Intraoperative Radiotherapy Is Not a Better Alternative to Whole Breast Radiotherapy as a Therapeutic Option for Early-Stage Breast Cancer

Abstract

ObjectiveIntraoperative radiotherapy (IORT) in early-stage breast cancer has been studied over the years. However, it has not been demonstrated whether IORT is more suitable as a therapeutic option for early-stage breast cancer than whole breast radiotherapy (WBRT). Therefore, we performed a meta-analysis to compare the efficacy and safety of IORT to those of WBRT as therapeutic options for early-stage breast cancer patients receiving breast-conserving surgery (INPLASY2020120008).MethodsPubMed, Embase, and Cochrane Library databases were searched from inception to October 2021. Computerized and manual searches were adopted to identify eligible randomized control trials from online databases. Risk ratio (RR) and 95% confidence intervals (CI) were calculated by random-effect models to assess the relative risk. Potential publication bias was quantified by Begg’s and Egger’s tests.ResultsBased on our inclusion criteria, 10 randomized control trials involving 5,698 patients were included in this meta-analysis. This meta-analysis showed that the IORT group was associated with a higher local recurrence risk (RR = 2.111, 95% CI, 1.130–3.943, p = 0.0191), especially in the long-term follow-up subgroup or published after 2020 subgroup or Caucasian subgroup (RR = 2.404, 95% CI, 1.183–4.885, p = 0.0154). Subgroup analysis showed that the IORT group had a higher recurrence risk than the WBRT group in the polycentric randomized controlled trial subgroup (RR = 1.213, 95% CI, 1.030–1.428, p = 0.0204). Pooled analysis showed that there was no statistically significant difference in overall survival, recurrence-free survival, distant metastasis-free survival, and cancer-specific survival between IORT and WBRT groups. Additionally, the risk of skin toxicity was reduced, but the incidences of fat toxicity, edema, and scar calcification were significantly increased in the patients who underwent IORT in comparison to those who underwent WBRT.ConclusionThis meta-analysis revealed that IORT was not a better alternative to WBRT. More large-scale and well-designed clinical trials with longer follow-up periods are encouraged to further investigate the value of IORT.Systematic Review Registrationhttps://inplasy.com/inplasy-2020-12-0008/.

Outcomes and complications of intraoperative radiotherapy versus external beam radiotherapy for early breast cancer

“…Our results align with the findings of previous studies, as we also observed a higher rate of local recurrence in the IORT group compared to the EBRT group. 40 , 42 , 43 Contrary to previous studies, our findings revealed a higher incidence of regional recurrence in the IORT group compared to the EBRT group. 14 , 44 Several factors may contribute to these variations, such as the sample size of our study and the limited occurrence of recurrence within our study population.…”

“…Our study found no statistically significant difference in recurrence‐free survival and overall survival rates between two groups of patients who received either IORT or EBRT 39–41 . These findings are consistent with a substantial body of previous research, including a meta‐analysis by Wang et al, which also failed to demonstrate a meaningful difference between the two treatment modalities in terms of recurrence‐free survival and overall survival.…”

“…These findings are consistent with a substantial body of previous research, including a meta‐analysis by Wang et al, which also failed to demonstrate a meaningful difference between the two treatment modalities in terms of recurrence‐free survival and overall survival. Our results align with the findings of previous studies, as we also observed a higher rate of local recurrence in the IORT group compared to the EBRT group 40,42,43 . Contrary to previous studies, our findings revealed a higher incidence of regional recurrence in the IORT group compared to the EBRT group 14,44 .…”

Postoperative cosmetic outcome of intraoperative radiotherapy in comparison to whole breast radiotherapy in early stage breast cancer; a retrospective cohort study

“…In a more recent meta-analysis, there were concerns regarding the high local recurrence risk associated with IORT, however, compared to WBR, overall survival, recurrence-free survival, distant metastasis-free survival, and cancer-specific survival was not significantly different. Therefore a proper patient selection strategy should always be applied to identify suitable candidates with a lower risk of local recurrence for IORT [ 21 ].…”

“…This finding is in agreement with other studies [ 32 – 34 ]. In a meta-analysis by Wang et al, the risk of skin toxicity was reported significantly lower in the IORT group, however, fat toxicity incident was 3.106 times higher compared to the WBR group [ 21 ]. In the report of the late side-effects and cosmetic outcomes of the phase III GEC-ESTRO trial, The risk of developing symptomatic fat necrosis in 5 years did not differ between APBI and WBR groups.…”