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Anees Chagpar

Professor of Surgery (Oncology, Breast); Affiliated Faculty, Yale Institute for Global Health

Research Summary

Dr. Chagpar's primary research area is in breast cancer. Her work spans from collaborative translational work, to clinical research including large randomized controlled trials, to large database studies involving population science. In addition to specific projects pertaining to breast cancer, she is also passionate about global health and health disparities, and has done extensive work in these areas.

Extensive Research Description

My research interests span from collaborative translational science to clinical research and trials to population science and outcomes research using large databases. My research focus is dedicated to breast cancer, but has touched a number of key themes over the evolution of my career.

  • Chest wall recurrence after mastectomy My early publications focused on the issue of chest wall recurrences after mastectomy – elucidating a simple clinical prediction model to predict prognosis that is used to this day, describing the role of post-mastectomy radiation therapy in reducing recurrence, and finding that reconstruction does not need to be taken down in order to effectively manage chest wall recurrences that occur in autologous flaps.
    1. Chagpar A, Meric-Bernstam F, Hunt KK, Ross MI, Cristofanilli M, Singletary SE, Buchholz TA, Ames F, Marcy S, Babiera G, Feig B, Hortobagyi GN, Kuerer HM.“Chest wall recurrence after mastectomy does not always portend a dismal outcome”, Annals of Surgical Oncology 2003; 10(6): 628-634.
    2. Chagpar A, Kuerer HM, Hunt KK, Strom EA, Buchholz TA.“Outcome of breast cancer patients with chest wall recurrence according to initial stage:Implications for post-mastectomy radiation therapy”, International Journal of Radiation Oncology, Biology and Physics 2003; 57(1):128-135.
    3. Chagpar A, Langstein H, Kronowitz S, Singletary SE, Ross MI, Buchholz TA, Hunt KK, Kuerer HM.“Treatment and outcome of patients with chest wall recurrence after mastectomy and breast reconstruction”, American Journal of Surgery 2004; 187: 164-169.
  • Sentinel node biopsy Beyond management of local recurrences, the understanding of how to optimally predict prognosis and manage regional disease became increasingly important, as it is known that lymph node status is the key determinant of outcome.I therefore did a number of studies evaluating sentinel node biopsy in breast cancer – identifying the most appropriate technique to use, characterizing the prognostic implications of micrometastases, and ultimately defining clinical prediction models for additional metastases in non-sentinel nodes in sentinel node positive patients.Many of these were seminal works from the largest study of patients who had sentinel node biopsy followed by axillary node dissection, and form the basis of our clinical practice today.
    1. Chagpar A, Martin RC, Chao C, Wong SL, Edwards MJ, Tuttle T, McMasters KM.“Validation of sub- and peri-areolar injection techniques for breast sentinel lymph node biopsy”, Archives of Surgery 2004; 139(6): 614-620.
    2. Chagpar AB, Martin RC, Scoggins CR, Carlson DJ, Laidley AL, El-Eid SE, McGlothin TQ, Noyes RD, Ley PB, Tuttle TM, McMasters KM. “Factors predicting failure to identify a sentinel node in breast cancer”, Surgery 2005; 138(1):56-63.
    3. Chagpar AB, Scoggins CR, Martin RC, Carlson DJ, Laidley AL, El-Eid SE, McGlothin TQ, McMasters KM. “Prediction of sentinel lymph node-only disease in women with invasive breast cancer”,American Journal of Surgery 2006; 192(6):882-887.
    4. Chagpar AB, Camp RL, Rimm DL.“Lymph node ratio should be incorporated into staging for breast cancer”, Annals of Surgical Oncology 2011; 18(11): 3143-8.
  • Screening:Costs and Value As the practice of sentinel node biopsy evolved, it became clear that minimal disease in the axilla did not have the same prognostic implications as more extensive disease.The once tightly held paradigm that we need to find any/all disease early and treat it therefore came under more scrutiny and my attention then turned to the critical evaluation of screening; national trends, the economic impact of this and ultimately, the value it brings in terms of improved outcomes.Some of this work has been used by national organizations, such as the US Preventative Services Task Force, in terms of guiding policy.I led several of these studies looking at data from the National Health Interview Survey, and collaborated on other studies evaluating data from SEER-Medicare with Yale’s Center for Outcomes Public Policy and Effectiveness Research (COPPER).
    1. Chagpar AB, Polk HC, McMasters KM. “Racial trends in mammography rates: A population-based study”, Surgery 2008; 144(3);467-472.
    2. Killelea B, Lannin D, Horvath, L, Chagpar AB.“Factors associated with breast MRI use:A population-based analysis”, Annals of Surgical Oncology 2013; 20(6): 1798-805.
    3. Gross CP, Long JB, Ross JS, Abu-Khalaf MM, Wang R, Killelea BK, Gold HT, Chagpar AB, Ma X.“The Cost of Breast Cancer Screening in the Medicare Population”, JAMA Internal Medicine 2013; 173(3): 220-6.
  • Margins In keeping with the overarching theme of optimal management of breast cancer and cost/value, our most recent work has been on looking at margins – how we evaluate these intraoperatively, and how we can reduce positive margin and re-excision rates.As a result, we recently completed the largest randomized controlled trial to date regarding the utility of cavity shave margins. We found that, with this technique, we could dramatically reduce the positive margin and re-excision rates for women undergoing partial mastectomy for breast cancer. This was the most rapidly accruing therapeutic clinical trial at Yale Cancer Center, and the data were published in the New England Journal of Medicine. I was the PI on this trial, and led many of the other studies we did on this topic.

    1. Chagpar AB, Killelea B, Tsangaris T, Butler M, Stavris K, Li F, Yao X, Bossuyt V, Harigopal M, Lannin D, Pusztai L, Horowitz N. "A Randomized, Controlled Trial of Cavity Shave Margins in Breast Cancer", N Engl J Med 2015; 373: 503-510.
    2. Chagpar A, Yen T, Whitman G, Sahin A, Hunt KK, Ames F, Ross MI, Meric F, Babiera GV, Singletary SE, Kuerer HM.“Intra-operative margin assessment reduces re-excision rates in patients with ductal carcinoma in situ treated with breast-conserving surgery”, American Journal of Surgery 2003; 186: 371-377.
    3. Chagpar A, Chao, C, Martin RCG, McMasters KM.“Lumpectomy margins are affected by tumor size and histologic subtype, not by biopsy type”, American Journal of Surgery 2004; 188(4):399-402.


Research Interests

Breast Neoplasms; Ethics; Health Services Research; Medical Oncology; Quality of Health Care; Health Care Quality, Access, and Evaluation; Health Care

Public Health Interests

Cancer; Global Health; Health Equity, Disparities, Social Determinants and Justice

Selected Publications