Diabetic ketoacidosis (DKA) is a potentially life-threatening complication of diabetes mellitus and can lead to death if untreated. It is a complex metabolic state characterised by hyperglycaemia, acidosis and ketonuria. Bonsai is one of the herbal incense products that contains synthetic cannabinoid and can be easily accessible via the internet in many countries. It cannot be detected in blood and urine studies using conventional methods. Synthetic cannabinoid abuse is associated with severe side effects, including tachycardia, high blood pressure, acidosis, excess sedation and coma. A 17-year-old male patient was brought to the emergency department with sudden onset of dyspnoea. Laboratory investigations revealed hyperglycaemia, acidosis and ketonuria. He was admitted to the intensive care unit with a diagnosis of diabetic ketoacidosis. He was not considered a typical case of diabetic ketoacidosis because of the tendency to hypokalaemia, persistent tachycardia and bronchoscopic findings. We learned from his friends that he had used cannabis for a week and used bonzai on the day that he was brought to the emergency service. Diabetic ketoacidosis with prolonged acidosis and tendency to hypokalaemia are investigated for the consumption of synthetic cannabinoids.

Background/Objectives: Metastatic testicular germ cell tumor (mGCT) is a highly curable disease with first-line cisplatin-based combination chemotherapy. This study aims to evaluate the clinicopathological characteristics and survival outcomes of patients with metastatic testicular cancer in a nationwide multicenter cohort. Methods: This multicenter retrospective cohort study included 316 male patients diagnosed with mGCT who were treated with first-line cisplatin-based chemotherapy across 10 institutions in Turkey between 2011 and 2024. Clinical and pathological data, including International Germ Cell Cancer Collaborative Group (IGCCCG) risk classification, treatment details, and survival outcomes, were analyzed. Results: The median age of the cohort was 28 years, and 76.3% of patients were diagnosed with non-seminoma. According to IGCCCG risk stratification, 53.2% had good-risk, 25.3% intermediate-risk, and 21.5% poor-risk disease. Median follow-up was 38.4 months. Among patients with seminoma, the 5-year overall survival (OS) rate was 100% in the good-risk group and 87.5% in the intermediate-risk group. In patients with non-seminoma, 5-year OS rates were 96.6%, 86.9%, and 65.1% in the good-, intermediate-, and poor-risk groups, respectively. Among 125 patients who received salvage treatment, high-dose chemotherapy (HDCT) significantly improved survival in the International Prognostic Factors Study Group (IPFSG) very high-risk group (3-year OS: 55.0% vs. 16.3% with conventional-dose chemotherapy (CDCT), p = 0.007). Conclusions: This study provides the first large-scale nationwide dataset on mGCT outcomes in Turkey, demonstrating overall survival rates comparable to international cohorts. The findings emphasize the importance of a multidisciplinary approach, adherence to treatment guidelines, and optimal surgical interventions in improving patient outcomes.

Background and Objectives: Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers and remains a leading cause of cancer-related mortality worldwide. EGFR-targeted tyrosine kinase inhibitors (TKIs) have substantially improved outcomes in EGFR-mutant NSCLC; however, primary and acquired resistance continues to limit their long-term efficacy. HER3 (receptor tyrosine-protein kinase ErbB3), a member of the ErbB receptor family, has been implicated in TKI resistance through heterodimerization with EGFR and HER2, leading to downstream PI3K/AKT pathway activation. Despite its biological plausibility as a resistance mediator, the clinical significance of HER3 expression as a prognostic and predictive biomarker in EGFR-mutant NSCLC has not been thoroughly characterized in real-world cohorts. Materials and Methods: This retrospective, single-center study included 52 patients diagnosed with EGFR-mutant NSCLC who received TKI therapy at Afyonkarahisar Health Sciences University between January 2011 and September 2023. HER3 protein expression was evaluated by immunohistochemistry (IHC) on formalin-fixed, paraffin-embedded tumor tissue sections using the Huabio anti-HER3 antibody (clone PD00-44, 1:2000 dilution). Staining in more than 30% of tumor cells was considered HER3-positive; membranous staining intensity was scored on a 1–3 scale. Progression-free survival (PFS1, PFS2) and overall survival (OS) were analyzed using the Kaplan–Meier method and log-rank test. Statistical significance was set at p < 0.05. Results: Of 52 patients (55.8% female; mean age 64.5 years), 59.6% received chemotherapy and 40.4% received an EGFR TKI as first-line treatment; erlotinib constituted 71.2% of targeted therapies. In the first-line TKI group, HER3-negative patients had a numerically longer median PFS1 compared with HER3-positive patients (14.0 vs. 7.1 months; p = 0.285); however, this difference did not reach statistical significance and should be interpreted with caution given the small sample size. In contrast, among patients receiving first-line chemotherapy, HER3 staining status did not meaningfully affect PFS1 (4.1 vs. 2.5 months; p = 0.063). In second-line treatment, HER3-positive patients who received TKI after prior chemotherapy demonstrated a PFS2 comparable to or slightly exceeding that of HER3-negative patients (21.8 vs. 19.8 months; p = 0.49), suggesting that the sequencing of chemotherapy before TKI may attenuate the adverse effect of HER3 positivity. Median OS was 15.1 months in HER3-negative patients and 12.7 months in HER3-positive patients (p = 0.824); this numerical difference of approximately 3 months did not reach statistical significance and should therefore be interpreted cautiously. Among patients receiving TKI in the first line, HER3-positive patients had a shorter median OS than HER3-negative patients (9.6 vs. 14.2 months), whereas those receiving TKI in the second line showed a trend toward longer OS in HER3-positive patients (20.5 vs. 17.2 months). Conclusions: HER3 expression was associated with reduced first-line TKI efficacy in EGFR-mutant NSCLC, suggesting a possible role for HER3 in primary TKI resistance; however, these findings are exploratory and did not reach statistical significance. The observation that HER3-positive patients who received chemotherapy before TKI demonstrated outcomes comparable to HER3-negative patients raises the hypothesis that treatment sequencing may potentially influence the impact of HER3 positivity, though this requires prospective validation before any clinical conclusions can be drawn. These results suggest that HER3 expression may warrant further investigation as a candidate biomarker for treatment sequencing decisions and as a potential therapeutic target in EGFR-mutant NSCLC. Prospective studies evaluating chemotherapy–TKI sequencing and HER3-directed agents such as patritumab deruxtecan (HER3-DXd) in HER3-positive patients are needed to confirm these preliminary observations.

Amaç: Bu çalışmanın amacı meme kanseri moleküler subgrup sıklığını belirlemek ve meme kanseri tanısı ile takip ettiğimiz hastalarda otoimmun tiroid hastalığı (OİTH) ile meme kanseri prognostik ve prediktif faktörleri arasındaki ilişkiyi araştırmaktır. Gereç ve Yöntem: Retrospektif tanımlayıcı bir araştırma olarak planlanan bu çalışmaya 01 Ocak 2012–31 Aralık 2015 tarihleri arasında endokrinoloji ve tıbbi onkoloji polikliniklerine başvurmuş, meme kanseri tanısı ile takip edilen 101 hasta dahil edildi, moleküler sınıflandırmaya göre subgruplara ayrıldı. Yüksek serum anti-TPO düzeyi olanlar OİTH pozitif kabul edildi. OİTH’nin eşlik ettiği meme kanseri hastalarında prognostik ve prediktif parametreler (tümör evresi, tümör boyutu, aksiller lenf nodu tutulumu, histolojik derece, lenfovaskuler invazyonu, perinöral invazyonu, hormon reseptör durumu, HER2 ekspresyonu) otoimmün tiroid hastalığının eşlik etmediği meme kanseri hastaları ile karşılaştırıldı. Bulgular: Çalışmaya dahil edilen meme kanseri hastalarında tiroid otoimmunite (yüksek serum anti-TPO düzeyi) prevalansı %23,8 (n=24) olarak saptandı. OİTH pozitif meme kanseri hastalarında aksiller lenf nodu tutulumu (%37,5’e karşı %61; p=0,043) OİTH negatif meme kanseri hastalarına göre daha düşüktü. Diğer parametreler açısından iki grup arasında anlamlı fark izlenmedi. Sonuç: OİTH’nin eşlik ettiği meme kanseri hastalarında önemli bir prognostik parametre olan aksiller lenf nodu tutulum oranı daha düşük bulunmuştur. Bu sonuç tiroid otoimmunitesinin meme kanseri açısından olumlu bir prognostik faktör olduğu görüşünü desteklemektedir. Bunun hangi mekanizma üzerinden etkili olduğu ise yeni çalışmalarla araştırılmalıdır.

Endokrin sistem hastalıklarının bir kısmını oluşturan ve Tıbbi Onkoloji ve Endokrinoloji bölümlerinin ortak konuları olan Endokrin Sistem Tümörleri şüphesiz multidisipliner yaklaşım gerektiren malign hastalıkların içerisinde yer almakta ve günlük pratiğimizde azımsanmayacak sıklıkta rastlanılmakta ve özel tedavi yaklaşımları gerektirmektedir. Bu bilgiler doğrultusunda onkolojinin özel konularından olan ENDOKRİN SİSTEM TÜMÖRLERİ konulu bu kitabımızı ülkemizin alanında uzman ve akademik vizyonu olan hocalarımızın katkılarıyla hazırladık. Emeği geçen hocalarımıza teker teker davetimi kırmayıp verdikleri destek için teşekkür ediyorum. Ayrıca Onkoloji alanında yayımladığımız ve yayımlamayı planladığımız kitapların hazırlanmasında emeği geçen ve her an yanımızda olan başta Akademisyen Yayınevi sahibi Yasin DİLMEN olmak üzere tüm yayınevi çalışanlarına da teşekkür ederim.