Management of the Axilla in Early-Stage Breast Cancer: Ontario Health (Cancer Care Ontario) and ASCO Guideline.

PURPOSE: To provide recommendations on the best strategies for the management and on the best timing and treatment (surgical and radiotherapeutic) of the axilla for patients with early-stage breast cancer. METHODS: Ontario Health (Cancer Care Ontario) and ASCO convened a Working Group and Expert Panel to develop evidence-based recommendations informed by a systematic review of the literature. RESULTS: This guideline endorsed two recommendations of the ASCO 2017 guideline for the use of sentinel lymph node biopsy in patients with early-stage breast cancer and expanded on that guideline with recommendations for radiotherapy interventions, timing of staging after neoadjuvant chemotherapy (NAC), and mapping modalities. Overall, the ASCO 2017 guideline, seven high-quality systematic reviews, 54 unique studies, and 65 corollary trials formed the evidentiary basis of this guideline. RECOMMENDATIONS: Recommendations are issued for each of the objectives of this guideline: (1) To determine which patients with early-stage breast cancer require axillary staging, (2) to determine whether any further axillary treatment is indicated for women with early-stage breast cancer who did not receive NAC and are sentinel lymph node-negative at diagnosis, (3) to determine which axillary strategy is indicated for women with early-stage breast cancer who did not receive NAC and are pathologically sentinel lymph node-positive at diagnosis (after a clinically node-negative presentation), (4) to determine what axillary treatment is indicated and what the best timing of axillary treatment for women with early-stage breast cancer is when NAC is used, and (5) to determine which are the best methods for identifying sentinel nodes.Additional information is available at www.asco.org/breast-cancer-guidelines.

Domain adaptation and self-supervised learning for surgical margin detection.

PURPOSE: One in five women who undergo breast conserving surgery will need a second revision surgery due to remaining tumor. The iKnife is a mass spectrometry modality that produces real-time margin information based on the metabolite signatures in surgical smoke. Using this modality and real-time tissue classification, surgeons could remove all cancerous tissue during the initial surgery, improving many facets of patient outcomes. An obstacle in developing a iKnife breast cancer recognition model is the destructive, time-consuming and sensitive nature of the data collection that limits the size of the datasets. METHODS: We address these challenges by first, building a self-supervised learning model from limited, weakly labeled data. By doing so, the model can learn to contextualize the general features of iKnife data from a more accessible cancer type. Second, the trained model can then be applied to a cancer classification task on breast data. This domain adaptation allows for the transfer of learnt weights from models of one tissue type to another. RESULTS: Our datasets contained 320 skin burns (129 tumor burns, 191 normal burns) from 51 patients and 144 breast tissue burns (41 tumor and 103 normal) from 11 patients. We investigate the effect of different hyper-parameters on the performance of the final classifier. The proposed two-step method performed statistically significantly better than a baseline model (p-value < 0.0001), by achieving an accuracy, sensitivity and specificity of 92%, 88% and 92%, respectively. CONCLUSION: This is the first application of domain transfer for iKnife REIMS data. We showed that having a limited number of breast data samples for training a classifier can be compensated by self-supervised learning and domain adaption on a set of unlabeled skin data. We plan to confirm this performance by collecting new breast samples and extending it to incorporate other cancer tissues.

TLD skin dose measurements and acute and late effects after lumpectomy and high-dose-rate brachytherapy only for early breast cancer.

PURPOSE: This report examines the relationships between measured skin doses and the acute and late skin and soft tissue changes in a pilot study of lumpectomy and high-dose-rate brachytherapy only for breast cancer. METHODS AND MATERIALS: Thirty-seven of 39 women enrolled in this pilot study of high-dose-rate brachytherapy (37.2 Gy in 10 fractions b.i.d.) each had thermoluminescent dosimetry (TLD) at 5 points on the skin of the breast overlying the implant volume. Skin changes at TLD dose points and fibrosis at the lumpectomy site were documented every 6 to 12 months posttreatment using a standardized physician-rated cosmesis questionnaire. The relationships between TLD dose and acute skin reaction, pigmentation, or telangiectasia at 5 years were analyzed using the GEE algorithm and the GENMOD procedure in the SAS statistical package. Fisher's exact test was used to determine whether there were any significant associations between acute skin reaction and late pigmentation or telangiectasia or between the volumes encompassed by various isodoses and fibrosis or fat necrosis. RESULTS: The median TLD dose per fraction (185 dose points) multiplied by 10 was 9.2 Gy. In all 37 patients, acute skin reaction Grade 1 or higher was observed at 5.9% (6 of 102) of dose points receiving 10 Gy or less vs. 44.6% (37 of 83) of dose points receiving more than 10 Gy (p < 0.0001). In 25 patients at 60 months, 1.5% telangiectasia was seen at dose points receiving 10 Gy or less (1 of 69) vs. 18% (10 of 56) telangiectasia at dose points receiving more than 10 Gy (p = 0.004). Grade 1 or more pigmentation developed at 1.5% (1 of 69) of dose points receiving less than 10 Gy vs. 25% (14 of 56) of dose points receiving more than 10 Gy (p < 0.001). A Grade 1 or more acute skin reaction was also significantly associated with development of Grade 1 or more pigmentation or telangiectasia at 60 months. This association was most significant for acute reaction and telangiectasia directly over the lumpectomy site (p < 0.001). Grade 1 or more fibrosis, in 25 patients with a 60-month follow-up, occurred in 47.4% (9 of 19) of patients with a volume of 45 cm3 or less covered by the 100% isodose vs. 83.3% (5 of 6) of patients with a larger volume (p = 0.180). Asymptomatic and biopsy-proven fat necrosis occurred in 5 patients. No significant differences in fat necrosis rates according to volume were detected. CONCLUSIONS: For high-dose-rate brachytherapy to the lumpectomy site, TLD skin dose was significantly related to acute skin reaction and to pigmentation and telangiectasia at 60 months. An acute skin reaction was also significantly associated with the development of telangiectasia at 60 months. TLD skin dose measurement may allow modification of the brachytherapy implant geometry (dwell times and position) to minimize late skin toxicity.

Patterns of breast recurrence in a pilot study of brachytherapy confined to the lumpectomy site for early breast cancer with six years' minimum follow-up.

PURPOSE: In this pilot study of high-dose-rate brachytherapy to the lumpectomy site as the sole radiation, ipsilateral and contralateral breast recurrences are documented with specific attention to the location of recurrence relative to the lumpectomy site. METHODS: Between March 1992 and January 1996, 39 patients with T1 (32 patients) and T2 breast cancers received 37.2 Gy in 10 fractions (b.i.d.) over 1 week prescribed to a volume encompassing the surgical clips. Thirteen received adjuvant tamoxifen, and 4 received chemotherapy. Follow-up included annual bilateral mammograms and clinical breast examination every 3 to 6 months. Whereas 13 patients had intraoperative implantation of the lumpectomy site, 26 had postoperative implantation. The latter group and 7 of the former group had surgical clips marking the lumpectomy site, which allowed estimates of the distance of any ipsilateral breast recurrence from the lumpectomy site, using the mediolateral and cranio-caudad mammographic views. RESULTS: At a median follow-up of 91 months, 33 women are alive, 4 have died of disease, and 2 have died of other causes. The 5-year actuarial rate of ipsilateral breast recurrence was 16.2%. Of 6 ipsilateral recurrences, 2 occurred within the lumpectomy site (in-field recurrences). One of the 2 patients had a 1-mm microscopic margin at initial diagnosis; the recurrence was a 3.5-mm microscopic focus of duct carcinoma in situ. The other patient had a 1.5-cm, high-grade infiltrating mammary carcinoma with no residual at wider resection at first diagnosis; the 5-mm invasive recurrence was also of high grade. Four women developed invasive recurrences at least 1.6 cm or more from the lumpectomy site (out-of-field recurrences). Two of these women had gross multifocal recurrences with two cancers in each patient; 1 of the 2 patients had an extensive intraductal component at initial diagnosis. The estimated nearest distances between the out-of-field recurrences and the surgical clips were 1.6, 5.5, 7.7, and 12.0 cm. All ipsilateral breast recurrences were salvaged by mastectomy (4 patients) or by repeat lumpectomy (2 patients) and whole-breast radiation. The interval postdiagnosis to ipsilateral recurrence ranged from 20 months to 58 months. There were two contralateral breast recurrences at intervals of 34 and 36 months; 1 of these patients also had a multifocal, ipsilateral recurrence at 58 months, as previously described. Among patients with any breast recurrence, 1 patient had a family history of prostate cancer; there was no family history of breast or ovarian cancer. Of 17 patients who received adjuvant systemic therapy, only 1 had a breast recurrence. CONCLUSIONS: In this pilot study, breast recurrences outside of the lumpectomy site were the predominant pattern of recurrence.