The Japanese Breast Cancer Society Clinical Practice Guideline for radiation treatment of breast cancer, 2015 edition

Data-driven treatment pathways mining for early breast cancer using cSPADE algorithm and system clustering

OBJECTIVES

Due to the multidimensional, multilayered, and chronological order of the cancer data, it was challenging for us to extract treatment paths. To determine whether the cSPADE algorithm and system clustering proposed in this study can effectively identify the treatment pathways for early breast cancer.

METHODS

We applied data mining technology to the electronic medical records of 6891 early breast cancer patients to mine treatment pathways. We provided a method of extracting data from EMR and performed three-stage mining: determining the treatment stage through the cSPADE algorithm → system clustering for treatment plan extraction → cSPADE mining sequence pattern for treatment. The Kolmogorov-Smirnov test and correlation analysis were used to cross-validate the sequence rules of early breast cancer treatment pathways.

RESULTS

We unearthed 55 sequence rules for early breast cancer treatment, 3 preoperative neoadjuvant chemotherapy regimens, three postoperative chemotherapy regimens, and 2 chemotherapy regimens for patients without surgery. Through 5-fold cross-validation, Pearson and Spearman correlation tests were performed. At the significance level of p < 0.05, all correlation coefficients of support, confidence and lift were greater than 0.89. Using the Kolmogorov-Smirnov test, we found no significant differences between the sequence distributions.

CONCLUSIONS

We have proved that cSPADE algorithm combined system clustering is an effective technique for identifying temporal relationships between treatment modalities, enabling hierarchical and vertical mining of breast cancer treatment models. In addition, we confirmed the robustness of the results by cross-validation of these treatment pathway ordering rules. Through this method, the treatment path of early breast cancer patients can be revealed, and the real-world breast cancer treatment behaviour model can be evaluated, which can provide reference for the redesign and optimization of treatment path.

Comparison of conventional and hypofractionated radiation after mastectomy in locally advanced breast cancer: a prospective randomised study on dosimetric evaluation and treatment outcome

Background:

Although hypofractionated radiotherapy has been standardised in early breast cancer, even in post-mastectomy no such consensus has been developed for locally advanced breast cancer (LABC), probably due to complex planning and field matching. This study is directed towards dosimetric evaluation and comparison of toxicity, response and disease-free survival (DFS) comparison between hypofractionation and conventional radiotherapy in post-mastectomy LABC.

Methodology:

In total, 222 female breast cancer patients were randomly assigned to be treated with either hypofractionated radiotherapy (n = 120) delivering 40 Gy in 15 fractions over 3 weeks or conventional radiotherapy (n = 102) with 50 Gy in 25 fractions over 5 weeks after modified radical mastectomy (MRM) along with neoadjuvant and/or adjuvant chemotherapy. All patients were planned with treatment planning software and assessed regularly during and after treatment.

Results:

Median follow-up period was 178 weeks in conventional arm (CRA) and 182 weeks in hypofractionation arm (HFA). There exists a dosimetric difference between the two arms of treatment, in spite of similar dose coverage [planning treatment volume (PTV) D90 92·04% in CRA versus 92·5% in HFA; p = 0·49], average dose in HFA is less than that of CRA (p < 0·001); so is the maximum clinical target volume (CTV) dose (p < 0·001). Similarly, average lung dose in HFA arm is significantly lower than CRA (9·9 versus 10·84; p = 0·06), but the V20Gy of lung and V30Gy of heart had no difference. The toxicity of radiation was comparable with similar mean time to produce toxicity [CRA: 7 W, HFA: 10 W; hazard ratio 0·64, 95% confidence interval (CI) = 0·28–1·45]. Three-year recurrence event was alike in two arms (CRA: 4·9%, HFA: 5·8%; p = 0·76). Mean DFS in CRA is 230 weeks and that of HFA is 235 weeks with hazard ratio 1·01 (95% CI = 0·32–3·19; p = 0·987).

Conclusion:

Though biologically effective dose (BED) in hypofractionation is lesser than that of conventional fractionation, there are indistinguishable toxicity, locoregional recurrence, distant failure rate and DFS between the two modalities.

Shared decision making in breast cancer treatment guidelines: Development of a quality assessment tool and a systematic review

BACKGROUND

It is not clear whether clinical practice guidelines (CPGs) and consensus statements (CSs) are adequately promoting shared decision making (SDM).

OBJECTIVE

To evaluate the recommendations about SDM in CPGs and CSs concerning breast cancer (BC) treatment.

SEARCH STRATEGY

Following protocol registration (Prospero no.: CRD42018106643), CPGs and CSs on BC treatment were identified, without language restrictions, through systematic search of bibliographic databases (MEDLINE, EMBASE, Web of Science, Scopus, CDSR) and online sources (12 guideline databases and 51 professional society websites) from January 2010 to December 2019.

INCLUSION CRITERIA

CPGs and CSs on BC treatment were selected whether published in a journal or in an online document.

DATA EXTRACTION AND SYNTHESIS

A 31-item SDM quality assessment tool was developed and used to extract data in duplicate.

MAIN RESULTS

There were 167 relevant CPGs (139) and CSs (28); SDM was reported in only 40% of the studies. SDM was reported more often in recent publications after 2015 (42/101 (41.6 %) vs 46/66 (69.7 %), P = .0003) but less often in medical journal publications (44/101 (43.5 %) vs 17/66 (25.7 %), P = .009). In CPGs and CSs with SDM, only 8/66 (12%) met one-fifth (6 of 31) of the quality items; only 14/66 (8%) provided clear and precise SDM recommendations.

DISCUSSION AND CONCLUSIONS

SDM descriptions and recommendations in CPGs and CSs concerning BC treatment need improvement. SDM was more frequently reported in CPGs and CSs in recent years, but surprisingly it was less often covered in medical journals, a feature that needs attention.

Distant Metastasis after Surgery for Encapsulated Papillary Carcinoma of the Breast: A Case Report

In the absence of clear interstitial invasion, encapsulated papillary carcinoma (EPC) of the breast may be attributed to an extremely good prognosis if handled similarly to ductal carcinoma in situ (DCIS) with suitable local treatment. Here, we report our experience with a case of EPC of the breast that presented with carcinomatous pleuritis and lymphangitis carcinomatosa postoperatively, which rapidly resulted in a poor outcome. A 67-year-old woman was diagnosed with DCIS of the left breast and underwent left partial mastectomy and sentinel lymph node biopsy. EPC was diagnosed because the pathological examination showed no sign of interstitial infiltration. Postoperative radiation therapy was performed. Five years and 9 months postoperatively, the patient began experiencing cough and shortness of breath on exertion. Imaging showed right pleural effusion and consolidation of the lung field, but nothing suggesting local recurrence in the preserved left breast, local lymph nodes, or opposite breast was observed. Postoperative recurrence of breast cancer, carcinomatous pleuritis, and lymphangitis carcinomatosa were diagnosed based on the results of pleural fluid cytology. One month later, multiple brain metastases were found, and the patient died of the primary disease 5 months after recurrence. After surgery for EPC without clear interstitial infiltration, there was a small possibility of a poor outcome from distant metastasis. Therefore, although distant metastasis is uncommon, regular examination and testing should be performed.

International Variation in Criteria for Internal Mammary Chain Radiotherapy

AIMS

Evidence has emerged that internal mammary chain (IMC) radiotherapy reduces breast cancer mortality, leading to changes in treatment guidelines. This study investigated current IMC radiotherapy criteria and the percentages of patients irradiated for breast cancer in England who fulfilled them.

MATERIALS AND METHODS

A systematic search was undertaken for national guidelines published in English during 2013-2018 presenting criteria for 'consideration of' or 'recommendation for' IMC radiotherapy. Patient and tumour variables were collected for patients who received breast cancer radiotherapy in England during 2012-2016. The percentages of patients fulfilling criteria stipulated in each set of guidelines were calculated.

RESULTS

In total, 111 729 women were recorded as receiving adjuvant breast cancer radiotherapy in England during 2012-2016 and full data were available on 48 095 of them. Percentages of patients fulfilling IMC radiotherapy criteria in various national guidelines were: UK Royal College of Radiologists 13% (6035/48 095), UK National Institute for Health and Care Excellence 18% (8816/48 095), Germany 32% (15 646/48 095), Ireland 56% (26 846/48 095) and USA 59% (28 373/48 095). Differences between countries occurred because in Ireland and the USA, treatment may be considered in some node-negative patients, whereas in the UK, treatment is considered if at least four axillary nodes are involved or for high-risk patients with one to three positive nodes. In Germany, treatment may be considered for all node-positive patients.

CONCLUSIONS

There is substantial variability between countries in criteria for consideration of IMC radiotherapy, despite guidelines being based on the same evidence. This will probably lead to large variations in practice and resource needs worldwide.

Results of a nationwide survey on Japanese clinical practice in breast-conserving radiotherapy for breast cancer

The Breast Cancer Group of the Japanese Radiation Oncology Study Group conducted a nationwide questionnaire survey on the clinical practice of postoperative radiotherapy for breast-conserving treatment for breast cancer. This questionnaire consisted of 18 questions pertaining to the annual number of treated patients, planning method, contouring structure, field design, dose-fractionated regimen, application of hypofractionated radiotherapy, boost irradiation, radiotherapy for synchronously bilateral breast cancer, and accelerated partial breast irradiation. The web-based questionnaire had responses from 293 Japanese hospitals. The results indicated the following: treatment planning is performed using relatively similar field designs and delivery methods; the field-in-field technique is used at more than one-third of institutes; the commonest criteria for boost irradiation is based on the surgical margin width (≤5 mm) and the second commonest criteria was age (≤40 or ≤50 years), although some facilities applied a different age criterion (>70 years) for omitting a tumor bed boost; for conventional fractionation, almost all institutes delivered 50 Gy in 25 fractions to the conserved whole breast and 10 Gy in 5 fractions to the tumor bed. This survey revealed that 43% of hospitals offered hypofractionated radiotherapy, and the most common regimens were 42.56 Gy in 16 fractions for whole-breast irradiation and 10.64 Gy in 4 fractions for boost irradiation. Almost all of the facilities irradiated both breasts simultaneously for synchronously bilateral breast cancer, and accelerated partial breast irradiation was rarely offered in Japan. This survey provided an overview of the current clinical practice of radiotherapy for breast-conserving treatment of breast cancer in Japan.

Clinical outcomes and prognostic factors in patients with stage II-III breast cancer treated with neoadjuvant chemotherapy followed by surgery and postmastectomy radiation therapy in the modern treatment era

Purpose

There are no randomized studies on the indication for postmastectomy radiation therapy (PMRT) in patients who receive neoadjuvant chemotherapy (NAC) followed by a mastectomy. The aim of this study was to determine clinical outcomes and identify reliable prognostic factors in patients with locally advanced breast cancer treated with NAC followed by a mastectomy and PMRT.

Methods and materials

We retrospectively evaluated the relationship between clinicopathological factors and outcomes in 351 patients with stage II or III breast cancer who underwent NAC followed by radical mastectomy and PMRT between March 2005 and December 2013.

Results

The median follow-up duration was 81 months (Range, 12-156 months). For all patients, the 5-year locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and overall survival (OS) rates were 91.3 %, 69.8 %, and 83.4 %, respectively. On multivariate analysis, estrogen-receptor positivity, and complete response of cancer in axillary nodes (ypN0) were significant prognostic factors for better LRFS, while lympho-vascular invasion and clinical stage IIIC were independent prognostic factors for worse LRFS. The number of axillary node metastasesafter surgery was an independent prognostic factor of DMFS and OS. Patients with hormone receptor- and human epidermal growth factor receptor 2 positivity had significantly better 5-year LRFS rates.

Conclusions

We identified several prognostic factors in our study. In particular, the number of axillary node metastases is significantly related to OS.

Sentinel node biopsy for axillary management after neoadjuvant therapy for breast cancer: a single-center retrospective analysis with long follow-up

PURPOSE

Sentinel node biopsy (SNB) after neoadjuvant therapy (NAT) for breast cancer remains controversial. We conducted a retrospective study of patients who underwent SNB after NAT to evaluate the effectiveness of this procedure.

METHODS

A consecutive 105 women with locally advanced breast cancer (cT1-4, cN0-3, M0) were treated with NAT between 2006 and 2015. The subjects were 80 of these patients who became or remained clinically node-negative after NAT, 53 of whom had axillary management determined by SNB (group A) and the other 27 underwent axillary lymph node dissection (ALND) without SNB (group B). SNB was performed using a modified dye method.

RESULTS

The sentinel node (SN) identification rate was 94.3% and the mean number of removed SNs was 2.4. ALND was avoided in 33 patients, who were confirmed as SN-negative. There was no difference in recurrence-free and overall survival rates between groups A and B (p = 0.71 and p = 0.46, respectively) during the median follow-up time of 63 months. Of the 33 patients who did not undergo ALND, 10 suffered recurrence (33%). One patient (3%) had recurrence in an axillary lymph node and four had recurrence in a supraclavicular lymph node.

CONCLUSION

Axillary SNB after NAT did not affect the axillary failure rate or the prognosis. SNB may be a reliable procedure, even after NAT.

Breast reconstruction and postmastectomy radiotherapy: complications by type and timing and other problems in radiation oncology

Breast reconstruction (BR) represents a suitable option for women who are not expected to require postmastectomy radiotherapy (PMRT). As recent evidence has led to an extension of the indications for PMRT, this has also appeared to increase the incidence of reconstructive complications. Nevertheless, in the USA at least, trends towards BR are changing. The frequency of immediate reconstruction continues to increase, even in the setting of PMRT. In immediate implant-based reconstruction, a staged approach is preferred. The failure rate of PMRT in implant patients is lower than that with expander patients. In delayed implant-based construction, tissue expansion of irradiated skin leads to a significantly increased risk of complications. In contrast, autologous tissue appears to tolerate radiation damage better than implant-based reconstructions. No significant differences have been described when complication rates of immediate autologous tissue BR with PMRT were compared with delayed autologous tissue BR following PMRT. In previously radiated patients, autologous tissue BR is preferred, and it may be safer when carried out ≥ 12 months after PMRT. Several other problems are associated with radiation delivery after BR and the clues to solve them are reviewed in this paper.