Pattern of Ipsilateral Breast Tumor Recurrence After Breast-Conserving Therapy

The role of 18F-FDG PET/CT in detecting synchronous regional and distant metastatic disease in patients with an in-breast tumour recurrence

BACKGROUND

In line with the trend towards minimally invasive, patient-tailored treatment, a selected group of patients with an in-breast tumour recurrence (IBTR) is treated by repeat breast-conserving treatment (BCT). To select eligible patients for repeat BCT, a reliable pre-operative work-up is essential. This study reports on the role of 18F-FDG PET/CT in detecting synchronous regional and distant metastases in patients with IBTR.

PATIENTS AND METHODS

A nation-wide data query was sent out to all Dutch hospitals offering breast cancer treatment. Breast cancer surgeons from 34 hospitals participated, filling electronic case report forms (eCRFs) on 549 patients treated for IBTR from 2016 to 2017.

RESULTS

Of the 549 included patients, 297 were screened using 18F-FDG PET/CT for the presence of distant metastases. Forty of them (13.5 %) presented with synchronous distant metastatic disease. In 168 clinically node-negative patients who underwent 18F-FDG PET/CT, a suspect regional lymph node was found in 18 (10.7 %). Final pathology of these lymph nodes yielded a positive lymph node in 12 patients (7.1 %). Positive predictive value (PPV) of 18F-FDG PET/CT in clinically node-negative patients was 66.7 % and negative predictive value (NPV) was 85.3 %.

CONCLUSION

The clinically relevant percentage of synchronous distant metastatic disease justifies the use of 18F-FDG PET/CT in the workup of patients with an IBTR. Furthermore, 18F-FDG PET/CT can assist in detecting regional axillary lymph node metastases, but requires histopathological confirmation given the moderate PPV, before clinical decisions can be made.

Efficacy of radiation therapy in Japanese patients with positive margins after breast-conserving surgery

BACKGROUND

Additional surgical resection is recommended after breast-conserving surgery if the surgical margin is pathologically positive. However, in clinical practice, radiation therapy is sometimes used instead for several reasons. Irradiation may be appropriate for some patients, but real-world data is still insufficient to establish it as standard treatment. We retrospectively investigated the status of local control in patients who received irradiation for positive margins.

METHODS

We investigated 85 patients with positive margins after curative partial mastectomy who were treated with irradiation instead of additional excision during the period 2006-2013. The patients received whole-breast irradiation (43.2-50 Gy) using photon beams and additional tumour-bed boost (8.1-16 Gy) using electron beams. Intrabreast tumour recurrence was defined as secondary cancer within the ipsilateral conserved breast. Surgical margin was defined as positive if tumour cell exposure was pathologically confirmed on the margin.

RESULTS

Seven patients (8.2%) developed intrabreast tumour recurrence during a mean observation period of 119 months. As to components of positive margin, 76 cases were positive for an intraductal component, of which seven (9.2%) developed intrabreast tumour recurrence. Meanwhile, all nine cases positive for an invasive component were free from intrabreast tumour recurrence. Two of the intrabreast tumour recurrence cases seemed to develop new lesions rather than recurrence, considering tumour location. The cumulative incidence of intrabreast tumour recurrence over 10 years was 6.1%. Limited to true recurrence, intrabreast tumour recurrence incidence was 4.9%.

CONCLUSION

Our real-world data supports irradiation as an alternative to additional surgical intervention for positive margins after breast-conserving surgery and offers a basis for further research.

Partial Breast Irradiation for Patients With Early-Stage Invasive Breast Cancer or Ductal Carcinoma In Situ: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations on appropriate indications and techniques for partial breast irradiation (PBI) for patients with early-stage invasive breast cancer and ductal carcinoma in situ.

METHODS

ASTRO convened a task force to address 4 key questions focused on the appropriate indications and techniques for PBI as an alternative to whole breast irradiation (WBI) to result in similar rates of ipsilateral breast recurrence (IBR) and toxicity outcomes. Also addressed were aspects related to the technical delivery of PBI, including dose-fractionation regimens, target volumes, and treatment parameters for different PBI techniques. The guideline is based on a systematic review provided by the Agency for Healthcare Research and Quality. Recommendations were created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

PBI delivered using 3-dimensional conformal radiation therapy, intensity modulated radiation therapy, multicatheter brachytherapy, and single-entry brachytherapy results in similar IBR as WBI with long-term follow-up. Some patient characteristics and tumor features were underrepresented in the randomized controlled trials, making it difficult to fully define IBR risks for patients with these features. Appropriate dose-fractionation regimens, target volume delineation, and treatment planning parameters for delivery of PBI are outlined. Intraoperative radiation therapy alone is associated with a higher IBR rate compared with WBI. A daily or every-other-day external beam PBI regimen is preferred over twice-daily regimens due to late toxicity concerns.

CONCLUSIONS

Based on published data, the ASTRO task force has proposed recommendations to inform best clinical practices on the use of PBI.

Impact of de-escalating systemic therapy guided by 21-gene assay on locoregional recurrence after partial-breast irradiation

PURPOSE

Partial-breast irradiation (PBI) has been performed as alternative to whole-breast irradiation (WBI) in breast-conserving therapy (BCT). Recently, the 21-gene recurrence score (RS) was introduced to determine the adjuvant therapy for estrogen receptor (ER)-positive, and human epidermal growth factor receptor 2 (HER2)-negative diseases. However, the impact of RS-based systemic therapy on locoregional recurrence (LRR) following BCT with PBI remains uninvestigated.

METHODS AND MATERIALS

Patients with ER-positive, HER2-negative, and node-negative breast cancer who underwent BCT with PBI were examined during May 2012-March 2022. In addition to immunohistochemistry (IHC), RS was available to decide on adjuvant therapy.

RESULTS

In total, 431 patients were evaluated with a median followup of 48.6 months. The 4-year LRR-free survival rates were 97.3% and 96.4% in the IHC and RS cohorts, respectively (p = 0.50). Ki67 of >20% was significantly associated with LRR in the multivariate analysis (HR 4.39, p < 0.05). For patients with Ki67 > 20%, 29 of 71 (40.8%) and 46 of 59 (78.0%) patients received only endocrine therapy in the IHC and RS cohorts, respectively (p < 0.0001). For patients with Ki67 >20% who received only endocrine therapy, the 4-year LRR-free survival rates were 91.8% in the IHC cohort and 94.6% in the RS cohort (p = 0.29) CONCLUSIONS: Although the introduction of RS increased the number of patients receiving endocrine therapy alone for Ki67 >20% of disease by two times, the LRR-free survival after BCT with PBI could be maintained. However, further studies from multiple institutions with longer followup data are required.

Partial breast irradiation: An updated consensus statement from the American brachytherapy society

PURPOSE

In recent years, results with mature follow-up have been reported for several Phase III trials randomizing women to receive whole breast irradiation (WBI) versus varying modalities of partial breast irradiation (PBI). It is important to recognize that these methods vary in terms of volume of breast tissue treated, dose per fraction, and duration of therapy. As such, clinical and technical guidelines may vary among the various PBI techniques.

METHODS

Members of the American Brachytherapy Society with expertise in PBI performed an extensive literature review focusing on the highest quality data available for the numerous PBI options offered in the modern era. Data were evaluated for strength of evidence and published outcomes were assessed.

RESULTS

The majority of women enrolled on randomized trials of WBI versus PBI have been age >45 years with tumor size <3 cm, negative margins, and negative lymph nodes. The panel also concluded that PBI can be offered to selected women with estrogen receptor negative and/or Her2 amplified breast cancer, as well as ductal carcinoma in situ, and should generally be avoided in women with extensive lymphovascular space invasion.

CONCLUSIONS

This updated guideline summarizes published clinical trials of PBI methods. The panel also highlights the role of PBI for women facing special circumstances, such as history of cosmetic breast augmentation or prior breast irradiation, and discusses promising novel modalities that are currently under study, such as ultrashort and preoperative PBI. Updated consensus guidelines are also provided to inform patient selection for PBI and to characterize the strength of evidence to support varying PBI modalities.

Margin status and survival outcomes after breast cancer conservation surgery: prospectively registered systematic review and meta-analysis

OBJECTIVE

To determine if margin involvement is associated with distant recurrence and to determine the required margin to minimise both local recurrence and distant recurrence in early stage invasive breast cancer.

DESIGN

Prospectively registered systematic review and meta-analysis of literature.

DATA SOURCES

Medline (PubMed), Embase, and Proquest online databases. Unpublished data were sought from study authors.

ELIGIBILITY CRITERIA

Eligible studies reported on patients undergoing breast conserving surgery (for stages I-III breast cancer), allowed an estimation of outcomes in relation to margin status, and followed up patients for a minimum of 60 months. Patients with ductal carcinoma in situ only or treated with neoadjuvant chemotherapy or by mastectomy were excluded. Where applicable, margins were categorised as tumour on ink (involved), close margins (no tumour on ink but <2 mm), and negative margins (≥2 mm).

RESULTS

68 studies from 1 January 1980 to 31 December 2021, comprising 112 140 patients with breast cancer, were included. Across all studies, 9.4% (95% confidence interval 6.8% to 12.8%) of patients had involved (tumour on ink) margins and 17.8% (13.0% to 23.9%) had tumour on ink or a close margin. The rate of distant recurrence was 25.4% (14.5% to 40.6%) in patients with tumour on ink, 8.4% (4.4% to 15.5%) in patients with tumour on ink or close, and 7.4% (3.9% to 13.6%) in patients with negative margins. Compared with negative margins, tumour on ink margins were associated with increased distant recurrence (hazard ratio 2.10, 95% confidence interval 1.65 to 2.69, P<0.001) and local recurrence (1.98, 1.66 to 2.36, P<0.001). Close margins were associated with increased distant recurrence (1.38, 1.13 to 1.69, P<0.001) and local recurrence (2.09, 1.39 to 3.13, P<0.001) compared with negative margins, after adjusting for receipt of adjuvant chemotherapy and radiotherapy. In five studies published since 2010, tumour on ink margins were associated with increased distant recurrence (2.41, 1.81 to 3.21, P<0.001) as were tumour on ink and close margins (1.44, 1.22 to 1.71, P<0.001) compared with negative margins.

CONCLUSIONS

Involved or close pathological margins after breast conserving surgery for early stage, invasive breast cancer are associated with increased distant recurrence and local recurrence. Surgeons should aim to achieve a minimum clear margin of at least 1 mm. On the basis of current evidence, international guidelines should be revised.

SYSTEMATIC REVIEW REGISTRATION

CRD42021232115.

Presence of Non-classic LCIS Is Not a Contraindication to Breast Conservation in Patients with Concomitant Invasive Breast Cancer or DCIS

BACKGROUND

Non-classic lobular carcinoma in situ (NC-LCIS) represents a spectrum of lesions, histologically distinct from classic LCIS (C-LCIS) and ductal carcinoma in situ (DCIS). Several studies have reported on the safety of breast conservation (BCS) in patients with DCIS or invasive breast cancer and concomitant C-LCIS, yet there are no data addressing this question for patients with concomitant NC-LCIS. We evaluated local recurrence (LR) after BCS in patients with DCIS or invasive cancer and concomitant NC-LCIS.

PATIENTS AND METHODS

We searched institutional databases using natural language processing to identify patients with DCIS or invasive breast cancer and concomitant NC-LCIS treated with BCS between 2000 and 2015. Charts were reviewed to collect demographics, disease and treatment details, and recurrence events. All results represent descriptive analyses.

RESULTS

We identified 71 patients with DCIS (n = 13) or invasive cancer (n = 58) and concomitant NC-LCIS treated with BCS. Median patient age was 59 years (33-77 years), and median invasive tumor size was 1.2 cm (0.1-6.9 cm); 62% of DCIS and 79% of invasive cancer patients had hormone receptor (HR)-positive disease. Among DCIS patients, seven (54%) received radiation and none hormonal therapy. Among those with invasive cancer, 52 (90%) received radiation, 17 (29%) received chemotherapy and 44 of 55 with HR-positive disease (78%) received hormonal therapy. At median follow-up of 79 months (1-265 months), the LR rate was 8% and 2% among patients with DCIS and invasive cancer, respectively.

CONCLUSION

NC-LCIS is rarely present in association with DCIS or invasive cancer, and it does not appear to impact LR outcomes following BCS.

Impact of lobular carcinoma in situ on local recurrence in breast cancer treated with breast conservation therapy: a systematic review and meta-analysis

BACKGROUND

Lobular carcinoma in situ (LCIS) is a known risk factor for breast cancer of unclear significance when detected in association with invasive carcinoma. This meta-analysis aims to determine the impact of LCIS on local recurrence risk for individuals with breast cancer treated with breast conservation therapy to help guide appropriate management strategies.

METHODS

We identified relevant studies from five electronic databases. Studies were deemed suitable for inclusion where they compared patients with invasive breast cancer and concurrent LCIS to those with breast cancer alone, all patients underwent breast conservation therapy (lumpectomy with adjuvant radiation therapy) and local recurrence was evaluated. Recurrence data were pooled by use of a random-effects model.

RESULTS

From 1488 citations screened by our search, nine studies were deemed suitable for inclusion. These studies comprised 990 cases and 12 870 controls. Median follow-up time was 104 months. There was a significantly increased risk of overall local recurrence of breast cancer for individuals with LCIS in association with breast cancer following breast conservation therapy (pooled odds ratio (pOR) 1.73; 95% confidence interval (CI) 1.10-2.71; P = 0.018). The risk of local recurrence was not significantly increased at 5 years (pOR 1.00; 95% CI 0.49-2.04; P = 0.995) and 10 years (pOR 1.52; 95% CI 0.72-3.23; P = 0.275).

CONCLUSION

Individuals with LCIS in association with invasive breast cancer have an increased risk of local recurrence following breast conservation therapy. This supports consideration of increased medical surveillance and exploration of further risk reduction strategies for such patients.

Second invasive breast cancers in patients treated with breast-conserving therapy

OBJECTIVE

Second breast cancers after breast-conserving therapy (BCT) include ipsilateral breast tumor recurrence (IBTR) and metachronous contralateral breast cancer (CBC). Each IBTR is further classified as true recurrence (TR) or new primary tumor (NP). We aim to compare survival outcomes of TR, NP and CBC, and explore the optimal treatments.

METHODS

168,427 patients with primary breast cancer who underwent BCT between 1990 and 2005 were identified in the SEER database. The risks of IBTR and CBC were estimated by annual hazard rate. The breast cancer-specific survival (BCSS) were assessed using multivariable Cox regression analysis.

RESULTS

With median follow-up of 13 years after BCT, 5413 patients developed an IBTR and 4050 patients had a CBC. The risk of IBTR peaked between 10 and 15 years after BCT, while the risk of CBC distributed evenly. 45.9% of IBTRs were classified as a TR and 54.1% as an NP. The time interval from primary breast cancer to NP was longer than to TR and CBC (P < 0.001). Patients with TR had a poorer BCSS than NP (P = 0.003) and CBC (P = 0.002). There was no difference in BCSS between mastectomy and repeat BCT for treating TR (P = 0.584) or NP (P = 0.243). The BCSS of CBCs treated with BCT was better than mastectomy (P = 0.010). Chemotherapy didn't improve the survival of patients with TR (P = 0.058). However, TRs with grade III or negative hormone receptors benefited from chemotherapy significantly.

CONCLUSION

Patients with TR had a poorer BCSS than NP and CBC. Classifying IBTR may provide clinical significance for treatments.

Interstitial multicatheter HDR-brachytherapy as accelerated partial breast irradiation after second breast-conserving surgery for locally recurrent breast cancer

Our aim was to evaluate the efficacy and toxicity of interstitial multicatheter high dose rate brachytherapy (imHDR-BRT) as accelerated partial breast irradiation (APBI) after second breast-conserving surgery (BCS) in patients with ipsilateral breast tumor recurrence (IBTR). Between January 2010 and December 2019, 20 patients with IBTR who refused salvage mastectomy (sMT) were treated with second BCS and post-operative imHDR-BRT as APBI. All patients had undergone primary BCS followed by adjuvant external beam radiotherapy. Median imHDR-BRT dose was 32 Gy delivered in twice-daily fractions of 4 Gy. Five-year IBTR-free survival, distant metastasis-free survival (DMFS), overall survival (OS) as well as toxicity and cosmesis were evaluated in the present retrospective analysis. Median age at recurrence and median time from the first diagnosis to IBTR was 65.1 years and 12.2 years, respectively. After a median follow-up of 69.9 months, two patients developed a second local recurrence resulting in 5-year IBTR free-survival of 86.8%. Five-year DMFS and 5-year OS were 84.6% and 92.3%, respectively. Grade 1-2 fibrosis was noted in 60% of the patients with no grade 3 or higher toxicity. Two (10%) cases of asymptomatic fat necrosis were documented. Cosmetic outcome was classified as excellent in 6 (37.5%), good in 6 (37.5%), fair in 3 (18.75%) and poor in 1 (6.25%) patient, respectively. We conclude that imHDR-BRT as APBI re-irradiation is effective and safe for IBTR and should be considered in appropriately selected patients.

Use of a Radiation Tumor Bed Boost After Breast-Conserving Surgery and Whole-Breast Irradiation: Time Trends and Correlates

PURPOSE

We sought to evaluate time trends and correlates of the use of a radiation tumor bed boost (TBB) after breast-conserving surgery and either conventional or hypofractionated whole-breast irradiation (CWBI or HWBI) for patients with early stage breast cancer.

METHODS AND MATERIALS

The National Cancer Database was queried for patients diagnosed between 2012 and 2016. We evaluated the utilization of TBB before and after publication of the Society of Surgical Oncology-American Society for Radiation Oncology margin guidelines in relation to sociodemographic variables, treatment facility, tumor characteristics, and whole-breast fractionation.

RESULTS

The population included 380,387 patients, of whom 76.7% received a TBB. Utilization of TBB decreased over time (2012-2013: 79.2%; 2014: 76.6%; 2015-2016: 74.7%; P < .001); this was seen for most subgroups evaluated. Rates of TBB differed by facility type and region. There was a decrease in TBB use in patients treated with CWBI over time (2012-2013: 84.9%; 2014: 83.5%; 2015-2016: 82.3%; P < .001) but an increase among patients treated with HWBI (2012-2013: 55.5%; 2014: 60.7%; 2015-2016: 65.1%; P < .001); this was also seen for low-risk patients (age >70 years, negative margins). Among patients undergoing HWBI, TBB was more frequently used when 15 fractions were used compared with 16 fractions (76.8% vs 59.1%; P < .001).

CONCLUSIONS

The use of TBB decreased over time, coinciding with the publication of new margin guidelines, for patients receiving CWBI and those with negative margins, but TBB use increased for patients treated with HWBI. Hence, fractionation regimen is a critical variable in analyzing changes over time in the practice patterns of TBB.

The Diminishing Impact of Margin Definitions and Width on Local Recurrence Rates following Breast-Conserving Therapy for Early-Stage Invasive Cancer: A Meta-Analysis

BACKGROUND

The optimal tumor-free margin definition and width following breast-conserving therapy (BCT) for early-stage invasive cancers has been evaluated in previous meta-analyses and guidelines. We performed an updated meta-analysis to assess how improvements in treatment over time have affected the impact of margins on local recurrence (LR) rates over time.

METHODS

A systematic literature review identified 38 eligible studies comprising 54,502 patients treated between 1968 and 2010. Inclusion criteria included patients treated with BCT and minimum follow-up of 50 months, pathologic definitions of margin status explicitly stated, and LR data in relation to margin status. Data were pooled using a Bayesian logistic regression model to evaluate the risk of LR in relation to both margin status and study enrollment periods.

RESULTS

Median follow-up was 7.25 years. Absolute LR rates decreased over time for each margin width cohort, with maximum differences between negative margin groups of less than 1% for the most recent enrollment period. However, relative rates of LR between different margin groups remained stable over time.

CONCLUSIONS

With an additional 22,000 patients compared with the previous meta-analysis, this updated meta-analysis supports the consensus guideline of "no tumor on ink" for the majority of patients. Additionally, while concerns exist regarding a benefit with wider margins from previous studies, the analysis demonstrates the impact of margin width on LR rates has declined substantially over time, with very small differences between the narrowest and widest margin groups in the most recent cohort. Hence, older studies appear to have limited value to inform current management guidelines.

Multifocality in ipsilateral breast tumor recurrence - A study in ablative specimens

BACKGROUND

The incidence and clinical significance of multifocality in ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy (BCT) are unclear. With growing interest in repeat BCT, this information has become of importance. This study aimed to gain insight in the incidence of multifocality in IBTR, to identify patient- and tumor-related predicting factors and to investigate the prognostic significance of multifocality.

METHODS

Two hundred and fifteen patients were included in this analysis. All had an IBTR after BCT and were treated by salvage mastectomy and appropriate adjuvant therapy. Predictive tumor- and patient-related factors for multifocality in IBTR were identified using X2 test and univariate logistic regression analyses. Prognostic outcomes were calculated using Kaplan Meier analysis and compared using the log rank test.

RESULTS

Multifocality was present in 50 (22.9%) of IBTR mastectomy specimens. Axillary positivity in IBTR was significantly associated with multifocality in IBTR. Chest wall re-recurrences occurred more often after multifocal IBTR (14% versus 7% after unifocal IBTR, p = 0.120). Regional re-recurrences did not differ significantly between unifocal and multifocal IBTR (8% vs. 6%, p = 0.773). Distant metastasis after salvage surgery occurred more frequently after multifocal IBTR (15% vs. 24%, p = 0.122). Overall survival was 132 months after unifocal IBTR and 112 months after multifocal IBTR (p = 0.197).

CONCLUSION

The prevalence of multifocality in IBTR is higher than in primary breast cancer. Axillary positivity in IBTR was associated with a multifocal IBTR. Chest wall re-recurrences and distant metastasis were, although not statistically significant, more prevalent after multifocal IBTR.

Influence of XRCC4 expression by breast cancer cells on ipsilateral recurrence after breast-conserving therapy

BACKGROUND

We examined the expression of nonhomologous end-joining (NHEJ) proteins by breast cancer cells in patients with or without ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy. We also investigated whether there was a difference of NHEJ-related protein expression by tumor cells between two types of IBTR, i.e., true recurrence (TR) with regrowth from the tumor bed or development of a new primary tumor (NP).

PATIENTS AND METHODS

The original cohort comprised 560 breast cancer patients who received breast-conserving therapy between February 1995 and March 2006, including 520 patients without IBTR and 40 patients with IBTR. Propensity score matching was employed to select 40 trios (120 patients) consisting of 1 patient with IBTR and 2 patients without IBTR. Immunohistochemical examination of proteins related to NHEJ was performed in surgical specimens.

RESULTS

The 40 patients with IBTR included 22 patients who developed TR and 18 who had NP. The 15-year overall survival rate was 85.9% for patients with NP and 95.5% for those with TR, while it was 96.5% for patients without IBTR. Patients with high XRCC4 expression in tumor cells had significantly higher IBTR rates than those with low XRCC4 expression (P < 0.001). The frequency of TR was significantly higher in patients with high expression of XRCC4 than in those with low XRCC4 expression (p < 0.001). XRCC4 expression by tumor cells was not significantly related to development of NP.

CONCLUSION

IBTR due to TR may be related to low radiosensitivity of tumor cells, possibly related to high XRCC4 expression.

Repeat breast-conserving therapy for ipsilateral breast cancer recurrence: A systematic review

The standard of care for patients with an ipsilateral breast tumour recurrence (IBTR) after breast-conserving therapy (BCT) is a salvage mastectomy. However, there is growing interest in the feasibility of repeat BCT for these patients. This systematic review contains the latest insights on BCT options for patients with an IBTR after initial BCT. A PubMed literature search was performed for articles on BCT options for IBTR after primary lumpectomy followed by radiotherapy. Weighted estimates were calculated for 5- and 10-year local control, distant metastasis-free and overall survival rates. Secondary outcomes were toxicity, cosmesis and quality of life. In total, 34 studies were eligible for analysis, of which 5 reported on repeat breast-conserving surgery (BCS) alone, 10 with mixed populations (BCS ± RT and/or mastectomy), 18 on repeat BCS followed by re-irradiation (whole-breast or partial) and one on quality of life. The weighted estimates for 5-year overall survival for repeat BCS and repeat BCS followed by reirradiation were 77% and 87%, respectively. Five-year local control was 76% for repeat BCS alone and 89% for repeat BCS followed by re-irradiation. Grade III-IV toxicity rates after re-irradiation varied from 0 to 21%, whereas the cosmesis was excellent-good in 29-100% of patients and unacceptable in 0-18%. Repeat BCS followed by re-irradiation, with either whole breast or partial breast re-irradiation, seems a feasible alternative to mastectomy in case of IBTR, in selected patients. Toxicity rates are low and the cosmetic outcome is good, but the size and follow-up of the published patient series is limited.

Contouring consensus guidelines in breast cancer radiotherapy: Comparison and systematic review of patterns of failure

Adequate coverage of sites harbouring potential microscopic disease is paramount, where the clinical decision has been made to include regional lymph node radiotherapy for patients with breast cancer. This must be achieved in balance with minimising dose to normal tissues. Several international consensus guidelines detailing clinical target volumes (CTVs) are available, but there is currently no agreement as to which is most appropriate for a given clinical situation. Contouring guidelines are beneficial for routine practice and essential for clinical trial quality assurance. The aims of this study were as follows: to provide a single point of comparison of four commonly used contouring guidelines, including one used in a current Trans-Tasman Radiation Oncology Group trial; and to undertake a systematic review of existing studies which map sites of breast cancer recurrence against contouring guidelines. Two international consensus guidelines (European Society for Radiotherapy and Oncology, and Radiation Therapy Oncology Group) were compared with two clinical trial guidelines (TROG 12.02 PET LABRADOR and the Proton/Photon trial NCT02603341 RADCOMP). Comprehensive literature search for patterns of failure studies was undertaken using Embase and Pubmed. We detail the small but significant differences between the breast consensus guidelines, particularly the supraclavicular (SCF) and internal mammary chain CTVs. Seven series were found mapping recurrence patterns. These results are discussed in the context of the contouring guidelines. Several studies found the SCF CTV is the area at greatest risk of geographical 'miss'. This review will facilitate further discussion about guideline selection and modification, particularly for future clinical trials in Australia and New Zealand.

Molecular determination of the clonal relationships between multiple tumors in BRCA1/2-associated breast and/or ovarian cancer patients is clinically relevant

Female BRCA1/2 mutation carriers affected with breast and/or ovarian cancer may develop new tumor deposits over time. It is of utmost importance to know the clonal relationships between multiple tumor localizations, enabling differentiation between multiple primaries or metastatic disease with consequences for therapy and prognosis. We evaluated the value of targeted next generation sequencing in the diagnostic workup of BRCA1/2 mutation carriers with ≥2 tumor localizations and uncertain tumor origins. Forty-two female BRCA1/2 mutation carriers with ≥2 tumor localizations were selected. Patients with inconclusive tumor origin after histopathological revision were 'cases'; patients with certain tumor origin of ≥3 tumors served as 'controls'. Tumors of cases and controls were analyzed by targeted next generation sequencing using a panel including CDKN2A, PTEN and TP53, hotspot mutation sites for 27 different genes and 143 single nucleotide polymorphisms for detection of loss of heterozygosity. Based on prevalence of identical or different mutations and/or loss of heterozygosity patterns, tumors were classified as 'multiple primaries' or 'one entity'. Conventional histopathology yielded a conclusive result in 38/42 (90%) of patients. Four cases and 10 controls were analyzed by next generation sequencing. In 44 tumor samples, 48 mutations were found; 39 (81%) concerned TP53 mutations. In all 4 cases, the intra-patient clonal relationships between the tumor localizations could be unequivocally identified by molecular analysis. In all controls, molecular outcomes matched the conventional histopathological results. In most BRCA1/2 mutation carriers with multiple tumors routine pathology work-up is sufficient to determine tumor origins and relatedness. In case of inconclusive conventional pathology results, molecular analyses using next generation sequencing can reliably determine clonal relationships between tumors, enabling optimal treatment of individual patients.

Pattern of relapse after breast conserving therapy, a study of 1519 early breast cancer patients treated in the Central Region of Denmark 2000-2009

BACKGROUND

The continuous improvements in diagnosing and treatment of breast cancer are reflected in the ever changing pattern of recurrence. The aim of the study was to investigating recurrence pattern and prognostic factors of recurrence in a population-based cohort.

MATERIAL AND METHOD

In total 1519 consecutive patients treated with breast conserving therapy (BCT) for invasive carcinoma between 2000 and 2009 in the Central Region of Denmark was included. Patients received adjuvant irradiation and systemic treatment according to the guidelines of the Danish Breast Cancer Cooperative Group, including boost for young women and those with a narrow margin.

RESULTS

Median follow-up was 5.3 years (range 0.3-14.4). In total 183 women experienced breast cancer recurrence, 44 ipsilateral breast cancer recurrence, 13 regional recurrences, and 126 distant metastasis (DM). This corresponds to a cumulative risk of DM as first event at five and nine years of 6.5% and 12.6%, respectively. Further 42 women developed breast cancer in the contralateral breast. Disease-free survival (DFS) at five and nine years was 88% and 76%, respectively. Large tumor size (>20 mm), lymph node involvement, and vascular invasion were significantly associated with increased risk of DM. Margin width and age were not associated with risk of DM.

CONCLUSION

Acceptable recurrence rates and DFS were observed. Patients with large tumors, lymph node involvement, and vascular invasion had an increased risk of DM.

[Non-metastatic triple-negative breast cancer in 2016: Definitions and management]

Triple-negative breast cancer (TN), as defined by the triple negativity in immunohistochemistry: the absence of estrogen receptor, progesterone receptor and the absence of overexpression or amplification of HER2, corresponds to 15 % of invasive breast cancers. This is a very heterogeneous group of tumors both at the genomic and transcriptomic level and at morphological, clinical and prognostic level. Although there are some good prognosis forms, the majority of TN tumors is characterized by a poor prognosis with a greater frequency of visceral metastases and a maximum risk of relapse in the first two years after diagnosis. Systemic adjuvant treatment with chemotherapy is almost always indicated. The surgical treatment and radiotherapy treatment should be comparable to the other subtypes and obey the same rules of oncologic surgery. TN tumors are not associated with a higher risk of locoregional relapse after conservative treatment and adjuvant radiotherapy. Optimization of systemic therapies is currently and for the last decade a challenge. A number of targeted therapies and efficiency biomarkers identification of these targeted therapies is essential to allow significant progress in optimizing systemic therapy for these tumors.

Comparison of ipsilateral breast tumor recurrence after breast-conserving surgery between ductal carcinoma in situ and invasive breast cancer

Background

We aimed to evaluate the differences in the rates and predictive factors for ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery (BCS) between ductal carcinoma in situ (DCIS) and invasive breast cancer. And, we evaluated the impact of IBTR on overall survival and distant metastasis.

Methods

We retrospectively reviewed 322 consecutive patients with DCIS or invasive breast cancer who underwent BCS between 2004 and 2010. We evaluated the rates of IBTR of DCIS and invasive breast cancer. Univariate and multivariate analyses were performed to determine the predictive factors for IBTR, and survival rates were analyzed with Kaplan-Meier estimates.

Results

With a median follow-up period of 57 months, 5 (10 %) out of 50 DCIS patients and 14 (5.1 %) out of 272 invasive cancer patients had developed IBTR. Factors associated with IBTR on univariate and multivariate analyses were positive resection margin status in DCIS and omission of radiotherapy in invasive cancer, respectively. The hormone receptor negativity was strong independent predictive factors for IBTR in both DCIS and invasive breast cancer. Although the differences of survival curve did not reach statistical significance, the 5-year overall survival and distant metastasis-free survival of invasive cancer patients who suffered IBTR were inferior to those without (84 vs. 98 % and 63.3 vs. 96.5 %, respectively). Advanced initial stage, lymph node metastasis and experience of IBTR were associated with poor overall survival and distant metastasis on univariate and multivariate analyses.

Conclusions

The hormone receptor negativity was revealed as independent predictive factor for IBTR after BCS in both DCIS and invasive cancer. Experience of IBTR was independent prognostic factor for poor overall outcome in patients with invasive breast cancer. Aggressive local control and adjuvant therapy should be made in hormone receptor-negative patients who receive treatment with BCS.

MicroRNA-Related DNA Repair/Cell-Cycle Genes Independently Associated With Relapse After Radiation Therapy for Early Breast Cancer

PURPOSE

Local recurrence and distant failure after adjuvant radiation therapy for breast cancer remain significant clinical problems, incompletely predicted by conventional clinicopathologic markers. We had previously identified microRNA-139-5p and microRNA-1274a as key regulators of breast cancer radiation response in vitro. The purpose of this study was to investigate standard clinicopathologic markers of local recurrence in a contemporary series and to establish whether putative target genes of microRNAs involved in DNA repair and cell cycle control could better predict radiation therapy response in vivo.

METHODS AND MATERIALS

With institutional ethics board approval, local recurrence was measured in a contemporary, prospectively collected series of 458 patients treated with radiation therapy after breast-conserving surgery. Additionally, independent publicly available mRNA/microRNA microarray expression datasets totaling >1000 early-stage breast cancer patients, treated with adjuvant radiation therapy, with >10 years of follow-up, were analyzed. The expression of putative microRNA target biomarkers--TOP2A, POLQ, RAD54L, SKP2, PLK2, and RAG1--were correlated with standard clinicopathologic variables using 2-sided nonparametric tests, and to local/distant relapse and survival using Kaplan-Meier and Cox regression analysis.

RESULTS

We found a low rate of isolated local recurrence (1.95%) in our modern series, and that few clinicopathologic variables (such as lymphovascular invasion) were significantly predictive. In multiple independent datasets (n>1000), however, high expression of RAD54L, TOP2A, POLQ, and SKP2 significantly correlated with local recurrence, survival, or both in univariate and multivariate analyses (P<.001). Low RAG1 expression significantly correlated with local recurrence (multivariate, P=.008). Additionally, RAD54L, SKP2, and PLK2 may be predictive, being prognostic in radiation therapy-treated patients but not in untreated matched control individuals (n=107; P<.05).

CONCLUSIONS

Biomarkers of DNA repair and cell cycle control can identify patients at high risk of treatment failure in those receiving radiation therapy for early breast cancer in independent cohorts. These should be further investigated prospectively, especially TOP2A and SKP2, for which targeted therapies are available.

Mammographic and Ultrasonographic Findings of Oxidized Regenerated Cellulose in Breast Cancer Surgery: A 5-Year Experience

BACKGROUND

The purpose of this study was to describe the ultrasonographic (US) and mammographic (MX) findings in patients who underwent breast-conserving surgery followed by oxidized regenerated cellulose (ORC) implantation in the surgical cavity and their size variations in follow-up.

MATERIALS AND METHODS

We retrospectively reviewed 417 MX and 743 US images performed between January 2009 and January 2014 for 262 women who underwent breast-conserving surgery. All patients underwent US, only 203 women underwent MX examination.

RESULTS

In 170 of 262 patients, US examinations showed abnormal findings. Three main US patterns were identified: (1) complex masses: well-encapsulated ipoisoechoic lesions with circumscribed margins with internal hyperechoic nodules (56%); (2) hypoanechoic lesions without internal hyperechoic nodules (24%); and (3) completely anechoic collections (20%). Moreover, Doppler ultrasound examination was performed on all of the patients. In 95 of 203 patients, MX examinations showed abnormalities. Four main MX patterns were identified: (1) round or oval opacity with circumscribed margins (58%); (2) round or oval opacity with indistinct or ill-defined margins (17%); (3) irregular opacity with indistinct or spiculated margins (9%); and (4) architectural distortion or focal asymmetry (15%). Most of the lesions showed a decrease in size at US and MX follow-up examination and the decrease was statistically significant (P < .01).

CONCLUSION

When applied to the surgical residual cavity, ORC aids to control local hemorrhage and reduce the risk of postoperative infections, but can lead to alterations in surgical scar. Thus, knowledge of the radiological findings might allow avoidance of misdiagnosis of tumor recurrence or unnecessary diagnostic examinations.