Radiotherapy and chemotherapy in high-risk breast cancer

Breast Cancer Presenting With Intravascular Tumor Emboli in Axillary Soft Tissue: Recurrence Risk and Radiation Therapy Outcomes

Purpose

Intravascular tumor emboli in axillary soft tissue (ITE) is a rare pathologic finding in breast cancer and is associated with higher axillary nodal disease burden. The independent prognostic and predictive value of this entity is unknown, as is the role of radiation therapy for ITE.

Methods and Materials

We analyzed a prospectively maintained database of breast cancer patients treated from 1992 to 2020. Patients with ITE were matched to those without (1:2) based on propensity scores to control for potential confounding factors. Locoregional (LRR) and distant recurrence (DR) were evaluated using competing risks methods accounting for death as a competing event. Overall survival (OS) and disease-free survival (DFS) were evaluated by Cox regression models. Among patients with ITE, we also evaluated whether RT improved outcomes.

Results

Among 2377 total patients, 129 had ITE, of whom 126 were propensity score matched to 252 without ITE. Median follow-up from time of surgery was 5.5 years (IQR 2.3, 9.7). There were no statistically significant differences in the 5-year incidence of LRR between groups (5.4% [95% CI, 1.6%-13%] with ITE vs 10% [95% CI, 6.7%-15%] without, P = .53) or DR (24% [95% CI, 15% 35%] with ITE vs 21% [95% CI, 16%-27%] without, P = .51). Five-year OS and DFS did not differ between groups (P > .9 for both comparisons, patients with ITE vs without ITE). In analyzing the effect of RT among patients with ITE, receipt of RT was associated with significantly improved DFS (HR, 0.34, 95% CI, 0.12-0.93, P = .04).

Conclusions

Patients with ITE do not exhibit significantly worse LRR, DR, DFS, or OS compared with a propensity-score-matched cohort without ITE. However, among patients with ITE, those who received RT demonstrated significantly improved DFS. Larger studies with longer follow-up are needed to evaluate the prognostic and predictive implications of ITE.

Post-mastectomy radiation therapy: Translating local benefits into improved survival

Several randomized trials and the most recent meta-analysis from the Oxford Overview have confirmed the efficacy of post-mastectomy radiation therapy (PMRT) in improving local control and long-term survival. The survival advantage of PMRT has been established in patients with a 10% risk of local regional recurrence. Patients with four or more positive lymph nodes fall in this category, even with effective systemic therapy. However, it remains difficult to identify the subset of patients with 1-3 positive lymph nodes at highest risk of local recurrence, who would most likely demonstrate a survival benefit with PMRT. When PMRT is used, careful treatment planning, particularly with regard to cardiac dose, is critical to minimizing serious late effects of treatment. Further developments in pathologic stratification of these patients, guided by expression profiles or novel biologic markers, are required to enable individualized assessment of long-term therapeutic risks and benefits.

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.

Site of primary tumor has a prognostic role in operable breast cancer: the international breast cancer study group experience

PURPOSE

Cancer presenting at the medial site of the breast may have a worse prognosis compared with tumors located in external quadrants. For medial tumors, axillary lymph node staging may not accurately reflect the metastatic potential of the disease.

PATIENTS AND METHODS

Eight-thousand four-hundred twenty-two patients randomly assigned to International Breast Cancer Study Group clinical trials between 1978 and 1999 were classified as medial site (1,622; 19%) or lateral, central, and other sites (6,800; 81%). Median follow-up was 11 years.

RESULTS

A statistically significant difference was observed for patients with medial tumors versus those with nonmedial tumors in disease-free survival (DFS; 10-year DFS, 46% v 48%; HR, 1.10; 95% CI, 1.02 to 1.18; P = .01) and overall survival (10-year OS 59% v 61%; HR, 1.09; 1.01 to 1.19; P = .04). This difference increased after adjustment for other prognostic factors (HR, 1.22; 95% CI, 1.13 to 1.32 for DFS; and HR, 1.24; 95% CI, 1.14 to 1.35 for OS; both P = .0001). The risk of relapse for patients with medial presentation was largest for the node-negative cohort and for patients with tumors larger than 2 cm. In the subgroup of 2,931 patients with negative axillary lymph nodes, 10-year DFS was 61% v 67%, and OS was 73% v 80% for medial versus nonmedial sites, respectively (HR 1.33; 95% CI, 1.15 to 1.54; P = .0001 for DFS; and HR 1.40; 95% CI, 1.17 to 1.67; P = .0003 for OS).

CONCLUSION

Tumor site has a significant prognostic utility, especially for axillary lymph node-negative disease, that should be considered in therapeutic algorithms. New staging procedures such as biopsy of the sentinel internal mammary nodes or novel imaging methods should be further studied in patients with medial tumors.

Locoregional radiation therapy in patients with high-risk breast cancer receiving adjuvant chemotherapy: 20-year results of the British Columbia randomized trial

BACKGROUND

The British Columbia randomized radiation trial was designed to determine the survival impact of locoregional radiation therapy in premenopausal patients with lymph node-positive breast cancer treated by modified radical mastectomy and adjuvant chemotherapy. Three hundred eighteen patients were assigned to receive no further therapy or radiation therapy (37.5 Gy in 16 fractions). Previous analysis at the 15-year follow-up showed that radiation therapy was associated with a statistically significant improvement in breast cancer survival but that improvement in overall survival was of only borderline statistical significance. We report the analysis of data from the 20-year follow-up.

METHODS

Survival was analyzed by the Kaplan-Meier method. Relative risk estimates were calculated by the Wald test from the proportional hazards regression model. All statistical tests were two-sided.

RESULTS

At the 20 year follow up (median follow up for live patients: 249 months) chemotherapy and radiation therapy, compared with chemotherapy alone, were associated with a statistically significant improvement in all end points analyzed, including survival free of isolated locoregional recurrences (74% versus 90%, respectively; relative risk [RR] = 0.36, 95% confidence interval [CI] = 0.18 to 0.71; P = .002), systemic relapse-free survival (31% versus 48%; RR = 0.66, 95% CI = 0.49 to 0.88; P = .004), breast cancer-free survival (48% versus 30%; RR = 0.63, 95% CI = 0.47 to 0.83; P = .001), event-free survival (35% versus 25%; RR = 0.70, 95% CI = 0.54 to 0.92; P = .009), breast cancer-specific survival (53% versus 38%; RR = 0.67, 95% CI = 0.49 to 0.90; P = .008), and, in contrast to the 15-year follow-up results, overall survival (47% versus 37%; RR = 0.73, 95% CI = 0.55 to 0.98; P = .03). Long-term toxicities, including cardiac deaths (1.8% versus 0.6%), were minimal for both arms.

CONCLUSION

For patients with high-risk breast cancer treated with modified radical mastectomy, treatment with radiation therapy (schedule of 16 fractions) and adjuvant chemotherapy leads to better survival outcomes than chemotherapy alone, and it is well tolerated, with acceptable long-term toxicity.

Postmastectomy radiotherapy and locoregional recurrence rate in high-risk breast cancer patients

BACKGROUND: Postmastectomy radiotherapy has been the topic for many debates over several years about its role on locoregional control as well as overall survival in premenopausal and postmenopausal breast cancer patients. METHODS: From 1994 till 1999, 233 patients underwent modified radical mastectomy for breast cancer. Among them there was 92 premenopausal patients (median age was 44 years) and 141 postmenopausal patients (median age was 60 years). Traditional prognostic factors were used to assess risk of locoregional recurrence: 84 patients were node-negative, 71 patients had 1 to 3 lymph nodes positive, and 71 patients had 4 and more positive lymph nodes; 103 patients had tumor less than 3 cm diameter and 130 patients had tumors grater than 3 cm. According to this, postmastectomy radio- therapy was applied in 125 patients of whom 117 patients (94%) had also adjuvant systemic therapy (chemotherapy and/or hormonal therapy). RESULTS: The locoregional recurrence was observed in 42 patients while 191 patients were free of (median follow-up time was 49 months). Locoregional recurrence developed in 10 patients who had postmastectomy radiotherapy and in 32 patients who did not had postmastectomy radiotherapy (p=0.0001). In the group of patients with locoregional recurrence event 5-year overall survival was 28% while 70% in the group of patients free of (p=0.00001). There was statistically significant advantage for post- mastectomy radiotherapy in the group of patients with 1 to 3 positive lymph nodes as well as for 4 and more positive lymph nodes group (p=0.0008). In addition there was statistically significant difference among postmastectomy radiotherapy group and no postmastectomy radiotherapy group for disease free survival (74% vs. 50%, 5-year disease free survival, p=0.0001) and overall survival (71% vs. 53%, 5-year overall survival, p=0.0422). CONCLUSION: Postmastectomy radiotherapy reduces locoregional recurrence rate and improves overall survival in premenopausal and postmenopausal breast cancer patients with tumors grater than 3cm diameter and positive axillary lymph nodes.

The process of metastasisation for breast cancer

To investigate the process of metastasis, primary clinical data and disease events such as metastases, local recurrence and survival (median follow-up 9.4 years) from the Munich Cancer Registry from 1978 to 1996 were analysed. Since metastases, even from small tumours, may be initiated before the diagnosis of the primary tumour, the growth of the primary tumour and metastasisation may be two autonomous processes. In our data, survival following metastases was almost unrelated to primary tumour size. However, the number of M1 cases and the time to metastasisation depended on the tumour diameter at diagnosis. The time from initiation of metastases to its diagnosis was estimated as 5.8 years. The growth of metastases was almost homogeneous. However, the growth time following metastasisation-depending on the metastases-free time, receptor status and histological grade-only varied by approximately a factor of 2. Local recurrence, above all, was an indicator of metastases. Furthermore, local recurrence may also have the potential to metastasise. Excess mortality due to local recurrence was estimated up to 9.3 years after diagnosis. Our hypothesised metastases model illustrates the importance of early detection, the concept of breast-conserving therapy and additional metastases from local recurrence. It highlights the benefits of optimal local therapy of the primary tumour and the limitations of systemic therapy. It also questions the use of axilla dissection and lymph node irradiation. Its generalisation to solid tumours may help to clarify many of the current controversial debates.

Changes in the treatment outcome of node-positive breast cancer stratified by menopausal status: comparison of patients treated in 1965-75 versus those treated in 1976-86

OBJECTIVE

The objective of this study was to examine whether and to what extent the outcome of treatment for lymph-node positive breast cancer patients improved between the periods 1965-75 and 1976-86.

METHODS

The subjects were 1595 patients with breast cancer positive for lymph node metastasis who were treated at the National Cancer Center Hospital between 1965 and 1986. In order to analyze background factors and treatment outcome, we classified the patients into four groups stratified by the time of initial surgery (1965-75/1976-86) and menopausal status (premenopause/postmenopause).

RESULTS

With respect to the clinicopathological background factors, significant changes between the periods 1965-75 and 1976-86 were more frequent use of modified radical mastectomy and postoperative adjuvant chemoendocrine therapy and less frequent use of postoperative radiotherapy in both pre- and postmenopausal patients. The 10-year disease-free and overall survival rates improved by approximately 15-20% between 1965-75 and 1976-86 in this group of patients, regardless of menopausal status.

CONCLUSION

The patients with node-positive disease treated at our hospital showed an increase in both disease-free and overall survival from 1965 to 1986.