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Patterns of Locoregional Recurrence in Breast Cancer Patients After Neoadjuvant Chemotherapy and Adjuvant Radiation Therapy
Volume 99 Number 2S Supplement 2017 increased muscle breakdown and amino acid release from normal tissue and amino acid uptake by injured tissue. This work examines the hypothesis that radiotherapy may induce similar metabolic changes leading to systemic muscle loss. Materials/Methods: This hypothesis was tested in a prospective one arm clinical study in subjects undergoing adjuvant radiotherapy after breast cancer surgery. Twenty subjects underwent CT scans prior to starting radiotherapy, on the last day of radiotherapy and at one and three months following radiation treatments. Cross sectional muscle area was determined at anatomic levels both within and outside the radiation treatment field from CT scans at each time point by quantifying tissue with muscle density (Hounsfield units -29 to 150) and excluding non-muscle organs. Infield muscle was primarily pectoralis muscle at the level of the second costochondral joint. Out of field muscle was primarily paraspinal muscles at the level of the second lumbar vertebral body. Self-reported fatigue was assessed at the same time points using a validated questionnaire. Results: Changes in muscle content both within and outside the treatment fields were common and evolved over time during and after radiotherapy. Muscle content within the treatment field showed a consistent increase with time after treatment. By three months after treatment, the crosssectional area of tissue with muscle density in the treatment region averaged 23% (p<0.01) greater than prior to beginning radiotherapy. The increase in muscle density within the treatment field three months following radiotherapy directly correlated with the volume of tissue irradiated. Changes in muscle outside the treatment region during radiotherapy were directly correlated with changes in weight. Most subjects (16 of 20) lost muscle outside the treatment field during the three months following treatment. The average out of field muscle loss was 2.5% at three months (p<0.01). Changes in muscle and weight were not correlated with each other after treatment. Changes in muscle outside the treatment fields during radiotherapy were inversely correlated with subsequent fatigue, such that muscle loss during treatment was correlated with a subsequent rise in fatigue (p<0.05). Conclusion: Radiotherapy leads to dynamic changes in muscle content both within and outside the treatment region. Ultimately, most patients experienced a decrease in muscle content outside the treatment region and an increase in tissue with muscle density within the treatment region. These changes are similar, albeit more subtle, to changes seen following other forms of injury such as thermal burn. Understanding the metabolic consequences of radiation treatment may lead to novel approaches to decrease toxicity such as fatigue and improve the therapeutic ratio. Author Disclosure: K. Dornfeld: None. R. Regal: Independent Contractor; Essentia Health. B. Libey: None.
2030 Patterns of Locoregional Recurrence in Breast Cancer Patients After Neoadjuvant Chemotherapy and Adjuvant Radiation Therapy M. Elebrashi, M.L. Abouegylah, L.W. Salama, A. Mina, and A.G. Taghian; Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA Purpose/Objective(s): Neoadjuvant chemotherapy is considered a viable option for patients with palpable breast cancer. There is limited information about patterns of locoregional recurrence (LRR) in breast cancer patients after neoadjuvant chemotherapy (NC), which has resulted in difficult identification of the rates and the predictors of LRR after NC. The main objective of this study is to determine the patterns of locoregional failure in breast cancer patients who received NC and adjuvant radiation. Materials/Methods: This is a retrospective analysis including 811women who received different chemotherapeutic agents as NC for stage I, II&III breast cancer and treated between 1997 and 2014. The patients’ median age was 49.2 (range 24.3-83.7 years). 28 patients (3.4%) were diagnosed with stage I, 479 (61.2%) with stage II, 229 (28.2%) with stage III and 58 (7.1%) with no preoperative staging. 391 patients underwent lumpectomy (48.2 %) while 417 (51.4%) underwent mastectomy and 3 didn’t undergo
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any surgery. 196 (24.2%) showed pathological complete response pCR, 566 (69.8%) with pathological partial response (pPR), 38 (4.7%) with pathological no response/progression (pNR) while 11 (0.1%) were not assessed for pathological response. 722 (89%) patients received radiotherapy and 83 (10.2%) did not. In 6 patients (0.4%) there was no available data on their radiation treatment. Factors associated with LRR were assessed utilizing the Kaplan-Meier method and Logistic regression model. Results: The median follow up period for all patients was 66.5 months. The rate of LRR was 5.1% at 5 years and 9% at 10 years. The overall and disease-free survival rates at five were (89.1%), (83.1%) respectively and at ten years were (80.9%) (68.7%) respectively. 184 patients (22.7%) developed distant metastasis and 52(7%) developed LRR. The median time for LRF was 1.5 years. 69% of LRF occurred in breast and or chest wall, 10% in axilla, and 15.4% in supraclavicular area and 5.6 in other sites. We found that LRR was significantly associated with the presence of lymphvascular invasion (LVI) at the time of surgery (PZ0.008). We also noticed that the rate of LRR was higher among patients who had pNR (PZ0.02). Other factors as age, tumor pathology and type of surgery were not significant. Conclusion: These data suggest that the presence of LVI and pNR at the time of surgery after NC is associated with a significantly higher rate of LRR, and both can be considered as predictors for local failure after NC. Author Disclosure: M. Elebrashi: None. M.L. Abouegylah: None. L.W. Salama: None. A. Mina: None. A.G. Taghian: Research Grant; Impedimed. Honoraria; UpToDate. Consultant; VisionRT.
2031 Incidence of PET/CT Detected Internal Mammary Nodal Involvement in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy M.K. Farrugia and G.M. Jacobson; West Virginia University, Morgantown, WV Purpose/Objective(s): Irradiation of the internal mammary nodes (IMNs) provides benefit to some breast cancer patients but contributes to lung and cardiac doses. It is important to identify factors which indicate the risk for IMN disease. Inner quadrant tumors and degree of nodal disease burden have been associated with higher incidence of IMN involvement. We investigated the incidence of IMN disease within our patient population and the association with features such as tumor location and axillary burden. Materials/Methods: We reviewed the charts of 128 breast cancer patients who had pre-treatment PET/CT imaging scheduled to receive chemotherapy seen from 2008-2014. Results: The cancer stages ranged from II-IV, with 43% stage II, 49% III, and 8% IV. The median age was 51 years with a median follow-up of 50 months. 53% of patients had hormone receptor positive/HER2 negative disease, 31% of tumors were HER2 positive, and 16% were triple-negative. Nodes with standard uptake values (SUV) >2 were considered positive. Of these patients, only 8 had PET/CT detected IMN involvement, comprising 6.3% of total patients and 8.1% of patients with regionally advanced disease. Although classically associated with inner quadrant tumors, there was no statistically significant association with IMN PET avidity and tumor characteristics such as location or pathologic subtype by 2x2 contingency tables. Only 1 tumor with PET/CT detected IMNs had involvement within the inner quadrant. There was no correlation between IMN PET/CT positivity and number of dissected lymph nodes with disease or percent of lymph nodes with disease by Spearman’s correlation. Of the patients with PET/CT detected IMN involvement, 62.5% had 2 or less lymph nodes with tumor on axillary lymph node dissection. Conclusion: These findings suggest that within this patient population metastatic involvement of the IMNs is relatively rare, even in patients with regionally advanced disease. Furthermore, classic associated factors such as tumor location and axillary burden had no association with IMN involvement. Author Disclosure: M.K. Farrugia: None. G.M. Jacobson: Overseas oncology programs; HVO health Volunteers Overseas.
2030 Patterns of Locoregional Recurrence in Breast Cancer Patients After Neoadjuvant Chemotherapy and Adjuvant Radiation Therapy M. Elebrashi, M.L. Abouegylah, L.W. Salama, A. Mina, and A.G. Taghian; Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA Purpose/Objective(s): Neoadjuvant chemotherapy is considered a viable option for patients with palpable breast cancer. There is limited information about patterns of locoregional recurrence (LRR) in breast cancer patients after neoadjuvant chemotherapy (NC), which has resulted in difficult identification of the rates and the predictors of LRR after NC. The main objective of this study is to determine the patterns of locoregional failure in breast cancer patients who received NC and adjuvant radiation. Materials/Methods: This is a retrospective analysis including 811women who received different chemotherapeutic agents as NC for stage I, II&III breast cancer and treated between 1997 and 2014. The patients’ median age was 49.2 (range 24.3-83.7 years). 28 patients (3.4%) were diagnosed with stage I, 479 (61.2%) with stage II, 229 (28.2%) with stage III and 58 (7.1%) with no preoperative staging. 391 patients underwent lumpectomy (48.2 %) while 417 (51.4%) underwent mastectomy and 3 didn’t undergo
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any surgery. 196 (24.2%) showed pathological complete response pCR, 566 (69.8%) with pathological partial response (pPR), 38 (4.7%) with pathological no response/progression (pNR) while 11 (0.1%) were not assessed for pathological response. 722 (89%) patients received radiotherapy and 83 (10.2%) did not. In 6 patients (0.4%) there was no available data on their radiation treatment. Factors associated with LRR were assessed utilizing the Kaplan-Meier method and Logistic regression model. Results: The median follow up period for all patients was 66.5 months. The rate of LRR was 5.1% at 5 years and 9% at 10 years. The overall and disease-free survival rates at five were (89.1%), (83.1%) respectively and at ten years were (80.9%) (68.7%) respectively. 184 patients (22.7%) developed distant metastasis and 52(7%) developed LRR. The median time for LRF was 1.5 years. 69% of LRF occurred in breast and or chest wall, 10% in axilla, and 15.4% in supraclavicular area and 5.6 in other sites. We found that LRR was significantly associated with the presence of lymphvascular invasion (LVI) at the time of surgery (PZ0.008). We also noticed that the rate of LRR was higher among patients who had pNR (PZ0.02). Other factors as age, tumor pathology and type of surgery were not significant. Conclusion: These data suggest that the presence of LVI and pNR at the time of surgery after NC is associated with a significantly higher rate of LRR, and both can be considered as predictors for local failure after NC. Author Disclosure: M. Elebrashi: None. M.L. Abouegylah: None. L.W. Salama: None. A. Mina: None. A.G. Taghian: Research Grant; Impedimed. Honoraria; UpToDate. Consultant; VisionRT.
2031 Incidence of PET/CT Detected Internal Mammary Nodal Involvement in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy M.K. Farrugia and G.M. Jacobson; West Virginia University, Morgantown, WV Purpose/Objective(s): Irradiation of the internal mammary nodes (IMNs) provides benefit to some breast cancer patients but contributes to lung and cardiac doses. It is important to identify factors which indicate the risk for IMN disease. Inner quadrant tumors and degree of nodal disease burden have been associated with higher incidence of IMN involvement. We investigated the incidence of IMN disease within our patient population and the association with features such as tumor location and axillary burden. Materials/Methods: We reviewed the charts of 128 breast cancer patients who had pre-treatment PET/CT imaging scheduled to receive chemotherapy seen from 2008-2014. Results: The cancer stages ranged from II-IV, with 43% stage II, 49% III, and 8% IV. The median age was 51 years with a median follow-up of 50 months. 53% of patients had hormone receptor positive/HER2 negative disease, 31% of tumors were HER2 positive, and 16% were triple-negative. Nodes with standard uptake values (SUV) >2 were considered positive. Of these patients, only 8 had PET/CT detected IMN involvement, comprising 6.3% of total patients and 8.1% of patients with regionally advanced disease. Although classically associated with inner quadrant tumors, there was no statistically significant association with IMN PET avidity and tumor characteristics such as location or pathologic subtype by 2x2 contingency tables. Only 1 tumor with PET/CT detected IMNs had involvement within the inner quadrant. There was no correlation between IMN PET/CT positivity and number of dissected lymph nodes with disease or percent of lymph nodes with disease by Spearman’s correlation. Of the patients with PET/CT detected IMN involvement, 62.5% had 2 or less lymph nodes with tumor on axillary lymph node dissection. Conclusion: These findings suggest that within this patient population metastatic involvement of the IMNs is relatively rare, even in patients with regionally advanced disease. Furthermore, classic associated factors such as tumor location and axillary burden had no association with IMN involvement. Author Disclosure: M.K. Farrugia: None. G.M. Jacobson: Overseas oncology programs; HVO health Volunteers Overseas.