Browsing by Author "Isikdogan, Abdurrahman"

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Cost effectiveness of Gene Expression Profiling in Patients with Early-Stage Breast Cancer in a Middle-Income Country, Turkey: Results of a Prospective Multicenter Study
(AVES, 2019-01-01) Ozmen, Vahit; Cakar, Burcu; Gokmen, Erhan; Ozdogan, Mustafa; Guler, Nilufer; Uras, Cihan; Ok, Engin; Demircan, Orhan; Isikdogan, Abdurrahman; Saip, Pinar
Objective: Breast cancer is a heterogenous disease, and genetic profiling helps to individualize adjuvant treatment. The Oncotype DX is a validated test to predict benefit of adjuvant systemic treatment. The aims of this study are to determine the costs of chemotherapy in government hospitals in Turkey and evaluate the cost-effectiveness of the Oncotype DX from the national insurance perspective. Materials and Methods: A Markov model was developed to make long term projections of distant recurrence, survival, quality adjusted life expectancy, and direct costs for patients with ER+, HER2-, node-negative or up to 3 node-positive early stage breast cancer. Turkish decision impact study patient data were captured for model reference. In that study, ten academic centers across Turkey participated in a prospective trial. Of 165 patients with pT1-3, pN0-N1mic, ER-positive, and HER-2 negative tumors, 57\% had low recurrence score (RS), 35\% had intermediate RS, and 8\% had high RS, respectively. The overall rate of change in chemotherapy treatment decisions following Oncotype DX was 33\%. Results: The cost of adjuvant chemotherapy in public hospitals was estimated at \$3.649, and Oncotype Dx test was \$5.141. Based on the cost-effectiveness analysis, Oncotype DX testing was estimated to improve life expectancy (+0.86 years) and quality-adjusted life expectancy (+0.68 QALYs) versus standard care. The incremental cost-effectiveness ratio (ICERs) of Oncotype DX was estimated to be \$7207.9 per QALY gained and \$5720.6 per LY gained versus current clinical practice. Conclusion: As Oncotype DX was found both cost-effective and life-saving from a national perspective, the test should be introduced to standard care in patients with ER+, HER-2 negative early-stage breast cancer in Turkey.
Efficacy and safety profile of COVID-19 vaccine in cancer patients: a prospective, multicenter cohort study
(FUTURE MEDICINE LTD, 2022-01-01) Yasin, Ayse Irem; Aydin, Sabin Goktas; Sumbul, Bilge; Koral, Lokman; Simsek, Melih; Geredeli, Caglayan; Ozturk, Akin; Perkin, Perihan; Demirtas, Derya; Erdemoglu, Engin; Hacibekiroglu, Ilhan; Cakir, Emre; Tanrikulu, Eda; Coban, Ezgi; Ozcelik, Melike; Celik, Sinemis; Teker, Fatih; Aksoy, Asude; Firat, Sedat T.; Tekin, Omer; Kalkan, Ziya; Turken, Orhan; Oven, Bala B.; Dane, Faysal; Bilici, Ahmet; Isikdogan, Abdurrahman; Seker, Mesut; Turk, Haci M.; Gumus, Mahmut
Aim: To compare the seropositivity rate of cancer patients with non-cancer controls after inactive SARS-CoV-2 vaccination (CoronaVac) and evaluate the factors affecting seropositivity. Method: Spike IgG antibodies against SARS-CoV-2 were measured in blood samples of 776 cancer patients and 715 non-cancer volunteers. An IgG level >= 50 AU/ml is accepted as seropositive. Results: The seropositivity rate was 85.2\% in the patient group and 97.5\% in the control group. The seropositivity rate and antibody levels were significantly lower in the patient group (p < 0.001). Age and chemotherapy were associated with lower seropositivity in cancer patients (p < 0.001). Conclusion: This study highlighted the efficacy and safety of the inactivated vaccine in cancer patients. Clinical Trials Registration: ClinicalTrials.gov) Plain language summary Cancer patients are at high risk for infection with SARS-CoV-2 and of developing the associated disease, COVID-19, which therefore puts them in the priority group for vaccination. This study evaluated the efficacy and safety of CoronaVac, an inactivated virus vaccine, in cancer patients. The immune response rate, defined as seropositivity, was 85.2\% in the cancer patient group and 97.5\% in the control group. The levels of antibodies, which are blood markers of immune response to the vaccine, were also significantly lower in the patient group, especially in those older than 60 years and receiving chemotherapy. These results highlight the importance of determining the effective vaccine type and dose in cancer patients to protect them from COVID-19 without disrupting their cancer treatment.
Impact of Oncotype DX Recurrence Score on Treatment Decisions: Results of a Prospective Multicenter Study in Turkey
(CUREUS INC, 2016-01-01) Ozmen, Vahit; Atasoy, Ajlan; Gokmen, Erhan; Ozdogan, Mustafa; Guler, Nilufer; Uras, Cihan; Ok, Engin; Demircan, Orhan; Isikdogan, Abdurrahman; Saip, Pinar
Introduction: Breast cancer is the most common malignancy among Turkish women and the rate of early stage disease is increasing. The Oncotype DX (R) 21-gene assay is predictive of distant recurrence in ER-positive, HER2-negative early breast cancer. We aimed to evaluate the impact of the Recurrence Score (R) (RS) on treatment decisions and physician perceptions in Turkey. We also studied correlations between RS and routine risk factors. Patients and Methods: Ten academic centers across Turkey participated in this prospective trial. Consecutive breast cancer patients with pT1-3, pN0-N1mic, ER-positive, and HER2-negative tumors were identified at multidisciplinary tumor conferences. The initial treatment decision was recorded before tumor blocks were sent to the central laboratory. Each case was brought back to tumor conference after receiving the RS result. Both pre- and post-RS treatment decisions and physician perceptions were recorded on questionnaire forms. Correlations between RS and classical risk factors were evaluated using univariate and multivariate analyses. Results: Ten centers enrolled a total of 165 patients. The median tumor size was 2 cm. Of 165 patients, 57\% had low RS, 35\% had intermediate RS, and 8\% had high RS, respectively. The overall rate of change in treatment decision was 33\%. Initially, chemotherapy followed by hormonal therapy (CT+HT) was recommended to 92 (56\%) of all patients, which decreased to 61 (37\%) patients post-RS assay (p<0.001). Multivariate analysis indicated that progesterone receptor (PR) and Ki-67 scores were significantly related to RS. Conclusion: Oncotype DX testing may provide meaningful additional information in carefully selected patients.