HJAR Mar/Apr 2026

HEALTHCARE JOURNAL OF ARKANSAS I  MAR / APR 2026 41 Foster Lasley, MD, DABR Radiation Oncologist Highlands Oncology cancer will continue to improve while the toxicity of surgery and radiation will con- tinue to diminish. n REFERENCES 1 EBCTCG (Early Breast CancerTrialists’Collaborative Group), et al.,“Effect of Radiotherapy After Mastec- tomy andAxillary Surgery on 10-Year Recurrence and 20-Year Breast Cancer Mortality: Meta-Analysis of Individual Patient Data for 8,135 women in 22 Ran- domised Trials,” Lancet 383, no. 9935 (2014): 2127– 35 ,https://doi.org/10.1016/S0140-6736( 14)60488-8. Erratum in: Lancet 384, no. 9957 (2014): 1848. 2 I. H. Kunkler, et al., “Ten-Year Survival After Post- mastectomy Chest-Wall Irradiation in Breast Cancer,” New EnglandJournal of Medicine 393,no.18 (2025): 1771–83, https://doi.org/10.1056/NEJMoa2412225. 3 A. E. Giuliano, et al., “Effect of Axillary Dissection vs NoAxillary Dissection on 10-Year Overall Survival AmongWomen with Invasive Breast Cancer and Sen- tinel NodeMetastasis:TheACOSOGZ0011 (Alliance) Randomized Clinical Trial,”JAMA 318, no. 10 (2017): 918–26 ,https://doi.org/10.1001/jama.2017.11470; S. A. L. Bartels, et al.,“Radiotherapy or Surgery of the Axilla After a Positive Sentinel Node in Breast Can- cer: 10-Year Results of the Randomized Controlled EORTC 10981-22023AMAROSTrial,”Journal of Clini- cal Oncology 41,no.12 (2023): 2159–65,https://doi. org/10.1200/JCO.22.01565;Jana de Boniface,et al., “Omitting Axillary Dissection in Breast Cancer with Sentinel-Node Metastases,” New England Journal of Medicine 390,no.13 (2024): 1163–75,https://doi. org/10.1056/NEJMoa2313487. 4 T.H.Lee,et al.,“Protocol for the Postoperative Radio- therapy in N1 Breast Cancer Patients (PORT-N1)Trial, a Prospective Multicenter, Randomized, Controlled, Non-InferiorityTrial of Patients Receiving Breast-Con- serving Surgery or Mastectomy,”BMCCancer 22,no. 1 (2022): 1179 ,https://doi.org/10.1186/s12885-022- 10285-0; W. R. Parulekar, et al., “Canadian Cancer Trials GroupMA.39TAILOR RT:ARandomizedTrial of Regional Radiotherapy in Biomarker Low-Risk Node- Positive Breast Cancer,”NCT03488693. 5 E. P. Mamounas, et al., “Omitting Regional Nodal Irradiation After Response to Neoadjuvant Che- motherapy,” New England Journal of Medicine 392, no. 21 (2025): 2113–24, https://doi.org/10.1056/ NEJMoa2414859. 6 P. Schmid P, et al., “Pembrolizumab for Early Tri- ple-Negative Breast Cancer,” New England Journal of Medicine 382, no. 9 (2020): 810–21, https://doi. org/10.1056/NEJMoa1910549. Foster Lasley, MD, earned a bachelor’s degree in chemistry and mathematics from Oral Roberts University and medical degree from the University of Oklahoma, where he was inducted into theAlpha OmegaAlphamedical honors society.He completed his internship in internal medicine at the University of Oklahoma’sTulsa campus and his radiation oncology residency at Indiana University. He is the co-author of the book, Basic Radiotherapy Physics and Biology . ypN0 status (no residual cancer in the arm- pit nodes after chemotherapy) to then be randomized to regional nodal irradiation or observation. The results were published in the New England Journal of Medicine in June 2025 5 and showed that regional nodal irradiation did not significantly increase the invasive breast cancer recurrence-free in- terval, locoregional recurrence-free interval, the distant recurrence-free interval, disease- free survival, or overall survival. The details of this trial have been heavily scrutinized by experts in radiation oncol- ogy, and there are questions as to whether this conclusion is valid for all cohorts. The main skepticism involves women with com- plete response in the lymph nodes but not in the primary tumor, and in women who are hormone receptor-positive. Neverthe- less, this trial does raise serious doubts as to the necessity of adjuvant radiation therapy to the chest wall and nodes in women who achieve a complete response in the armpit to chemotherapy. This question is becom- ing more relevant as continued advances are made in neoadjuvant systemic therapy regimens, such as Keynote 522 6 and others that are awaiting publication. Applying Emerging Evidence in Multidisciplinary Care These nuances are being discussed for individual patients regularly every week in breast tumor boards across various Ar- kansas health systems. For women who do eventually require postmastectomy radia- tion, recent trials over just the last few years have shown the safety of shortened courses of radiation (around three to four weeks). Advances have been made in reducing skin toxicity and sparing the heart. As science continues to advance, it is expected that the local control and overall survival of breast between N0 and N1 patients, although the number of patients with tumors greater than five centimeters (T3) was unfortunately very small. For patients with one to three lymph nodes, the data is less useful since most of those patients enrolled in the trial at the time would no longer get an armpit node dissec- tion today. This practice developed since the publication of ACOSOG Z0011, AMAROS, and SENOMAC trials 3 that showed an arm- pit dissection is not needed if the armpit will be radiated for N1 patients. It is worth noting that the SUPREMO trial included a majority of patients having had chemotherapy, al- thoughmost of the chemotherapy recipients were adjuvant instead of neoadjuvant. The question of postmastectomy radiation in this cohort may become more clear as the Korean PORT-N1 and the TAYLOR RT trials 4 eventually show data regarding the same question but with less aggressive armpit dissection requirements and more T3N0 patients. The TAYLOR RT trial, in particular, is interesting, as patients with only one to two lymph nodes positive on sentinel node biopsy will not need an armpit dissection before being randomized to radiation versus observation. Another factor that makes decisions dif- ficult for postmastectomy radiation is the introduction of neoadjuvant chemotherapy or other systemic therapies prior to mastec- tomy. It was previously noted in retrospec- tive analyses that women who had known armpit metastases prior to chemotherapy and then had a complete response to che- motherapy at the time of surgery (ypN0), subsequently had extremely low recurrence rates. A trial was then set up to further eval- uate this hypothesis. NSABP B51 enrolled 1,641 women with clinical stage T1–T3 and cN1 (biopsy proven) who then achieved