Analysis of Treg Cell Population Alterations in the Peripheral Blood of Patients Treated Surgically for Ovarian Cancer – A Preliminary Report Lukasz Wicherek 1,2 , Wojciech Jozwicki 3 , Wieslawa Windorbska 4 , Krzysztof Roszkowski 5 , Ewelina Lukaszewska 3 , Michal Wisniewski 1 , Anna Aneta Brozyna 3 , Pawel Basta 1 , Joanna Skret-Magierlo 1 , Krzysztof Koper 1,2 , Wojciech Rokita 1 , Magdalena Dutsch-Wicherek 6 1 Department of Gynecology and Oncology, Lukaszczyk Oncological Center, Bydgoszcz, Poland; 2 Chair of Gynecology, Oncology and Gynecological Nursing, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland; 3 Department of Tumor Pathology and Pathomorphology, Lukaszczyk Oncological Center, The Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland; 4 Department of Teleradiotherapy, Lukaszczyk Oncological Center, Bydgoszcz, Poland; 5 Department of Radiotherapy, Lukaszczyk Oncological Center, Bydgoszcz, Poland; 6 Outpatient Unit of Otolaryngology, The Lukaszczyk Oncological Center, Bydgoszcz, Poland Keywords Ovarian cancer, treg, tumour, microenvironment Correspondence Lukasz Wicherek, MD, PhD, Department of Gynecology and Oncology, Lukaszczyk Oncological Center, Bydgoszcz, Poland. E-mail: mowicher@cyf-kr.edu.pl Submitted February 28, 2011; accepted April 25, 2011. Citation Wicherek L, Jozwicki W, Windorbska W, Roszkowski K, Lukaszewska E, Wisniewski M, Brozyna AA, Basta P, Skret-Magierlo J, Koper K, Rokita W, Dutsch-Wicherek M. Analysis of Treg cell population alterations in the peripheral blood of patients treated surgically for ovarian cancer – a preliminary report. Am J Reprod Immunol 2011; 66: 444–450 doi:10.1111/j.1600-0897.2011.01024.x Problem Treg cells constitute the main cell population that enables cancer cells to evade immune surveillance. An alteration in the Treg cell population might correspond to the diminishment of the tumour mass in patients with cancer and could therefore be a useful marker of the intensity of the selective suppression of the host immune system and also of the degree of radicalism of a procedure. Certainly, it is well known that in order for anti- cancer therapy to succeed the proper immune response against cancer cells must be restored. Furthermore, monitoring the level of selective immune system suppression during cancer therapy might yield information that would support a decision to supplement standard therapy by immuno- therapy or to increase the degree of radicalism of the applied therapy. Method of study We examined the Treg cell populations in the peripheral blood of a group of patients treated surgically for ovarian cancer. In each patient, the peripheral blood samples were collected both prior to and 1 day after the surgical procedure, and then again 5 days after the procedure. The presence of regulatory T cells in the samples was analyzed by means of flow cytometry. Results In our study, the percentages of FOXP3 + cells in the subpopulation of CD4 + T lymphocytes found in the peripheral blood of the patients before the sur- gical intervention were statistically significantly higher than those observed in the peripheral blood of these same patients after the surgical procedure. Conclusion It would seem that the alteration in the Treg cell subpopulation could be a key factor in determining the status of the tumour microenviron- ment. Most likely, it could provide information about whether the proper level of anti-cancer immune response could be restored. The pos- sibility of restoring the immune response may directly correspond to the degree of radicalism of the surgical intervention. SHORT COMMUNICATION American Journal of Reproductive Immunology 66 (2011) 444–450 444 ª 2011 John Wiley & Sons A/S