Long-term survival effect of the interval between mastectomy and radiotherapy in locally advanced breast cancer

Timing of postmastectomy radiotherapy following adjuvant chemotherapy for high-risk breast cancer: A post hoc analysis of a randomised controlled clinical trial

PURPOSE

To investigate the appropriate timing of radiotherapy (RT) after mastectomy and adjuvant chemotherapy for women with high-risk breast cancer.

PATIENTS AND METHODS

Post hoc analyses of 584 patients with stage II and III breast cancer from a randomised controlled clinical trial were performed. All patients underwent mastectomy followed by sequential chemotherapy and RT. The optimal cut-off values for the surgery-RT interval (SRI) and the chemotherapy-RT interval (CRI) for overall survival (OS) were determined using the hazard ratio for continuous predictors. The locoregional recurrence (LRR), distant metastasis (DM), disease-free survival (DFS), and OS rates were estimated using the Kaplan-Meier method. Multivariate analyses were performed using Cox proportional hazards regression.

RESULTS

Median follow-up time was 83.5 months. Median SRI and CRI were 168 and 27 days, respectively. An SRI of >210 days was independently associated with higher DM (HR 2.65, 95% CI: 1.49-4.71; HR 2.78, 95% CI 1.51-5.26), lower OS (HR 2.44, 95% CI: 1.28-4.54; HR 2.50, 95% CI: 1.41-4.35), and lower DFS (HR 2.57, 95% CI: 1.45-4.57; HR 2.70, 95% CI: 1.45-5.00) than SRI of <180 or 180-210 days. Furthermore, a CRI of more than 42 days was independently associated with higher DM (HR 1.89, 95% CI: 1.17-3.06; HR 1.96, 95% CI: 1.19-3.22), lower OS (HR 2.44, 95% CI: 1.41-4.35; HR 1.92, 95% CI: 1.10-3.33), and lower DFS (HR 1.84, 95% CI: 1.14-2.96; HR 1.82, 95% CI: 1.12-2.94) than a CRI of <28 or 28-42 days. However, SRI and CRI had no significant effect on LRR.

CONCLUSIONS

Based on the present findings, the timing of the initiation of RT both after mastectomy and after the completion of adjuvant chemotherapy is crucial for patients with high-risk breast cancer.

Influence of Adjuvant Radiotherapy Timing on Survival Outcomes in High-Risk Patients Receiving Neoadjuvant Treatments

Purpose

To determine the relationship between time to radiotherapy (TTR) and survival outcomes in breast cancer (BC) patients treated with neoadjuvant treatments (NATs).

Methods

Continuous non-metastatic BC patients receiving NAT and adjuvant radiotherapy (RT) from 2009 to 2016 were retrospectively reviewed. A multivariable Cox model with restricted cubic splines (RCSs) was used to determine the panoramic relationship between TTR and survival outcomes. Multivariable analysis was used to control for confounding factors between the groups of TTR.

Results

A total of 315 patients were included. The RCS modeling demonstrated a non-linear relationship between TTR and survival outcomes. The lowest risk for distant metastasis-free survival (DMFS) and recurrence-free survival (RFS) was observed at the TTR of 12 weeks, and the lowest risk of BC-specific survival (BCSS) at 10 weeks. TTR was accordingly transformed into categorical variables as ≤10, 11–20, and &gt;20 weeks. Multivariable analysis revealed that the TTR of ≤10 weeks was an independent prognostic factor for worse DMFS (HR = 2.294, 95% CI 1.079–4.881) and RFS (HR = 2.126, 95% CI 1.038–4.356) compared with the TTR of 10–20 weeks, while the is no difference in DMFS, RFS, and BCSS between TTR &gt;20 weeks and TTR of 10–20 weeks.

Conclusion

There exists a non-linear relationship between TTR after surgery and survival outcomes in patients treated with NAT. Early initiation of RT following surgery does not seem to be associated with a better therapeutic outcome. A relatively flexible recommendation of TTR could be adopted in clinical practice.

Impact of time to initiation of postoperative radiotherapy after neoadjuvant chemotherapy on the prognosis of breast cancer: a retrospective cohort study in China

The optimal time to the initiation of postoperative radiotherapy (TTR) in breast cancer patients after neoadjuvant chemotherapy (NAC) and surgery is unclear. We explored the association between TTR and outcomes among breast cancer females to determine the optimal timing for radiotherapy. We included 1022 women with breast cancer who underwent NAC and surgery between 1997 and 2019. Patients were categorized into three groups based on the TTR: <8 weeks, 8-16 weeks, and > 16 weeks. We used Cox proportional hazards models and analyzed the hazard ratios (HRs) for breast cancer-specific mortality (BCSM) and all-cause mortality (ACM). The median TTR for the cohort was 97 days. Compared to patients with TTRs of 8-16 weeks, those with TTRs <8 weeks or > 16 weeks had an increased risk of BCSM (HR, 2.59; 95% confidence interval [CI], 1.26-5.36 and HR, 2.01; 95% CI, 1.24-3.28, respectively) and ACM (HR, 2.32; 95% CI, 1.17-4.56 and HR, 1.92; 95% CI, 1.24-2.98, respectively) after adjusting for the confounders. Furthermore, at TTR of >16 weeks, each additional week of TTR was associated with a 3% increase in BCSM risk and 2% increase in ACM risk. Our findings suggest that patients who have undergone NAC and surgery show lower BCSM and ACM risks at TTR of 8-16 weeks compared with <8 weeks or > 16 weeks. This article is protected by copyright. All rights reserved.

Immediate breast reconstruction has no impact on the oncologic outcomes of patients treated with post-mastectomy radiation therapy: a comparative analysis based on propensity score matching

PURPOSE

To investigate the impact of immediate breast reconstruction (iBR) on patients treated with post-mastectomy radiation therapy (PMRT) using propensity score matching (PSM).

METHODS

After a retrospective review of patients treated with PMRT between 2008 and 2017, we included 153 patients who underwent iBR and 872 patients who did not undergo iBR. Among the 153 patients who underwent iBR, 34 received one-stage iBR with autologous tissue and 119 received two-stage iBR. Conventional fractionated PMRT with a total dose of 50-50.4 Gy in 25-28 fractions was performed in all patients. Propensity scores were calculated via logistic regression.

RESULTS

Patients who underwent iBR were younger, had early stage disease, and had more frequent hormone receptor-positive tumor than those who did not undergo iBR. After PSM, 127 patients from each group with well-balanced characteristics were selected. With a median follow-up of 67.5 months, iBR led to better 6-year disease-free survival rates compared to no iBR before PSM (84.8% vs. 71.4%, p = 0.003); after PSM, there was no significant difference (84.8% vs. 75.5%, p = 0.130). On multivariable analysis in the matched cohort, iBR was not associated with inferior disease-free survival (hazard ratio, 0.67; p = 0.175). In the sensitivity analysis, iBR was not associated with a lower disease-free survival across all prognostic groups. The 5-year cumulative incidence of iBR failure was 15.0%.

CONCLUSION

In patients with adverse pathologic factors planning to receive PMRT, iBR did not compromise oncologic outcomes. In addition, iBR can be considered in patients treated with PMRT with several clinicopathologic risk factors.

Delayed initiation of radiation therapy is associated with inferior outcomes for breast cancer patients with hormone receptor-negative tumors after breast-conserving surgery

Background

To investigate whether the interval between adjuvant chemotherapy (CT) completion and postoperative radiation therapy initiation (ICR) after breast-conserving surgery (BCS) affects ipsilateral breast tumor recurrence (IBTR) or survival.

Methods

All women who were diagnosed with invasive breast cancer and underwent BCS between 2005 and 2014 were included. In total, 1,472 patients underwent adjuvant CT followed by postoperative radiation therapy (RT) (CT+), whereas 402 patients received postoperative RT alone (CT-). Analyses were stratified by ICR and the interval between surgery and the initiation of postoperative RT (ISR) in these two cohorts. The cutoff points for treatment delay were 47 days in the CT+ cohort and 69 days in the CT- cohort. IBTR, local-regional failure (LRF), disease-free survival (DFS), and overall survival (OS) were assessed through Kaplan-Meier (K-M) analysis. Univariate and multivariate regression analyses were performed to determine the prognostic factors of survival outcomes.

Results

The median follow-up duration was 56 months. There was an association between a delay in ICR and an increase in IBTR in the CT+ group (P=0.014 for intervals ≤47 vs. >47 days). This association was confirmed by multivariate analyses [hazard ratio (HR) of 2.766; P=0.046] in the hormone receptor-negative subgroup. The 5-year cumulative incidence rates of IBTR were 1.3% and 3.3% (≤47 vs. >47 days, respectively) in the CT+ cohort. For patients in the CT- cohort, a longer delay of initiation of postoperative RT (≤69 vs. >69 days) significantly decreased DFS (HR of 6.430; P=0.002). The 5-year cumulative incidence rates of disease recurrence were 3.0% for RT starting ≤69 days after surgery and 12.6% for RT starting >69 days after surgery.

Conclusions

A high IBTR rate was related to an ICR beyond 47 days. Delay of RT after CT or surgery among patients who undergo BCS should be avoided, especially among patients in the hormone receptor-negative subgroup.

How Does the Interval Between Completion of Adjuvant Chemotherapy and Initiation of Radiotherapy Impact Clinical Outcomes in Operable Breast Cancer Patients?

Purpose

The aim of this study was to evaluate the impact of time to radiotherapy (TTR) after completion of chemotherapy (CT), and TTR after surgery, in breast cancer (BC) patients.

Patients and Methods

Continuous breast cancer patients treated with surgery and CT followed by radiotherapy (RT) from 2009 through 2015 were retrospectively reviewed. Patients were categorized into four groups with respect to TTR after CT, i.e. <4, 4–8, 8–12, and >12 weeks, and TTR after surgery, i.e. <147, 147–180, 180–202, and >202 days. The Cox proportional hazards model was used to identify the independent effect of TTRs.

Results

Overall, 989 patients were enrolled. Patients with a TTR of >12 weeks after CT showed significantly worse breast cancer-specific survival (BCSS) and overall survival (OS) compared with those who had a TTR of <4 weeks (BCSS: hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.1–0.76; OS: HR 0.33, 95% CI 0.13–0.88), 4–8 weeks (BCSS: HR 0.23, 95% CI 0.08–0.66; OS: HR 0.29, 95% CI 0.11–0.8), and 8–12 weeks (BCSS: HR 0.22, 95% CI 0.05–0.96; OS: HR 0.23, 95% CI 0.06–0.99). TTR after surgery showed no significant association with survival outcomes in the entire cohort, except in patients with hormone receptor (HR)-positive disease and those receiving mastectomy. In HR-positive tumors, a TTR after CT of >12 weeks remained an independent predictor for adverse BCSS and OS.

Conclusion

Initiation of RT beyond 12 weeks after CT might compromise survival outcomes. Efforts should be made to avoid delaying RT, especially after completion of CT and in patients with HR-positive tumors, positive lymph nodes, and those receiving mastectomy.

The association of delay in curative intent treatment with survival among breast cancer patients: findings from the Women's Health Initiative

PURPOSE

Delays in adjuvant breast cancer (BC) therapy have been shown to worsen outcomes. However, thus far studies have only evaluated delays to initial treatment, or a particular modality, such as chemotherapy, leaving uncertainty about the role of delay to subsequent therapy and the effects of cumulative delay, on outcomes. We investigated the associations of delays across treatment modalities with survival.

METHODS

We included 3368 women with incident stage I-III BC in the Women's Health Initiative (WHI) enrolled in fee-for-service Medicare who underwent definitive surgery. This prospective analysis characterized treatment delays by linking WHI study records to Medicare claims. Delays were defined as > 8 weeks to surgery, chemotherapy, and radiation from diagnosis or prior treatment. We used Cox proportional hazards models to estimate BC-specific mortality (BCSM) and all-cause mortality (ACM) in relation to treatment delays.

RESULTS

We found 21.8% of women experienced delay to at least one therapy modality. In adjusted analysis, delay to chemotherapy was associated with a higher risk of BCSM (HR = 1.71; 95% CI 1.07-2.75) and ACM (HR = 1.39; 95% CI 1.02-1.90); delay in radiation increased BCSM risk (HR = 1.49; 95% CI 1.00-2.21) but not ACM risk (HR = 1.19; 95% CI 0.99-1.42). Delays across multiple treatment modalities increased BCSM risk threefold (95% CI 1.51-6.12) and ACM risk 2.3-fold (95% CI 1.50-3.50).

CONCLUSIONS

A delay to a single treatment modality and delay to a greater extent an accumulation of delays were associated with higher BCSM and ACM after BC. Timely care throughout the continuum of breast cancer treatment is important for optimal outcomes.

The impact of the interval between the induction of chemotherapy and radiotherapy on the survival of patients with nasopharyngeal carcinoma

Background

There have been no reliable scientific studies examining whether the interval between induction chemotherapy (IC) and initiating radiotherapy is associated with poor outcomes of nasopharyngeal carcinoma (NPC).

Patients and methods

In this retrospective study, we included a total of 239 local advanced NPC patients who underwent concurrent chemoradiotherapy and IC. Based on the interval between IC and intensity-modulated radiation therapy (IMRT), the patients were classified into three groups as follows: Group A (≤7 vs >7 days), Group B (≤14 vs >14 days), and Group C (≤ 21 vs >21 days). Univariate and multivariate regression analyses were performed to determine the prognostic factors of survival outcomes. The differences between the two groups were compared by the log-rank test.

Results

The median IC-IMRT interval was 9 days (range, 1–76 days). The median follow-up time was 40 months (range, 4–58 months). The IC-IMRT interval including Group A, Group B, and Group C was not significantly associated with overall survival (OS), distant metastasis-free survival (DMFS), locoregional relapse-free survival (LRFS), or disease-free survival (DFS). Multivariate analysis showed that the tumor stage was the independent significant predictor for OS, DMFS, LRFS, and DFS. But it appears that there was a trend toward improvement in the outcome of ≤7 days group in OS from the Kaplan–Meier curves.

Conclusion

It is also feasible to postpone radiotherapy for 1–3 weeks if patients were unable to receive treatment immediately due to chemotherapy complications such as bone marrow suppression. However, we suggest that patients should start IMRT as soon as possible after IC.

The clinical significance of CHEK1 in breast cancer: a high-throughput data analysis and immunohistochemical study

Breast cancer (BC) is a kind of malignant cancer that seriously threatens women's health. Research scientists have found that BC occurs as the result of multiple effects of the external environment and internal genetic changes. Cell cycle checkpoint kinase 1 (CHEK1) is a crucial speed limit point in the cell cycle. Alterations of CHEK1 have been found in various tumors but are rarely reported or verified in BC. By mining database information, a large amount of mRNA and protein data was collected and meta-analyzed. Also, in-house immunohistochemistry was carried out to validate the results of the CHEK1 expression levels. Relative clinical features of BC patients were calculated with the CHEK1 expression levels to determine their diagnostic value. The mRNA levels of CHEK1 were higher in 1,089 cases of BC tissues than in 291 cases of non-BC tissues. We observed that the mRNA levels of CHEK1 are related to the clinical stages of BC patients (P = 0.008) and are also significant for overall survival (HR = 1.6, P = 0.0081). Using the immunohistochemistry method, we calculated and confirmed, using Fisher's exact test (P < 0.001), that a high-level CHEK1 protein is exhibited in BC tissues. Overexpressed CHEK1 mRNA promotes the occurrence of BC. Also, up-regulated CHEK1 could serve as an independent risk biomarker in BC patients' prognoses.