Do all patients require radiotherapy after breast-conserving surgery?

Whole Breast Irradiation in Comparison to Endocrine Therapy in Early Stage Breast Cancer-A Direct and Network Meta-Analysis of Published Randomized Trials

BACKGROUND

Multiple randomized trials have established adjuvant endocrine therapy (ET) and whole breast irradiation (WBI) as the standard approach after breast-conserving surgery (BCS) in early-stage breast cancer. The omission of WBI has been studied in multiple trials and resulted in reduced local control with maintained survival rates and has therefore been adapted as a treatment option in selected patients in several guidelines. Omitting ET instead of WBI might also be a valuable option as both treatments have distinctly different side effect profiles. However, the clinical outcomes of BCS + ET vs. BCS + WBI have not been formally analyzed.

METHODS

We performed a systematic literature review searching for randomized trials comparing BCS + ET vs. BCS + WBI in low-risk breast cancer patients with publication dates after 2000. We excluded trials using any form of chemotherapy, regional nodal radiation and mastectomy. The meta-analysis was performed using a two-step process. First, we extracted all available published event rates and the effect sizes for overall and breast-cancer-specific survival (OS, BCSS), local (LR) and regional recurrence, disease-free survival, distant metastases-free interval, contralateral breast cancer, second cancer other than breast cancer and mastectomy-free interval as investigated endpoints and compared them in a network meta-analysis. Second, the published individual patient data from the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) publications were used to allow a comparison of OS and BCSS.

RESULTS

We identified three studies, including a direct comparison of BCS + ET vs. BCS + WBI (n = 1059) and nine studies randomizing overall 7207 patients additionally to BCS only and BCS + WBI + ET resulting in a four-arm comparison. In the network analysis, LR was significantly lower in the BCS + WBI group in comparison with the BCS + ET group (HR = 0.62; CI-95%: 0.42-0.92; p = 0.019). We did not find any differences in OS (HR = 0.93; CI-95%: 0.53-1.62; p = 0.785) and BCSS (OR = 1.04; CI-95%: 0.45-2.41; p = 0.928). Further, we found a lower distant metastasis-free interval, a higher rate of contralateral breast cancer and a reduced mastectomy-free interval in the BCS + WBI-arm. Using the EBCTCG data, OS and BCSS were not significantly different between BCS + ET and BCS + WBI after 10 years (OS: OR = 0.85; CI-95%: 0.59-1.22; p = 0.369) (BCSS: OR = 0.72; CI-95%: 0.38-1.36; p = 0.305).

CONCLUSION

Evidence from direct and indirect comparison suggests that BCS + WBI might be an equivalent de-escalation strategy to BCS + ET in low-risk breast cancer. Adverse events and quality of life measures have to be further compared between these approaches.

No Difference in Overall Survival and Non-Breast Cancer Deaths after Partial Breast Radiotherapy Compared to Whole Breast Radiotherapy-A Meta-Analysis of Randomized Trials

Purpose/objective: Adjuvant radiotherapy after breast conserving surgery is the standard approach in early stage breast cancer. However, the extent of breast tissue that has to be targeted with radiation has not been determined yet. Traditionally, the whole breast was covered by two opposing tangential beams. Several randomized trials have tested partial breast irradiation (PBI) compared to whole breast irradiation (WBI) using different radiation techniques. There is evidence from randomized trials that PBI might result in lower mortality rates compared to WBI. We aimed to reassess this question using current data from randomized trials. Material/methods: We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect sizes for overall survival (OS), breast cancer-specific survival (BCSS), and non-breast cancer death (NBCD) as investigated endpoints. Analysis of subgroups using different radiation techniques was intended. We used hazard ratios (HR) and risk differences (RD) to estimate pooled effect sizes. Statistical analysis was performed using the inverse variance heterogeneity model. Results: We identified eleven studies randomizing between PBI and WBI. We did not find significant differences in OS (n = 14,070; HR = 1.02; CI-95%: 0.89–1.16; p = 0.810, and n = 15,203; RD = −0.001; CI-95%: −0.008–0.006; p = 0.785) and BCSS (n = 15,203; RD = 0.001; CI-95%: −0.002–0.005; p = 0.463). PBI also did not result in a significant decrease of NBCD (n = 15,203; RD = −0.003; CI-95%: −0.010–0.003; p = 0.349). A subgroup analysis by radiation technique also did not point to any detectable differences. Conclusion: In contrast to a previous assessment of mortality, we could not find a detrimental effect of WBI on OS or NBCD. A longer follow-up might be necessary to fully assess the long-term mortality effects of PBI compared to WBI.

Radiation-Induced Brachial Plexopathy in Breast Cancer and the Role of Surgical Treatment

Objective We aimed to evaluate improvement in the pain, motor, and sensory functions after neurosurgical intervention, by objective methods in patients with radiation-induced brachial plexopathy (RIBP), as a complication of radiotherapy (RT).

Materials and Methods In our study, 11 patients, who experienced grade 3 or 4 brachial plexopathy according to the LENT-SOMA (late effects of normal tissue—subjective, objective, management, analytic) side-effect index, as a complication of RT which was performed after being operated for breast cancer, were included. In the postoperative period pain, sensation, and motor function loss were followed.

Results There was apparent regression in the pain. The mean visual analogue scale (VAS) value decreased to 4 from the preoperative VAS value of 9.4. However, no significant improvement was observed in either sensory and motor functions.

Conclusion RIBP is a progressive disease in breast cancer patients after radiotherapy. Evaluation of the results of applied surgical treatments and changes in the results with time is important to direct the treatment. Neurolysis should only be considered when other treatment methods fail and should be considered as an irreversible and potentially permanent procedure.

Impact of young age on local control after partial breast irradiation in Japanese patients with early stage breast cancer

BACKGROUND

Partial breast irradiation (PBI) is an alternative to whole breast irradiation (WBI) for breast-conserving therapy (BCT). A randomised phase 3 trial demonstrated that PBI using multicatheter brachytherapy had an equivalent rate of local recurrence, disease-free survival, and overall survival as compared to WBI. However, limited data are available on PBI efficacy for young patients with breast cancer.

METHODS

We evaluated consecutive patients with Tis-2 (≤ 3 cm) N0-1 breast cancer who underwent BCT. For PBI, patients received radiotherapy using multicatheter brachytherapy in an accelerated manner with a dose of 32 Gy in eight fractions over 5-6 days. For WBI, patients received an external beam radiation therapy that was applied to the entire breast with a total dose of 50 Gy in fractions of 2 Gy for 5 weeks. Two hundred seventy-four patients with 278 lesions received PBI; 190 patients with 193 lesions received WBI.

RESULTS

Patients aged <50 years including 98 women with 99 lesions receiving PBI and 85 women with 85 lesions receiving WBI were selected. Ipsilateral breast tumor recurrence rate was 3.0 and 2.4 % by PBI and WBI, respectively (P = 0.99). There was no significant difference in 4-year probability of disease-free survival (97.6 and 91.4 % for PBI and WBI, respectively; P = 0.87).

CONCLUSIONS

This is the first report of PBI efficacy in young patients in Asia. Although it is a nonrandomized retrospective chart review of a small cohort of patients with a relatively short follow-up period, PBI may be a better option than WBI following BCS in some young patients with breast cancer.