10-year Ipsilateral Breast Tumor Recurrence Research Articles

Comparison of long-term oncologic outcomes of central lumpectomy and conventional breast-conserving surgery for invasive breast cancer: propensity score matching analysis.

Central lumpectomy (CL) is a breast-conserving surgical (BCS) technique that involves excision of the nipple-areolar complex with breast tumor in centrally located breast cancers. We aimed to investigate the long-term clinical outcomes of CL in comparison with conventional BCS (cBCS). Patient records who underwent BCS with clear resection margins for invasive breast cancer between 2004 and 2018 were retrospectively reviewed. Of the total 6,533 patients, 106 (1.6%) underwent CL. Median follow-up duration was 73.4months. 1:3 propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to minimize selection bias. The CL group showed a significantly higher ipsilateral breast tumor recurrence (IBTR) rate than the cBCS group (10-year IBTR rate: 5.8% vs. 3.1%, p = 0.004), even after adjusting for other variables (hazard ratio (HR), 2.65; 95% confidence interval (CI), 1.07-6.60, p = 0.048). However, there were no significant differences observed inregional recurrence, distant metastasis, oroverall survival rates between the two groups. Both PSM and IPTW analyses showed significantly higher IBTR in the CL group (PSM HR, 3.27; 95% CI, 0.94-11.36; p = 0.048 and IPTW HR, 4.66; 95%CI, 1.85-11.77; p < 0.001). Lastly, when analyzing 2,213 patients whose tumors were located within 3cm of the nipple, the CL group showed a significantly higher IBTR than the cBCS group before and after PSM. CL was associated with a higher rate ofIBTR compared to cBCS, while other survival outcomes were comparable. For centrally located tumors, CL may be considered for patients preferring breast preservation. However, higher risk for IBTR should be informed and careful surveillance may be necessary during the early post-operative follow-up periods.

Locoregional Recurrence Patterns in Patients With Different Molecular Subtypes of Breast Cancer

While numerous studies have consistently reported that the molecular subtypes of breast cancer (BC) are associated with different patterns of distant metastasis, few studies have investigated the association of tumor subtypes with locoregional recurrence. To investigate the patterns of ipsilateral breast tumor recurrence (IBTR), regional recurrence (RR), and contralateral BC (CBC) according to tumor subtypes. This retrospective cohort study used the clinical records of patients who underwent BC surgery at a single institution in South Korea between January 2000 and December 2018. Data were analyzed from May 1, 2019, to February 20, 2023. Ipsilateral breast tumor recurrence, RR, and CBC events. The primary outcome was differences in annual incidence patterns of IBTR, RR, and CBC according to tumor subtypes. Hormone receptor (HR) status was assessed by immunohistochemical staining assay, and ERBB2 status was evaluated according to American Society of Clinical Oncology and College of American Pathologists guidelines. A total of 16 462 female patients were included in the analysis (median age at time of operation, 49.0 years [IQR, 43.0-57.0 years]). The 10-year IBTR-, RR-, and CBC-free survival rates were 95.9%, 96.1%, and 96.5%, respectively. On univariate analysis, HR-/ERBB2+ tumors had the worst IBTR-free survival (vs HR+/ERBB2- subtype: adjusted hazard ratio, 2.95; 95% CI, 2.15-4.06), while the HR-/ERBB2- subtype had the worst RR- and CBC-free survival among all subtypes (vs HR+/ERBB2- subtype, RR: adjusted hazard ratio, 2.95; 95% CI, 2.37-3.67; CBC: adjusted hazard ratio, 2.12; 95% CI, 1.64-2.75). Subtype remained significantly associated with recurrence events in Cox proportional hazards regression analysis. Regarding the annual recurrence pattern, the IBTR patterns of HR-/ERBB2+ and HR-/ERBB2- subtypes showed double peaks, while HR+/ERBB2- tumors showed a steadily increasing pattern without distinguishable peaks. Additionally, the HR+/ERBB2- subtype seemed to have a steady RR pattern, but other subtypes showed the highest RR incidence at 1 year following surgery, which then gradually decreased. The annual recurrence incidence of CBC gradually increased among all subtypes, and patients with the HR-/ERBB2- subtype had a higher incidence than patients with other subtypes over 10 years. Younger patients (age ≤40 years) had greater differences in IBTR, RR, and CBC patterns between subtypes than did older patients. In this study, locoregional recurrence occurred with different patterns according to BC subtypes, with younger patients having greater differences in patterns among subtypes than older patients. The findings suggest that tailoring surveillance should be recommended regarding differences in locoregional recurrence patterns according to tumor subtypes, particularly for younger patients.

A prospective analysis of two studies that used the 5-mm interval slices and 5-mm margin-free method for ipsilateral breast tumor recurrence after breast-conserving surgery without radiotherapy

BackgroundBreast-conserving surgery with radiotherapy is one of standard treatments for early breast cancer. However, it is regarded as an option to treat elderly patients with small hormone receptor-positive breast cancer with breast-conserving surgery and hormone therapy without radiotherapy. We conducted two sequential prospective studies to examine the feasibility of breast-conserving surgery without radiotherapy since 2002 and present the results.Patients and methodsPrimary female breast cancer patients who fulfilled the strict eligibility criteria were prospectively enrolled in two sequential studies named WORTH 1 and 2. The surgical materials were sliced in 5-mm intervals and all slices were examined microscopically. Postoperative radiotherapy was not allowed, but tamoxifen or anastrozole was administered for 5 years. Ipsilateral breast tumor recurrence (IBTR)-free survival was the primary outcome.ResultsThe data of the two studies were combined (N = 321). The median follow-up period for IBTR was 94 months (4–192 months). Only three patients were treated with adjuvant chemotherapy. The 5- and 10-year IBTR-free rates were 97.0% and 90.5%, respectively. The age at operation and PR status affected IBTR rates independently. When we calculated IBTR-free rates of patients who were 65 years of age or older at the time of surgery and had PR-positive tumors, the 5- and 10-year IBTR rates were both 98.4%.Conclusions Our “5-mm-thick slice and 5-mm free-margin” method may be effective to select patients who can be treated by breast-conserving surgery and hormone therapy without radiotherapy.

Biosignatures to Optimize Adjuvant Radiation Therapy Use in Patients With DCIS With High Risk Clinicopathologic Features

There is an unmet need to identify women diagnosed with DCIS who have a low recurrence risk and could omit radiotherapy (RT) after breast conserving surgery (BCS), or an elevated recurrence risk after treatment with BCS plus RT.Pathology, clinical data, and FFPE tissue samples were evaluable for 485 women treated for DCIS with BCS with negative margins, with or without whole breast RT, at centers in Sweden, US and Australia. A subset with large tumor size (> 2.5 cm) &/or nuclear grade III DCIS was assessed (n = 250). A validated biosignature (Prelude, Laguna Hills CA) and a novel response subtype biosignature to RT after BCS were determined using protein biomarkers (p16/INK4A, Ki-67, COX-2, PgR, HER2, FOXA1, SIAH2) assayed on FFPE tissue. The two biosignatures classified women into three risk groups: Low risk, Elevated risk with a good response subtype (Rst) and Elevated risk with a poor Rst to RT after BCS. Ipsilateral breast tumor recurrence (IBTR) included DCIS or Invasive Breast Cancer (IBC) that was local, regional, or metastatic. Hazard ratios and 10-year risks were calculated using Cox proportional hazards and Kaplan-Meier analyses.Of 250 women with nuclear grade III DCIS and/or size > 2.5 cm, biosignatures classified 72% (n = 179) of patients into an Elevated risk group consisting of those with a good (n = 122) or a poor (n = 57) response subtype (Rst) to RT after BCS. The remaining 28% of women were classified into a low-risk group (n = 71). In the low-risk group (n = 71), women treated without RT had good 10-year outcomes with no (0%) 10-year IBC events, and derived no significant RT benefit (1%) in 10-year IBTR rates (IBTR P = 0.81). Of all women treated without RT (n = 102), those in the elevated risk group (good and poor Rst combined, n = 61) had significantly worse 10-year IBTR/IBC rates (31%/17%) than those in the low-risk group, (IBTR HR = 12, P = 0.01). Women treated with RT in the elevated risk group with a good Rst (n = 77) had significantly reduced 10-year IBTR/IBC rates of 5%/3%. However, no significant benefit to RT was noted for women within the elevated risk group with a poor Rst (n = 41) who had 10-year IBTR/IBC rates of 25%/20%. Of all women treated with RT in the elevated risk group (n = 118), those with a poor Rst had significantly worse outcomes than those with a good Rst (IBTR HR = 4.1, P = 0.035, IBC HR = 8, P = 0.053).In women with nuclear grade III DCIS &/or size > 2.5 cm, DCISionRT combined with a novel response subtype biosignature (Rst) identified an elevated risk group with two distinct subtypes of women: (1) a poor Rst that had high IBTR/IBC rates with or without RT and (2) a good Rst deriving significant benefit from adjuvant RT. Women in the corresponding low risk group had low 10-year IBTR/IBC rates and derived no significant benefit from adjuvant RT.

Increased Risk for Ipsilateral Breast Tumor Recurrence in Invasive Lobular Carcinoma after Accelerated Partial Breast Irradiation Brachytherapy.

The suitability criteria for accelerated partial breast irradiation (APBI) from the American Brachytherapy Society (ABS), American Society for Radiation Oncology (ASTRO), and The Groupe Européende Curiethérapie European SocieTy for Radiotherapy & Oncology (GEC-ESTRO) have significant differences. This is a single institution retrospective review of 946 consecutive patients with invasive breast cancer who underwent lumpectomy and APBI intracavitary brachytherapy from 2003 to 2018. Overall survival (OS), breast cancer-specific survival (BCSS), relapse-free survival (RFS), and ipsilateral breast tumor recurrence (IBTR) were estimated with Kaplan-Meier method. Median follow-up time was 60.2 months. Median age was 68 years (46-94 years). The majority of patients had estrogen receptor (ER)-positive disease (94%). There were 821 (87%) cases of invasive ductal carcinoma and 68 cases (7%) of invasive lobular carcinoma (ILC). The 5-year OS, BCSS, RFS, and IBTR were 93%, 99%, 90%, and 1.5%, respectively. Upon univariate analysis, ILC (hazard ratio [HR], 4.6; p=.008) and lack of nodal evaluation (HR, 6.9; p=.01) were risk factors for IBTR. The 10-year IBTR was 2.5% for IDC and 14% for ILC. While the ABS and ASTRO criteria could not predict IBTR, the GEC-ESTRO intermediate risk group was associated with inferior IBTR (p=.04) when compared to both low risk and high risk groups. None of the suitability criteria was able to predict RFS. These results show that APBI is an effective treatment for patients with invasive breast cancer. Expansion of the current eligibility criteria should be considered, although prospective validation is needed. Caution is required when considering APBI for patients with ILC. In a large retrospective review of 946 patients with early breast cancer treated with partial mastectomy and accelerated partial breast irradiation (APBI) intracavitary brachytherapy, this study demonstrates durable local control. Patients deemed unsuitable or high risk by the American Brachytherapy Society, American Society for Radiation Oncology, and European Society for Radiotherapy and Oncology guidelines were not at increased risk for ipsilateral breast tumor recurrence (IBTR), suggesting that expansion of the current criteria should be considered. Importantly, however, these results demonstrate that caution should be taken when considering APBI for patients with invasive lobular carcinoma, as these patients had relatively high risk for IBTR (10-year IBTR, 14%).

Abstract PS1-01: Combined analysis of the WORTH 1 and WORTH 2 studies of ipsilateral breast tumor recurrence after breast conservative surgery without radiotherapyusing the “5-mm thick slice and 5-mm free margin method”

Abstract Background: Breast conserving surgery with radiotherapy is one of the standard treatment methods for early breast cancer. However, it is regarded as an option to treat elderly patients with small hormone receptor positive breast cancer with breast conserving surgery and hormone therapy without radiotherapy. Two sequential prospective studies were conducted to examine the efficacy of breast conserving surgery without radiotherapy from 2002. Patients and Methods: Primary breast cancer patients were divided into the WORTH 1 (n=123) group (Oct. 2002 and Mar. 2005) and the WORTH 2 (n=198) group (Dec. 2006 and Nov. 2011) and the data was retrospectively combined and analyzed. The eligibility criteria of the two sequential studies were a tumor ≥3cm determined by palpation, pathologically node negative by axillary dissection or sentinel node biopsy and M0, no preoperative treatment, postmenopausal patients ≥50 years of age at surgery, no tumor cells within 5 mm from the margins, no lymphatic invasion around the primary tumor, and estrogen receptor positive. The surgical specimens were sliced at 5 mm intervals and all the slices were examined microscopically. Postoperative radiotherapy was not conducted and adjuvant chemotherapy was optional. The patients were treated with tamoxifen or anastrozole in WORTH 1 and anastrozole in WORTH 2 for 5 years. Ipsilateral breast tumor recurrence (IBTR)-free survival and distant relapse-free survival (DRFS) were recorded as the interval from initial surgery until IRTR or distant relapse. The factors related to IBTR were evaluated using the proportional hazard model. Patients who did not develop IBTR or distant relapse were statistically censored at the time of the last follow-up or death. Survival rates were calculated using the Kaplan-Mayer method. Statistical analyses were conducted using the log rank test. Values &amp;lt; 0.05 were considered statistically significant. Results: The median age at surgery was 65 (range 50-84). The median tumor size was 1.5 cm (range 0-4.0 cm). The median follow-up period for IBTR was 95 months (range 4-192 months). Only 3 patients were treated with adjuvant chemotherapy. The 5- and 10-year overall survival rates were 98.7% and 95.1%, respectively and the 5- and 10-year distant DRFS rates were 99.3% and 96.3%, respectively. The 5- and 10-year IBTR free rates were 97.0% and 89.7%, respectively. Older patients had significantly less IBTR rates (5-year IBTR free rates: 95.8% for ≤64 vs. 98.1% for ≥65, p=0.019). There was no difference in IBTR rates between the large and small tumors (5-year IBTR free rates: 96.9% ≤1.4 cm vs. 96.8% for ≥1.5 cm, p=0.094). PR positivity had a significantly lower IBTR free rates (5-year IBTR free rates: 98.3% for PR positive vs. 91.5% for PR negative, p=0.009). The age at surgery (≤64, p=0.017, Hazard ratio 3.07, 95% CI 1.22-7.70) and the PR status (PR negative, p=0.024, Hazard ratio 2.54, 95% Cl 1.13-5.69) independently affected the IBTR rates. Both the 5- and 10-year IBTR free rates of the patients who were ≥65 at surgery and had PR positive tumors (n=136) were 98.4%. Conclusions: The findings suggest that the “5-mm thick slice and 5-mm free margin” method may be effective in selecting patients who can be treated with breast conserving surgery and hormone therapy without radiotherapy. Citation Format: Norikazu Masuda, Shozo Ohsumi, Reiki Nishimura, Sadako Akashi-Tanaka, Kimito Suemasu, Hideko Yamauchi, Eriko Tokunaga, Tadashi Ikeda, Tsunehiro Nishi, Hiroto Hayashi, Yuichi Iino, Yuichi Takatsuka, Hideo Inaji. Combined analysis of the WORTH 1 and WORTH 2 studies of ipsilateral breast tumor recurrence after breast conservative surgery without radiotherapyusing the “5-mm thick slice and 5-mm free margin method” [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-01.

Accelerated Partial Breast Irradiation (APBI): Where Are We Now?

Purpose of ReviewAccelerated partial breast irradiation (APBI) is an alternative approach to breast conserving therapy (BCT) where radiation (RT) is delivered over a shorter period of time compared with whole breast irradiation (WBI), resulting in improved patient convenience and cost savings. APBI can be delivered using brachytherapy, intraoperative RT, or conformal external beam radiation therapy (EBRT) techniques. In this review, the authors appraise the latest modern randomized controlled trials (RCTs) of APBI and discuss the application of the data to clinical practice.Recent FindingsThe OCOG-RAPID and NSABP B-39/RTOG 0413 trials recently reported long-term outcomes of APBI. The OCOG-RAPID trial delivered 38.5 Gy/10 fractions twice daily (at least 6 h apart using EBRT) or WBI and demonstrated non-inferiority of APBI compared with WBI (8-year cumulative rate of ipsilateral breast tumor recurrence (IBTR) was 3% after APBI or 2.8% after WBI, HR 1.27, 90%CI: 0.84–1.91). While acute toxicity was reduced, late toxicity and breast cosmesis were worse with APBI. The NSABP B-39 trial included higher risk patients and was unable to demonstrate equivalence between APBI (38.5 Gy/10 fractions delivered twice daily using EBRT or brachytherapy techniques) and WBI. However, 10-year IBTR rates were low: 4.6% vs. 3.9%, respectively, HR 1.22, 90%CI: 0.94–1.58. The University of Florence demonstrated low rates of local recurrence at 10 years and overall excellent breast cosmetic outcomes when APBI was delivered using EBRT to a dose of 30 Gy/5 fractions delivered on non-consecutive days.SummaryRecent RCTs of APBI have shed light on important factors for the integration of APBI into clinical practice, including patient selection and treatment delivery. APBI should be limited to patients with low-risk ductal carcinoma in situ or early stage (T1) invasive ductal cancer with clear margins of excision, estrogen receptor positivity, and node negative disease. Ongoing research should focus on the optimal dose/fractionation for delivery of EBRT-based APBI.

Accelerated Partial-Breast Irradiation Compared With Whole-Breast Irradiation for Early Breast Cancer: Long-Term Results of the Randomized Phase III APBI-IMRT-Florence Trial

To report the long-term results of external-beam accelerated partial-breast irradiation (APBI) intensity-modulated radiation therapy (IMRT) Florence phase III trial comparing whole-breast irradiation (WBI) to APBI in early-stage breast cancer. The primary end point was to determine the 5-year difference in ipsilateral breast tumor recurrence (IBTR) between 30 Gy in 5 once-daily fractions (APBI arm) and 50 Gy in 25 fractions with a tumor bed boost (WBI arm) after breast-conserving surgery. Five hundred twenty patients, more than 90% of whom had characteristics associated with low recurrence risk, were randomly assigned (WBI, n = 260; APBI, n = 260) between 2005 and 2013. Median follow-up was 10.7 years. The 10-year cumulative incidence of IBTR was 2.5% (n = 6) in the WBI and 3.7% (n = 9) in the APBI arm (hazard ratio [HR], 1.56; 95% CI, 0.55 to 4.37; P = .40). Overall survival at 10 years was 91.9% in both arms (HR, 0.95; 95% CI, 0.50 to 1.79; P = .86). Breast cancer-specific survival at 10 years was 96.7% in the WBI and 97.8% in the APBI arm (HR, 0.65; 95% CI, 0.21 to 1.99; P = .45). The APBI arm showed significantly less acute toxicity (P = .0001) and late toxicity (P = .0001) and improved cosmetic outcome as evaluated by both physician (P = .0001) and patient (P = .0001). The 10-year cumulative IBTR incidence in early breast cancer treated with external APBI using IMRT technique in 5 once-daily fractions is low and not different from that after WBI. Acute and late treatment-related toxicity and cosmesis outcomes were significantly in favor of APBI.

Efficacy of radiation boost after breast-conserving surgery for breast cancer with focally positive, tumor-exposed margins.

Many patients with positive margins following breast-conserving surgery (BCS) undergo re-excisions that aim to remove residual disease from the breast, which brings a tremendous emotional burden in addition to financial consequences. We sought to determine whether re-excisions could be safely avoided without compromising local control and survival by using whole-breast radiation therapy (WBRT) with a tumor bed boost in patients with early-stage breast cancer with focally positive, tumor-exposed margins after BCS. All patients with ductal carcinoma in situ (DCIS) and/or invasive breast cancer (IBC) who had pathologically tumor-exposed margins following BCS, without re-excision and treated with WBRT with tumor bed boost between March 2005 and December 2011, were included. The radiotherapy consisted of WBRT at a dose of 50 Gy in 25 fractions, followed by a tumor bed boost with an additional dose of 16 Gy in eight fractions. A total of 125 patients fulfilled the eligibility criteria; of the 125 patients, 1 had bilateral breast cancer, resulting in 126 cases. Invasive disease was found in 102 (81%) cases and purely ductal carcinoma in situ (DCIS) disease in 24 (19%) cases. The 10-year ipsilateral breast tumor recurrence (IBTR) -free survival, progression-free survival (PFS), and 10-year overall survival (OS) rates were 95%, 92.5% and 96%, respectively. Patients with early-stage breast cancer who receive BCS and have focally positive, tumor-exposed margins can avoid re-excision by undergoing WBRT followed by a sufficient dose of tumor bed boost, without negatively impacting local control and survival.

Validation of a Novel Nomogram for Prediction of Local Relapse after Surgery for Invasive Breast Carcinoma.

Around 7% of women who undergo breast-conserving surgery (BCS) or mastectomy are at risk of developing ipsilateral breast tumor recurrence (IBTR). When assessing risks that, like that of IBTR, depend on multiple clinicopathological variables, nomograms are the predictive tools of choice. In this study, two independent nomograms were constructed to estimate the individualized risk of IBTR after breast surgery. In this retrospective study, 18,717 consecutive patients with primary invasive breast cancer were enrolled. The training set used for building the nomograms comprised 15,124 patients (11,627 treated with BCS and 3497 with mastectomy), while the validation set included 3593 women (2565 BCS and 1028 mastectomy). Median follow-up time was 8years in the training set and 6years in the validation set. Multivariable Cox proportional hazards regression was used to identify independent factors for IBTR. Two separated nomograms were constructed on multivariate models for BCS and mastectomy. The factors that associated with IBTR after either BCS or mastectomy were identified. The two multivariable models were used to build nomograms for the prediction of IBTR 1year, 5years, and 10years after BCS or after mastectomy. Five-year and 10-year IBTR rates in the BCS training set were equal to 3.50% and 7.00%, respectively, and to 5.39% and 7.94% in the mastectomy training set. The nomograms were subsequently validated with c-index values of 0.77 and 0.69 in the BCS and mastectomy validation sets, respectively. The nomograms presented in this study provide clinicians and patients with a valuable decision-making tool for choosing between different treatment options for invasive breast cancer.

218P - Oncological impact of re-excision for positive margin status after breast conserving surgery in invasive breast cancer

BackgroundPositive margin of breast-conserving surgery (BCS) is well known to be a risk factor for ipsilateral breast tumor recurrence (IBTR). SSO/ASTRO guidelines defined ink on invasive cancer or DCIS as positive margin and recommend considering doing re-excision of the site of positive margin. However, whether re-excision can reduce IBTR has not been fully investigated yet. The aim of this study was to retrospectively assess the oncological impact of re-excision for positive margin status after BCS in invasive breast cancer. MethodsThe subjects were 196 invasive breast cancer patients who underwent BCS, and who were found to have positive margin. Of the 196 patients, 55 underwent re-excision after initial BCS (group A), and 139 did not (group B). We analyzed IBTR free survival in each group and evaluated the predictors for IBTR and overall survival (OS) using Cox proportional hazards modeling. ResultsOf the 196 patients, 188 (96%) underwent adjuvant radiotherapy and 24 of 55 re-excision (43%) identified residual disease. There was no significant difference in 10-year IBTR free survival between group A and group B (94.4% versus 93.8%; P=0.58). In a multivariate analysis, re-excision was not associated with IBTR and OS, while younger age, lack of adjuvant radiotherapy, and invasive component of margin status were independent predictors of IBTR. ConclusionsIn our retrospective study, re-excision for positive margin after initial BCS in invasive breast cancer does not contribute to prevent IBTR and may not translate into improved OS. Further treatment should be considered when patient was younger and margin status was invasive component. Legal entity responsible for the studyKenjiro Jimbo. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Lymphopenia as a Potential Predictor of Ipsilateral Breast Tumor Recurrence in Early Breast Cancer.

The aim of this study was to investigate the association between lymphopenia after breast conserving therapy (BCT) and ipsilateral breast tumor recurrence (IBTR) in early breast cancer (EBC). We examined 216 EBC patients treated with partial mastectomy followed by radiotherapy (RT), none of whom received chemotherapy. Absolute lymphocyte counts (ALCs) during the two years after RT were collected from each patient: pretreatment ALC, ALC at 3-5 months (ALC1), ALC at 9-11 months, ALC at 15-17 months, and ALC at 21-23 months. The 102 patients with ALC1 ≤1,479 cells/μl (defined as lymphopenia) had significantly higher 10-year IBTR rate than the 102 patients with ALC1 >1,479 cells/μl (16.2% vs. 1%, p=0.0034). The multivariate analysis showed that age, resection margins, human epidermal growth factor receptor, and lymphopenia were significant predictors of IBTR. Lymphopenia is a potential predictor for IBTR in EBC patients treated with BCT.

The impact of age on the risk of ipsilateral breast tumor recurrence after breast-conserving therapy in breast cancer patients with a\u2009>\u20095\u2009mm margin treated without boost irradiation

BackgroundThe boost irradiation to the tumor bed following whole-breast irradiation (WBI) reduced the risk of ipsilateral breast tumor recurrence (IBTR). However, in Japan, almost all patients with a margin ≤5 mm receive boost irradiation to the tumor bed, but the decision to perform boost irradiation for those with a margin > 5 mm is dependent on the institution. Thus, institutional guidelines on utilizing boost irradiation for patients aged ≤40 or ≤ 50 years vary. We investigated the IBTR rate to assess the appropriate age for boost irradiation to the tumor bed with a margin > 5 mm.MethodsFrom January 1993 to December 2010, 419 patients with early-stage breast cancer and negative margins (> 5 mm) after breast-conserving surgery received WBI without boost irradiation. The Gray test was used to compare the cumulative incidence of IBTR among patients aged ≤40, 41–50, and ≥ 51 years. Hazard ratios were estimated using the Fine and Gray models. Furthermore, as a subgroup analysis, we investigated whether IBTR depended on the use of systemic therapy, such as anthracycline or taxane regimens.ResultsThe median follow-up time was 9.3 years. In multivariate analysis, only age predicted IBTR (p = 0.047). The 10-year IBTR rate was 15.7% in patients aged ≤40, 3.8% in those aged 41–50, and 2.0% in patients aged ≥51 years. The difference between patients aged ≤40 and 41–50 years was statistically significant (p = 0.045), whereas the difference between patients aged 41–50 and ≥ 51 years was not significant (p = 0.21).ConclusionsIn our institutional surgical setting, when boost irradiation is performed only for patients with a margin ≤5 mm, the IBTR rate after WBI without boost irradiation was significantly higher in patients aged ≤40 years, suggesting that boost irradiation should be used for patients in this age group.

External Validation of IBTR! 2.0 Nomogram for Prediction of Ipsilateral Breast Tumor Recurrence

PURPOSE IBTR! 2.0 nomogram is web-based nomogram that predicts ipsilateral breast tumor recurrence (IBTR). We aimed to validate the IBTR! 2.0 using an external data set. Materials and. METHODS The cohort consisted of 2,206 patients, who received breast conserving surgery and radiation therapy from 1992 to 2012 at our institution, where wide surgical excision is been routinely performed. Discrimination and calibration were used for assessing model performance. Patients with predicted 10-year IBTR risk based on an IBTR! 2.0 nomogram score of 10% were assigned to groups 1, 2, 3, and 4, respectively. We also plotted calibration values to observe the actual IBTR rate against the nomogram-derived 10-year IBTR probabilities. RESULTS The median follow-up period was 73 months (range, 6 to 277 months). The area under the receiver operating characteristic curve was 0.607, showing poor accordance between the estimated and observed recurrence rate. Calibration plot confirmed that the IBTR! 2.0 nomogram predicted the 10-year IBTR risk higher than the observed IBTR rates in all groups. High discrepancies between nomogram IBTR predictions and observed IBTR rates were observed in overall risk groups. Compared with the original development dataset, our patients had fewer high grade tumors, less margin positivity, and less lymphovascular invasion, and more use of modern systemic therapies. Conclusions: IBTR! 2.0 nomogram seems to have the moderate discriminative ability with a tendency to over-estimating risk rate. Continued efforts are needed to ensure external applicability of published nomograms by validating the program using an external patient population.

External validation of IBTR! 2.0 nomogram for prediction of ipsilateral breast tumor recurrence.

PurposeIBTR! 2.0 nomogram is web-based nomogram that predicts ipsilateral breast tumor recurrence (IBTR). We aimed to validate the IBTR! 2.0 using an external data set.Materials and MethodsThe cohort consisted of 2,206 patients, who received breast conserving surgery and radiation therapy from 1992 to 2012 at our institution, where wide surgical excision is been routinely performed. Discrimination and calibration were used for assessing model performance. Patients with predicted 10-year IBTR risk based on an IBTR! 2.0 nomogram score of <3%, 3%–5%, 5%–10%, and >10% were assigned to groups 1, 2, 3, and 4, respectively. We also plotted calibration values to observe the actual IBTR rate against the nomogram-derived 10-year IBTR probabilities.ResultsThe median follow-up period was 73 months (range, 6 to 277 months). The area under the receiver operating characteristic curve was 0.607, showing poor accordance between the estimated and observed recurrence rate. Calibration plot confirmed that the IBTR! 2.0 nomogram predicted the 10-year IBTR risk higher than the observed IBTR rates in all groups. High discrepancies between nomogram IBTR predictions and observed IBTR rates were observed in overall risk groups. Compared with the original development dataset, our patients had fewer high grade tumors, less margin positivity, and less lymphovascular invasion, and more use of modern systemic therapies.conclusionsIBTR! 2.0 nomogram seems to have the moderate discriminative ability with a tendency to over-estimating risk rate. Continued efforts are needed to ensure external applicability of published nomograms by validating the program using an external patient population.

Delay in radiotherapy is associated with an increased risk of disease recurrence in women with ductal carcinoma in situ.

The current study was conducted to examine the association between ipsilateral breast tumor recurrence (IBTR) and the timing of radiotherapy (RT) in women with ductal carcinoma in situ (DCIS) undergoing breast-conserving surgery (BCS). Women with DCIS who were treated with BCS and RT from 1980 through 2010 were identified from a prospectively maintained database. IBTR rates, measured from the time of RT completion, were compared between those who initiated RT ≤8 weeks, >8 to 12 weeks, and >12 weeks after the completion of surgery. The association between RT timing and IBTR was evaluated by Kaplan-Meier and log-rank analyses; Cox modeling was used for multivariable analysis. A total of 1323 women met the inclusion criteria. The median follow-up was 6.6 years, with 311 patients followed for ≥10 years. A total of 126 IBTR events occurred. Patients were categorized by RT timing: 806 patients (61%) with timing of ≤8 weeks, 386 patients (29%) with timing of >8 to 12 weeks, and 131 patients (10%) with timing >12 weeks. The 5-year and 10-year IBTR rates were 5.8% and 13.0%, respectively, for RT starting ≤8 weeks after surgery; 3.8% and 7.6%, respectively, for RT starting >8 to 12 weeks after surgery; and 8.8% and 23.0%, respectively, for an RT delay >12 weeks after surgery (P = .004). On multivariable analysis, menopause (hazard ratio [HR], 0.54; P = .0009) and endocrine therapy (HR, 0.45; P = .002) were found to be protective against IBTR, whereas a delay in RT >12 weeks compared with ≤8 weeks was associated with a higher risk of IBTR (HR, 1.92; P = .014). There was no difference in IBTR noted between RT initiation at ≤8 weeks and initiation at >8 to 12 weeks after BCS (P = .3). A delay in RT >12 weeks is associated with a significantly higher risk of IBTR in women undergoing BCS for DCIS. Efforts should be made to avoid delays in starting RT to minimize the risk of disease recurrence. Cancer 2018;124:46-54. © 2017 American Cancer Society.

Contralateral Breast Cancer Risk in Women with Ductal Carcinoma In Situ: Is it High Enough to Justify Bilateral Mastectomy?

Women with ductal carcinoma in situ (DCIS) are increasingly choosing bilateral mastectomy. We sought to quantify rates of contralateral breast cancer (CBC) and ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery (BCS) for DCIS, and to compare risk factors for CBC and IBTR. From 1978 to 2011, DCIS patients undergoing BCS with a contralateral breast at risk were identified from a prospectively maintained database. The association of clinicopathologic and treatment factors with CBC and IBTR were evaluated using Kaplan-Meier analysis, multivariable Cox regression, and competing risk regression (CRR). Of 2759 patients identified, 151 developed CBC and 344 developed IBTR. Five- and 10-year Kaplan-Meier CBC rates were 3.2 and 6.4%. Overall, 10-year IBTR rates were 2.5-fold higher than CBC rates, and, without radiation, 4-fold higher. On CRR, 5- and 10-year rates were 2.9 and 5.8% for CBC, and 7.8 and 14.5% for IBTR. CBC risk and invasive CBC risk were not significantly associated with age, family history, presentation, nuclear grade, year of surgery, or radiation. By multivariable Cox regression, endocrine therapy was associated with lower CBC risk (hazard ratio 0.57, p=0.03). Ten-year risk of subsequent CBC in the subset of patients who developed IBTR was similar to the cohort as a whole (8.1 vs. 6.4%). CBC rates were low across all groups, including those who experienced IBTR. CBC was not associated with factors that increase IBTR risk. While factors associated with IBTR risk are important in decision making regarding management of the index DCIS, they are not an indication for contralateral prophylactic mastectomy.

Women with Low-Risk DCIS Eligible for the LORIS Trial After Complete Surgical Excision: How Low Is Their Risk After Standard Therapy?

Identifying DCIS patients at low risk for disease progression could obviate need for standard therapy. The LORIS (surgery versus active monitoring for low-risk DCIS) trial is studying the safety of monitoring low-risk DCIS, although ipsilateral breast tumor recurrence (IBTR) rates in patients meeting enrollment criteria after complete surgical excision are unknown. Women with pure DCIS treated with breast-conserving surgery (BCS) with/without radiation therapy (RT) from 1/1996-1/2011 were included from a prospectively maintained database. IBTR rates were compared between those who did and did not meet LORIS eligibility criteria (age≥46years, screen-detected calcifications, nipple discharge absence, minimal family history, non-high-grade DCIS) after complete surgical excision. A total of 2394 women were identified; 401 met LORIS criteria. Median follow-up was 5.9years; 431 had ≥10years follow-up. LORIS cohort median age was 61years (range 46-86years); 207 (52%) underwent RT, 79 (20%) received endocrine therapy. Of 401 patients, 24 experienced an IBTR. Overall 10-year IBTR rates were 10.3% (LORIS) versus 15.4% (non-LORIS) (p=0.08); without RT, 12.1 versus 21.4%, respectively (p=0.06). The 10-year invasive-IBTR rates for women meeting LORIS criteria were: 5.3% BCS overall, 6.0% without RT. Women meeting LORIS criteria (after complete surgical excision) are at somewhat lower risk for IBTR. Among such women undergoing excision without RT, the 10-year invasive-IBTR rate was 6%. Given that approximately 20% of women with core biopsy-proven non-high-grade DCIS have invasive cancer at excision, women managed without excision would be expected to incur higher invasive cancer rates. Additional criteria are needed to identify women not requiring intervention for DCIS.

Validation of the Web-Based IBTR! 2.0 Nomogram to Predict for Ipsilateral Breast Tumor Recurrence After Breast-Conserving Therapy

Toevaluate the IBTR! 2.0 nomogram, which predicts 10-year ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy with and without radiation therapy for breast cancer, by using a large, external, and independent cancer center database. We retrospectively identified 1898 breast cancer cases, treated with breast-conserving therapy and radiation therapy at the University Hospital Leuven from 2000 to 2007, with requisite data for the nomogram variables. Clinicopathologic factors were assessed. Two definitions of IBTR were considered where simultaneous regional or distant recurrence were either censored (conform IBTR! 2.0) or included as event. Validity of the prediction algorithm was tested in terms of discrimination and calibration. Discrimination was assessed by the concordance probability estimate and Harrell's concordance index. The mean predicted and observed 10-year estimates were compared for the entire cohort and for 4 risk groups predefined by nomogram-predicted IBTR risks, and a calibration plot was drawn. Median follow-up was 10.9years. The 10-year IBTR rates were 1.3% and 2.1%, according to the 2 definitions of IBTR. The validation cohort differed from the development cohort with respect to the administration of hormonal therapy, surgical section margins, lymphovascular invasion, and tumor size. In univariable analysis, younger age (P=.002) and a positive nodal status (P=.048) were significantly associated with IBTR, with a trend for the omission of hormonal therapy (P=.061). The concordance probability estimate and concordance index varied between 0.57 and 0.67 for the 2 definitions of IBTR. In all 4 risk groups the model overestimated the IBTR risk. In particular, between the lowest-risk groups a limited differentiation was suggested by the calibration plot. The IBTR! 2.0 predictive model for IBTR in breast cancer patients shows substandard discriminative ability, with an overestimation of the risk in all subgroups.

Very low local recurrence rates after breast-conserving therapy: analysis of 8485 patients treated over a 28-year period.

The purpose of this study was to study the impact of changes in clinical practice on outcome in patients treated with breast-conserving therapy (BCT) over a period of 28years. Patients with early invasive breast cancer, who were treated with BCT at the Netherlands Cancer Institute between 1980 and 2008, were studied. Clinical characteristics, treatment and outcome were compared between groups (1980-1987; 1988-1998; 1999-2008). The main endpoint analyzed was ipsilateral breast tumor recurrence (IBTR). 8485 patients with a median follow-up of 9 years (IQR 6-14 years) were analyzed. The cumulative 5- and 10-year IBTR incidences were, respectively, 2 and 5% for the whole cohort and 4 and 9% in patients ≤40years. Young age was a significant risk factor for IBTR in multivariable analysis. IBTR-free interval was better for patients who received a RT boost (HR 0.65) or systemic therapy (HR 0.52). In later years, patients less often received a boost and more often underwent adjuvant systemic treatment. 761 patients (9.0%) underwent a re-excision; the tumor resection margins were tumor free for 85%. In later years (1999-2008), 89% of patients had a tumor-free margin. The margin status of invasive carcinoma did not influence IBTR, DM rate, or OS. Between 1980 and 2008, locoregional control after BCT remained stable with low IBTR rates, even in young patients. These good results were achieved under the policy of accepting close or focally positive margins, indicating this is a safe approach. The results of this study may help in lowering the re-excision rates, which are high in many centers.