. __LIMITATIONS__ This article is an editorial commentary, not an original data report; it draws on, but does not fully present, the underlying trial data.,The SUPREMO trial delivered chest-wall-only radiotherapy, not comprehensive regional nodal irradiation (including internal mammary nodes); this limits applicability to current practice, where nodal irradiation is increasingly standard.,All lymph node-positive patients in SUPREMO underwent complete axillary dissection — not sentinel node biopsy — making findings potentially outdated given modern surgical practice.,The QOL substudy was restricted to UK patients only, limiting international generalizability of the QOL findings.,Protocol modifications during the trial (including reduced sample size and broadened eligibility) may have compromised statistical power and internal consistency.,The trial enrolled a heterogeneous population including ~25% node-negative patients and ~41% with only a single micro- or macrometastatic lymph node, groups at particularly low baseline recurrence risk where radiation benefit would be expected to be minimal.,The absolute local recurrence reduction (~2%) is small; the trial may have been underpowered to detect modest survival differences within the follow-up window.,No overall survival benefit was demonstrated, and the clinical significance of a ~2% reduction in local recurrence in a contemporary systemic therapy context remains debatable.,No industry funding is reported; however, the commentary itself does not present independent statistical analyses. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ Chest wall radiotherapy after mastectomy reduces local recurrence by approximately 2% (absolute) in intermediate-risk breast cancer but confers no 10-year overall survival benefit, while producing clinically meaningful patient-reported chest wall symptoms persisting to at least 5 years — particularly in patients who undergo combined axillary procedures. This QOL evidence, now formally embedded in SUPREMO reporting, strengthens the case for individualized shared decision-making rather than routine post-mastectomy radiotherapy in this population. Clinicians should also note that SUPREMO's design (chest-wall-only RT, complete axillary dissection) does not reflect current practice using comprehensive regional nodal irradiation and sentinel node staging.