Background/Objectives: Trastuzumab emtansine (T-DM1) is widely used in Human Epidermal Growth Factor Receptor2 (HER2)-positive metastatic breast cancer; however, outcomes vary, and reliable prognostic markers remain limited. We developed the CALA index as a composite biomarker integrating CA15-3, lactate dehydrogenase (LDH), and albumin. This study aimed to evaluate the prognostic value of the CALA index in metastatic breast cancer treated with T-DM1. Methods: This multicenter retrospective study included 168 patients treated with T-DM1 across four tertiary centers. The CALA index was calculated using pretreatment levels of CA15-3, LDH, and albumin. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff value, and patients were stratified into groups accordingly. Survival outcomes and independent risk factors were assessed using Kaplan–Meier and Cox regression analyses. Results: The median overall survival (OS) was 26 months (95% CI: 21.3–30.7). ROC analysis identified an optimal CALA cutoff value of 118.3. Patients with CALA ≤ 118.3 demonstrated significantly longer OS compared with those with CALA > 118.3 (log-rank p = 0.006), with 1- and 3-year OS rates of 81.2% and 43.2% versus 69.8% and 22.7%, respectively. In univariate analysis, CALA > 118.3 was associated with worse OS (HR: 1.699; 95% CI: 1.151–2.506; p = 0.008), and this association remained significant in multivariate analysis (HR: 1.671; 95% CI: 1.088–2.565; p = 0.019). Conclusions: The CALA index was associated with overall survival in metastatic breast cancer treated with trastuzumab emtansine and may serve as a practical tool for risk stratification.

Periferik nöropati kanser hastalarında kronik hastalıklara bağlı, paraneoplastik olarak veya kemoterapi ilişkili olarak en çok karşımıza çıkan semptomlardan biridir. Paraneoplastik nöropati etyolojisinde daha çok antikorlar rol oynarken; kemoterapiye bağlı nöropatide klinik kullanımımızda önemli bir yeri olan taksan ve platin bazlı tedaviler daha çok etkendir. Hastalar genel olarak el ve ayaklarda uyuşma, karıncalanma ,soğuk hassasiyeti, yanma, ağrı gibi semptomlardan yakınırlar. Bazı hastalar için bu yakınmalar hayat kalitesini olumsuz yönde etkiler ve tedaviye devam edememe ile sonuçlanabilir. Teşhis için elektrodiyagnostik testler kullanılabilmektedir. Periferik nöropati tedavisinde araştırılan pek çok uygulama ve etken madde olmasına rağmen gösterilmiş yararları sınırlıdır. Bu konuda ilerleyen süreçte daha kapsamlı çalışmalara ihtiyaç duyulmaktadır. Bizler de hastalarımızda, nöropatiye sebep olabilecek olası diğer etkenleri önlemek için gerekli tedbirleri almalı ve aktif tedavi aldıkları süreç boyunca her kemoterapi vizitinde nöropatik yakınmalar yönünden sorgulamalıyız. Peripheral neuropathy is one of the most common symptoms in cancer patients due to chronic diseases, paraneoplastic or chemotherapy related. While antibodies play a role in the etiology of paraneoplastic neuropathy. Taxane and platinum-based therapies, which have an important place in our clinical use, are more effective in chemotherapy-related neuropathy. Patients generally complain of symptoms such as numbness, tingling, cold sensitivity, burning and pain in the hands and feet. For some patients, these complaints negatively affect the quality of life and may result in discontinuation of treatment. Electrodiagnostic tests can be used for diagnosis. Although there are many applications and active substances being investigated in the treatment of peripheral neuropathy, their demonstrated benefits are limited. More comprehensive studies are needed in this regard in the future. We should take the necessary precautions to prevent other possible factors that may cause neuropathy in our patients and question them for neuropathic complaints at each chemotherapy visit during the active treatment period.