Lung cancer remains one of the most prevalent and lethal malignancies worldwide. Most cases are caused by non-small-cell lung cancer (NSCLC). Over the past three decades, the treatment landscape of NSCLC has been profoundly reshaped by the discovery of epidermal growth factor receptor (EGFR) mutations and the subsequent development of EGFR-targeted therapies. This review provides a comprehensive overview of the evolution of four generations of EGFR tyrosine kinase inhibitors (EGFR-TKIs): first-generation reversible inhibitors such as gefitinib and erlotinib; second- and third-generation irreversible inhibitors, including afatinib, dacomitinib, and osimertinib; and emerging fourth-generation agents, such as amivantamab. Each generation has contributed to efficacy improvement, central nervous system penetration, and resistance management. Despite remarkable advances in development of EGFR-TKIs, acquired resistance and tumor heterogeneity remain major challenges. Bioinformatic analyses using The Cancer Genome Atlas (TCGA) datasets highlight the high mutation frequency and clinical significance of EGFR alterations, underscoring their pivotal role in tumor progression and prognosis. Future studies should explore combination therapies, antibody–drug conjugates, and next-generation allosteric inhibitors as promising strategies to overcome resistance. The evolution of EGFR-targeted therapy exemplifies the progress of precision oncology and serves as a basis for designing new paradigms in the management of lung cancer.

Melanoma is a malignant tumor originating from melanocytes, characterized by its high invasiveness and metastasis, leading to poor prognosis and high mortality. Early-stage melanoma is primarily treated with surgery; however, due to its metastatic nature, surgery becomes challenging in advanced stages. Treatment strategies for advanced or metastatic melanoma include chemotherapy, radiation therapy, and targeted therapy. However, melanoma’s propensity for rapid drug resistance remains a significant clinical challenge. This review summarizes the developments in the treatment of drug-resistant melanoma over the past decade and discusses the advantages and disadvantages of various therapeutic approaches and their clinical significance implications.

Purpose: Claudin 18.2 (CLDN18.2) has emerged as a promising therapeutic target for CLDN18.2-expressing gastric cancer (GC). We sought to examine the heterogeneity of CLDN18.2 expression between primary GC (PGC) and metastatic GC (MGC) using various scoring methods. Materials and Methods: We retrospectively analyzed data from 102 patients with pathologically confirmed paired primary and metastatic gastric or gastroesophageal junction adenocarcinomas. CLDN18.2 expression was evaluated through immunohistochemistry on formalin-fixed paraffin-embedded tissue samples. We assessed CLDN18.2 positivity using multiple scoring approaches, including the immunoreactivity score, H-score, and the percentage of tumor cells showing moderate-to-strong staining intensity. We analyzed the concordance rates between PGC and MGC and the association of CLDN18.2 positivity with clinicopathological features. Results: CLDN18.2 positivity varied from 25% to 65% depending on the scoring method, with PGC consistently showing higher expression levels than MGC. Intratumoral heterogeneity was noted in 25.5% of PGCs and 19.6% of MGCs. Intertumoral heterogeneity, manifesting as discordance in CLDN18.2 positivity between PGC and MGC, was observed in about 20% of cases, with moderate agreement across scoring methods (κ=0.47 to 0.60).In PGC, higher CLDN18.2 positivity correlated with synchronous metastasis, presence of peritoneal metastasis, poorly differentiated grade, and biopsy specimens. In MGC, positivity was associated with synchronous metastasis, presence of peritoneal metastasis, and metastatic peritoneal tissues. Conclusions CLDN18.2 expression demonstrates significant heterogeneity between PGC and MGC, with a 20% discordance rate. Comprehensive tissue sampling and reassessment of CLDN18.2 status are crucial, especially before initiating CLDN18.2-targeted therapies.

Melanoma is a malignant tumor originating from melanocytes, characterized by its high invasiveness and metastasis, leading to poor prognosis and high mortality. Early-stage melanoma is primarily treated with surgery; however, due to its metastatic nature, surgery becomes challenging in advanced stages. Treatment strategies for advanced or metastatic melanoma include chemotherapy, radiation therapy, and targeted therapy. However, melanoma’s propensity for rapid drug resistance remains a significant clinical challenge. This review summarizes the developments in the treatment of drug-resistant melanoma over the past decade and discusses the advantages and disadvantages of various therapeutic approaches and their clinical significance implications.

Purpose: Claudin 18.2 (CLDN18.2) has emerged as a promising therapeutic target for CLDN18.2-expressing gastric cancer (GC). We sought to examine the heterogeneity of CLDN18.2 expression between primary GC (PGC) and metastatic GC (MGC) using various scoring methods. Materials and Methods: We retrospectively analyzed data from 102 patients with pathologically confirmed paired primary and metastatic gastric or gastroesophageal junction adenocarcinomas. CLDN18.2 expression was evaluated through immunohistochemistry on formalin-fixed paraffin-embedded tissue samples. We assessed CLDN18.2 positivity using multiple scoring approaches, including the immunoreactivity score, H-score, and the percentage of tumor cells showing moderate-to-strong staining intensity. We analyzed the concordance rates between PGC and MGC and the association of CLDN18.2 positivity with clinicopathological features. Results: CLDN18.2 positivity varied from 25% to 65% depending on the scoring method, with PGC consistently showing higher expression levels than MGC. Intratumoral heterogeneity was noted in 25.5% of PGCs and 19.6% of MGCs. Intertumoral heterogeneity, manifesting as discordance in CLDN18.2 positivity between PGC and MGC, was observed in about 20% of cases, with moderate agreement across scoring methods (κ=0.47 to 0.60).In PGC, higher CLDN18.2 positivity correlated with synchronous metastasis, presence of peritoneal metastasis, poorly differentiated grade, and biopsy specimens. In MGC, positivity was associated with synchronous metastasis, presence of peritoneal metastasis, and metastatic peritoneal tissues. Conclusions CLDN18.2 expression demonstrates significant heterogeneity between PGC and MGC, with a 20% discordance rate. Comprehensive tissue sampling and reassessment of CLDN18.2 status are crucial, especially before initiating CLDN18.2-targeted therapies.

Melanoma is a malignant tumor originating from melanocytes, characterized by its high invasiveness and metastasis, leading to poor prognosis and high mortality. Early-stage melanoma is primarily treated with surgery; however, due to its metastatic nature, surgery becomes challenging in advanced stages. Treatment strategies for advanced or metastatic melanoma include chemotherapy, radiation therapy, and targeted therapy. However, melanoma’s propensity for rapid drug resistance remains a significant clinical challenge. This review summarizes the developments in the treatment of drug-resistant melanoma over the past decade and discusses the advantages and disadvantages of various therapeutic approaches and their clinical significance implications.

Purpose: Claudin 18.2 (CLDN18.2) has emerged as a promising therapeutic target for CLDN18.2-expressing gastric cancer (GC). We sought to examine the heterogeneity of CLDN18.2 expression between primary GC (PGC) and metastatic GC (MGC) using various scoring methods. Materials and Methods: We retrospectively analyzed data from 102 patients with pathologically confirmed paired primary and metastatic gastric or gastroesophageal junction adenocarcinomas. CLDN18.2 expression was evaluated through immunohistochemistry on formalin-fixed paraffin-embedded tissue samples. We assessed CLDN18.2 positivity using multiple scoring approaches, including the immunoreactivity score, H-score, and the percentage of tumor cells showing moderate-to-strong staining intensity. We analyzed the concordance rates between PGC and MGC and the association of CLDN18.2 positivity with clinicopathological features. Results: CLDN18.2 positivity varied from 25% to 65% depending on the scoring method, with PGC consistently showing higher expression levels than MGC. Intratumoral heterogeneity was noted in 25.5% of PGCs and 19.6% of MGCs. Intertumoral heterogeneity, manifesting as discordance in CLDN18.2 positivity between PGC and MGC, was observed in about 20% of cases, with moderate agreement across scoring methods (κ=0.47 to 0.60).In PGC, higher CLDN18.2 positivity correlated with synchronous metastasis, presence of peritoneal metastasis, poorly differentiated grade, and biopsy specimens. In MGC, positivity was associated with synchronous metastasis, presence of peritoneal metastasis, and metastatic peritoneal tissues. Conclusions CLDN18.2 expression demonstrates significant heterogeneity between PGC and MGC, with a 20% discordance rate. Comprehensive tissue sampling and reassessment of CLDN18.2 status are crucial, especially before initiating CLDN18.2-targeted therapies.

Tooth autotransplantation and surgical extrusion can preserve natural dentition, but outcomes are often compromised under nonideal periodontal conditions. The viability of the periodontal ligament (PDL) is essential for regeneration. This case series introduces a zonebased approach of donor–recipient interfaces: zone I (intact PDL and bone), II (one intact, one damaged), and III (both damaged).Three cases involving hemisection, intentional replantation with rotation, and autotransplantation were managed by repositioning the tooth to maximize zones I and II while minimizing zone III. After 5–12 months, probing depths decreased by 2–4 mm, Periotest values improved, and radiographs confirmed bone stability. This approach consistently transformed unfavorable zone III interfaces into more biologically favorable contacts. A zone-based repositioning strategy leveraging residual PDL may promote periodontal healing even under compromised conditions. Further prospective studies are needed to validate this system.

Oral cancer is a major global health concern, with high incidence and mortality rates, especially in high-risk populations. Early diagnosis remains a challenge, and current treatments, such as surgery, radiation, and chemotherapy, have limited effectiveness, particularly in advanced stages. Recent advances in targeted therapies and immunotherapy offer promising alternatives, providing more precise and personalized treatment options. Targeted therapies, such as epidermal growth factor receptor inhibitors, aim to disrupt specific molecular pathways in tumor growth, while immunotherapies, including immune checkpoint inhibitors and chimeric antigen receptor-T cell therapy, enhance the body’s immune response to fight cancer. Combination therapies, integrating both targeted and immune strategies, are being explored to overcome the limitations of single-agent treatments. This review highlights the current strategies in the prevention and treatment of oral cancer, discusses emerging therapies, explores future research directions, focusing on optimizing existing treatments, identifying new biomarkers, and developing innovative therapeutic approaches. The potential of personalized medicine and combination therapies offers new hope for improving survival rates and quality of life for oral cancer patients.

Esophageal squamous cell carcinoma (ESCC) is among the most prevalent forms of esophageal cancer globally, with a particularly high incidence in developing countries. Notably, Asia accounts for approximately 80% of global esophageal cancer cases, with China alone contributing to 54% of this burden. The primary treatment modality for ESCC remains esophagectomy, primarily employed for locally advanced disease, often in combination with chemotherapy and radiotherapy for advanced-stage cases. Despite significant advancements in surgical techniques and the advent of precision medicine, which has facilitated the development of targeted and immune-based therapies, critical challenges persist, including suboptimal therapeutic efficacy and the emergence of drug resistance. A comprehensive understanding of the current treatment landscape for ESCC is essential to overcoming these barriers and improving patient outcomes.