Accelerated partial breast irradiation in early breast cancer: focus on intraoperative treatment with electrons (ELIOT)

Prognosis comparison between intraoperative radiotherapy and whole-breast external beam radiotherapy for T1–2 stage breast cancer without lymph node metastasis treated with breast-conserving surgery: A case–control study after propensity score matching

Background

External beam radiotherapy (EBRT), an adjuvant to breast-conserving surgery (BCS), requires a long treatment period, is costly, and is associated with numerous complications. Large sample studies with long follow-up periods are lacking regarding whether intraoperative radiotherapy (IORT), an emerging radiotherapy modality, can replace EBRT for patients with T1–2 early stage breast cancer without lymph node metastasis treated with BCS.

Methods

We identified 270,842 patients with T1-2N0M0 breast cancer from 2000 to 2018 in the Surveillance, Epidemiology, and End Results (SEER) database. A total of 10,992 patients were matched by propensity score matching (PSM). According to the radiotherapy method, the patients were divided into the IORT and EBRT groups. Overall survival (OS) and breast cancer-specific survival (BCSS) rates were analyzed and compared between the IORT and EBRT groups by Kaplan–Meier analysis. Bilateral P < 0.05 was considered to indicate significance.

Results

After PSM, the survival analysis showed no significant differences in OS or BCSS rates between the IORT and EBRT groups. In the subgroup analysis, the IORT population diagnosed from 2010 to 2013 (HRs = 0.675, 95% CI 0.467–0.976, P = 0.037) or with T2 stage (HRs = 0.449, 95% CI 0.261–0.772, P = 0.004) had better OS rates, but in the overall population, the OS and BCSS rates were better in patients with T1 stage than in patients with T2 stage (P < 0.0001), and the proportion of chemotherapy was significantly higher in T2 stage than in T1 stage. Patients who had EBRT with unknown estrogen receptor had better OS rates (HRs = 3.392, 95% CI 1.368–8.407, P = 0.008). In addition, the IORT group had better BCSS rates for married (HRs = 0.403, 95% CI 0.184–0.881, P = 0.023), grade III (HRs = 0.405, 95% CI 0.173–0.952, P = 0.038), and chemotherapy-receiving (HRs = 0.327, 95% CI 0.116–0.917, P = 0.034) patients with breast cancer compared to the EBRT group.

Conclusion

Intraoperative radiotherapy results of non-inferior OS and BCSS rates, compared to those of EBRT, in patients with early stage breast cancer without lymph node metastasis treated with BCS, and IORT may provide substantial benefits to patients as an effective alternative to standard treatment. This finding provides new insights into radiotherapy strategies for early stage breast cancer.

Conservative mastectomy versus nipple-sparing mastectomy: preliminary considerations of oncological safety on 30 patients not receiving intra-operative radiotherapy

Background

For several years, there has been broad consensus that nipple-sparing mastectomy is a safe surgical treatment for breast cancer. However, the technique is associated with a relatively high risk of local recurrence (LR) behind the nipple-areola complex (NAC). It is for this reason that some years ago we introduced intraoperative radiotherapy with electrons (ELIOT) targeted specifically to the NAC to reduce the probability of recurrence there. However, in some cases we preferred to avoid ELIOT when the NAC appears to have a poor blood supply to ensuring the best chance of NAC survival.

Methods

From July 2003 to April 2010 at our institute, 30 patients received nipple-sparing mastectomy but neither ELIOT nor external radiotherapy, as the surgeon considered the irradiation would markedly compromise the chances of NAC survival, because of sub-optimal vascularization.

Results

After a median follow-up of 5 years there were no LRs with minor post-operative complications.

Conclusions

This preliminary case series indicates that the presented technique can be a safe procedure in breast cancer surgery, but requires greater number of cases and a longer follow-up to confirm the oncological safety.