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

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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. IMPLICATIONS FOR PRACTICE: 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%).

Management of ductal carcinoma in situ with accelerated partial breast irradiation brachytherapy: Implications for guideline expansion.

PURPOSE: Accelerated partial breast irradiation (APBI) for patients with ductal carcinoma in situ (DCIS) is controversial, and the suitability criteria from the American Brachytherapy Society (ABS), American Society of Therapeutic Radiology and Oncology (ASTRO), and the European Society for Radiotherapy and Oncology (GEC-ESTRO) have important differences. METHODS AND MATERIALS: This is a single-institution retrospective review of 169 consecutive patients with DCIS who underwent lumpectomy followed by APBI intracavitary brachytherapy from 2003 to 2018. Outcomes, including overall survival, recurrence-free survival (RFS), ipsilateral breast tumor recurrence, and distant metastasis, were estimated with the Kaplan-Meier method. RESULTS: The median followup time was 62.5 months. Median age was 66 years (47-89 years). The majority of patients had estrogen receptor-positive disease (89%). Fifty patients (30%) had Grade 3 disease. Of the 142 patients with adequate pathology interpretation, 91 and 108 cases had margins ≥ 3 mm and ≥2 mm, respectively. Most patients (72%) were prescribed and started endocrine therapy. Of the patients evaluable for ABS criteria (N = 130), 97 met the suitability criteria. Of the patients evaluable for ASTRO criteria (N = 129), 42 were deemed cautionary and 33 were deemed unsuitable. Of the patients evaluable for GEC-ESTRO criteria (N = 143), 141 cases were at intermediate risk and two were at high risk. Five-year ipsilateral breast tumor recurrence, RFS, and overall survival were 0.6%, 97.7%, and 97.2%, respectively. The ABS, ASTRO, and GEC-ESTRO criteria failed to significantly predict for RFS. CONCLUSIONS: These results, although limited by short-term followup, indicate that expansion of the eligibility criteria of APBI for patients with DCIS should be considered.

Survival and patterns of relapse in patients with oral tongue cancer.

PURPOSE: To evaluate the survival and patterns of relapse for patients with squamous cell carcinoma (SCC) of the oral tongue. PATIENTS AND METHODS: Between 1999 and 2007, 50 patients with SCC of the oral tongue were treated at the University of Colorado Denver. Of the 50 patients, 38 had newly diagnosed SCC of the oral tongue (13 with stage I-II and 25 with stage III-IV disease), and 12 presented with locally recurrent SCC. Of the 50 patients, 49 were treated with initial surgery and 1 with definitive chemoradiotherapy. Adjuvant radiotherapy or chemoradiotherapy was administered to 42 patients after surgery. Of the 13 patients with newly diagnosed stage I-II disease, 7 did not receive adjuvant therapy. The actuarial locoregional control, freedom from distant relapse, and survival were determined using the Kaplan-Meier method, and comparisons were made using the log-rank test. RESULTS: The median follow-up was 29 months (range 4 to 95) for living patients. The 2-year locoregional control and freedom from distant relapse rate was 58% and 83%, respectively. Locoregional control was particularly low among patients with stage I-II disease, for whom the 2-year locoregional control rate was only 35%. The median survival time and 2-year survival rate for all patients was 42 months and 65%, respectively. The 2-year survival rate for patients with stage I-II oral tongue cancer was 77% compared with 52% for patients with stage III-IV disease (P = .04). CONCLUSIONS: Despite aggressive therapy, patients with SCC of the oral tongue have a low rate of local tumor control and survival, particularly among those with stage I-II disease. These patients should be considered for inclusion in clinical trials evaluating novel postoperative therapies.