Radiotherapy, Chemotherapy and Immunotherapy-Current Practice and Future Perspectives for Recurrent/Metastatic Oral Cavity Squamous Cell Carcinoma

First‑line programmed cell death 1 inhibitor plus chemotherapy vs. standard treatment in patients with recurrent or metastatic oral squamous cell carcinoma: A retrospective cohort study

Programmed cell death 1 (PD-1) inhibitor revives the killing effect of immune cells to prevent tumor progression. The present study aimed to evaluate the efficacy and safety of first-line PD-1 inhibitor + chemotherapy vs. standard treatment in recurrent or metastatic (R/M) oral squamous cell carcinoma (OSCC). A total of 51 patients with R/M OSCC were reviewed and divided into the PD-1 inhibitor + chemotherapy (n=21) and standard treatment (n=30) groups based on their actual treatments. The results of the present study demonstrated that the objective response rate (52.4 vs. 36.7%, P=0.265) and disease control rate (81.0 vs. 70.0%, P=0.377) were numerically elevated in the PD-1 inhibitor + chemotherapy group compared with those in the standard treatment group; however, the results did not reach statistical significance. The progression-free survival (PFS) was numerically increased (without statistical significance) in the PD-1 inhibitor + chemotherapy group compared with that of the standard treatment group (P=0.057). Specifically, the PD-1 inhibitor + chemotherapy group and the standard treatment group exhibited a median [95% confidence interval (CI)] PFS duration of 6.7 (1.6-11.8) and 5.2 (3.4-7.0) months, respectively. In addition, the PD-1 inhibitor + chemotherapy group demonstrated increased overall survival (OS) compared with that of the standard treatment group (P=0.032). Specifically, the PD-1 inhibitor + chemotherapy group and the standard treatment group exhibited a median (95% CI) OS duration of 18.3 (11.9-24.7) and 10.3 (7.9-12.7) months, respectively. Furthermore, multivariate Cox regression analysis indicated that PD-1 inhibitor + chemotherapy was independently associated with improved PFS [hazard ratio (HR)=0.308, P=0.002] and OS (HR=0.252, P=0.003). In addition, the incidence of grade 3-5 adverse events (AEs) was relatively low in both groups and the incidence of any grade of each AE was not significantly different between groups (all P>0.050). In conclusion, the first-line PD-1 inhibitor + chemotherapy group had improved efficacy and comparable safety compared with those of the standard treatment in patients with R/M OSCC.

Matrix-based molecular mechanisms, targeting and diagnostics in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a head and neck cancer (HNC) with a high mortality rate. OSCC is developed in the oral cavity and it is triggered by many etiologic factors and can metastasize both regionally and distantly. Recent research advances in OSCC improved our understanding on the molecular mechanisms involved in and the initiation of OSCC metastasis. The key roles of the extracellular matrix (ECM) in OSCC are an emerging area of intensive research as the ECM macromolecular network is actively involved in events that regulate cellular morphological and functional properties, transcription and cell signaling mechanisms in invasion and metastasis. The provisional matrix that is formed by cancer cells is profoundly different in composition and functions as compared with the matrix of normal tissue. Fibroblasts are mainly responsible for matrix production and remodeling, but in cancer, the tumor matrix in the tumor microenvironment (TME) also originates from cancer cells. Even though extensive research has been conducted on the role of ECM in regulating cancer pathogenesis, its role in modulating OSCC is less elucidated since there are several issues yet to be fully understood. This critical review is focused on recent research as to present and discuss on the involvement of ECM macromolecular effectors (i.e., proteoglycans, integrins, matrix metalloproteinases) in OSCC development and progression.

Re-irradiation for head and neck cancer: outcome and toxicity analysis using a prospective single institution database

Purpose

Re-irradiation (re-RT) in head and neck cancer is challenging. This study prospectively explored the feasibility of re-RT in patients with loco-regionally recurrent or second primary head and neck cancer (LRR/SP HNC).

Methods

From 2004 to 2021, 61 LRR/SP HNC patients were treated with re-RT, defined as having a second course of RT with curative intent resulting in a cumulative dose of ≥100 Gy in an overlapping volume. Postoperative or definitive dynamic intensity-modulated and/or volumetric modulated re-RT was administered using twice daily hyperfractionation to 60 Gy combined with cisplatin or carboplatin/5-fluorouracil. Overall survival (OS), progression-free survival (PFS), locoregional control (LRC) and distant metastasis control (DMC) were analyzed and prognostic factors evaluated. Toxicity was prospectively recorded and graded.

Results

The median follow-up was 9.8 months. In 41 patients (67.1%), complete administration of the intended treatment was not feasible. In 9 patients (15%) re-RT was interrupted prematurely and in other 9, the complete re-RT dose was lower than 60 Gy, and 37 patients (61%) could not receive or complete chemotherapy. Two-year OS, PFS and LRC rates were 19%, 18% and 30%, respectively. 20 patients (33%) received the complete intended treatment, and 1- and 2-year OS rates were 70% and 47%, respectively. Charlson comorbidity index was an important predictor for treatment completion. Multivariate analysis revealed recurrent N stage 0-1, age, chemotherapy administration and re-RT dose of 60 Gy as prognostic factors for clinical outcomes. No grade 5 re-RT-related toxicity was observed. The most common new grade ≥3 acute toxicities were dysphagia (52%) and mucositis (46%). Late toxicity included grade ≥3 dysphagia in 5% and osteoradionecrosis in 10% of evaluable patients, respectively. 6 patients (10%) were alive after 9 years without progression and no late toxicity grade ≥3, except for 2 patients presenting with osteoradionecrosis.

Conclusion

Hyperfractionated re-RT with 60 Gy combined with platinum-based chemotherapy was a curative treatment option with acceptable toxicity in LRR/SP patients. Patients with higher comorbidity had a higher probability of failing to receive and complete the intended therapy. Consequently, they derived unsatisfactory benefits from re-RT, highlighting the importance of patient selection.