Chemotherapy and Radiation Therapy for Breast Cancer: What Is the Optimal Sequence?

Association between waiting time for radiotherapy after surgery for early-stage breast cancer and survival outcomes in Ontario: a population-based outcomes study

Background

After surgery for early-stage breast cancer (bca), adjuvant radiotherapy (rt) decreases the risk of locoregional recurrence and death from bca. It is unclear whether delays to the initiation of adjuvant rt are associated with inferior survival outcomes.

Methods

This population-based retrospective cohort study included a random sample of 25% of all women with stage i or ii bca treated with adjuvant rt in Ontario between 1 September 2001 and 31 August 2002, when, because of capacity issues, wait times for radiation were abnormally long. Pathology reports were manually abstracted and deterministically linked to population-level administrative databases to obtain information about recurrence and survival outcomes. Cox proportional hazards modelling was used to evaluate the association between waiting time and survival outcomes. A composite survival outcome was used to ensure that all possible measurable harms of delay would be captured. The composite outcome, event-free survival, included locoregional recurrence, development of metastatic disease, and bca-specific mortality.

Results

We identified 1028 women with stage i or ii bca who were treated with breast-conserving surgery and adjuvant rt. For the 599 women who were treated with adjuvant radiation without intervening chemotherapy, a waiting time of 12 weeks or more from surgery to the start of radiation appeared to be associated with worse event-free survival after a median follow-up of 7.2 years (hazard ratio for the composite outcome: 1.44; 95% confidence interval: 0.98 to 2.11; p = 0.07). For the 429 women who received intervening adjuvant chemotherapy, a waiting time of 6 weeks or more from completion of chemotherapy to start of radiation was associated with worse event-free survival after a median follow-up of 7.4 years (hazard ratio: 1.50; 95% confidence interval: 1.00 to 2.22; p = 0.047).

Conclusions

Delay to the initiation of adjuvant rt after breast-conserving surgery is associated with inferior bca survival outcomes. The good prognosis for patients with early-stage bca limits the statistical power to detect an effect of delay to rt. Given that there is no plausible advantage to delay, we agree with Mackillop that time to initiation of rt should be kept "as short as reasonably achievable."

Should all breast cancer patients with four or more positive lymph nodes who underwent modified radical mastectomy be treated with postoperative radiotherapy? A population-based study

Postmastectomy radiotherapy (PMRT) has become a standard adjuvant postoperative therapy for breast cancer patients with four or more positive lymph nodes. However, some studies have demonstrated that some subgroups of the breast cancer patients with four or more positive lymph nodes did not benefit substantially from PMRT. Therefore, it is of great necessity to identify whether all breast cancer patients with four or more positive lymph nodes who underwent modified radical mastectomy be treated with PMRT. In our study, we first established a prognostic model using the Surveillance Epidemiology and End Results (SEER) database between 1998 and 2001. Univariate and multivariate Cox models were used to assess the prognostic factors, and five risk factors individually associated with prognosis including AJCC stage, AJCC T, Grade, ER status, PR status. Prognostic index of PMRT were defined as the number of risk factor (NRF). The NRF scores correlated well with overall survival of PMRT even if the patients were in the sub-poor prognosis group. Then the prognostic model was validated using the SEER database between 2006 and 2009, and the same results were obtained. In conclusion, different from others studies, our study demonstrated that all patients with four or more positive lymph nodes after modified radical mastectomy need to be treated with PMRT ever if the patients belonged to AJCC T4 in a poor prognosis group.

Timing of Radiation Therapy and Chemotherapy After Breast-Conserving Surgery for Node-Positive Breast Cancer: Long-Term Results From International Breast Cancer Study Group Trials VI and VII

PURPOSE

To update the previous report from 2 randomized clinical trials, now with a median follow-up of 16 years, to analyze the effect of radiation therapy timing on local failure and disease-free survival.

PATIENTS AND METHODS

From July 1986 to April 1993, International Breast Cancer Study Group trial VI randomly assigned 1475 pre-/perimenopausal women with node-positive breast cancer to receive 3 or 6 cycles of initial chemotherapy (CT). International Breast Cancer Study Group trial VII randomly assigned 1212 postmenopausal women with node-positive breast cancer to receive tamoxifen for 5 years, or tamoxifen for 5 years with 3 early cycles of initial CT. For patients who received breast-conserving surgery (BCS), radiation therapy (RT) was delayed until initial CT was completed; 4 or 7 months after BCS for trial VI and 2 or 4 months for trial VII. We compared RT timing groups among 433 patients on trial VI and 285 patients on trial VII who received BCS plus RT. Endpoints were local failure, regional/distant failure, and disease-free survival (DFS).

RESULTS

Among pre-/perimenopausal patients there were no significant differences in disease-related outcomes. The 15-year DFS was 48.2% in the group allocated 3 months initial CT and 44.9% in the group allocated 6 months initial CT (hazard ratio [HR] 1.12; 95% confidence interval [CI] 0.87-1.45). Among postmenopausal patients, the 15-year DFS was 46.1% in the no-initial-CT group and 43.3% in the group allocated 3 months initial CT (HR 1.11; 95% CI 0.82-1.51). Corresponding HRs for local failures were 0.94 (95% CI 0.61-1.46) in trial VI and 1.51 (95% CI 0.77-2.97) in trial VII. For regional/distant failures, the respective HRs were 1.15 (95% CI 0.80-1.63) and 1.08 (95% CI 0.69-1.68).

CONCLUSIONS

This study confirms that, after more than 15 years of follow-up, it is reasonable to delay radiation therapy until after the completion of standard CT.

Better survival in PMRT of female breast cancer patients with >5 negative lymph nodes: A population-based study

Many studies have confirmed the role of postmastectomy radiotherapy (PMRT) for breast cancer patients with at least 4 lymph nodes invasion in the postoperative therapy. Recently, the number of negative lymph nodes (NLNs) has been increasingly paid attention to and recognized as a prognostic indicator in different kinds of caners. Therefore, it is very necessary to study the association between the number of NLNs and the prognosis of PMRT in breast cancer patients. In our study, we used Surveillance, Epidemiology, and End Results (SEER) population-based data and identified 16,686 breast cancer patients to explore their correlation. The ROC curve and the log-rank χ test were applied to determine the appropriate cutoff point of the number of NLNs and 5 was selected as the cutoff point. Furthermore, the cutoff point 5 was validated as an independent prognostic factor affecting cancer-specific survival (CSS) and overall survival (OS) in breast cancer patients, as confirmed by both univariate and multivariate analysis (P < 0.001). In addition, subgroup analysis showed that the number of NLNs >5 can be a prognostic indicator in patients with PMRT according to different clinical variables (all, P < 0.001). Importantly, our results showed that PMRT obviously improved CSS and OS in patients regardless of the number of NLNs (P < 0.001). In conclusion, our study showed the number of NLNs is an independent prognostic factor for breast cancer patients with PMRT, and those who have higher number of NLNs have an increased CSS and OS.

The optimal sequence of radiotherapy and chemotherapy in adjuvant treatment of breast cancer

BACKGROUND

The optimal time sequences for chemotherapy and radiation therapy after breast surgery for patients with breast cancer remains unknown. Most of published studies were done for early breast cancer patients. However, in Egypt advanced stages were the common presentation. This retrospective analysis aimed to assess the optimum sequence for our population.

METHODS

267 eligible patients planned to receive adjuvant chemotherapy [FAC] and radiotherapy. Majority of patients (87.6%) underwent modified radical mastectomy while, 12.4% had conservative surgery.We divided the patients into 3 groups according to the sequence of chemotherapy and radiotherapy. Sixty-seven patients (25.1%) received postoperative radiotherapy before chemotherapy [group A]. One hundred and fifty patients (56.2%) were treated in a sandwich scheme (group B), which means that 3 chemotherapy cycles were given prior to radiotherapy followed by 3 further chemotherapy cycles. A group of 50 patients (18.7%) was treated sequentially (group C), which means that radiotherapy was supplied after finishing the last chemotherapy cycle. Patients' characteristics are balanced between different groups.

RESULTS

Disease free survival was estimated at 2.5 years, and it was 83.5%, 82.3% and 80% for patient receiving radiation before chemotherapy [group A], sandwich [group B] and after finishing chemotherapy [group C] respectively (p > 0.5). Grade 2 pneumonitis, which necessitates treatment with steroid, was detected in 3.4% of our patients, while grade 2 radiation dermatitis was 17.6%. There are no clinical significant differences between different groups regarded pulmonary or skin toxicities.

CONCLUSION

Regarding disease free survival and treatment toxicities, in our study, we did not find any significant difference between the different radiotherapy and chemotherapy sequences.

Radiotherapy timing in 4,820 patients with breast cancer: university of florence experience

PURPOSE

To analyze the relationship between a delay in radiotherapy (RT) after breast-conserving surgery and ipsilateral breast recurrence (BR).

METHODS AND MATERIALS

We included in our analysis 4,820 breast cancer patients who had undergone postoperative RT at the University of Florence. The patients were categorized into four groups according to the interval between surgery and RT (T1, <60 days; T2, 61-120 days; T3, 121-180 days; and T4, >180 days).

RESULTS

On multivariate analysis, the timing of RT did not reach statistical significance in patients who received only postoperative RT (n = 1,935) or RT and hormonal therapy (HT) (n = 1,684) or RT, chemotherapy (CHT), and HT (n = 529). In the postoperative RT-only group, age at presentation, surgical margin status, and a boost to the tumor bed were independent prognostic factors for BR. In the RT plus HT group, age at presentation and boost emerged as independent prognostic factors for BR (p = 0.006 and p = 0.049, respectively). Finally, in the RT, CHT, and HT group, only multifocality was an independent BR predictor (p = 0.01). Only in the group of patients treated with RT and CHT (n = 672) did multivariate analysis with stepwise selection show RT timing as an independent prognostic factor (hazard ratio, 1.59; 95% confidence interval, 1.01-2.52; p = 0.045). Analyzing this group of patients, we found that most patients included had worse prognostic factors and had received CHT consisting of cyclophosphamide, methotrexate, and 5-fluorouracil before undergoing RT.

CONCLUSION

The results of our study have shown that the timing of RT itself does not affect local recurrence, which is mainly related to prognostic factors. Thus, the "waiting list" should be thought of as a "programming list," with patients scheduled for RT according to their prognostic factors.

Sequencing chemotherapy and radiotherapy in locoregional advanced breast cancer patients after mastectomy - a retrospective analysis

BACKGROUND

Combined chemo- and radiotherapy are established in breast cancer treatment. Chemotherapy is recommended prior to radiotherapy but decisive data on the optimal sequence are rare. This retrospective analysis aimed to assess the role of sequencing in patients after mastectomy because of advanced locoregional disease.

METHODS

A total of 212 eligible patients had a stage III breast cancer and had adjuvant chemotherapy and radiotherapy after mastectomy and axillary dissection between 1996 and 2004. According to concerted multi-modality treatment strategies 86 patients were treated sequentially (chemotherapy followed by radiotherapy) (SEQgroup), 70 patients had a sandwich treatment (SW-group) and 56 patients had simultaneous chemoradiation (SIM-group) during that time period. Radiotherapy comprised the thoracic wall and/or regional lymph nodes. The total dose was 45-50.4 Gray. As simultaneous chemoradiation CMF was given in 95.4% of patients while in sequential or sandwich application in 86% and 87.1% of patients an anthracycline-based chemotherapy was given.

RESULTS

Concerning the parameters nodal involvement, lymphovascular invasion, extracapsular spread and extension of the irradiated region the three treatment groups were significantly imbalanced. The other parameters, e.g. age, pathological tumor stage, grading and receptor status were homogeneously distributed. Looking on those two groups with an equally effective chemotherapy (EC, FEC), the SEQ- and SW-group, the sole imbalance was the extension of LVI (57.1 vs. 25.6%, p < 0.0001).5-year overall- and disease free survival were 53.2%/56%, 38.1%/32% and 64.2%/50%, for the sequential, sandwich and simultaneous regime, respectively, which differed significantly in the univariate analysis (p = 0.04 and p = 0.03, log-rank test). Also the 5-year locoregional or distant recurrence free survival showed no significant differences according to the sequence of chemo- and radiotherapy. In the multivariate analyses the sequence had no independent impact on overall survival (p = 0.2) or disease free survival (p = 0.4). The toxicity, whether acute nor late, showed no significant differences in the three groups. The grade III/IV acute side effects were 3.6%, 0% and 3.5% for the SIM-, SW- and SEQ-group. By tendency the SIM regime had more late side effects.

CONCLUSION

No clear advantage can be stated for any radio- and chemotherapy sequence in breast cancer therapy so far. This could be confirmed in our retrospective analysis in high-risk patients after mastectomy. The sequential approach is recommended according to current guidelines considering a lower toxicity.

Evidence based radiation oncology: Breast cancer

PURPOSE

Radiotherapy is, similar to surgery, a local treatment. In the case of breast cancer, it is generally given after conservative or after more extensive, tumour and patient adapted, surgery. The target volumes can be the breast and/or the thoracic wall and/or the regional lymph node areas. The integration and the extent of radiotherapy as part of the comprehensive treatment of the breast cancer patient, including the amount of surgery and the sequencing with the systemic treatments, has to be well discussed with all medical specialists involved in treating breast cancer on a multidisciplinary basis. Guidelines for the appropriate prescription and execution of radiotherapy are of utmost importance. However, individualisation based on the individual patients' and tumours' characteristics should always be envisaged.

MATERIALS AND METHODS

Based on a review of the literature the level of evidence that is available for the indications for radiotherapy is summarised, as well as the main clinical questions that are unanswered today. An overview of the recent and ongoing clinical trails in breast cancer will highlight some of the current ongoing debates.

CONCLUSIONS

In the case of breast cancer, radiotherapy, given after as well conservative as extensive risk-adapted surgery, significantly reduces the risk of local and regional recurrences. Especially for patients with an intermediate to high absolute risk for local recurrences, a positive influence on overall survival has been shown, notably when appropriate radiotherapy techniques are used. Most important is that the best results that we can offer to our breast cancer patients for all clinical endpoints (local and regional control; quality of life; cosmetic results; survival) can be obtained by a multidisciplinary and patient-oriented approach, involving all those involved in the treatment of breast cancer patients.

Concurrent chemo-radiation in the conservative management of breast cancer

PURPOSE

Sequencing of chemotherapy (CTX) with radiation (RT) in the conservative management of breast cancer (CS+RT) remains controversial. We report here the results of a retrospective analysis of all patients treated with CTX and RT, with specific focus on outcome as a function of sequencing of CTX with RT.

METHODS AND MATERIALS

A total of 535 patients treated with CS+RT received CTX as a component of therapy. RT was administered concurrently with CTX in 109 (CONCTX). CTX was administered before RT in 276 patients, after RT in 106 patients, and in "sandwich" fashion in 44 patients. These three groups comprise the sequential chemotherapy group (SEQCTX).

RESULTS

With follow-up of 8.8 years, the 10-year survival rate was 78% and the distant metastasis-free rate was 75%. Despite more adverse factors for local control, patients in the CONCTX group had superior local control rate of 92% at 10 years compared with 83% in the SEQCTX group (p < 0.001). In multivariate analysis, CONCTX was associated with a significant improvement in local control (HR = 0.338, 95% CI = 0.141-0.809, p = 0.015). Cosmetic results, toxicities, and long-term complications were acceptable using this CONCTX regimen.

CONCLUSIONS

CONCTX was associated with a reduction in local relapse rates, acceptable cosmesis, and toxicities. These data support the use of concurrent RT and CTX in selected patients at high risk for local failure. Future prospective trials should explore the use of concurrent CTX and RT in high-risk patients using currently employed agents.

Placing the boost in breast-conservation radiotherapy: A review of the role, indications and techniques for breast-boost radiotherapy

Randomised trials have established that the addition of a boost dose of radiotherapy to the lumpectomy site after whole-breast adjuvant radiotherapy further improves local control achieved by whole-breast radiotherapy alone. The absolute size of this benefit varies according to the baseline risk of local recurrence. Age is the strongest predictor of benefit. Below the age of 40 years, the absolute benefit of a boost seems to be substantial, and there are no clearly identified groups unlikely to benefit. Above the age of 50 years, the benefit is small, and several additional risk factors for local failure would need to be present to merit boost treatment. These may include tumour size, high grade, high mitotic rate, lymphovascular invasion, extensive and high grade associated with intraduct carcinoma, receptor-positive tumours when avoidance of anti-oestrogen therapy is desired or receptor-negative tumours. Other independent reasonable indications for the use of a boost would be positive margins where further surgery is not indicated. If a boost is indicated, a variety of techniques may be used and toxicity and cosmetic results remain highly acceptable. Overall, there seems to be no substantial differences in boost technique results; however, interstitial techniques may have advantages for deeper targets compared with electrons. Irrespective of technique, accurate localisation will maximise the benefit of a boost. Surgical clips are strongly recommended to facilitate localisation.

Study of failure pattern among high-risk breast cancer patients with or without postmastectomy radiotherapy in addition to adjuvant systemic therapy: long-term results from the Danish Breast Cancer Cooperative Group DBCG 82 b and c randomized studies

PURPOSE

Postmastectomy radiotherapy (RT) in high-risk breast cancer patients can reduce locoregional recurrences (LRRs) and improve disease-free and overall survival. The aim of this analysis was to examine the overall disease recurrence pattern among patients randomly assigned to receive treatment with or without RT.

PATIENTS AND METHODS

A long-term follow-up was performed among the 3,083 patients from the Danish Breast Cancer Cooperative Group 82 b and c trials, except in those already recorded with distant metastases (DM) or contralateral breast cancer (CBC). The end points were LRR, DM, and CBC, and the follow-up continued until DM, CBC, emigration, or death. Information was selected from medical records, general practitioners, and the National Causes of Death Registry. The median potential follow-up time was 18 years.

RESULTS

The 18-year probability of any first breast cancer event was 73% and 59% (P < .001) after no RT and RT, respectively (relative risk [RR], 0.68; 95% CI, 0.63 to 0.75). The 18-year probability of LRR (with or without DM) was 49% and 14% (P < .001) after no RT and RT, respectively (RR, 0.23; 95% CI, 0.19 to 0.27). The 18-year probability of DM subsequent to LRR was 35% and 6% (P < .001) after no RT and RT, respectively (RR, 0.15; 95% CI, 0.11 to 0.20), whereas the probability of any DM was 64% and 53% (P < .001) after no RT versus RT, respectively (RR, 0.78; 95% CI, 0.71 to 0.86).

CONCLUSION

Postmastectomy RT changes the disease recurrence pattern in high-risk breast cancer patients; fewer patients have LRR as first site of recurrence, and overall fewer patients have DM.