Pectoralis Muscle Dosimetry and Posttreatment Rehabilitation Utilization for Patients With Early-Stage Breast Cancer.

PURPOSE: Up to 50% of women treated for localized breast cancer will experience some degree of arm or shoulder morbidity. Although radiation is thought to contribute to this morbidity, the mechanism remains unclear. Prior studies have shown biologic and radiographic changes in the pectoralis muscles after radiation. This study thus aimed to investigate the relationship between radiation to the pectoralis muscles and referrals for rehabilitation services posttreatment for arm and shoulder morbidity. METHODS AND MATERIALS: A retrospective 1:1 matched case-control study was conducted for patients with breast cancer who were and were not referred for breast or shoulder rehabilitation services between 2014 and 2019 at a single academic institution. Patients were included if they had a lumpectomy and adjuvant radiation. Patients who underwent an axillary lymph node dissection were excluded. Cohorts were matched based on age, axillary surgery, and use of radiation boost. Muscle doses were converted to equivalent dose in 2 Gy fractions assuming an α:ß ratio of 2.5 and were compared between the 2 groups. RESULTS: In our cohort of 50 patients of a median age 60 years (interquartile range, 53-68 years), 36 patients (72%) underwent a sentinel lymph node biopsy in addition to a lumpectomy. Although pectoralis muscle doses were generally higher in those receiving rehabilitation services, this was not statistically significant. Pectoralis major V20-40 Gy reached borderline significance, as did pectoralis major mean dose (17.69 vs 20.89 Gy; P = .06). CONCLUSIONS: In this limited cohort of patients, we could not definitively conclude a relationship between pectoralis muscle doses and use of rehabilitation services. Given the borderline significant findings, this should be further investigated in a larger cohort.

Factors affecting timing of surgery following neoadjuvant chemoradiation for esophageal cancer.

Background: Neoadjuvant chemoradiation with esophagectomy is standard management for locally advanced esophageal cancer. Studies have shown that surgical timing following chemoradiation is important for minimizing postoperative complications, however in practice timing is often variable and delayed. Although postoperative impact of surgical timing has been studied, less is known about factors associated with delays. Materials and methods: A retrospective review was performed for 96 patients with esophageal cancer who underwent chemoradiation then esophagectomy between 2018 and 2020 at a single institution. Univariable and stepwise multivariable analyses were used to assess association between social (demographics, insurance) and clinical variables (pre-operative weight, comorbidities, prior cardiothoracic surgery, smoking history, disease staging) with time to surgery (≤8 weeks "on-time" vs. >8 weeks "delayed"). Results: Fifty-one patients underwent esophagectomy within 8 weeks of chemoradiation; 45 had a delayed operation. Univariate analysis showed the following characteristics were significantly different between on-time and delayed groups: weight loss within 3 months of surgery (3.9 ± 5.1 kg vs. 1.5 ± 3.6 kg; P = 0.009), prior cardiovascular disease (29% vs. 49%; P = 0.05), prior cardiothoracic surgery (4% vs. 22%; P = 0.01), history of ever smoked (69% vs. 87%; P = 0.04), absent nodal metastasis on pathology (57% vs. 82%; P = 0.008). Multivariate analysis demonstrated that prior cardiothoracic surgery (OR 8.924, 95%CI 1.67-47.60; P = 0.01) and absent nodal metastasis (OR 4.186, 95%CI 1.50-11.72; P = 0.006) were associated with delayed surgery. Conclusions: Delayed esophagectomy following chemoradiotherapy is associated with prior cardiothoracic surgery and absent nodal metastasis. Further investigations should focus on understanding how these factors contribute to delays to guide treatment planning and mitigate sources of outcome disparities.