Radiotherapy as part of a multidisciplinary treatment strategy in early breast cancer

Intensity modulated radiation therapy for breast cancer: current perspectives

Background

Owing to highly conformed dose distribution, intensity modulated radiation therapy (IMRT) has the potential to improve treatment results of radiotherapy (RT). Postoperative RT is a standard adjuvant treatment in conservative treatment of breast cancer (BC). The aim of this review is to analyze available evidence from randomized controlled trials (RCTs) on IMRT in BC, particularly in terms of reduction of side effects.

Methods

A literature search of the bibliographic database PubMed, from January 1990 through November 2016, was performed. Only RCTs published in English were included.

Results

Ten articles reporting data from 5 RCTs fulfilled the selection criteria and were included in our review. Three out of 5 studies enrolled only selected patients in terms of increased risk of toxicity. Three studies compared IMRT with standard tangential RT. One study compared the results of IMRT in the supine versus the prone position, and one study compared standard treatment with accelerated partial breast IMRT. Three studies reported reduced acute and/or late toxicity using IMRT compared with standard RT. No study reported improved quality of life.

Conclusion

IMRT seems able to reduce toxicity in selected patients treated with postoperative RT for BC. Further analyses are needed to better define patients who are candidates for this treatment modality.

MicroRNA-302 replacement therapy sensitizes breast cancer cells to ionizing radiation

PURPOSE

Solid tumors can be resistant or develop resistance to radiotherapy. The purpose of this study is to explore whether microRNA-302 is involved in radioresistance and can be exploited as a sensitizer to enhance sensitivity of breast cancer cells to radiation therapy.

METHODS

MiR-302 expression levels in radioresistant cell lines were analyzed in comparison with their parent cell lines. Furthermore, we investigated whether enforced expression of miR-302 sensitized radioresistant breast cancer cells to ionizing radiation in vitro and in vivo.

RESULTS

MiR-302 was downregulated in irradiated breast cancer cells. Additionally, the expression levels of miR-302a were inversely correlated with those of AKT1 and RAD52, two critical regulators of radioresistance. More promisingly, miR-302a sensitized radioresistant breast cancer cells to radiation therapy in vitro and in vivo and reduced the expression of AKT1 and RAD52.

CONCLUSION

Our findings demonstrated that decreased expression of miR-302 confers radioresistance and restoration of miR-302 baseline expression sensitizes breast cancer cells to radiotherapy. These data suggest that miR-302 is a potential sensitizer to radiotherapy.

Postoperative radiotherapy in DBCG during 30 years. Techniques, indications and clinical radiobiological experience

During the time period 1977-2007 postoperative radiotherapy in DBCG has varied considerably with regard to techniques and indications together with changes in the extent of surgery and adjuvant systemic therapy. The radiation treatment has been developed on the basis of clinical, radiophysical and radiobiological principles, encompassing also practical problems such as available equipment in the different centres and at times lack of sufficient machine capacity. The paper focus especially on the comprehensive work done prior to the DBCG 82 b&c studies, in order to optimize radiotherapy in all aspects prior to the evaluation of the efficacy of this treatment modality. The results from these trials did succeed in clear evidence that radiotherapy has an important role in the multidisciplinary treatment of early breast cancer. In parallel to these studies a new and challenging use of radiotherapy after breast conserving surgery was evaluated in the DBCG TM 82 protocol. The experience obtained with different techniques in this study formed the basis for the current principles of radiotherapy after lumpectomy. Reduction of radiation related morbidity has been a major issue for the DBCG radiotherapy group, and in this aspect several studies, including quality control visits, have been carried out to make the relevant modifications and to evaluate deviations from the guidelines between the centres. The background for the changes in radiotherapy is described for each of the programme periods as well as future perspectives which will include further refinements of the target and adjustments of dose and fractionation in selected patients.

Cost-effectiveness of intensive adjuvant chemotherapy for high-risk breast cancer: is tailored and dose-escalated chemotherapy with growth factor support (GFS) more costly and less effective than marrow-supported high-dose chemotherapy - results from a randomized study

Based on randomized studies bone-marrow supported (BMS) high-dose chemotherapy (HDCT) is not superior to conventional CT as adjuvant treatment for high-risk breast cancer. To compare the cost-effectiveness of these treatments we examined the data of Finnish patients in the SBG9401 trial 1. Patients were randomized to receive either dose-escalated (de FEC) (group A, n =59) or FEC and HDCT+BMS (group B, n =70). They received adjuvant radiotherapy (RT) + tamoxifen. All direct health care costs of first line treatment at the oncology units were considered as well as productivity costs within the first 3 years of follow-up. Effectiveness was measured by the number of survival days during 5 years of follow-up. The mean direct health care costs were significantly higher in group B (25829 euro in group A vs. 36605 euro in group B, p <0.001), mainly due to a higher number of hospital days. Half of the costs in group A was due to the use of filgrastim (15335 euro in A and 2969 euro in B, p <0.001). The costs of RT were only 5% of total costs. There was no statistically significant difference between the groups in the number of survival days, but sensitivity analysis based on bootstrapping suggested that treatment A would be a less costly and more effective alternative in a great majority of cases.

Is the benefit of postmastectomy irradiation limited to patients with four or more positive nodes, as recommended in international consensus reports? A subgroup analysis of the DBCG 82 b&c randomized trials

BACKGROUND AND AIM

Numerous consensus reports recommend that postmastectomy radiotherapy (RT) in addition to systemic therapy is indicated in high-risk patients with 4+ positive nodes, but not in patients with 1-3 positive nodes. A subgroup analysis of the DBCG 82 b&c trials was performed to evaluate the loco-regional recurrence rate and survival in relation to number of positive nodes.

MATERIALS AND METHODS

In the DBCG 82 b&c trials 3083 pre- and postmenopausal high-risk women were randomized to postoperative RT in addition to adjuvant systemic therapy. Since many patients had relatively few lymph nodes removed (median 7), the present analysis was limited to 1152 node positive patients with 8 or more nodes removed.

RESULTS

The overall 15-year survival rate in the subgroup was 39% and 29% (p=0.015) after RT and no RT, respectively. RT reduced the 15-year loco-regional failure rate from 51% to 10% (p<0.001) in 4+ positive node patients and from 27% to 4% (p<0.001) in patients with 1-3 positive nodes. Similarly, the 15-year survival benefit after RT was significantly improved in both patients with 1-3 positive nodes (57% vs 48%, p=0.03) and in patients with 4+ positive nodes (21% vs 12%, p=0.03).

CONCLUSION

The survival benefit after postmastectomy RT was substantial and similar in patients with 1-3 and 4+ positive lymph nodes. Furthermore, it was not strictly associated with the risk of loco-regional recurrence, which was most pronounced in patients with 4+ positive nodes. The indication for RT seems therefore to be at least equally beneficial in patients with 1-3 positive nodes, and future consensus should be modified accordingly.

Variation in survival after diagnosis of breast cancer in Switzerland

BACKGROUND

Survival after diagnosis of cancer is a key criterion for cancer control. Major survival differences between time periods and countries have been reported by the EUROCARE studies. We investigated whether similar differences by period and region existed in Switzerland.

METHODS

Survival of 11,376 cases of primary invasive female breast cancer diagnosed between 1988 and 1997 and registered in seven Swiss cancer registries covering a population of 3.5 million was analysed.

RESULTS

Comparing the two periods 1988-1992 and 1993-1997, age-standardized 5 year relative survival improved globally from 77% to 81%. Furthermore, multivariate analysis adjusting for age, tumour size and nodal involvement identified regional survival differences. Survival was lowest in the rural parts of German-speaking eastern Switzerland and highest in urbanised regions of the Latin- and German-speaking northwestern parts of the country.

CONCLUSIONS

This study confirms that survival differences are present even in a small and affluent, but culturally diverse, country like Switzerland, raising the issue of heterogeneity in access to care and quality of treatment.

Assessment of the quality of breast cancer care: a single institutional study from Saudi Arabia

OBJECTIVE

To evaluate the quality of operable breast cancer care in a tertiary care institution.

DESIGN

A retrospective analysis of all breast cancer patients seen in our institution between 1995 and 2000. Data were abstracted from the charts of these patients. Indicators were based on an international consensus conference and other publications.

SETTING

A tertiary care health care institution.

MAIN MEASURES

We evaluated the charts and calculated the percentage for which the internationally accepted quality care indicators were followed during the continuum of care. We also reviewed the histopathological reports to evaluate conformation with the accepted indicators.

RESULTS

Charts of 75 patients (four exclusions, three metastatic, and one male), diagnosed to have breast cancer during the study period were reviewed. Only 28 (37%) patients had triple assessment before a definitive surgical procedure. Pre-operative staging including a CT and bone scan was performed in 58 (77.3%). Among the 50 patients who had definite surgical intervention, the majority had mastectomy (44/50, 88%) whereas axillary dissection was performed in 46 (46/50, 92%). Estrogen and progesterone receptor status was reported in only four (4/50, 8%) and the exact tumor size in 24 (24/50, 48%) of the histopathological reports. Adjuvant chemotherapy was used in accordance with the international standards but radiotherapy was under-utilized.

CONCLUSION

Our study demonstrated that the quality of breast cancer care in this institution was below the accepted international standards. This study may be used to make interventions for improvement of quality in similar institutions all over the kingdom.

[Indications for neoadjuvant therapy in rectal carcinoma]

Pre- and postoperative adjuvant treatments for locally advanced, operable (R0 resection) rectum carcinoma have led to improved results. In principle, according to the interdisciplinary consensus of the German Cancer Society, the recommended treatment for rectum carcinoma (T3/4; N0; M0; any T stage; N+; M0) is still postoperative adjuvant radiochemotherapy. In the meantime, however, based on the good results obtained from various clinical trials preoperative adjuvant treatment is favored internationally. Not only does this treatment scheme show a comparably better compliance of the patients but it also seems to be better tolerated. One treatment option for resectable T3 tumors immediately followed by surgery is the sole hypofractionated preoperative 3-4 field external beam radiotherapy. An additional benefit can be expected from protracted preoperative radiochemotherapy (single dose 2 Gy, total dose >40 Gy, chemotherapy based on 5-FU) followed by operation several weeks later. For T4 tumors with expected R1 or R2 resection, preoperative treatment is urgently recommended. A further aim in compliance with the surgical approach (R0 resection!) and multimodal treatment may be for individual cases the preservation of continence.